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Are compounds that contain radioactive elements also radioactive? | Asked another way: is radioactivity affected by the fact that the radionuclide is bound with other atoms in a compound? | There are obscure corner cases where chemistry influences radioactivity (largely when electron capture is the only option), but generally: Radioactivity is not affected. Radioactive decays happen in the nucleus, what happens around it doesn't matter. | 250 | 361 |
ELI5: Why has China devalued its currency, and what will that mean for other countries? | When your currency becomes stronger, it becomes much harder for you to export your country's goods, because your goods become more expensive for other countries. China doesn't want that because they are the biggest export nation that there is. | 14 | 21 |
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ELI5: When going to bed after a day at the waterpark, doing rollercoaster or at sea, I can feel the "movements" of the day. Why is that? | Also, why does it only happens with some activities (ie: i don't feel myself walking) ? | Your inner ear detects your movements and send signals to your brain so you can respond to the situation and balance. Your eyes are also sending similar information. Eventually your brain gets used to the same signals being sent at regular intervals (waves being regular at the beach). Your brain starts to expect this movement as normal, and keeps compensating. When you return to land, your brain is still compensating for motion that isn't there. There's lots of other stimulus for the rest of your day at the beach so you might not notice, but at the end of the day when you are in a quiet, dark room with little stimuli you'll feel that compensation again, and feel like you're still rocking.
You can override the signal by giving your brain something else to base stability on (same thing for when you have the dizzies after a few too many drinks). You can put your hand or foot on a flat surface and your brain will recognize that you aren't actually moving. Anecdotally, I've found that touching the floor or a table works better than a wall when lying down. | 18 | 32 |
I don't think I should try to reduce my carbon footprint. CMV. | I DO think that we, as a species, should reduce our carbon footprint. But I think this change will happen over the next few years due to economic incentives (solar getting cheaper, gas getting more expensive, etc).
Classic tragedy of the commons, but I don't see why I should reduce my carbon footprint when my personal contribution to atmospheric carbon is negligible. I could multiply it by 100 or reduce it to nothing and it wouldn't hurt or help anyone. | You individually will probably not have a significant impact, but if you convince a large number of other people to do it, that will make a difference, and taking part yourself would certainly help with that. | 30 | 45 |
ELI5: Why do we need patents? | First point to understand is that it is way easier to make something than it is to come up with the idea to make it.
People and companies often spend a lot of time and money thinking, modeling, prototyping, testing, rethinking, etc before they come up with something people like enough to buy.
The government has decided that it appreciates this time and effort. That because of this time and effort, the public gets to have lots of cool stuff.
But there is a problem. People go through that effort and invest the resources in large part because they think if they do end up worth something that the public wants, they will be able to sell it and make money for themselves and their family or their company.
But remember point one. The hard part of most products isn't making it, it's coming up with it. Without patents, people would just wait until an invention happens, buy one, make lots of copies, and undercut the original inventor (after all, they don't have to make up for years of investment cost, so they can sell them cheaper.
If that happens too much, the government fears people will stop inventing.
At the same time, one of the ways society progresses us improving on other people's designs.
So. .. patent us the compromise. The government says "you tell us exactly how your product works, we will make sure nobody copies it for a few years, and in return, when your time is up, society can take your invention and tweak it to keep us progressing. | 26 | 15 |
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What effects would castration have on a man's body? | Effects of castration are largely dependent on WHEN that castration takes place.
A primary hypothesis that describes hormonal actions is called the 'organization and activation' model.
During development in the womb, the body (more specifically the nervous system) is organized by high testosterone (if you're a male): male traits are emphasized while female traits are 'defeminized'.
After birth there is a nadir in T, followed by another peak during the first few months after birth.
Then T levels drop until late adolescence at the time of puberty, where this organization is 'activated' by another induction of high testosterone.
After this, testosterone declines with age.
In short: Castration before puberty would have detrimental effects on both brain and body development, afterwords not so much...but would effect sperm counts, fertility, etc... | 376 | 745 |
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Best data structure for a spare array | I'm working on a font library. The format I'm using provides a list of UTF-16 codes and their offsets in a spritesheet, so each entry might look like:
​
0089 X=100 Y = 200
1500 X=32 Y=10
etc.
There are 2\^16 possible values in this format, but in practice there will never actually be that many, as users tend to only export the character they need (English characters, spanish characters, Korean characters, etc.) and the vast majority of the available character codes go undefined.
What is the best data structure to represent a 1 dimensional array that's easily indexible by these character codes, but where the majority of them at any time will be empty? The idea is fast lookup (array access) but without having a huge empty array | The other answers you've gotten already are good - some form of map or hash table. But, assuming this is a real programming problem and not homework, another alternative is just to use a real array most of which is empty. The advantage is that it is incredibly simple, requires very little code and will be very unlikely to have bugs. The disadvantage is just the wasted space, but 2\^16 is a very small number compared to modern computer memory sizes. | 11 | 20 |
CMV: President Regan is the most economically and socially destructive president we will ever have in America. | I'll try and keep this brief
In my opinion, President Reagan is probably the most destructive, corrupted president we will ever have. He has does more destruction of the American life and the American dream then any president before him has done and after.
To be fair, this is like who's the tallest kids in elementary school. Every president doesn't have a golden pedestal that is spotless on morally righteous, foreign policies .ect. But, Reagan is at the top, or damn well near.
But, allow me to go category by category
ECONOMICS / SOCIAL
One of I think the biggest complaints about Reagan is his trickle down theory and how he drastically reduced the corporate tax's from I think 88% down to the 20%, while also raising the taxes for middle incoming family whom before him could get a master degree in Accounting or whatnot and easily be the single provider for a family of 4. Which in today's era is nothing short of a bed time stories.
You may argue that he had well intention, I would disagree with that, since even if you accept the fact of limited government, under a utilitarian approach he should have seen this coming. He was trying to fix what wasn't broken.
American wages used to be tied to productivity the harder that employees work the more they would get paid (correct me on that), but when Reaganomics came into play wages have ultimately gone down.
Lately, I almost forgot was the one who started moving our job's overseas. All of our manufacturing job, so thank him for the ascension of China as a superpower.
Abolished mental health research.
ostracized homeless people claiming "They are broke because they don't want to work", or at the least popularized it.
There is probably more thing I could talk about but I think this is suffice.
This man single handed change America to a oligarchy in his entire presidency and has ruined economics for middle class America forever.
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CORRUPTION
One thing I think comes to mind was with his Iran contra affair, Reagan was illegally selling arms to Iran in exchange for holding off giving back American hostages so this'll give him more political points in then upcoming election. Then took the arms from Isreal, gave to the contra and contras gave us coke and which started the coke epidemic in America. When US Congress investigated this, he appointed the Tower Commission that he himself appoint to investigate it, which reeks of corruption. This is on the scale of police investigating themselves and absolving themselves.
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Change my view | Andrew Jackson is generally agreed to have participated in ethnic cleansing against the first nations/Indians at the time, committed War Crimes, supported Slavery and Profited from it, and during his life time duelled about a hundred people.
Regan is a bad president may be true, the worst is a stretch. | 15 | 19 |
ELI5: What specifically are doctors looking for when they check your eyes, nose, mouth, and breathing? Why is this standard practice? | When looking in your eyes they want to make sure the pupils are dilating like they are supposed to. If not there could be a lesion among the cranial nerves. They also look at your retina. There are little arteries in your retinas that can look different with different types of heart disease. A problem with these can lead them to check other things.
In your nose they are looking for any polyps or lesions. They’ll shine the light in there too to check to make sure your sinuses “light up” meaning they are clear.
Checking the mouth, they look at your tonsils if you still have them. They’ll also look at your uvula (hangy ball) to make sure it isn’t leaning to one side. This can also mean a lesion in a cranial nerve. They check the tongue to make sure it isn’t deviated to one side or the other (if it is it means there is a lesion in a cranial nerve).
The check your breathing to make sure your lungs are clear. Any weird sounds could mean infection, asthma, COPD, etc.
They also check your heart at 4 separate points to check each valve of the heart for murmurs.
They’ll use the stethoscope to check your neck for bruit (basically if there is blockage in the carotid arteries leading to the head it makes a weird sound through the stethoscope).
They’re also supposed to check your neck under your chin from behind to feel for your thyroid.
There are other things they are looking at while they are checking these things you just might not notice.
TL;DR: they’re checking for abnormalities in the cranial nerves, heart and lungs. These are super easy tests and should be done to make sure something isn’t starting to go on with a patient before they even know themselves that it is. | 55 | 18 |
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On the atomic level, what is happening when I spill acid on myself? Is it the same with bases? | Thanks in advance!
edit: also, are there any other "corrosive" substances that are dangerous to humans other than acids/bases? The only counterexample I could think of was chlorine gas, but that's acidic too... | The process is called hydrolysis. The name is the same for acids and bases, however the reaction and end-product can be different. It's called hydrolysis because water is involved in breaking down the molecules.
Proteins hydrolyze easily. This is one of the reasons animal tissue breaks down so easily under alkaline conditions.
edit: Any highly reactive chemical can cause chemical burns in a similar way, however it is not called hydrolysis because water is typically not involved. | 12 | 18 |
How does the CPU know not to write into read only memory? | Or outside of the program, for that matter. Is there a check for what segment it is in in every read/write instruction? How does it work? | It depends on the system, but typically yes, every write has to be translated into physical address space and posted to the memory system, and the access levels will be available in the translation buffer.
The check is very cheap. It's an AND gate between read-only and write enable. | 18 | 20 |
Why are planets always round? (Not a flat earther at all here btw) just wondering why a planets are not a more random shape? | The definition of a planet has a few criteria and one of them is that it has to be round. So if an object isn't a sphere, we wouldn't call it a planet.
But that's a bit of a lame explanation. The reason why the things we call planets are round (and the reason that we added "being round" as a requirement for something to be called a planet) is that a sphere is the most energy efficient state for an object to be in when its own gravity is sufficiently strong.
So if a celestial body becomes large enough, its gravity will automatically force it more and more towards a spherical shape. Imagine an object that is otherwise spherical, but contains a large mountain-like structure sticking out from the spherical surface. A rock will roll down from this mountain without requiring additional energy input. This rock rolling down the mountain brings the object closer to a spherical shape. But rolling a rock from the surface up the mountain, making the object less spherical, requires some external force.
So any objects in space that are not spherical are simply too small for their own gravity to pull them together into a ball. | 250 | 109 |
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ELI5: why are time zones a thing? Why not just have a global time and some places the sun is up at 12am and down at 12pm? Why must (generally) the sun be up 6am to 6pm? | Across most of human history, time was always determined by the apparent local time. Noon was when the sun was highest in the sky & there was no complication about it. Since people had to walk, take horses or get on a boat to get anywhere, this was adequate.
...then we developed telegraphs & trains. Suddenly we had instant communication across vast distances and giant machines that needed to be synchronized so they didn't ram into each other & cause massive destruction.
Time zones were a compromise between our historical use of time being relative to the sun & the need to have a standardized time so people could coordinate across large distances.
If you want just one time, you're free to use UTC (time-zone 0) for everything. Many multinational companies, militaries and computer database programmers use it to avoid the confusion of timezones & the headaches of daylight savings times.
China has taken the approach of a single unifying time zone across the whole country. It would cover 5 standard time zones but they put the whole country on the same time as the capital. | 162 | 207 |
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How are electronic systems on spacecraft protected from "bit flips" caused by cosmic rays? | A number of ways, depending on a lot of factors. There are two categories of protection- physical and logical.
Physical protections are things like:
* Larger feature (transistor) sizes, as larger circuit elements need more energy to flip.
* Radiation resistant materials, meaning building circuit elements out of materials that are less likely to absorb radiation.
* More expensive doping agents and insulators, to make sure that stray voltages go where they're supposed to in a controlled fashion.
* Extra shielding, both at the component level and the spacecraft level
Logical protections are things done in software or the design of a system to build in logical redundancy in case things do go wrong. Most of these techniques also apply to regular safety-critical systems to improve resiliency to regular failures as well.
* Use error-correcting codes and schemes. These methods use extra bits of data (such as parity bits) to indicate when something is wrong, or even provide redundancy so that a bit-flip can occur without affecting the logical outcome of a computation.
* Built-in redundancy. You can build multiple parallel systems that all do the same thing, and compare outcomes at the end of the process. For example, instead of running a program one time, you could physically load three copies of a program into memory, physically run the program three times, and then compare the outputs. The programs "vote" on the correct answer at the end of the process, so if two programs have answer A and the third program has answer B, the answer with the most votes wins. You can even build physically redundant hardware, if you have the budget for it (multiple processors, sensors, memory banks, etc.).
* Watchdog elements. The easiest way to fix a faulty computer after a bit-flip is to reboot it. Spacecraft have built-in "watchdogs" that monitor the status of the spacecraft, and if something doesn't happen the way that it's supposed to happen then it triggers an automatic reboot of the system. The most common type here is a watchdog timer- for example the spacecraft operating system might be designed to reset a timer every 60 seconds, and if the timer ever goes off without being reset it can trigger a hard CPU interrupt that triggers a CPU reboot. You can have multiple levels of watchdogs for different systems or different levels of reboot.
There is a whole field of study that is dedicated to building resilient systems, and there are lots more techniques that may or may not be applicable to specific spacecraft. You could really go on all day. | 43 | 37 |
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Electromagnetic Waves: How is the transparency/opacity of materials defined? | I think that you are confused about the permittivity. High permittivity generally means that a substance can become more polarized. The conductivity of a material is a completely separate measure.
Classically, a good conductor will reflect light, as the incoming waves cause charge to move freely in the material, these charges oscillate with the fields, effectively destroying the incoming wave, and producing outgoing waves with most of the energy.
So conductors, such as most metals, are generally shiny.
The permittivity of an insulator generally determines how much it refracts light. Materials with high permittivity such as diamond have a higher index of refraction, and bend incoming light more than something such as glass.
So conductors are shiny, and insulators transparent. Materials that we think of as dull or opaque are typically insulators with some irregular structure causing the light to refract in various directions and become scattered. To understand this, take a transparent piece of quartz crystal, and then smash it into a fine powder, and the resulting powder will be opaque.
Permeability also affects the index of refraction, although the permeability of most insulators is so close to the vacuum permeability that it barely makes a difference and is typically ignored.
Hopefully this clears up a few questions. This is a topic about which a lot can be written! | 31 | 249 |
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CMV: girls flirting with guys just to get drinks (with no genuine romantic interest in the dudes) is manipulative and shouldn't be glorified as "finessing" | No one's making these dudes buy her a drink. Totally agree on that, if he chooses to buy her a drink then he made that choice himself. But if a girl's deliberately trying to get free drinks like this, that's just being a bad person imo. I don't see how [some] girls can celebrate stuff like this as "finessing" or anything like that. Leading people on- no matter what the genders or orientation is- is not cool. Even if you just ask a guy to buy you a drink without being overly or noticeably flirty, imo you can't blame him for being annoyed when you just leave after he gets you a drink. It's reasonable for a guy to interpret a request to buy her a drink as a show of interest. Now to be clear, just because he buys her a drink doesn't mean she owes him anything. She's not obligated to do anything just because he said yes and bought her a drink. He made that choice himself. But it's still a crappy and manipulative thing to do if girls intentionally try to get free drinks from guys if they're not genuinely interested in them.
Change my view- is it ok (or not manipulative/leading on) when girls try to get free drinks like this? All comments and perspectives are welcome and encouraged. | Clarifying question: do you think it's actually common that girls flirt with guys while asking for a drink, and then simply leave without even any conversation (minimal though it might be) once the drink arrives?
Parallel clarifying question: Do you have any opinions about guys that buy a girl a drink without any expression of interest or request? | 95 | 468 |
Since economics is often considered the “dismal science”, what are some truly interesting/fun facts about Econ? | There have been many strange applications of economic knowledge. Several books have been written about them recently. The most well known is "Freakonomics" (and it's sequels) by Stephen Dubner and Steven Levitt.
One of the things that book is Sumo wrestling. Economic methods have been used to detect cheating in Sumo wrestling and in some other situations. | 12 | 23 |
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CMV: Diversity in gender and race is not important | I don't think diversity is important. I never understand why people complain about movies and companies that have for example, only white people, or significantly less women than men. If we believe in equality, and if we say that we should not care about anyone's gender or race, then why is it important (for example) for a movie to star an equal amount of black and white people? The actors' skills are much more important than the race or gender.
Sorry if my English is bad, it's not my first language. Feel free to ask me, if you don't understand something.
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> *This is a footnote from the CMV moderators. We'd like to remind you of a couple of things. Firstly, please* ***[read through our rules](http://www.reddit.com/r/changemyview/wiki/rules)***. *If you see a comment that has broken one, it is more effective to report it than downvote it. Speaking of which,* ***[downvotes don't change views](http://www.reddit.com/r/changemyview/wiki/guidelines#wiki_upvoting.2Fdownvoting)****! Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | So, the value of diversity in general is that a group of people with multiple perspectives will be able to make better decisions and more efficiently tackle problems than a group with only one or two perspectives. Things like race and gender influence people's perspectives on particular issues and the world at large. So do things like socioeconomic status, sexual orientation, where you were born, where you grew up, etc.
When people complain about a lack of diversity, they're addressing multiple problems. So, let's say a company is primarily made up of white men. Not only will they lack perspectives of non-white people and non-men when making decisions, there's also a question of power and discrimination. If we believe things like gender and race don't influence skill level, then we should expect to see people of different genders and races represented roughly proportionally to population, right? If men and women are equally capable and businesspeople, most business should have roughly equal numbers of men and women, since there are roughly equal numbers of men and women in the world. When a company is 80% male and only 20% female, it's an indicator that the company *isn't* in fact hiring the best candidates, but that either they're valuing male applicants over female ones, or female applicants are being discouraged from applying in the first place.
When it comes to things like movies, we're talking about representation, and that's a slightly different beast. People tend to identify with others who are like them. There's also a lot of research that shows that children need to identify with adults in order to understand that they will grow up, and to form ideas about what their life will look like when they do. This is particularly applicable to people of color, who rarely see themselves represented in media, especially in positive ways. It's important for Latino children to see Latino characters in films, because that teaches them they can be anything. It also teaches children of other races that Latino people can be anything, and that's important for getting rid of racism. When a boy says to his sister, "Girls can't be doctors," if she can turn around and say, "Yes they can, Doc McStuffins is a doctor!" both of them learn a lesson about gender equality. When we make movies, we create representations of the world, and those representations can shape our society. | 49 | 31 |
A lot of economists argue that a minimum wage is not good for low level employees. What is a ground level empirical example of how a low skilled worker would benefit from there being no minimum wage? | As a basic rule of thumb you use a minimum wage to guarantee a certain minimum standard, the downside of this is that sometimes an employer might want to hire someone to do something, but doesn't think it's quite worth that minimum wage and would rather have his current employees work a bit of overtime, or have whatever he is lag a bit instead.
So practically speaking, you can have a minimum wage at the cost of having higher unemployment, this is generally agreed. What people don't agree over is exactly the ratio between the two, or what value to place on the two, so not many people agree on exactly where the line should be drawn. | 19 | 27 |
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Has the cost of living gotten higher or do people just live higher? | Usually cost of living is measured with a "basket of goods and services" which changes from year to year. If we applied an old basket to today, what would the cost of living look like?
E.g. the 1950 basket probably has more cigarettes, and less broccoli, than the 2022 basket.
What if people in 2022 bought the same things as people in 1950? | It would be very difficult for a 1950 basket to include computers, radio telephones, electric cars, MRI scans, internet services, or even birth control pills.
A 1950's era car would be illegal to sell in the US: leaded gasoline, no passive restraint, no pollution controls. The nearest equivalent would be a gasoline-powered golf cart.
Houses in the 1950s were not (for the most part) very well insulated, so they wasted a lot of energy for heating. However, air conditioning was relatively rare and was often confined to certain rooms. As building codes have gotten stricter, houses use energy more efficiently, but cost more for the same reason.
If one looks at the kind of living arrangements in Brazil or the Philippines, it's possible to get some idea of what live in the US might have been like in the 1950's. Costs in these countries are 1/5th to 1/10th those in the US in dollar terms. | 45 | 22 |
CMV: That players from national teams (English, Spanish etc) should be from, or have heritage from that respective nation | It always confuses me when I see the "English Football Team" whilst some players aren't even English (Full list of all Footballers for the English team over-time who aren't from England: https://en.m.wikipedia.org/wiki/List_of_England_international_footballers_born_outside_England). Since any player can play for any team it makes supporting teams based on patriotism pointless since you would be supporting those not from your country.
I can see the arguments that it allows for people from Scotland, for example, to support the Portuguese team if they have a Scottish player. Perhaps clubs benefit from profit when they buy and sell players too - I don't understand football so I may not be correct on this.
At the least I believe that players should've lived in their country's team for a year prior to joining that team.
TL;DR - Only English-born or closely related should be able to play in the English team; and that should be the same for all teams | So long as you haven't played for another national team at senior level (that immediately disqualifies you from playing for another, different national team) you have to fulfil at least one of these criteria:
* (a) He was born on the territory of the relevant Association;
* (b) His biological mother or biological father was born on the territory of the relevant Association;
* (c) His grandmother or grandfather was born on the territory of the relevant Association;
* (d) He has lived continuously for at least five years after reaching the age of 18 on the territory of the relevant Association.
FIFAs existing rules are, if anything, already stricter than the ones you are suggesting. | 20 | 29 |
Can single-celled organisms get cancer? | Well, let's look at the six hallmarks of cancer:
* self-sufficiency in growth signalling - already present
* insensitivity to anti-growth signals - not really applicable
* evasion of apoptosis - probably possible
* enabling of a limitless replicative potential - already present
* induction and sustainment of angiogenesis - nope, can't happen
* activation of metastasis and invasion of tissue - nope, can't happen
So, you see, they can't. Can they get something similar? Sure, a virus infection can be analogous to cancer to a single cell organism. But they can't get cancer | 29 | 71 |
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ELI5: Why can't I use a telescope to look at really small things? Why can't I use a microscope to look at things that are far away? | Focal length.
Microscopes use shorter focal length to view small objects, while telescopes use longer focal length to view far-away objects.
Focal length is basically where the image is located relative to the lens. A shorter focal length means that you can resolve images that are very close to the lens, while a longer focal length means that you can resolve images that are very far from the lens.
It's sort of like trying to design a laser vs a flashlight. Lasers must be very focused to be useful for the tasks they're designed for, but flashlights should be dispersed to illuminate more area and not blind people. A laser makes a bad flashlight, and a flashlight makes a bad laser. | 11 | 15 |
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How did such a diverse Universe form from a Big Bang singularity? | I only have a basic understanding of the fundamentals of this, but what I'm wondering is since at the point of or just before the big bang all matter was a part of the singularity and I'll assume uniformly compressed, why did it not form a perfectly ordered universe? Since there would be no outside interference (I'm assuming again) this disorder would have to come from within. So what caused this disorder? Was it the matter itself, was the "bang" decentralized, or something wildly different? | The diversity that we observe in the Universe today was likely seeded after an epoch of rapid expansion (called inflation) in the early moments of the Universe. Although the Universe was extremely homogeneous and isotropic at that time, quantum fluctuations caused small overdensities which, by gravitational collapse, grew quickly (well, fast compared to the Hubble time.) They eventually collapsed into the first stars and then (by a mechanism that isn't very well understood), galaxies formed. | 10 | 15 |
ELI5: How do they determine the total human population of the world when so many nations are too underdeveloped or corrupt to be able to keep track of all their citizens effectively? | Census is the scientific term for taking account of a national asset such a population, number of households etc.
There is no one methodology for carrying out a population census. In most developed countries all citizens have social security number and births/deaths are recorded. This type of date gives a lot of insight into population statistics, such a growth pr. generation, fertility rate and more.
In countries where citizens do not have a social security number and where births and deaths are not tracked, a population census will have to do with proxy data.
Proxy data can be other data sources which can serve as a reliable indicator of population information. Such data will not be final and will involve uncertainties.
One common proxy is questionnaires which are distributed not to all households but a representative selection. Questions in such a questionnaire will include, how many people live in a house hold, how many children are born in last year and how many have died.
Another typical source of proxy data is aerial and satellite photography. This data can give an insight into changes in settlements on a larger scale. If a city has grown/diminished can be used to derive amount of people living in a given area and other information. | 816 | 2,432 |
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Can someone explain the equation E=mc2 in terms a 16 years old can understand? | I've tried to read about it, but, well... I don't get it. Does it mean every object with a mass contain energy? Or something like that? Educate me, science. | Prior to Einstein, people thought energy came in two varieties: kinetic energy, which is energy that comes from motion; and potential energy, which is energy that comes from location or configuration. When you accelerate a car, you increase its kinetic energy, and when you stretch a rubber band, you increase its potential energy.
Einstein demonstrated that there was a third form of energy. This energy is energy that things have just because they exist. It is essentially what we had previously identified as mass; in fact, this energy is proportional to mass and has value *mc^2*.
Why does this matter? It matters because energy is conserved; the total amount of energy doesn't change, but it can shift from one form to another. Drop a ball and it speeds up; it loses potential energy but gains a corresponding amount of kinetic energy. Thanks to Einstein's insight, we learn that mass must be included when we look at how energy can shift forms. In accelerators like the LHC, the kinetic energy of colliding protons is converted, in part, into mass, in the production of new particles. When a muon decays, it ceases to exist, but the energy from its mass becomes the combined mass and kinetic energy of the decay products (an electron, a neutrino, and an antineutrino). And, at root, these things can happen because of *E=mc^2*. | 32 | 30 |
Why is it that "continental" philosophers are still highly popular and influential in Anglophone social science, despite mostly not being especially well-liked by most philosophers in the same region? | In a lot of social science stuff I read in English, I tend to see a lot of philosophers typically considered to be "continental" (if that's still an intelligible category any more) referenced and drawn from, especially Butler, Foucault, Marx, etc. It seems very unusual to me, considering that so many American and British philosophers ("analytic philosophers", if you want to call them that), tend to either be dismissive of or even outright hostile to them. Why is it that social scientists tend to draw from those continental sources rather than the dominant philosophical attitudes of their own regions? | While the generalization is unfair to the interesting work being done which contradicts it, it seems to me that if you look at at least the big names in analytic (logical positivists through the post-positivists) and continental (phenomenology through the post-structuralists, perhaps also the Frankfurt school) philosophy, there has tended to be more contact with the natural sciences in analytic philosophy and more contact with the human/social sciences in continental philosophy. If this is true, then the prevalence of continental philosophy in the theory of the social sciences isn't that unexpected. | 24 | 21 |
CMV: Homework should be used to introduce new concepts, not to practice and reinforce concepts from class. | As said in the title, I feel that learning concepts in class and practicing said concepts for homework is inferior to introducing and possibly learning the concepts at home and practicing them in class. This is because while learning the concepts is something that can be done on one's own, it is often helpful to have someone available to help when doing the work. For example, my brother (7th grade) often needs a little help on his homework every night, so switching them would help prevent him from having to bother me and my parents. Also, it is good to provide a time to ask questions before doing the work, not afterward.
The logistics for this would be that a student would read something (like a small packet or a textbook section) and then maybe answer a few questions about this. Then, the class would start off with a question session about the reading or whatever from the previous night. After, the students would work on more challenging work (harder than current homework) in class. This would be possible because with the teacher there, they can ask questions and get input to help them along.
Change my View.
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> *This is a footnote from the CMV moderators. We'd like to remind you of a couple of things. Firstly, please* ***[read through our rules](http://www.reddit.com/r/changemyview/wiki/rules)***. *If you see a comment that has broken one, it is more effective to report it than downvote it. Speaking of which,* ***[downvotes don't change views](http://www.reddit.com/r/changemyview/wiki/guidelines#wiki_upvoting.2Fdownvoting)****! Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | >This is because while learning the concepts is something that can be done on one's own, it is often helpful to have someone available to help when doing the work
The reverse seems true to me: it's particularly helpful to have a knowledgeable person there to explain a concept when you learn it, and less important to have someone there when you practice it (although obviously, having someone there is always helpful).
Let me also suggest that learning concepts at home allows for a potentially big problem: people learning the concepts wrongly. If this happens (especially for those unfortunate kids that don't have good help with their homework at home), not only does time and effort have to go into teaching the concept, but the student will have to *unlearn* the false understanding they've already built up. | 20 | 18 |
Tree rings are often used to estimate historical atmospheric temperatures. However, numerous other variables (rainfall/snowpack, herbivory, volcanic activity, fires, etc) also affect the growth rates of trees, so why do we place so much trust in tree rings to measure past temperatures? | For example, say a tree was in its optimal temperature condition for two consecutive years in the distant past. Also imagine that the same tree was in sub-optimal rainfall conditions in the first of those two years, but in optimal rainfall conditions in the second year. This change in conditions would cause the tree to grow faster in the second year than in the first.
*From what I understand* (which may be wrong), scientists today would see that tree's rings and, in the absence of other evidence, surmise that the temperature was higher in the first year than in the second simply because of the difference in size between those consecutive rings. Obviously, this would be false, because the temperature was the same in both years. | You're absolutely right that other factors need to be considered. Here's how it works:
1) Be careful when picking trees. To get an estimate of past temperature, pick trees that get plenty of water but a very short growing season, for instance trees on mountaintops. If you want an estimate of rainfall, pick trees in deserts, and so on.
2) Correlate the tree data with historical observations. Compare the tree growth with human measurements of temperature, rainfall, and other data, over the past century or two. If you can show, say, that a given tree grows more when temperatures are high 90% of the time, and the other 10% it's due to other factors, that gives you good confidence in using it to estimate temperature farther back in time before thermometers were invented.
3) Use lots of trees. If one tree's growth is only partly due to temperature and partly just random, then averaging over 100 trees will cancel out the random errors and give you a much cleaner estimate of temperature. But you do have to worry about whether *all* the trees are responding to some other factor (say, rainfall) which is why steps #1 and #2 are so important. | 20 | 19 |
CMV: While "Radical Islam" is currently the religion causing issues across the world, it is really just the next iteration of religions as a whole acting to tear people apart. | Regardless of the particular belief, the real problem is that religion has NO PLACE in the modern world. It was used as a method of explain wonders of the world when there were no other ways. Now we have advanced technologies and established scientific methods which can answer those questions for us as well as many more that religions would deem heretical by their mere existence.
The argument that religion "teaches morals" isnt solid either. Read directly, most stories from the bible/Torah/Quran are brutal and teach morals in direct contrast with today's standards and/or laws. Usually the stories we tell young children are so watered down that they're barely reminiscent of the original story. 90% of practicing people use religion as a safety net for their fear of a lack of an afterlife while the others use it to support lunatic beliefs.
Religion absolutely has done *SOME* good and has brought meaning to many people's lives, but that doesn't mean it's the best path for us to continue down. As a planet we need to work together. Man-made separations such as religions and borders only work to separate us and invent reasons to not trust our neighbors. | A radical or fundamentalist perspective on religion is a distinctly modern phenomenon. Prior to the modern era, religion and religious institutions were not seen as these marginal sidelined things. They were mainstream concentrations of power, wealth, and divine knowledge, and basically everyone had a religion they were born into. Heaven and Hell were literal real places and had physical locations (in the sky and under the earth), and the church was the formal institution which connected you to them. Being religious wasn't a marker of identity like it is today--the catholic church has been around more than a thousand years and in medieval Europe, it was the most permanent thing around. So it had an obvious function. Faith wasn't magic, it was the most logical thing around. It was a logical response to a confusing and uncertain world.
As you pointed out, technology and science have sidelined religious beliefs which are demonstrably untrue. Plenty of religious people today (in developed countries especially) are fine with giving God a smaller role in public life, as the have longer lifespans, better health, and most public institutions are run by the state instead of by the church. (or the mosque). For most religious people today, faith communities offer a family, tradition, ritual, and a sense of togetherness. It has a place in modern life, and that place is non-political for the most part, but still can offer a lot in terms of emotional support.
But on the radical side, consider: capitalism and politics offer solutions only to material problems. Life in a developed democratic capitalist country is pretty comfortable and practical, but it provides no definitive answers as to what we should *do* with ourselves. Modern ideologies do not offer solutions to spiritual problems. Regardless of what advancements we make you're still gonna die someday. (unless you go for that anti-aging Singularity crap like Ray Kurzweil, which is in itself a kind of faith). And if you grow up without a community or a close family, without access to modern amenities, under an autocratic regime where power is concentrated beyond a place you can touch, then radical faith offers a LOT. You suddenly have spiritual certainty that your uncomfortable and difficult life isn't just a stupid pointless thing where you die in the ground--it's a thorough test of your toughness. You have knowledge that the divine kingdom will outlast any oppressive governments or other institutions. You have a mission and an underdog identity and a new group of friends. Those in power call you stupid, and it just makes you prouder that you've glimpsed at eternal secrets they'll never understand. "It teaches morals" is a diluted way of saying of what radical faith actually offers: an alternative value system not based on material reality. Religion has always offered that, now it's just a way more radical thing to say in light of what we know about the empirical world.
You seem to be arguing that the pursuit of radical religion divides us and hinders progress; practitioners of radical faith would agree, as that's exactly what they're trying to do. It's not a "we're in it all together" sort of mentality--it's a "the saved vs. the sinners" mentality, and it is much stronger than you give it credit for. Scorning it only makes it grow. | 28 | 106 |
[Mass effect] Is there an in universe reason to why ships in the Mass Effect universe are smaller in comparison to other Science fiction series? | The largest ships in mass effect are the dreadnoughts which range from 800 meters to a kilometer. This seems large but when you compare it to the Punic-class supercarrier seen in Halo (4,000 meters longer) it just seems strange. Especially considering the tech level differences in these series. The mass effect universe seems far more advanced than other series and yet it's ships are a quarter the size.
Obviously the universes are completely different but I would think with a mini cold war between the humans and the turians that they would just keep building ships larger and larger.
| While you can get bigger, you also have to scale up the size of mass effect fields you have to create for them.
Additionally, the drive cores make a lot of heat and build up a charge that can fry the crew if not discharged, and the rate of both scales with the size of the drive core, and past a certain point you end up where you are having to discharge even before making it between planets. | 36 | 21 |
ELI5: Why do abrasions weep? | After hurting myself, I noticed that abrasions on the skin always produce a lot of fluid. Cuts or scratches usually never do that. What has a abrasion that something like that happens? | When tissues are damaged, part of the body's response is inflammation. Inflammation includes increased blood flow to bring in nutrients and oxygen to start repair and white blood cells to clean up damaged cells and catch any invaders that may be in the wound. Also, the surrounding blood vessels getting slightly leaky so that plasma (the clear, straw-coloured part of blood) get right up around the damaged area to provide a good environment for the white blood cells to work in and more direct access to the nutrients that are dissolved in the plasma.
When you get a cut or scratch mostly you see blood, but sometimes you might still get a little plasma seepage after the bleeding stops. In abrasions you haven't damaged deep enough to get good bleeding going, but still get the inflammation related seepage. Abrasions also tend to be over larger areas so it takes longer for clotting to take place and stop all the leaking. | 57 | 72 |
What would be a good alternative to how today's academic jobs are handled? | I've thought about doing a PhD on numerous occasions but have always been scared off by stories of a shrinking job market for traditional academics (tenure-track). It also seems like the adjunctification/post-doctorization (are these even words?) of faculty is a huge trend that doesn't seem to be going away anytime soon.
So this got me thinking. For the academics who are already established and have tenure or tenure-track positions, and for those who are hopelessly stuck in the post-doc/adjunct glut, what would be an acceptable alternative to how universities hire faculty?
Would you want to keep the system as is, or would you rather have academic positions evolve into more of how non-academic staff are managed (perhaps less pay, but benefits)? I may be completely wrong, but it seems like the way the system is run now is not sustainable for the long run. | Longterm contracts: at least 5 years so you can be enlisted in different shorter projects. It's more about constant insecurity rather than low pay. If you have a 1-year contract you have to start looking for the next one almost immediately after starting.
If a contract ends, offer bridge funding if you are working on a grant application. Why would you, as a temporary employee, work to get a large grant to an institution that does not want to support you?
Both measures also allow you to identify with a Uni/College, rather than feeling like a mercenary who sells his/her services to the best bidder. | 20 | 17 |
Why shouldn’t you get the COVID-19 vaccine if you have a cold/flu? | I’ve had a bit of a google and the closest answer I can get is that given some people experience mild to severe cold/flu like symptoms after receiving their shot - especially the 2nd shot - is that if you get the vaccine and are already unwell, that you are more likely to feel even worse than if you weren’t unwell? Is that correct? And if so, is it the vaccine making your cold/flu symptoms worse or is your cold/flu making the vaccine side effects worse?
Thank you, fine people of r/askscience!
EDIT: Wow guys! What a surprise to wake up too! Thank you to everyone who has commented, I’m sorry I can’t get them all but I really appreciate the comments and the conversations that have come from them.
I got Pfizer dose #2 yesterday and I have woken up this morning feeling wrecked. Body and joints ache, my arm hurts so bad, skin hurts and standing too long makes me feel like passing out…you know when you get all hot and your body feels…like static? And of course a headache. But I’d rather this than Covid!
So again, thank you all for commenting, and I hope wherever you are in the world that you are safe (as can be) and I hope you and your loved ones all stay healthy <3 | Vaccines are always tested in healthy people. For good reason. Vaccines are there to train your immune system. If your immune system is already fighting other things, it might give an overreaction or the opposite: too little of a reaction. The effectiveness of the vaccine and the amount of side effects can therefore be affected by the current state of your immune system.
As a result, we simply don't know how the vaccine works when you're already ill (because it was tested on healthy people), but it is expected it won't work as well. | 2,266 | 1,730 |
Case studies are inherently flawed and are ultimately inferior to scientific studies. CMV | So on issues social in nature, the first thing a lot of individuals do is throw down on some case study or other to reinforce their point. I don't find there to be any value in case studies due to the volatile nature of how data is collected from them, even leaving in standard deviation and margin for error, every case study ultimately leaves out any concept that undermines it in favor of enforcing it's goal to the extent that I think it bears no real credibility. That is to say in laymen's terms, it's just really complicated "He says, She says" nonsense.
Some examples of this are the following:
Wage gaps.
Hiring statistics.
The impact of the smart phone on social interaction.
The only thing case studies can glean from such arguments is that people have "motivations for doing something." Which is ultimately common sense.
Scientific studies on the other hand, offer indubitable proof of the matter at hand. Now I know that on issues of a social nature you can't really have a scientific study really comment on anything, but my point is that people pay too much credence to case studies because of emotional attachment to the issue at hand and for no other reason than that.
CMV if you please. | For the examples you listed, case studies would probably be inappropriate. For other situations, say, an uncommon/complex mental health problem like Dissociative Identity Disorder (formerly "Multiple Personality Disorder"), case studies or other qualitative research methods can add to our understanding of overwhelmingly complicated phenomena. (In cases where the phenomenon of interest is very rare, case studies and similar methods may be the only options!)
Whether you should use quantitative or qualitative research methods also depends on the kind of question you're trying to answer. If you want to ask "How big is the wage gap?", you should use a quantitative study. If you want to know what is it like to be a female engineer in the US, you'll get useful data using qualitative methods. As a side note, case studies can examine multiple subjects so you could interview a handful of female engineers and look for common themes in their experiences.
Qualitative and quantitative methods can complement one another in exploring a topic. However, they sometimes have different purposes. If you want to design educational materials for aspiring female engineers, or write a textbook chapter about sexual harassment in the workplace, qualitative studies will help. If you want to push for a policy change, quantitative is usually the way to go. :) | 15 | 18 |
I need some help defending philosophy as a legitimate profession | I love philosophy, but I can also understand how someone may misunderstand it and think it's bullshit or doesn't do anything. So for the sake of the topic I'm going to assume a devil's advocate position in the beginning and then at the end offer some refutations that I've been thinking about. I'd appreciate any more objections or refutations you have. So here goes:
1.) Philosophy doesn't use evidence. It doesn't go out and use the Scientific Method to find evidence and create theories about the world. Without evidence, there is no way to actually know whether or not what you are thinking is actually "right". A thousand years of philosophical thought could be immediately thrown out the window by a single scientific observation.
2.) So much of philosophy is just semantics or word games, in the end.
3.) Do philosophers make up problems that didn't exist prior to them making them? Should we hate them for making them? (ironically enough I am doing philosophy here).
4.) How has philosophy actually been applied in real life? Science has been applied in terms of engineering and technology, as well as just general satiating our curiosity, but philosophy seems to just be philosophers conversing with other philosophers.
Alright, so those are the basic ideas I think someone who thinks philosophy is just a bunch of mumbo-jumbo would bring up. Here are my responses:
1.) I think Wittgenstein said it best; that science is all about discovery, but philosophy doesn't discover anything. Rather, it analyzes it, makes connections, and realizes the extent of the possibilities. In this way, science and philosophy are extremely compatible.
Furthermore, philosophy *can* make some progress, in that is can find out what is definitely *not* right (i.e. logical positivism). This narrows down the playing field, so the speak. Philosophers use logic and thought experiments to "test" their hypotheses, and the tests are all the other philosophers thinking about it.
2.) For the amateur, yes, the arguments may seem like splitting hairs. That's why they're professionals.
The average person may think an astronomer nit-picking over the radiation of a white dwarf is like splitting hairs (why does it matter?)
3.) Essentially someone who asks this is saying is ignorance bliss?
4.) Science used to be called natural philosophy. It technically is still a philosophy.
Ethics is a great example for the application of philosophy. How do we act, what are morals, do morals even exist? How can we possibly ask these questions using science (stfu sam harris, read some hume).
For every academic pursuit, there is almost always a philosophy behind it, for example, physics relies on metaphysics (even if physicists don't realize it).
The application of philosophy may not be easily apparent, but it's most definitely there.
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Okay, so at least for now, I've put down what I think are the most common reasons why people think philosophy is bullshit, and my responses to them. I would like to see what you guys have to think and if you have anything to add. Thank you. | 1. This is blatantly false. Philosophy obviously uses evidence. Often, it uses scientific evidence (empirical evidence often informs philosophical questions without entirely solving them). Further, it uses non-scientific evidence. True theories tend to be consistent, parsimonious, explanatory - if we show that some philosophical theory fails to meet these criteria, that is a mark against it.
2. Definitions matter. One could say that "law is just semantics, because it's all about how we define certain crimes and punishments." But, that's misleading. We could say "medicine is just semantics, because it's all about how we define health and disease." But that's misleading. We could say "psychology is just semantics, because it's all about how we define mental states, emotions, and things like that." But, again, that's misleading. Conceptual clarity is a necessary condition of doing good research in any field, and what looks like "bickering over semantics" to an uninformed outsider is usually actually working on conceptual clarity, which is vastly important.
3. The problems already existed - people just weren't aware of them.
4. There are lots of posts already about different ways that philosophy has influenced the world, so you should be able to find them with some quick searching. Here are some obvious answers: Work in ethics has been tremendously influential, politically. Work in political philosophy has been (unsurprisingly) tremendously influential, politically. Work in philosophy of science and epistemology has influenced how scientists view their own projects, and this deeply influenced science. | 24 | 16 |
ELI5: Why eating Sushi is healthy and safe and why other raw meats can't achieve this. | I was always curious about this. Anyone care to help? | It all depends on the likelihood of parasites and how the meat was handled. There's nothing wrong with raw beef, for example.
The problem with raw chicken is that it's often contaminated with salmonella and raw pork can have trichinosis. Cooking is necessary to kill those pathogens. They could theoretically be okay if not contaminated (but that's a very risky and nasty if).
On the other hand, some fish are not always safe to eat raw either. Swordfish can have parasitic worms and must be checked thoroughly. | 11 | 17 |
Would it be possible for a planet with a 24-hour day to have seasons that last for years? And if so, how would it differ from our own planetary system? | Yes, I'm trying to find out if a George R.R. Martin *Song of Fire and Ice*-type world is possible. | the length of the day is determined by the rotation of the planet and the length of the year is determined by the size of the orbit. So, yes, absolutely you could have a planet that rotates every 24 hours and has a very large orbit. However, a larger orbit means greater distance from the star, so it would have to be a hotter star* and prolonged seasons would likely mean that the cold and hot extremes are much greater than we are used to.
EDIT - *if the planet were to have a temperate climate as in the books. Rushed comment left some ambiguity. | 10 | 19 |
Okay, so what the hell is dialectics? Anything that I've read about it seems like gibberish. Do any of you have some resources that can aid my understanding? | Dialectics is an abstract description of the movement that the understanding does. The mind sorts the world in ideas. Those ideas are reasonably good and reasonably clear. However, an idea will always prove to be insufficient or internally contradictory. So the mind will realise this and leave the old idea behind and develop a new idea which incorporates the good parts of the old idea and update it to accommodate the weaknesses previously discovered.
The new idea will also prove to be insufficient and/or internally contradictory, so it too will have to be *sublated*, that is, deleted and reconstructed. | 119 | 162 |
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Where can a masters (MA) in economics take me besides a path to a PhD program? | I’m currently pursuing a BA in Economics and my university (UT Austin) offers a 5th year MA in economics program. I’m currently not interested in pursuing a PhD so I’m wondering if obtaining a masters is worth it. Can a MA in economics bring more opportunities than a BA? Does it “unlock” more paths? And is it worth it if I’m not interested in pursuing a PhD?
I just want to hear some perspectives on this, thanks. | * Economic consulting: Economic consultants provide advice and analysis to businesses, governments, and other organizations on a variety of economic issues, including market trends, policy analysis, and financial forecasting.
* Research: Researchers in economics conduct academic or applied research on economic issues, and may work for universities, government agencies, or private research firms.
* Financial analysis: Financial analysts use economic and financial data to evaluate the performance of companies and industries and to make recommendations to investors.
* Data analysis: Economists with strong analytical skills may be well-suited to careers in data analysis, where they can use their skills to interpret and analyze large sets of data.
* Teaching: Individuals with a master's degree in economics may be qualified to teach economics at the community college or university level.
* Government: Economists may work for government agencies at the federal, state, or local level, where they can use their skills to analyze and develop economic policy.
* \\Nonprofit sector: Economists may work for nonprofit organizations, where they can use their skills to address economic and social issues. | 14 | 17 |
ELI5: out of all the voices I am capable of making, how does one of these become my natural speaking voice? | Unless you consciously make an effort to change it (eg. Transgendered woman trying to sound more feminine), the pitch of your natural voice is the one which you have the least strain on your vocal chords. | 42 | 50 |
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CMV: Personal privacy is more important than the conveniences of modern technology with smart phones and social media | Privacy has become less and less of a priority for people over the course of the smart phone evolution. Our lives depend on them and how much "easier" they make our day. You can do everything from mobile banking, shopping, dating, gaming, photography, GPS, the list is really endless at this point, but there's a trade off that comes with all of these benefits, and that comes in the form of privacy, or lack of, and the internet. What you put out there becomes a beacon of information about you with social media and anything else you put online. How many times have you heard that "your phones always listening." Your favorite apps request permissions to access your microphone, camera and location. For some people, they casually click accept like it's not a big deal, but it is.
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Everything we've put into smart phones to make our lives easier used to be a normal thing we'd go out and do instead of do from our phones. Before social media, you had to make more of an effort to stay in touch with family and friends, but you did it. Phone calls, hand written emails, and just generally staying in touch. Dating meant going out and meeting someone in person, not getting to know then over text before you've even met face to face. Going to the store, visiting the bank and anything social whatsoever was done in person. Looking at a map, getting lost but finding your way around eventually, but all of these things were seen as something "fixable" and able to be improved by taking away the "work." Now people are so fixated on their phones and what they do that they don't want to even consider going without them, so privacy is signed away without concern, because it's more important to the masses for life to be easier than retain their privacy.
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Now, I can't ignore that smartphones and where technology as a whole has come is also beneficial for a bunch of other reasons that don't "fix" our lives as much as they enhance them, but all of these capabilities dinish real interactions and investing in the world before it became an option to sit out and do it all from our cell phones instead. It's not worth our privacy, and more people should be worried about it, but they just don't care because the convenience in their lives outweighs everything else. Privacy is more important than what your smart phone offers.
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I'd be open to changing my view if I can be convinced of a smart phone benefit/convenience that can't be solved with a real world equivalent for similar results. An example being mobile banking vs going into the bank, going to the grocery store vs online shopping, etc. If there's a function or tech advancement so massive and necessary in our lives, what is it and why is it worth more than my privacy?
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CMV.
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Edit: I wasn't very clear on why person privacy is important to me, so let me add that: A lot of it falls on trust, and whether or not a company or these app providers use your information or not, it's still your information. When you share something personal by word, it's trusting the person you tell with that information. If my smartphone can freely use my microphone, location, search history to personalize ads or make suggestions even outside of the time I'm using their product. There's a lack of control and boundaries in one's life when your phone and these apps can just tune into your conversations and listen whenever, or use your location to make suggestions I never asked for. I understand that the world revolves around huge corporations making money, but there's such a thing as freedom of speech and a degree of control over how what I say can be used, whether it's to make my life easier, or just annoy me with copious amounts of ads and spam related to 1 thing I might have mentioned in an out loud conversation or searched on Google. I'm of the opinion that my info should be mine unless I explicitly share it with an entity, not just for when they want to tune in and listen. | Why does your personal privacy matter to billion dollar companies?
**You're not special.**
You personally don't matter to them. **You are numbers and data** in an algorithm that lets them make money.
The reason why personal privacy isn't more important than many other conveniences of modern technology is because **the type data your giving them doesn't matter in the grand scheme**. **People don't care because at the end of the day they get a better product.** In 99.99999% of cases these companies don't use your data in any way against you.
**So why is how often you buy cereal on amazon, or how often you drive to your friends house on Google maps in any way important?** Companies want money and personalizing it off of data makes more of it. Thats it. | 193 | 1,020 |
ELI5: Why do some lawyers help bad people? (Question from 8-yr-old) | Hey everyone,
Could you help me explain this to my sister in a way she can understand. Her exact words were 'why do some lawyers help people who have done horrible things, like killing lots of people or hurting their own kids? do the lawyers feel bad about helping them?' | 1.) Because some lawyers believe in equality of representation. Everyone deserves a voice in our society, no matter what they have done.
2.) Some might actually be innocent. The small chance that someone might be innocent is enough for you to fight for them. It is better to let a 100 criminals go free than to condemn an innocent man. Benjamin Franklin said that. He was a wise man.
3.) Money. You make a lot more in private practice than you do being a public defender.
Some lawyers have a conscience, some don't. Lawyers are not magically moral, they are humans too.
ELI5: If your little brother was caught doing something bad, and you got blamed for it, you would want to fight for yourself, right? Even though everyone thinks you did it. Without our laws, you wouldn't even get a chance to tell mommy your side of it. If you did do it, maybe you had a good reason, and would at least want mommy to hear it, before she grounds you.
| 48 | 31 |
ELI5: Why do some websites require credit card CVC and some do not at checkout? | Seems if someone could charge without it, why is it needed some places? What's more, why is it needed a'tall? | Fraud prevention. Asking for the CVC is a much stronger proof that the purchaser actually has the card in question. The three digits of the CVC you are talking about are not stored electronically on the card so it can't be skimmed. Far from a bullet proof security measure, but does add security for remote transactions such as online and avoids situations such as telephone operators asking for your PIN, which is the security measure for the card being present at the transaction. | 10 | 19 |
ELI5: how did most teachers come to be female when historically women got less education than men? | Traditionally, up until the middle of the 19th century most teachers were male. That's because most formalized teaching was for older students.
Around that time, the concept of elementary aged education grew. Because it was for younger children, there was a perspective that it was considered women's work, as it was child rearing. On top of that, much of the teaching of young children was already being performed by mothers. In some countries this has grown to go all through high school.
Two other factors come in to play here. Being "women's work", it wasn't originally taken as seriously, resulting in lower pay and a poor reputation, both of which have lingered on in some ways, some subtle, some overt. Also, as women were entering the work force, it was a place where they *could* get a job, which hasn't always been the easiest for women. | 54 | 48 |
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[Physics] [Chemistry] Why does something smoulder instead of be on fire with a flame? What's happening physically? | its important to realize that burning and smoldering are both examples of exothermic oxidation reactions. Smoldering usually occurs because there is some impurity absorbing some of the heat energy causing the reaction to proceed more slowly than outright burning. For example a fresh leaf has a great deal of water in it. Water has a very high specific heat capacity, so it is great at absorbing all the extra energy given off from the exothermic reaction of combustion. | 21 | 18 |
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How does the earth make water? Or is there a fixed supply. | Water is chemically composed of Oxygen and Hydrogen, both of which are found in large quantities on our planet, but not always together as water. The amount of Hydrogen and Oxygen is relatively fixed - discounting the small amount added by meteorites entering our atmosphere, and space craft and the solar wind releasing some back into space.
So there's a maximum amount we could have if all the oxygen and hydrogen on the planet was used to make water, but there would be some hydrogen or oxygen left over, as it's unlikely the mounts match up exactly 2:1.
Life and human activity constantly moves Hydrogen and Oxygen from one chemical composition to another via chemical reactions: Plants exchange oxygen (both ways) with the atmosphere via photosynthesis and growth; animals breathe in oxygen from the atmosphere and combine it with sugars from food and breathe out carbon dioxide and water vapour produced in respiration. On top of that, the human activity of burning wood and fossil fuels also produces carbon dioxide and water (among other things). Other industrial and natural chemical processes also produce or consume water. | 14 | 15 |
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ELI5: Why do some injuries "sting", while others may give a more "dull" pain? | The type of pain is an indication of what kind of injury you have. It's your brain categorizing what's happening. For example if you have a sore muscle it's probably dull because your brain knows it's pain, but it's not an immediate danger pain. Then take stinging pain. Those are meant to warn you of something immediate or major. Like if you step on a broken hanger you have a stinging that says "stop stepping on a hanger you idiot and remove your foot immediately" it's evolutionary to tell you the extent of pain and the severity and immediateness of the injury | 1,040 | 1,137 |
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{Economics} How widely accepted is the efficient market hypothesis? | Undergrad Economics / Finance student here.
I am currently working on a chapter on the transmission of information in financial markets and weak, semi-strong and strong forms of efficiency. This includes the efficient market hypothesis
Although this is an interesting idea, I have some reservations about it. There are several 'anomalies' that don't seem to fit with the EMH:
A) consistently high returns achieved by investors such as Warren Buffet. Buffet claims that he simply analyses fundamentals and buys undervalued stocks, but this should not lead to excess returns even under weak form efficiency I believe. I find it hard to believe that Buffet is simple incredibly lucky, and Buffet himself suggests that a number of people following investment advice by Benjamin Graham have prospered: http://en.wikipedia.org/wiki/The_Superinvestors_of_Graham-and-Doddsville
B) Bubbles in markets such as the tech bubble in late 1990s to early 2000s.
C) Shorting opportunities may not exist, and the 'smart money' investors that will supposedly drive up / down the price of under/overvalued assets may not have the capital to shift prices sufficiently.
D) Incentives for traders and financial managers may lead to them maximize their own earnings rather than company profits. For example, fund managers with high returns in the first half of the year may switch to low risk assets for the rest of the year to lock in high returns, thus ensuring that they receive their bonus.
Is the EMH just a useful idea that is a starting point for analysis, or is it considered to be a perfect model?
Are there any alternative theories to the EMH?
EDIT: Thanks for all the replies everyone, this is all really useful
| Read random walks in stock market prices by Eugene Fama. Answers pretty much all your questions. Its a fairly accessible read but you can go through his sources (such as his PhD dissertation) to get a more detailed explanation.
Also, there's no such thing as a perfect model. If there was it wouldn't be a model it would be reality. | 17 | 33 |
Forbidding private currency is a good policy for the economy of a country? | I was reading that most of governments made them illegal last century, but none of pages talked about the economic impact of such policy. | Generally, governments have moved to a single accepted currency to simplify the mediums of exchange. Simply, if a person wants to buy a car, it is easier for that person and the owner of the car if they can only transact in a single accepted currency. If a country essentially had an internal exchange market of multiple currencies, people would constantly have to monitor their assorted or chosen currency for its relative value which would be stressful and, depending on the market, leave some people with worthless currency over others. | 19 | 20 |
[Michael Jackson - Billie Jean] Why do the tiles light up below Michael when he has his invisibility field on? Surely this side effect defeats the whole purpose of this technology? | The tiles appear to be either pressure sensitive or capacitance/proximity sensitive. Neither would be effected by invisibility as that is a different effect than levitation or fading to the astral. So in the particular such tiles would be created to do that very thwarting.
It would indeed defeat the purpose of being "invisible" if that purpose is to "pass without trace", as opposed to being "unseen" or immune to laser fire.
But you've missed the actual point, and technologies, completely.
There is actually no technology in "the tiles". Those objects are all completely mundane. Michael himself is causing them to glow at his touch by act of will. This is why the concrete, the pole, and the mailbox all act identically despite having distinctly different construction, composition, and purpose.
So why go invisible and still cause the objects to glow? To fuck with people.
Michael is "The Cheshire Cat", appearing at will and affecting what he desires to affect. | 31 | 69 |
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ELI5: Libertarianism (U.S. Politics) | What do they represent?
What are their stands on major issues?
How do they differ from Democrats and Republicans?
etc. etc. etc.
(This post spawned by the idea that I am refusing to vote for either Obama or Romney. Time for me to look into other options.) | Before we look at Libertarianism, let's establish there's two major types of policies a political group can support or enact. There is fiscal policy (dealing with money) and social policy (dealing with human rights). Taxation is a fiscal issue and abortion is a social issue, for example.
Democrats are both fiscally and socially liberal. They are in favor of more government (fiscal) and are usually more supportive of expanding civil rights (think LGBT rights and similar things). Republicans are the opposite. They are fiscally and socially conservative. They favor less government and are generally in support of traditional social values (think nuclear family kind of values).
Libertarians are fiscally conservative and socially liberal. Libertarians are in favor of smaller government (like Republicans) and in favor of expanding civil rights (like Democrats).
Like Republicans and Democrats, not every Libertarian will have exactly the same views as others. Libertarians generally hold that individuals, and not government, know what is best for themselves, and are in favor of stronger personal freedoms. Some of the views a Libertarian might have include:
1) Less welfare programs
2) Less military
3) Decriminalized or legalized drugs
4) Less or no restrictions on abortions
| 18 | 28 |
CMV: Cultural squeamishness about bare feet in public is irrational and arguably responsible for the majority of foot problems | I grew up in a country (South Africa) where bare feet are much more acceptable in public. Children are widely allowed, even encouraged, to attend primary school barefoot. The same situation applies in New Zealand and possibly a few other countries. Yet the vast majority of cultural norms elsewhere in the world dictate that feet should be hidden away, locked up in shoes ('little coffins for the feet' as someone once described them) - a sweaty, bacteria-rich, damp and cramped environment that creates unpleasant smell and often long-term problems of painful and unsightly deformities. That's led to a sort of vicious circle, where people are ashamed of their feet because they smell and/or look ugly, but they smell/look ugly because.. they're cramped up in shoes because.. they're ashamed of being smelt/visible in public, and everybody will judge you etc. etc.
There are of course many situations in which you \*would\* want shoes.. if it's cold, for example, or if your feet genuinely need protecting from sharp or falling objects, such as on a building site or on a rocky trail. But shoes in those situations are like protective gloves. And we don't wear gloves at all times in public do we?
One might counter this by saying that surfaces you walk on are worse than those you touch with your hands, but this is largely untrue. There are far worse things on door handles than there are on a clean sidewalk or in a mall, or in an office. And when you walk barefoot, you look where you walk, and avoid stuff if you need to. It isn't difficult, and the risks are far outweighed by the benefits.
My view is that we're long overdue for a rational change of our cultural biases on this subject (those biases originating at various points in history e.g. associations of poverty, or 'those damned hippie liberals' etc.) and just come to terms with the fact that we'd be far healthier and happier without shoes most of the time.
Update edit:
Brilliant to read everyone's responses, it's fascinating and thanks for engaging (sorry I've not replied to all..)
No deltas awarded yet though because as far as I can see, loads of folk are just posting here about their (mostly unfounded) fears about what they might tread on, which doesn't acknowledge the point I made in my OP: in any \*real\* risky situations (of which there are plenty) then yes shoes are needed - but much of what people think is dangerous or risky really is imaginary. Or at least very much overhyped/catastrophised - including in city environments, by the way. South African schools know this. They wouldn't allow kids to school barefoot if they thought it was a significant risk.
But it seems to me what we \*don't\* have is a universal cultural environment in which each person can judge the dangers/inconveniences and make their own decisions on being barefoot in public or not without being on the receiving end of disapproving stares, tutting, 'no shoes no service' signs and the like. In other words, it's gone beyond a rational, personal, practical decision and become a \*cultural taboo \*- even at the expense of foot health problems. But a taboo only in certain countries. That's what's interesting to unpack. | But shoes were invented in the purpose for reasons of practicality. You don't usually *want* to be walking outside barefoot. Even if you tried to make the world accepting of bare feet in public, no one would do it, because shoes are just more comfortable, especially if you live in a relatively high latitude country where the floor is always fucking freezing. For the record though, most countries take their shoes off at home, either replacing them with very loose slippers or just going fully barefoot. America is the weird one on this. | 52 | 85 |
ELI5: How do insurance companies make money? Who insures insurance companies? | If I pay $150/month and total my car after 12 months, I've only paid in $1800, yet I will get back ~$10,000 (depending on the vehicle, of course). How do insurance companies make a profit from that, and how are said companies insured? Can they insure themselves? Who do they pay? Wouldn't it be like writing a check to yourself? Also, how do people start up their own insurance companies? | The main thing you need to know about how they function is this:
They are INVESTMENT ENTITIES.
Nominally, the thing most people see is the spreading of risk, pooling money from lots of people to transfer that catastrophic risk from the one person who loses a home, wrecks a car, or gets cancer, to the group of people that all buy insurance.
But what does an insurance company do with that pool of money in the meantime?
See, the company has a bunch of money called a "surplus" which is mandated by law based on line of business (health, auto, home, life), AND it has a bunch of money from what people have paid in but hasn't been assigned to pay a claim yet, AND it has a bunch of money "reserved" for claims that are submitted, but not yet paid out (like worker's compensation claims, etc.).
This money is INVESTED.
You may be surprised to know the that the biggest buyers of bonds are insurers. (because of regulation, the amount of stocks bought by most insurers is pretty minimal).
Also, note that "life insurance" companies are primarily about selling investment products to customers; the products that pay out based on insured deaths are a small portion of the total sales.
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As to "who insures them," you need more to the question, as in "insures them for what?"
Your typical "personal lines" (i.e. auto, home) insurer will have its workers' comp, health, life, and its buildings' and infrastructures' property (assuming it doesn't just rent those facilities) with other companies.
And, typically home insurers will purchase reinsurance from global companies to protect against large-scale losses (Hurricane Rita, for example). | 62 | 101 |
eli5: How were square roots calculated in the first place, before calculators? | You would look them up in a table. The tables were populated by hand calculation.
For example, what's the square root of 20? Well, you know it's going to be more than 4 and less than 5, because 16 is 4² and 25 is 5². So you might try 4.5. So then you would square 4.5 and get 20.25. This tells you that the square root of 20 must be a bit less than 4.5. So you could try 4.4. You square 4.4 and you get 19.36.
So now you know that the square root of 20 must be 4.4xxx. So you might try 4.45. 4.45² is 19.8025, so that's too low. 4.46² is 19.8916, so that's too low. 4.47² is 19.9809.
That gives us a second decimal place. Now let's add another decimal place. 4.475² is 20.025625. 4.474² is 20.016676. 4.472² is 19.998784...
So now by essentially guessing and checking, we've gotten three decimal places on the square root of 20. 4.472. We could keep going and keep adding decimal places through the exact same method. | 46 | 17 |
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If all knowledge were destroyed and had to be rediscovered, how would philosophy look different? How would it look the same? | For context, I'm from physics/mathematics where I think that the same concepts would be discovered and the same theories would be developed and organized in largely the same way. There might be different 'strange coincidences' between seemingly disparate subfields discovered at different times that are later reconciled within a larger theory but the fact will remain that the fields of math and physics divide themselves neatly in a way such that if any one subfield were missing, we would still stumble upon it at roughly the same point in history and it would illuminate the remaining subfields.
Is the same true in philosophy? Is it possible to imagine an alternate history where X subfield never developed? Which subfields would always arise? Which wouldn't? Could some emerge in fragments or as hybrids? | This may be interesting to you, because Alisdair MacIntyre would say that not only would philosophy be completely different, science would be as well because of the lack of a proper cultural context to situate a proper methodology and facts in. Think Canticle for Leibowitz if you know it. This was a famous point he made in the opening pages of After Virtue, where he argues that this scenario has indeed happened to moral philosophy, which has been at a dead end because of it. He’s a bit more optimistic of the ability to actually do proper moral philosophy if we return to a proper cultural context though. | 69 | 196 |
ELI5: Why does urine come out yellow and not green or blue? | When you're hydrated your urine comes out clear but after a long night of drinking it can come out darker yellow. Why not blue after drinking something blue or brown assuming all the colors mixed together? | Only certain specific foods (such as beets) and some medications change the colour of your urine to a colour other than yellow. When you drink a blue drink for example, most of the time your urine won’t become blue because the molecule that makes the drink blue doesn’t pass through into your urine. Beets contain a pigment called betanin which does pass through to your urine, resulting in pinkish-red urine if you eat enough beets!
(Also certain diseases can cause your urine to become different colours. Go to a doctor if you have any worrisome changes such as blood in your urine or a different colour urine.)
What gives urine its yellow colour is a pigment molecule called urobilin which is a waste product from your body (it comes from dead red blood cells). When you’re well-hydrated, there’s way more water compared to urobilin, so your urine looks pale yellow. When you’re dehydrated, there’s less water and more urobilin, so your urine looks darker yellow. It’s like when you’re making juice from one of those frozen juice concentrates... the more water you add, the paler the juice gets :)
Hope that makes sense :) | 55 | 36 |
[Star Trek ToS/TNG/VOY/DSN/ENT] Body snatching is so unbelievably common how in gods name is there not a protocol for "Hey the captain just out of the blue acted entirely out of character and threw our diplomatic mission out the window. We should really stop and take a close look at him."? | It's important to keep the missions we see on the Star Trek television shows in perspective. The ships and crews shown in them usually represent the best of the best in the Federation, with the Enterprise being the Federation's flagship that is generally only sent on the most pressing/dangerous missions. Because of this they experience unique situations at a far higher rate than your typical crew and are the ones that the protocols are written for based on their experiences. So body snatching and other wacky scenarios may seem very common from our point of view, but from the perspective of the Federation it never happens to probably 99% of their ships. | 202 | 391 |
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CMV: Modern capitalism cannot exist in a future society. | Now, before you start calling me a communist, I think capitalism can work in the future with changes such as UBI. In fact, that would be the best system for the near future in my opinion.
Now, the reason I'm saying changes need to be made is because of automation. Automation isn't something your grandkids or even your kids have to worry about. You have to worry about it too. Automation isn't something that will be here in the future, it's already here, and it's spreading quickly. By 2030, roughly 30% to 50% of jobs are going to be taken by automation, with some people saying the job loss could be even bigger. Keep in mind, the unemployment rate during the great depression was 25%! And remember, by 2030 that's supposed to happen. What about 2045? The unemployment rate then could easily be 75% to 95%, if not more. If no one has any jobs, how can people live? No money equals no food, no homes, no anything really.
I just want to know if anyone thinks todays capitalism can work in tomorrow's society.
Oh, and if you think your job can't be taken in the near future, go ahead and tell me why. I could probably think of a good reason why it could be. | There was a time that the bulk of people worked in agriculture. Not any more...what happened? Industrialization of agriculture; the use of machines to let fewer people do the same work. Automation is the same thing; machines allowing one or two people to fun an entire factory instead of a few dozen. So what will happen? Well, what happened with the extra agricultural workers? We created other jobs, more jobs; jobs in the tech industry, more entertainers, more social workers and other jobs that basically didn't exist at one point. The average level of education went up, and people found other functions. And, perhaps, the average person worker fewer hours per week. The same thing can happen here. Every truck driver that gets displaced, every factory worker, can maybe move on to something else; opening a small brewery, farming local chickens in their back yard, becoming an EMT, and so on. Is this the BEST solution? Heck, no. But it's perfectly plausible. | 208 | 512 |
Is there a reason why bigger animals tend to have bigger eyes. What advantage is it having eyes in proportion to body size? | Bigger eyes generally mean better visual resolution and better light-gathering abilities. It's basically the same reason that big telescopes are better than small ones. For example, on the reef at dawn and dusk big predators come out to hunt. They have the advantage over small reef fish because their larger eyes allow them to see better in the dim light.
So big animals basically just have bigger eyes because they _can_. You couldn't stick a human sized eye on a mouse, because the poor thing would be about half eyeball. But there are diminishing returns, and eyeball size levels off. Cows are a lot bigger than people, but their eyes aren't all that much bigger. The animal with the largest eye of all, the giant squid, hunts in deep dark water and needs extra-large eyes to see. The much larger blue whale has smaller eyes, due to the fact that it doesn't rely on vision, especially vision in dark water, nearly as much. | 116 | 183 |
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Why is everything so slow at the universities? | As the title asks, why things like getting contracts, admin related work, joining labs, working in the labs and logistics around it so slow? Do you experience the same? If so, how do you cope up with it?
Edit: Thank you for the responses! I am surprised to see so many responses. It is heartbreaking to see that many people have been affected by this situation. Hope that the problems go away soon! | At a US public university it’s often because 1 person often has the workload of what used to be supported by anywhere from 2 people to a whole department of staff. There simply are not enough hands on deck at the lower end of the pay scale to do all the work that needs to be done, but there’s always money for a new VP of Innovative Strategic Directions. | 144 | 182 |
What is the difference between mortgage, rent and lease? |
Mortgage: You get a loan for house. You buy the house with this loan. You pay interest and principle over decades. After you're done paying, you own the house.
Rent/Lease: You pay weekly/monthly for the privilege to live there. You don't own it.
| 20 | 33 |
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ELI5: Why does putting cold fingers or toes in comfortably warm water cause a burning sensation? | A combination of two things working together:
1. Your skin doesn't sense the actual temperature of things, you sense the *rate* that heat is entering or leaving the skin.
2. The rate of heat transfer gets faster the bigger the temperature difference between two things.
When your skin surface is cold, the "warm" water is hotter by comparison than it usually is. When you put freezing hands in warm water, heat starts entering your skin at a fast rate, a rate that tells your brain "water 50 degrees warmer than skin temperature". Your skin temp is usually body temperature, so your brain goes "oh shit, nearly-boiling water!" Except your skin was way colder than usual and the water was only normally-warm. But your temp sensors can only tell temperature *differences*, so there's no way to tell the difference.
Extra info:
Think about how a metal railing outside in the winter feels colder than something wood like a tree, even they're both the exact same temperature. That only happens because metal is a way better heat-conductor than wood. So cold metal can draw heat from your skin's surface faster than cold wood of the same temperature can, so you feel the metal as being "colder" because the *rate* of heat loss is faster..
Another example in case you don't live somewhere with cold winters: wooden toilet seats vs plastic toilet seats. The wood ones feel warmer, right? Both are the same room temp, but again wood is a poor heat conductor while the plastic seat draws your heat away faster. | 46 | 24 |
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Eli5: If heat from the sun is radiated onto Earth, doesn’t that mean multiple layers of air are being heated up? If so, why isn’t the top layer really hot and the lower ones cold? | Air is not good at absorbing radiation, which is evident from the fact that you can see very clearly in the air. This is possible because light waves pass through the air with little interference. The same is true for infrared radiation, which is what heats up Earth mostly. Rather than being absorbed by the air it’s absorbed by the Earth’s surface. The surface, in turn, heats up the layer of air next to it. This down-to-surface air then rises up, because warm air is less dense than cold air, making that colder upper air settle down somewhere else. This process causes most of what we call weather, by the way. | 10,835 | 11,687 |
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ELI5: Why are crescent moons cut into the doors of old-timey outhouses? | Edit: Holy shit guys!! This is my second post on Reddit and it made front page! Thanks guys | In colonial times when literacy was poor, the crescent was a symbol for women and a star for men. These are actually tremendously rare now but were perpetuated by old cartoons to provide a clear designation of a building as an outhouse.
| 532 | 1,009 |
ELI5: How did sheep shed their wool before the emergence of humans? | Humans have selectively bred a small number of species to help provide better for human needs at the expense of the animals natural survival. Sheep are one of those species.
Prior to domestication sheep would have grown a much smaller amount of wool up to the point where it served their needs, like the hair on a bear or a wolf. It doesn't grow indefinitely.
Then humans came along and found these relatively docile sheep sitting around and someone realised their wool was very useful to make things like clothing out of. Over many generations humans captured and bred these sheep to harvest their wool from. Humans also realised that by breeding the males and females with the most and best wool, the offspring would usually end up with even more wool than the parents. By repeating this process over time we ended up with the types of sheep we have today, who are completely reliant on humans to regularly shear them and remove the wool. This is domestication and selective breeding. Without us they would suffer many problems like overheating and being far too heavy. | 1,182 | 958 |
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Eli5: How the finger light thing can tell how much oxygen is in your blood? | As the the title suggests, how is it that a little light they put on our finger when at the doctors/hospital/etc.. is able to tell us our blood oxygen levels? | In blood, the oxygen is carried by some molecules.
It just so happens when the oxygen binds to those molecules they change color.
So they shine a light, read the color and that figures out what proportion of those molecules have changed to that color. | 449 | 344 |
CMV: More nations should adopt Autobahn-style speed limits | I live in Southern Ontario and frequently drive on 400-series highways which have a limit of 100kmh and other highways have speed limits around 90kmh and 80kmh.
I believe that this causes problems, mainly people going at or below the speed limit in passing lanes with people tailgating or lane-changing rapidly around them.
A better system would be to remove speed limits except in built up areas, and have people stay in the right-most lanes except when actively passing someone or approaching a split (401 Express/Collectors).
Meaning that people who like the current 100-110kmh flow of traffic in the right lane can stay there and leave the other lane(s) open for people who want to go faster.
I believe this would reduce collisions because it would help segregate cautious drivers from aggressive drivers, and it would likely reduce tailgating as people would just pass through the open space.
To CMV please provide either evidence that this system is statistically more dangerous or at least on par with our current system.
Edit- /u/RagingNerdaholic changed my view. I was of the mind that we just needed to remove the limits, but his comment made me realize it would also require a lot of re-education and retraining as well as a revamp of the licensing system. | One thing to consider is that this really doesn't work unless you *also* greatly increase the difficulty and requirements of getting a drivers' license. Germany is one of the most grueling and technically challenging countries in the world in which to be allowed to drive.
So they can get away with this. An autobahn also only works in a culture with a serious obsession with rules and regulations, because it becomes an enormous bloodbath if people don't strictly follow rules like maintaining their cars to strict standards, passing on the left only, and not staying in the left lane all the time. | 35 | 92 |
ELi5: Why do some colleges send mass emails saying something along the lines of, "You have been selected for a prime selection status! Blah blah blah!" Do they not have enough applicants or are they generally interested? | The more applicants they get, the better. Part of these college rankings is their acceptance rate, with lower being better. For example, if a college aims to admit 1,000 students every year, they'll have a lower acceptance rate if they chose those 1,000 out of 2,000 applicants instead of 1,500.
Elite schools in particular will reject highly qualified students just so they can say "we're so exclusive that we rejected this guy with a perfect GPA, all-state athlete in 3 sports, all state in band, and captain of the debate team". | 21 | 67 |
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According to the theory of relativity, do all observers agree on causality? | This is a question that I posed to my astronomy 101 teacher, but I don't think she understood my question. So, as I've heard relating to the theory of relativity, if observer A is on Earth, and observer B goes at ½c to the nearest star and back, observer B will have experienced far less time than observer A. But that's from the perspective of observer A. From the perspective of observer B, observer A is receding at ½c away from them, and so observer A should be experiencing less time. How is this resolved within the theory, or am I just not getting it? | Events which are causally related must have a definite ordering in time that all observers agree on. Pairs of events like this are called *timelike-separated*. Events that are not causally related don’t have a definite ordering in time. Pairs of these events are called *spacelike-separated*. | 25 | 15 |
cmv: We should still do social events, even if they are not accessible to everyone. | Bottom Line Up Front:
“If it isn’t accessible to everyone, it isn’t accessible to anyone.” is a really good tagline, and a really good idealistic goal, but the fact that something isn’t accessible to everyone shouldn’t stop us from doing things.
Context: I tend to be at the table, or at least in the room, for event planning…a lot. Usually I either started the thing because it was an event i was looking for and it didn’t exist (I.e. local gaming group or celebration) or something someone felt I could help with (I.e. planning a local parade or community party).
I believe I understand that how these things are setup or run can be exclusive. For example when we setup our local gaming group we eliminated game shops where the game room was only accessible via stairs. We found places that have elevators or game rooms on a main floor.
What I struggle with is the idea that we shouldn’t even have these in-person gaming events because we don’t have an audio-visual system setup to allow people who (tragically) are home-bound to attend virtually…and we don’t have spaces set aside for folks who have sensory issues…and we don’t have an ASL interpreter for folks who can’t hear…and a narrator for folks who can’t see…
I would LOVE to be able to ensure everyone can take full enjoyment and participation at every event I’m a part of, but that simply isn’t within my capabilities. Many people, from experts to everyday people are saying we shouldn’t do it at all, because “if it isn’t accessible to everyone, it isn’t accessible to anyone”.
Obviously it IS accessible to some folks, but I fully admit it isn’t fair or equitable.
But what is the solution?
This feels like a false dichotomy:
Since not everyone can go to game night, nobody should go to game night.
Since not everyone can hike, nobody should join hiking clubs.
Since not everyone is comfortable around animals, nobody should have pets.
Obviously there are differing levels of ridiculous and understandable points here.
For example, I do think tax money should not be spent directly on things that aren’t able to be enjoyed by a majority of the taxpayers (e.g. if a city builds a stadium, they should make sure it is accessible; if a township wants to host a picnic, they should make sure the members of their township are able to attend).
I feel like I’m missing something and I REALLY want to understand where reality meets ideology. I would absolutely love to have a game night where everyone can participate…but I don’t have that ability…should I really NOT do any game nights at all? I don’t think that’s reasonable. | Tax funded events should certainly be accessible to everyone who helped pay those taxes.
If you contributed, you should be allowed to participate.
For personal events that aren't tax funded, do what you conveniently can. If you want to set up a game night because there isn't one locally, DO IT. Doesn't matter if it's accessible to everyone.
Accessibility is nice, but should only be required for people who contributed imo.
If a bunch of people pull money from their own pockets to set up a game night, you cannot expect them to dish out more out of pocket money to make sure it is accessible.
"We have $1000, we can make it happen for $1000, but to make it accessible would cost $1500."
That doesn't mean it shouldn't happen, that just means they can't make it accessible.
But if one of those people contributing to that $1000 is in a wheelchair, it would be very wrong to not make it accessible to him, as it only happened because of him. | 10 | 21 |
How does Mecca cope with the fact that there are now 1,250,000,000 Muslims in the world, all of whom want to visit? | The Hajj, the pilgrimage Muslims make to Mecca, is one of the Five Pillars of Islam, something every Muslim should make in their life, health permitting. I'm sure this worked out much better a few centuries ago, when most Muslims lived within a few hundred miles of Mecca.
In the modern world, the number of pilgrims converging on Mecca must be a huge logistical problem. I'm curious about how the folks that run things there (visit to the Kaaba, hotel accommodations, etc.) deal with all the pilgrims.
Related question: Is it common for pilgrims to make acquaintances with fellow pilgrims that might lead to later international business relationships ("networking")?
Related question: What about the poor bastards that can't afford the trip? Indonesia has [123,000,000 Muslims](http://www.wolframalpha.com/input/?i=number+muslims+in+Indonesia), ~10% of the [world Muslim population](http://www.wolframalpha.com/input/?i=number+muslims+in+the+world). Most of these folks will never be able to afford the trip. What are they supposed to do?
Thank you for your help. | Thanks for the question. I'll try to answer some of the points you raise.
Although there are 1.2-1.5 Billion Muslims in the world, not all of them will make it and most will only go once in their life time. The numbers are increasing every year and it is a huge challenge logistically now that travel is easier as compared to before.
With regards how the local authorities deal with it,I have been told by family members that the local authorities although not perfect they are remarkably organized and they have the yearly experience. The Saudi gov. has made design changes to the holy sites so that more people can come and visit and in a safe manner. This includes more accommodation, better travel facilities and also better routes so the sacred practices can be made in a quick and safe manner.
The Saudi gov. has also given certain Hajj visa quotas to each country in the world, esp. the Muslim ones so that it is a fair balance and also a measure to prevent a huge influx of visitors in the season. This way the Saudi authorities will know roughly how many people will come and thus prepare accordingly.
With regards to the actual Hajj it self, although it is a pillar in Islam, if you can not afford it, or if you have debt or you are unwell, then you are definitely not obliged to go.
One interesting point you make about the millions of people that gather in one place is that one of the goals of Hajj is that people of all walks of life from different cultures and colours all meet and great each other. Many friendships have been created this way that lasted a life time. In fact religious tradition encourages that you greet your fellow person conducting Hajj and engage in friendly dialog, all this to promote a sense of unity and humanity.
It is also a time to reflect that no matter how rich or poor you are, we are all equal in the eyes of God. To symbolize this equality, everyone wears the same simple cloth, whether billionaire or a poor, black or white, all will wear the same. We will all die and in the hear-after we will come back to face our maker and the only thing that will have bearing is our conduct in our life time not how rich or important we were.
The process is a wonderfully spiritual affair, esp. if the Muslim in question prepares in advance and reads and asks on how to best conduct the Hajj. Many converts to Islam who went to Hajj not only loved it but found that it changed their lives for the better.
I am sure others will be able to answer more than this, also there are many videos online that explain the process itself and what it means for Muslims.
Edit: Spelling. | 67 | 73 |
How does water traveling up a dry rag not break the laws of thermodynamics? | When you dip a rag in water, how can the entire rag become soaked over time despite fighting gravity? Where does the energy come from to allow the water to travel up the rag? | There is potential energy resulting from intermolecular forces.
If it is energetically more favorable for the water molecules to be adhering to the molecules of the rag than to each other (because the attractive intermolecular forces between the two are stronger than those within just water) then water will be pulled into the rag. This will continue until the gravitational potential energy gained by increasing in elevation balances the reduction in potential energy that comes from sticking to the rag. | 20 | 15 |
When is assembly language needed? | Is assembly language completely obsolete or are there useful purposes for it? What kind of a job would require those skills? | High level languages expect certain civilized niceties to exist.
&#x200B;
For example a stack.
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For example the BSS segment to have been initialized.
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For example a stack frame to have been created and sane things happen when you "return".
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Something has to do that.
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If you have a nice OS... most of that will have been magically done for you.
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If you don't, or you are writing said OS... then a little bit of assembler is needed.
&#x200B;
For example when you have a hardware interrupt... what the CPU does is fairly rude. It's quite common to have a tiny bit of assembler that sets things up so a high level language service routine can run successfully (and return successfully and return to interrupted code).
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Many weirder CPU's have insanely weird instructions.
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If you're lucky, you have them neatly wrapped and handed to you as \_\_builtin\_XXX() compiler intrinsics.
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However, especially on DSP's you have weird highly vectorised and /or pipelined instructions that expect you to set up a data pipeline and stoke that pipeline with data and tear it down with careful handling of boundary conditions.
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Sometimes assembler is the only way, but hopefully the vendor of said CPU had packaged it all up as a library routine to do a fft or convolution or whatever.
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Conversely you can only really understand what the hell your optimiser is doing with your code by looking at the disassembler listing.
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Quite often you get horrid surprises when you do. (Not because the optimizers are Bad, usually they are quite good. But because we're humans are quite bad at understanding exactly what the language standard implies.) | 16 | 25 |
[Pokemon] Who rules the world of Pokemon? Is there a government? Are there countries? Are the Gym leaders essentially warlords/chieftains running their town under the watchful eye of their Elite Four Overlords? | Essentially.....what is going on in Pokemon world?
Are the Elite 4 the heads of government supported by various gym leaders/warlords who only allow the strong to join their ranks?
Who funds the Pokémon Centres? Do the elite four fund them to encourage fighting and to make the new generation of leaders battle hardened?
So many questions! | We know government and nation-states both exist; the Pokémon world has mayors, uniformed police, armed forces who go to war, and Pokémon Centers exist even in regions where there is no League system (Orre), implying they're government-funded.
Since any serious trainer is walking around with a belt of serious portable firepower, and trainers are everywhere, conflicts can arise rapidly. There is a cultural understanding that strong trainers are responsible for intervening when other trainers abuse the power of their Pokémon. This usually means Gym leaders and the Elite members, but on rare occasions a roaming trainer of extraordinary skill steps up to the plate. | 39 | 46 |
A very bright light can damage your sight, and very loud sounds can do the same to your hearing. Can a very strong odour damage your sense of smell? | Both a bright light and a loud sound are high concentrations of energy, but a strong smell is a high concentration of particles. That means the smell can get saturated to the point that it really can't smell any stronger.
[edit]: any smell that would damage your olfactory sense receptors would likely do so at any concentration. Corrosive chemicals cause less damage at lower concentration but there is no point where the damage would suddenly start like it does with light and sound. Furthermore extreme concentrations of chemicals and particles tend to experience state changes so you could argue that a high density of smell might drown you, but if you stick your head in a bucket of liquid and inhale it probably won't be your sense of smell that is damaged. | 2,093 | 2,685 |
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Is the vapor from a liquid in equilibrium hotter than the liquid itself and if so does that violate thermodynamic principles? | In an adiabatic container, if you put a liquid there, at certain pressure there would be some particles with enough kinetic energy to overcome the inter-molecular forces and escape. So the gas must be made only of particles with high energy so the temperature must be higher.
Summing up, what would happen is that an object at temperature T would spontaneously "split up" into an object with less temperature and another with higher temperature. **Isn't this against thermodynamic principles? What is wrong with my reasoning?** | 1. Temperature is a statistical property. An object with uniform temperature may still contain individual constituents with a range of kinetic energies
2. Vapor pressure doesn't necessarily require that the vapor molecules are more energetic than the liquid molecules. The binding forces are different for molecules at the surface.
3. At a triple point, you can have a solid, liquid, and gas all in thermal equilibrium | 68 | 190 |
How do we calculate current world population? Also, how accurate is that count? | Burning question on my mind for awhile now. How do scientists calculate the current number of people on the planet? Is it some massive database, clever *guesstimation*, or something else? | Censuses, surveys and estimation. Most (all?) countries have some sort of census, literally asking everyone in them how many people are there. This can be validated by taking smaller populations and checking the numbers (like census data says 100 people live in this district, lets go door to door and physically count them and see how much the census was off). Sometimes people from outside (like another international organization) will do these checks.
Then other people might do their own independent estimates, find X buildings in a city, Y apartments per building, and Z people per apartment. Multiply it out and see what you get. And then extrapolate those numbers to similar areas.
There are also records for stuff like new housing, death records and birth records, it gives you an idea of where people are moving and how the population is growing. Current numbers are estimated with the best known numbers plus estimated growth rates.
This is generally done from the lower level up, and each country gets their own population count, and experts figure out how accurate it is and get that best estimate. Add up all countries and you get a very good estimate of population. | 24 | 65 |
What did Hegel think was the end goal of history? Do any current philosophers believe that history has a goal/purpose? | As a history major turned philosophy enthusiast, Im interested in Hegel's historical commentary. and the notion he seemed to have that there was some guiding force guiding the "geist" through history. im trying to get straight what he thought it was all leading to, something about the actualization of mankind's freedom, or the worlds spirit setting itself free? At the "end" of history, what did Hegel think civilization would be like?
Id also be curious to read any current Hegelian philosophers that are still writing with a similar view of history today. | 1) Hegel's concept of history is different to what common people mean by history. In the introduction to the *Lectures on the Philosophy of History* Hegel makes arguments against different conceptions of what history can *mean,* much of the attack being that in truth these concepts are empty/meaningless, that they are useless despite claiming use, and that really the discipline of history is entirely presumptuous about its object of study. Hegel conceives history as specifically the history of states and nothing more.
2) The end of history isn't something Hegel assumes, but something that arises from the conceptual organization of states from simplest to most complex according to their generative social principle. Why is this complexity measured by 'freedom'? Because freedom is the form of all truth.
3) Just as the history of the wheel *as wheel* is over once we invent it, so too is the history of freedom in the state over when we have discovered/constructed the organizational process that allows the self-engendering of freedom. Obviously we've modified the wheel to perfect its operation in various conditions, likewise the state is going to forever be modifying to fit its conditions, i.e. its people and times. This modification being *internal* to the form and content of a state would reveal that such a state was the proper form which needs no reinvention. Time shall move on and *History* may be over, but history for plenty of other things will always be ongoing. | 16 | 22 |
ELI5: Why Does curly hair stay curly? | I understand *why* people have curly hair, but why/how does it go back to being curly after using a straight iron, or after being pulled straight in a ponytail all day? | There are actually a lot of different things that factor into making your hair curly. If i remember right the amount of Sulfur-Sulfur bonds or "disulfide" bonds. These are from the tertiary structure of the protein in your hair. The more disulfide bonds your hair naturally has, the more curly. | 15 | 46 |
Understanding Lacan's object petit a and anxiety as 'lack of the lack' | Ok, so in trying to understand the ins and outs of Lacan I am going through a variety of texts, which tbh, just leave me more confused than when I started.
So this is what my texts seem to be suggesting
\- object a is formulated as 'lack incarnated'
\- object a is 'the Real - the symbolic = more or less a fraction of the Real'
\- but this fraction of the Real is also the surplus which is jouissance.
**Question 1**: I have one text differentiating jouissance from desire, as the former goes 'beyond the pleasure principle' and I have one text stating that it is jouissance *cause desire*. If both right, how are these combined?
Furthermore:
\- One text states that object a, by 'not being there' allows for fantasy to cover and secure the lack (driving desire)
\- However, anxiety is mapped out as a 'too close proximity to the object cause of desire' (object a), which erases the necessary lack - thus hindering fantasy, hindering desire = anxiety (too close to the Real)
**Question 2:** If object a is 'lack incarnated' - how does the 'too close proximity' to it cancel out the lack necessary for desire? Because the above reasoning seems to suggest that removing object a would cure anxiety, but object a cannot be removed from the equation, right?
I feel like I am missing a vital step /component, but at this point, all texts are muddled and I can't detangle these questions on my own. Help is much appreciated!
And this might be baby-level Lacan, but what I am trying to get at is how anxiety is 'the failure of the fantasy' (fantasy as a compass and organiser of meaning for the subject and the connection to the Other and the symbolic order etc.) | I think the main issue with those concepts is that the meaning will depend on the period of Lacan we are talking about. In fact, object a is different if it's object a, object (a), or object *a*
I would recommend to take a step back and first tell us why do you need to understand object a, so we can point to what text will answer better that particular issue.
PS: Try to read Bruce Fink's translations, it tends to be much clearer than any other. | 15 | 47 |
[Avatar TLA/LOK] Airbending vs Earthbending vs Firebending vs Waterbending; What are the pros and cons of each element and which would be better for combat, defense, and mundane uses? | Also, what kind of creative and unique techniques could a bending master of each element perform if they mastered each specialised technique for their element. Morals off for each bending master. | All have great industrial benefits. You could make buildings with earth, have furnaces and heating with fire, irrigation with water, wind turbines with air.
Fire and earth have the most powerful attacks.
Earth, air and water offer great defense.
I'd take earth. | 50 | 95 |
How did we discover that space was a vacuum? | Who first proposed that space was a vacuum?
What did they base their hypothesis on?
How did we ultimately prove space was a vacuum? | "greek understanding of physics also progressed under Strato of Lampascus (c.335 - 269BCE.). He rejected the idea of a force pushing light objects, such as air, upwards to counter the force that pulls heavy objects down. He argues for the existence of a vacuum and showed that, because air can be compressed, voids must exist between the particles of which it is made up." - Source, a DK "Science Year by Year" Encyclopedia/book.
Later on it describes this "[Blaise] Pascal (1640's) also predicted that this pressure would diminish as higher altitudes. He asked his bother in law Florin Perier, who lived near a mountain, to test the idea. Receiving proof, Pascal suggested that air would thin out into a vacuum at still greater altitudes."
It also says this. "for centuries, it was believed that air had no weight. But in fact it exerts a measurable force per surface area of the earth. Blaise Pascal demonstrated atmospheric pressure by inverting a mercury filled glass tube over a mercury reservoir. The tube's mercury falls to create an airless space (a vacuum), but atmospheric pressure pushes down on the reservoir to maintain a column: the bigger the pressure, the taller the column."
I hope this provides you with some of the insight you wanted. | 136 | 212 |
Why Is Religious Belief Often Considered Part Of Someone's Identity? | Hello everyone. I am autistic and I am having trouble understanding the concept of identity, particularly identity in terms of religious identity.
Why on earth would someone consider a bunch of metaphysical and philosophical claims to be "part of them"? A claim is not part of someone. I accept evolution, but according to my mother, this would not be part of my identity, but my acceptance of Hinduism is?
Yes, I understand that evolution and religion are different types of claims people may or may not accept, but why is one considered part of someone's identity and the other isn't?
How can a religious/metaphysical/philosophical belief be "part of someone and how they view themselves"? Please explain. This has been bugging me and worrying me for ages. I want to understand, but I just can't. Please explain. | Religion doesn't just involve beliefs, but also membership in a community of believers, which ties it to identity. In cases like Hinduism, it is especially difficult to separate membership in a religious community from membership in a society generally. | 60 | 65 |
How do stains work on the molecular level? | How are the particles that become stuck on clothing so difficult to remove? And as a follow up question, how do stain removers work? | I can tell you how bleach works on some types of stains. So some Compounds have color because of the molecule is a conjugated system. Meaning that more than 8 groups of alternating double then single bonds in a row all share electrons. When light hits this conjugated system it absorbs then releases energy that we see in the visible spectrum. Bleach comes in and breaks double bond(s) in this system making them single bonds. This breaks the conjugated system up either completely or into smaller conjugated systems. So for example, where you had 8 groups of alternating double then single bonds you now have 2 conjugated systems of 4 groups which emit light in the ultraviolet spectrum and it’s not visible, BUT the stain is still there, you just can’t see it.
I suspect the stains are hard to remove because intermolecular forces between the stain maker to the fabric. | 683 | 2,013 |
ELI5:what is the difference in economic policy between Republicans and Democrats? (U.S.) | edit: thank you all for your comments. all quite helpful. I was also interested in the explanation of the Republican and Democrat viewpoint of International economic policy as well. | Democrats want to put money into social programs. They believe that given the chance, most people will work. However there are a significant percentage of people who are not working because of issues surrounding education, child care, health or other aspects of being poor. Essentially they want to "help people up, so they can get back to work"
Getting more people to work will improve their quality of life AND bring in additional tax money (because working people pay more taxes). Basically they want to soften the landing so when people fall off the ladder they can get back on and keep climbing.
Democrats feel that if you give extra money to rich people they are only going to spend it on rich people things and that won't benefit poor people at all.
Republicans are the opposite. They think that if you give money to people who are not working, you create an incentive to be a lazy ass. They think that if you make it harsher to be poor, fewer people will want to be poor and therefore more people will work.
They also feel that if you give tax breaks to the wealthy then those wealthy people will use that money to invest in businesses who will turn that investment into jobs.
Generally republicans favor lower taxes in an effort to increase the tax basis. Democrats want to increase the tax basis by spending money to bring poor people up to a level where they can be productive workers. | 10 | 16 |
CMV: Subsidized gender assignment surgery should take a backseat to critical life saving surgery. | I believe that government subsidized health care is critical to having a healthy and productive nation (I'm Australian FFIW). However I believe that the focus of this should be on attempting to prevent acute deaths and performing critical transplant surgeries, directly not indirectly saving lives, as opposed to improving the quality of life for a very slim minority of the population.
I am aware of the increased incidence of mortality as a consequence of mental health issues suffered by the transgender collective, however their specific needs are very narrow and for every surgeon that specializes in gender reassignment we have a specialist who doesn't specialize in cardiac surgery, or oncology, or transplant surgery, or pediatric acute care.
For every transgender person requiring very specialized care that isn't being provided there are dozens of people who require care that isn't being provided but is comparable to many more others in their situation, there is an economics of scale in treating those dozens in lieu of treating the few. | It costs perhaps 13k Australian dollars for SRS surgery for mtf and it reduces the suicide risk from 40% to 4%.
Lifetime treatment costs for cancer range from about 3k for melanoma to 60k for leukemia, average 17k.
Given the expensive nature of being trans, since a lot of them try to kill themselves, it's quite cost effective to fix those issues with SRS. 40% of those with leukemia die every five years, their health and physical effectiveness sharply drops. A trans person who you fix with SRS can be a productive civilian for much longer.
Cancer treatment is also a very different specialism from doing sex reassignment surgery. Typically a urologist will do that. They do things like treat erectile dysfunction, deal with kidney stones, deal with overactive bladders, handle infection of the bladder. There's no real shortage of urologists. Re modelling genitals is already quite common since people often injure their genitals. | 233 | 569 |
Historically, why did fevers used to kill so many people, but now they're a rarely fatal annoying symptom? | "Fever" was just a colloquial term used to describe any illness that presented a raised temperature. Ebola will kill you, influenza may kill you, a common cold probably wont. All three of these illnesses were referred to by their symptoms aka. "She died of a fever after visiting Africa". We know now the underlying cause of the fever and can treat (and name) not only the illness, but the fever itself, much more successfully. | 7,904 | 7,429 |
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Are Earth's ecosystems interdependent on each other? | Marine algae "produce" the majority of Earth's oxygen. Are there other examples of how there may be interdependence *among* ecosystems, rather than *within* them? | Yes, all ecosystems are interdependent. The sum of all ecosystems is the biosphere, the thin region on and near the crust of the earth that supports life.
The water cycle is a good example of how ecosystems are interdependent on one another. Water from clouds rains down to the ground. The rain often absorbs pollutants and chemicals in the air, which are deposited on the ground. This affects everything from plant growth to amphibian survival rates, from insect populations to soil acidity.
Ground water collects, and forms lakes and rivers. The rivers transport water and other substances across landscapes through sediment, percolation (absorption into the ground), and eventually as deposit in oceans. This acts somewhat similarly to an artery in an organism, carrying nutrients and oxygen across physical space.
If pollutants get into a river, everything downstream, be it fish in the river or trees on the riverbanks, is affected. Often, pollution from rivers gets deposited in the oceans, where it contributes to ocean acidification and physical pollution. Ocean acidification is a serious issue for corals, which are as safe, food-rich regions for an enormous variety of marine life. If the corals are unable to grow/form, and begin decaying, the habitats of thousands of species will be destroyed.
If small fish populations crash, their predator populations crash. If larger fish populations crash, human fish consumption necessarily crashes as well. More effort is put into other means of food production, which usually always has ecological consequences of some sort. Say we were to grow more crops, which would require more pesticides. Some pesticides have negative effects on nearby species, and can cause their populations to crash as well. A perfect example of this is bees.
Consider that bees and flowers have had *millions* of years of evolutionary symbiosis. One cannot exist without the other. If the bee population crashes, so will the populations of many angiosperms, and with them goes almost the entire planet. It's very scary that within less than a century of "intelligent" 20th/21st century agriculture, we've seriously disrupted this symbiosis that more-or-less all life on earth is dependent on.
There are no sharp lines anywhere in nature. Everything affects everything else in some way. Everything flows between everything else, the only thing that varies between substances is the rate.
edit: words | 32 | 103 |
Why are astronomers focused on creating giant telescopes as opposed to giant arrays of smaller telescopes (lets ignore radio telescopes for now)? | One would think it would be cheaper to use Interferometry than build something like the ELT?
Or am I missing something about how hard it is to combine the signals? | Radio interferometry is staggeringly easier to do than optical interferometry. To do interferometry, you need full information about the incoming wave so you can set up the interference, i.e. you need the amplitude and the phase/timing of the wave in order to combine it later. For radio, the frequencies are low enough that we can record the signals on hard media, precisely timestamp it, and combine the data whenever we want. The first VLBI stuff done in the 70's/80's actually used cassette-style tapes which were later played back simultaneously.
Optical interferometry is a whole different ballgame. Radio is in the hundreds of GHz at most; optical is several PHz (petahertz = one quadrillion hertz). We don't have a time standard that fast, nor can we record an astronomical source quickly enough to take advantage of such a time standard. So, we have to combine the light as it is collected and make an interferogram that way. This requires very carefully controlling the path length each light beam travels so that the combined light is coherent and generates an interference pattern. Note that you must do this to within a fraction of the wavelength of light - the CHARA array on Mt. Wilson controls the path length to nanometer precision, and has to do this over its several hundred meter baseline. Doing this across the radius of the Earth like you can with radio is a total pipe dream.
Also consider that an interferometer is not the ideal choice for all science. While no instrument is sensitive to anything smaller than the resolution provided by its longest baseline (for single-aperture telescopes, this is the diameter of the primary optic), an interferometer is also insensitive to anything larger than that resolved by its smallest baseline. For example, say you have a 10-meter telescope, and an interferometer which has a 100-meter and a 300-meter baseline. The 10-meter telescope might only resolve scales of 0.01" or larger, say, but the interferometer in the same wavelength range will only effeciently detect objects which are between 0.0003 and 0.001" in size. It can't see a galaxy 10' across, but the big telescope can. | 25 | 53 |
CMV: voluntarily unvaccinated people should be given the lowest priority for hospital beds/ventilators | I firmly believe that healthcare should be denied to no one regardless of their economic or social conditions.
However, what boils my blood the most is that we have so many perfectly good vaccines against Covid that are readily available and accessible in most first-world countries, and yet people refuse to take them.
If you have the chance to take a vaccine and still don’t, then whatever happens when you get Covid is on YOU.
YOU are being a burden on an already overloaded (in some places) healthcare system, which could have been avoided by taking a goddamn shot.
To allege that it is all a ‘conspiracy’ by (insert ‘Fauci’, ‘Bill Gates’, ‘Communists’, whatever other figure the right likes to bash) is irresponsible and poses a danger not only to themselves, but to the community at large (as more cases = more risk of mutation = more new variants = less effective vaccine)
EDIT: I don't think all the obese/smokers/alcoholics arguments work, because:- fixing all of those conditions entails significant lifestyle changes as opposed to vaccination, which is a one-off event.- they don't directly affect anyone other than that specific person.- they take up a maximum of one bed, as opposed to covid patients, who can infect others and lead to more people taking up beds. | Hospitals operate under the principle that what constitutes urgency is need, not culpability. If two patients come in from a car crash, the responsible one barely alive, ribs shattered, organs haemorrhaging while the innocent party has a sprained wrist and mild whiplash, you don't treat the innocent one first because he's not culpable, you treat the culpable one first because his need is more dire. That way, overall more lives are saved (this principle is the guiding philosophy of triage which is a protocol which saves a shitload of lives) and you remove personal value judgements of blame as a factor in doctor's actions, which is a bias nobody want healthcare professionals to be influenced by. | 2,916 | 33,452 |
How do I actually do philosophy when I'm reading philosophy? How do I critically examine the arguments in philosophical texts and essays? | How do I actually begin doing philosophy myself? How do I learn how to critically examine the arguments and ideas in various philosophical text and essays? For instance, I often find a big problem for beginners of philosophy is that many of their objections to arguments or theories they encounter when reading simply stem from their misunderstanding of the author.
I how do I learn to actually develop meaningful and thoughtful objections and criticisms of philosophical ideas I encounter while reading? While I eventually plan to study philosophy in college, how do I begin developing this skill as an amateur reader still in high-school? | Begin by restating the argument or idea in your own words. You may not get it exactly right. That's fine. You will get better with practice and as you get exposed to more philosophical ideas. Then pick out the strong and weak points of the argument. Are they enough to make you agree/disagree with the idea? Can you state your reasons for agreement/disagreement? | 95 | 157 |
ELI5: why do suicide rates increase during the holiday season? | Christmas is usually a time when families and loved ones get together to celebrate. During the holiday season, people who are lonely feel more alone than ever because everyone else is celebrating with their loved ones while they are on their own.
Add to that that, in the Northern Hemisphere, winter is cold, dark and hostile and many countries rarely see the sun, making seasonal depression a lot more common and intense than usual. | 67 | 17 |
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Metabolically, what advantages are there to "Carbo-Loading" by loading up on rice/pastas the day before a big marathon or hike? | The most important thing about carb loading is the fact that it replenishes and maximizes your glycogen stores. When you carb load, your body digests those carbs into glucose, fructose, and galactose (mostly glucose). Fructose and galactose can be converted to glucose through a series of chemical reactions in the body. The thing is, you don't need all the energy at that moment. So, when you have such an excessive amount of glucose in the body, insulin is secreted which stimulates glyconeogenesis: glucose gets polymerized in a chain to form glycogen. Glycogen is almost entirely stored in muscles and the liver.
The importance of this is that when the body needs energy, it can then break down the glycogen through a process known as glycogenolysis. This process is stimulated most directly by the epinephrine that is pulsating through your body during physical exercise (it can also be stimulated by glucagon, but during exercise it is primarily epinephrine doing the stimulation).
By maximizing your glycogen stores, you maximize the energy your body has stored, therefore, maximizing your energy output and your success in any physical activity. That is why for practically any sport, you are supposed to carb load, not protein or fat load, the day before. This is also why everyone says you should eat the majority of your carbs a couple hours before you workout; you need your glycogen stores filled to push yourself.
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[MCU] When Kilgrave is talking to more than one person, how do they distinguish who he is commanding if he doesn't specific who the command is to? | I mostly picked this up from rewatching the finale of JJS1. Kilgrave gives a few commands that are directed at Trish and Jessica (such as kissing him passionately or saying "I love you"), but aren't directly specified to be commands that only Trish or Jessica should follow. Of course we (and the characters obviously) know via context that Kilgrave doesn't want the crowd of people running up to kiss him passionately or confess their love for him, but how are they supposed to know that?
Kilgrave could go into his favourite restaurant and see his idyllic seat is taken. He angrily tells the man to fuck off, shouting "fuck off out of here", but what's stopping everyone else in earshot also fucking off? Surely if they have the control to believe the command was directed at someone else then they also have the Willpower to misinterpret his commands. But as we see if they're driven to do his bidding, why don't we see a bunch of people following vague commands before Kilgrave has to then stop them and clarify who he wanted to do what?
(Apologies if this lost sense at some point. Currently ill in bed with bad fever and incredibly delirious.) *edit: Specify. See, already found one mistake. | The same way people know when they're being addressed or not - things like context, tone, body language, eye contact.
Most people learn these things at an early age. Mistakes still happen though and some people don't learn to interpret the cues as well as others, such as with autism. So it's possible that Kilgrave has had his commands misinterpreted from time to time. It probably just makes him madder and the poor person who made the mistake ends up suffering for it. | 88 | 86 |
How does the photon of specific phase that causes stimulated emission in a laser device arise? | I understand that when a photon of specific properties (phase, wavelength..) comes near an excited atom with sufficient energy, the atom will most probably release a photon that has the same properties as the first photon and will fall to a lower energy state. I understand this is how light is amplified in a laser device after population inversion is achieved. I just don't understand one thing. Where does the photon that causes stimulated emission in the device come from in the first place? I tried to think of an explanation taking spontaneous emissions as a factor and using brewster's window for polarization but that seemed really unintuitve for some reason. Is there an external entity that increases the probability of the spontaneously emitted photons to be in a specific phase? It would be a great help if someone could explain this. Thanks! | The first photon doesn't have to have a specific phase. Whatever it has determines the phase of the laser. In terms of direction and polarization: If it is not aligned with the laser cavity (or has the wrong polarization, if that is relevant), this chain of photons dies down quickly and another "first photon" will start the laser. Note that actual lasers do not emit *perfect* laser light. You can still get all sorts of weird effects in between. | 10 | 19 |
MATH IN ECONOMICS? | Good day, I'm a freshman taking AB Economics (i really thought this would take less math).
My first year is proceeding not as I've expected it thanks to our math subjects. Algebra for this year, two calculus for next. Econometrics, Math for Economics, and Statistics are following. The term is ending and I'm planning to self-study mathematics before things take a wrong turn. But studying from scratch would just lead me nowhere. I even saw, from an earlier post I made, that trig is barely used but our subject is Alg + Trig.
I won't say I'm terrible in math but I also won't say I'm good in it. I'm just pretty average who didn't take calculus during high school (regretting I didn't, thankfully I did during middle).
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So can anyone provide me a grasp of what topics I should focus on?
Here are what I know:
Algebra
Calculus
Statistics
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But these are too broad, tbh. I do know, however that I need to focus in Algebra is Linear Algebra, yet not disregard the others. Also I should learn a lot about matrices. In calculus I'm not really sure but I did see some online videos saying that it'll mostly be about optimization, differentials, and integrals. For statistics, on Linear Regressions.
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Statistics may be difficult, yet that's the only subs we're allowed to use tools so I really wouldn't focus on that much (still i'm planning to study it). Can anyone provide me the topics I should focus on and focus on the most. Espeically with econometrics and all the scary ones.
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Thank you for the help! I'm falling in love with the program! | Economics is really wide field. And thus can have plenty of different math applications.
Learning Matrices, statistics and logarithms can help with Econometrics.
Learn to solve problems with Lagrangian methods in Microeconomics. So basically you need to know how to partial derivate different functions.
I'd recommend you to learn how to code with Stata / R. They will later help you out. | 27 | 33 |
ELI5: How the human brain can go years without hearing a song, and still remember every single lyric of it when it forgets other things like the names of old friends or coworkers. | Memory that is stored with multiple sensorial associations is more likely to be unique and thus easier to recall. A song lyric is associated with rhymes, instruments, vocalists and personal experiences while listening, creating a very unique data point. On the contrary, a person's name is likely not very unique and a brief, ordinary encounter with someone will leave the cortex unimpressed and less likely to store it. | 13 | 28 |
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ELI5: How does super glue work and how is it different from a regular glue stick? | Most regular types of glue just harden as water or solvent in them evaporates. If you want to glue something really well, you have to stick it really tight together with a clamp and let it cure for a bit.
Superglue however doesn't need to dry out. Instead, it "polymerizes" - that means the individual liquid molecules start attaching to each other until they become a solid. This reaction is triggered by moisture in the air, and happens so quickly that you don't need to hold it clamped for hours. | 408 | 526 |
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Mentorship |
How do you find deep mentorship in a lab where the PI isn’t super accessible? There are several labs I’m interested in rotating in, but they are larger and the PIs are somewhat well-known I’m the field and as such are busy people! Aside from that, they seem like great people, just not people I could pop in and ask a question without setting up a meeting. The mentorship they give would be great, there’s just not enough of them to go around, if that makes sense. I feel like I want more mentorship and guidance, but understand the demands that PIs have.
I don’t want to let this deter me from working in a great lab with exciting science being done. Any advice? | Larger labs with busy PIs usually have something like an upper management level. There are usually staff scientists, research scientists, postdocs and similar more senior people that manage research projects and students. Of course, ideally you should also have semi-regular meetings with your PI, but the senior scientists are usually the ones handling the day-to-day affairs. | 20 | 18 |
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