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ELI5: what would happen to a person being turned upside down indefinitely? What is happening inside the body? | The human body normally works with gravity as much as possible, and has to develop methods to work against it. Our legs have a very powerful hookup to pull the blood back up from the bottom, for example.
However, our brain doesn't. Normally, blood will flow back out of the head with little effort due to gravity. If placed upside down, the blood would begin to pool in the head, as the vessels there are not expecting to work against gravity.
Eventually, this would cause the blood vessels to burst. Apparently, reverse hanging was a fairly common form of torturous execution in the past, and they would frequently right the victim every 4 - 6 hours to let the blood leave the head -- the idea being not to provide relief, but to extend the suffering.
Supposedly, it's lethal after 10 - 24 hours. It obviously depends on the level of physical fitness. | 52 | 91 |
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Instantaneous communication via quantum entanglement? | I've done some reading about the nature of quantum physics, and have heard it explained how despite the ability for quantum particles to effect each other at great distance, there is no transfer of "information." Where the arbitrary states of "up" and "down" are concerned there is no way to control these states as the receiver sees them. They are in fact random.
But I got to thinking about how we could change what event constitutes a "bit" of information. What if instead of trying to communicate with arbitrary and random spin states, we took the change in a state to be a "1" and the lack of change to be a "0."
Obviously the biggest argument against this system is that sometimes a quantum state will not change when measured. Therefore, if the ones and zeros being transmitted only have a 50% chance of being the bit that was intended.
What if then, to solve this problem, we created an array of 10 quantum particles which we choose to measure, or leave alone in exact 1 second intervals. If we want to send a "1" to the reciever we first measure all 10 particles simultaneously. If any of the receiver's 10 particles change state, then that indicates that a "1" was sent. If we want to send a zero, we "keep" the current measurement. Using this method there could only be a false zero 1 out of 2^10 times. Even more particles in the array would ensure greater signal accuracy.
Also, we could increase the amount of information being sent by increasing the frequency of measuremt. Is there something wrong with my thinking? | Your proposal runs into the problem that it is not possible to detect the fact that a particle has changed it state. On the receiving end, all you can do is measure the particle, and when you do you have no idea whether the result you got was determined ahead of time by the sending making a measurement, or if you were the first to measure and collapse its state. | 23 | 20 |
ELI5: Where does all the salt come from | Where does all the salt in the ocean come from. I get that salt is a very common mineral but it seems extremely abundant and it must have been created in some sort of way. Did earth just have a lot of sodium and chlorine once upon a time and how on earth was there that much salt as to make the entire ocean which consists of a whole lot of water, to make all the water have a pretty decent salt content disolved in it. | Eons of erosion solved minerals into the rivers and oceans. Water evaporates and can erode more, but the minerals don't evaporate, so the concentration will increase in the ocean (end point of rivers).
Some minerals will combine to solid again (calcium etc) but some do not combine that easy to solid (not solvable) Chloride and Natrium are both ions that will stay solvable and so increasing the saltiness of the ocean | 13 | 23 |
CMV: Married couples that maintain separate finances are, at best, not fully committing to the true spirit of marriage as a partnership. At worst, their reasoning is cynical and/or selfish. | I’ve been reading /r/financialindependence lately. It’s an interesting sub, and an excellent resource for ideas related to saving and planning for retirement. However, I’ve noticed something which I think may increasingly common among younger people at large, namely that more couples these days seem to maintain separate finances. Even prior to finding /r/financialindependence, I have known a few friends who did this. Each partner will have their own accounts and, generally speaking, this one will pay this bill and that one will pay that bill until it’s close enough that they consider it square. When I’ve asked why they do it that way, rather than just share money and expenses, I’ve always gotten some variation of “it’s just simpler.” Indeed some people I asked in the sub echo that reasoning.
It’s certainly none of my business, so I don’t “care” per se, but that explanation has always bugged me from a logical standpoint. Keeping track of who owes what or devising shorthand/rules of thumb about who pays what bills, rather than just paying bills jointly, is by definition more complex. It may make you more comfortable, but it’s certainly not *simpler*. The addition of kids or a hardship into the mix can only serve to complicate things more.
Once you accept the simplicity argument as illogical, the other explanations I can come up with all seem to hinge on fear, mistrust, or plain old selfishness, and start to sound very cynical to me. Genuinely looking for other ideas as to why this might be.
*I will make an exception for couples who maintain personal accounts, but fund a joint account for bills. At least they are acknowledging that the responsibilities are shared, even if they keep some money just for themselves. I've never encountered anyone who does this, however.*
edit: I'm getting off for a while, but will be back. I'll say, most of the arguments I'm seeing are simply seeking to justify or rationalize selfishness or cynicism. I'm not saying there aren't reasons to maintain separate finances, just that doing so seems inherently selfish ("I want my own money so no one can give me shit for going to lunch or buying a video game") or cynical ("I don't need to worry about whether I can trust my spouse's financial decisions because that's *their* money, not *our* money.") The best answers so far hinge on the idea that it's more of a non-decision than a decision. "We never opened a joint account because we couldn't be bothered." That doesn't really strike me as too committed, though. I also wonder about future accounts (IRAs, 529s for the kids, investments). Should they be joint, or not? If I have a lot of money, can I retire while my spouse keeps working?
edit 2: Thanks for the answers. I have seen a few that gave me insight, and I'll pass out some deltas. I think my mistake was assuming that if people don't share an account or a debt, then they must not share resources, which was pretty far off. I did see a lot of people basically saying "I want to keep some of my money just for me," but the good answers were more focused on the fact that having just one name on a bank account doesn't mean you don't have each others' backs. View changed.
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> *Hello, users of CMV! This is a footnote from your moderators. We'd just like to remind you of a couple of things. Firstly, please remember to* ***[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)****! If you are thinking about submitting a CMV yourself, please have a look through our* ***[popular topics wiki](http://www.reddit.com/r/changemyview/wiki/populartopics)*** *first. Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | 1. Who says that the "spirit" of marriage has to be the way *you* define it?
2. If a married couple finds that keeping finances separate leads to a less stressful and therefore more successful relationship, doesn't that mean they're correct in their action?
3. Selfishness is a motivation, not an action. If a couple keeps their finances separate because they find that they are less prone to arguments over it, is that selfish? Or is that reasonable and caring? Could it not be that the selfishness you're attributing comes from your own history, and not theirs? | 13 | 15 |
Why do we still have to work when a fraction of our population can produce most things we need? | This might be a really dumb question and might end up on r/badphilosophy, but honestly, I have no starting point here and very little structure at hand to examine the topic at hand, so please allow me to share a few snippets of where this question is coming from.
* I saw a meme about how the ancient Greeks would be outraged if they found out that most of us can't enjoy a leisured life although we invented machines that make food production so much easier. That is such a simple thought but I can't really wrap my head around why that should be overly naive or whatnot.
* Still, most things I use daily e.g. the technology I am using to type this requires people working, like metal that some children mine in a very grim place. So there's many many areas that still require workforce – but is that worth it? Do we need these things? What if we reevaluated our resources on food, housing, health and education?
* Why are things the way they are? Which things we buy do we need to live good lives? Why is everyone participating in this? Is it impossible to go back after having tasted the cheap sugary taste of capitalism? Couldn't we all live much better lives with what we could have instead of what we think we want to have?
Again, sorry if this is out of place here and it really sounds like you needed to explain to a five year old how capitalism developed and why we like it. But something keeps me from shrugging this off. How to go about this? How to start thinking properly here? | Well one way to think about things differently is that you seem to be thinking of in terms of like everyone, at least in countries like yours, participating in a system openly and freely, via their own volition, while they could be materially better off if we had some other kind of system. But the important thing to remember is that there are a small minority of people who don't have to work, and they don't have to work because they have most of the money, own nearly all the land, own nearly all the means of production and so on, and via this have a massively outmoded influence on society in general, and these people would *not* materially benefit from a change in how things go, and this will resist utterly any attempts. We *are not* all in the same boat. | 149 | 200 |
ELI5: Where do the extra bits of root go when baby teeth are pushed out? | A question from my 5 year old, who hath a looth tooth. | As the adult tooth develops beneath the baby tooth, it signals the body to resorb (eat) the roots of the baby teeth. So while baby teeth do start off with fully-formed baby-tooth roots, they get shorter and shorter as the adult tooth grows, which is why the baby teeth start wiggling in the first place.
So there are no extra bits, they are resorbed over time. | 21 | 15 |
I'm supposed to finish my PhD this year in Molecular Neuroscience, but I want to leave academia after. What jobs can I look for? | I have decided to finish my PhD but leave academia after that.The field has become too stressful and it's taken a heavy toll on my mental and physical health. I have decided to seek jobs outside of academic research now but I never thought about this before and I don't know where to start.
Most of my skills lie in molecular biology lab experience. I know how to do minipreps or transcription or PCR mutations and I became experienced in two electrode voltage clamp in the past 3 years. However I don't have any computer programming knowledge, I'm taking an online course in Python programming, but it's difficult to keep up with my work schedule and mental health state.
But I want to seek out realistic options of what jobs I could look and apply for. I would appreciate a nudge in any direction. Thanks a lot!! | There's load of options out there for you, and it depends what you want to do. There are lots of organisations that like PhDs even if they're not necessary for the job.
Organisations:
* Government Funders
* Research/medical charities
* Foundations
* Civil service
* Universities (adminstration)
* Consultancies
* Think tanks
* Pharma
* Start-ups
* Biotech
*Journals
Jobs:
* Tech transfer
* Policy
* Public engagement
* Government affairs
* Science Comms
* Portfolio management for funders
* Strategy
* Grants management
* Editor
* Administration
* Consultant
* Scientist
* Project manager
* Research management
* Programme management
* Impact and evaluation
* Compliance
Good luck! | 60 | 62 |
CMV: "Work B**ch" is Britney's least Marxist song | Here is why I feel "Work Bitch" is Britney Spears' least Marxist song.
- The title degrades the worker by calling him/her a bitch. Marx was pro-worker.
- The song pushes the message that whenever someone acquires some money, they should spend it on frivolous consumer goods rather than invest it in productive enterprises. "Youwannabugatti?" What about "Youwannameansofproduction?" Marx would sees this as protecting the existing economic powers from challengers.
- By creating this demand for commodities, and in turn demanding that the listener work harder and longer to buy commodities, the song serves the interest of the capitalist class who primarily reap the benefits of this increased production and consumption. Marx wouldn't like that.
- The music video shows Britney whipping her backup dancer.
- The music video also shows Britney dancing among sharks, which are a symbol of aggressive consumption.
- Unlike "Work Bitch," Britney's older songs expressed critiques of our economic system that were more in line with Marx. For example, she previously saw her own celebrity as "Toxic" and even was aware that even she was a "Slave 4 U" ('U' obviously being the capitalist social hierarchy). Her older music also made clear that even the upper class suffers under capitalism. For example, even though Britney herself was "Lucky" and "a Star," she still "cry cry cried in her lonely heart."
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> *Hello, users of CMV! This is a footnote from your moderators. We'd just like to remind you of a couple of things. Firstly, please remember to* ***[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)****! If you are thinking about submitting a CMV yourself, please have a look through our* ***[popular topics wiki](http://www.reddit.com/r/changemyview/wiki/populartopics)*** *first. Any questions or concerns? Feel free to* ***[message us](http://www.reddit.com/message/compose?to=/r/changemyview)***. *Happy CMVing!* | I can offer an alternative interpretation:
The song glorifies the proletarian work ethic, and takes the position that luxury should be earned through honest labor instead of being inherited in the form of accumulated capital or extracted from the labor value produced by an exploited underclass. Britney's use of abusive slurs and master/slave imagery should not be understood as an *endorsement* of the present state of affairs, but rather as a satirical attempt to foreground the injustice thereof, in order to expose it to criticism and promote class consciousness. | 233 | 798 |
ELI5: Please explain to me how prisons are allowed to be privatized, and what their purpose is compared to public (as in, are they better for prisoners, better for the state, etc?) | Prisons are allowed to be privitized because local and state governments passes laws saying they were allowed to be privitized.
The purpose was an effort to reduce the incredibly high cost of prisons (and lots of corruption by people who have financial gain from it--which from any perspective or stance on the situation cannot be ignored). It hasn't really reduced costs, conditions are questionable, but people (private prison companies) are making shit tons of money off of it from the government. | 14 | 28 |
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ELI5: How do we calculate the force acting on a wall by an object leaning against it? | A modified version of Newton's 2nd Law. Consider the pivot point located where the object touches the ground. The sum of the moment (rotational force) around that point must be zero, since the object is leaning against the wall, and not accelerating. So you know that the reaction force from the wall * the lever arm for that force must equal the gravitational force acting on the object * the lever arm for that force. And then you know by Newton's 3rd law that the object's force on the wall is the same as the wall's force on the object. | 19 | 44 |
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Can we and how do we determine if a sound is produced in front or behind us? | Obviously we can tell if a sound is on either side of us, but can we - without visual aid - tell if it’s in front, behind, above or below us? If so, how? | Something called "spectral cues" comes into play. Sound interacts with the actual surface of your ear lobes before it gets processed (similar factors in skull shape, nasal passages, etc.). This changes the timing, resonance, etc. in minute ways but your brain is able to recognize these patterns and use them to help recognize the direction even in the plane between ears.
There's actually a really cool experiment you can do to show this. Have one person blindfolded and stand in the center of an area. Have another person stealthily move around and clap from various directions, and have the person point to where they heard the noise come from. Then, use a soft clay or similar substance (bread dough works) to fill the grooves of their ear lobes without obstructing the ear canal. Repeat the experiment, and you will find that they sometimes point in the completely wrong direction (especially for positions directly above or below them). They may also get confused and have no idea where a sound is coming from. | 60 | 48 |
Can someone explain Maxwell's Equations? | Reference Image: https://goo.gl/o7vnv6 I am interested in the Integral form specifically.
Can someone explain what each equation means, and how it can be used/applied?
Bonus Question: I can't for the life of me figure out what ds represents | The first equation is an expression of Gauss' Law and states that the integral of the electric field over a closed surface (specifically the component of the field normal to the surface) is proportional to the charge enclosed by that surface. This law can be used to, among other things, derive the inverse-square-law for electric fields (field strength goes down with the square of the distance).
The second equation expresses the same for the magnetic field. But since magnetic charge doesn't exist in isolation (as far as we know), the righthand side is always zero. From this equation, we learn that the surface integral of a magnetic field over any closed surface has to be zero.
The third equation is Faraday's Law. The "ds" term indicates that we're dealing with a line integral. Specifically, this equation expresses that the line integral of the electric field over a closed loop is equal to the negative of the change in magnetic flux through the area enclosed by that loop. The line integral of the electric field represents a voltage and from Faraday's Law you can see that a changing magnetic field through the area enclosed by a loop generates a non-zero voltage in that loop. This is the core principle behind electric generators.
Finally, the fourth equation mirrors the third, somewhat. It expresses that the line integral of the magnetic field over a closed loop is proportional to the rate of change of the electric flux over the area enclosed by the loop. Plus an additional term that represents the electric current that flows through the surface enclosed by the loop. This is Ampere's Law.
It is interesting to note that there some degree of symmetry between the equations 1 and 2 and between 3 and 4. The difference between them is the presence of electric charge, but the absence of isolated magnetic charge (or magnetic monopoles). If magnetic monopoles would exist, the necessary modifications to the Maxwell equations would turn them into 2 pairs of symmetric equations where magnetic and electric components may be interchanged. | 32 | 48 |
We get more daylight during summer and less during winter. Does the amount of moonlight change depending on year? | Say comparing an equal phase moon from June and December. | The other answers here are incorrect, because they're not considering the combination of 1) the importance of different phases to the amount of moonlight received by Earth 2) where in the sky those phases would appear at various seasons.
When the Moon is close to full, it will appear on the opposite side of the sky as the Sun. That means that in summer when the Sun passes high in the sky and is above the horizon for a greater number of hours, that night the full Moon will pass low in the sky and be above the horizon for a fewer number of hours. Similarly, in winter, when the Sun passes low in the sky and is above the horizon for a fewer number of hours, that night the Moon will pass high in the sky and be above the horizon for a greater number of hours.
When the Moon is close to new, it will appear on the same side of the sky as the Sun. The means that in summer, both the Sun and New Moon will be above the horizon longer and pass closer to overhead. In winter, the Sun and New Moon will both be above the horizon for fewer hours and pass lower in the sky.
At first glance, it looks like that should all balance out over a one month set of complete moon phases. However, what's important here is that the the Moon is much, *much* brighter when it's near full than near new. As a result, we get much more moonlight during winter, since that's when the Full Moon will be above the horizon much longer and pass much closer to overhead.
**TL;DR**: We get more moonlight during winter. | 15 | 36 |
ELI5:Why do people stutter? | There are four factors most likely to contribute to the development of stuttering: genetics (approximately 60% of those who stutter have a family member who does also); child development (children with other speech and language problems or developmental delays are more likely to stutter); neurophysiology (recent neurological research has shown that people who stutter process speech and language slightly differently than those who do not stutter); and family dynamics (high expectations and fast-paced lifestyles can contribute to stuttering).
Stuttering may occur when a combination of factors comes together and may have different causes in different people. It is probable that what causes stuttering differs from what makes it continue or get worse.
| 244 | 646 |
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ELI5: When I get a bad cold, why does every muscle in my body ache? | Muscle ache (myalgias) and joint aches (arthalgias) are due to multiple factors, but they can both be traced back to the immune system doing its normal job.
Many chemicals are released anytime a cell is injured (from trauma or infection) or anytime a foreign looking protein (think bacteria & viruses & vaccines) gets into your body. Specific immune cells respond to those chemicals by (1) moving towards the source, and (2) releasing other chemicals (cytokines). This is the beginning of an inflammatory reaction.
Inflammation is simply a word describing the collection of effects that result from those chemicals. They include (a) redness (rubor), (b) swelling (tumor), (c) heat (calor), and (d) pain (dolor). (Yes. Some of those chemicals will actually cause you direct pain, so that's part of the answer.)
Now imagine you just stepped on a nail. Cells are damaged and an inflammatory reaction has been started. Some of the chemicals that are produced at the site of the injury/infection make the blood vessels near your foot get bigger and more leaky. A larger diameter blood vessel means more blood flow to the area, which means more blood cells are nearby. Leakier vessels means that more blood cells are able to leave the blood stream in this local area. This is helpful because you want certain immune cells to collect near the injury site and begin attacking any germs that may have been let in by the nail and to start repairing tissues.
Likewise, a bigger sized blood vessel with more blood flow and more red cells will look more red in color! More blood flow also means more heat! A leakier blood vessel doesn't just let out more cells, but it also lets out more water. Water leaving your blood stream ends up gathering in the surrounding tissues, leading to swelling. Swelling causes pressure and can cause some aches.
The example gave is a nail in the foot. How does that translate to having a cold? Well, the answer is that the immune system doesn't really discriminate and pretty much reacts the same way for anything it thinks "isn't normal." Having a rhinovirus or the flu virus buys you the same basic inflammatory process. SO DOES GETTING A VACCINATION!
One type of chemical that's made is prostaglandin. Prostaglandin E2 makes you have a fever and directly causes pain. Non-steroidal anti-inflammatory drugs (NSAIDs), like ibuprofen and naproxen, block the production of these chemicals. That's why they are considered a fever and pain reliever.
**TL;DR** When your immune system is doing its job, inflammation helps get the proper immune cells to the invading pathogens, so it can identify it and make effective antibodies against it. The chemicals involved in the inflammatory process are pretty harsh and can have unwanted side effects on other parts of your body. This is necessary for acquiring "immunity." *People often mistake these annoying symptoms for "getting sick" after they receive a vaccination.* | 40 | 127 |
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Joints hurting when it's going to rain? | Hey everyone,
I was reading the "what makes you realize you're old?" topic on askreddit and a fair amount of people mentioned their joints (particularly knees) aching right before it rains. I've also heard this in my life but I never thought much of it.
Now I'm wondering if there is any scientific reason as to why joints hurt before it rains? I thought it could be just a case of people hearing it a lot and thus noticing the rain and thinking "Oh my knee hurt before, they must be related"
Can anyone shed some insight? | I believe it has to do air pressure. Low pressure systems usually precede rain. A low pressure system causes moist ground level air to rise to higher altitudes where the temperature is much colder. The moisture in the air then condenses and rains. The low pressure precedes the rain by some time.
Your joints and tendons are cushioned by sacks of fluids called bursae. These small fluid filled sacks respond to pressure changes, similar to a weather balloon that expands and eventually pops high up in the atmosphere where the pressure is lower.
When these fluid sacks expand it can cause discomfort and pain. Bursae can become infected as well (though this is clearly unrelated to weather) and the inflammation associated with infection is called Bursitis and often requires surgery to help with the pain.
As you get older, the cushioning systems of your joints breaks down and you feel these small things a lot more than in your youth. | 16 | 20 |
ELI5: Why is acne so hard to get rid of? | You have different types of acne, so it’s really difficult to just talk about one cause and propose one treatment to get rid of it.
Very broadly, you have three types of acne: comedonal acne, inflammatory acne, and drug-induced acne. I’ll just focus on the first two, because that’s what most people are concerned about.
The root of most acne lies in the hair follicle. Your skin produces oils called sebum to lubricate your hair and skin. These pores can become clogged and produce comedones (which are your “blackheads” or “whiteheads” depending on whether the comedone surface has been oxidized by the air). If you want to treat comedonal acne, you need to use a topical retinoid (which is a derivative of Vitamin A) and this will interfere with sebum production.
Now in other cases, these plugged pores can become a site where bacteria take up residence, and this leads to pustules, papules, cysts. This is inflammatory acne. At that point, you need to add an antibiotic or two along with a retinoid to attack both problems. So you really need a doctor to classify what type of acne you have before you can figure out what treatments you need.
Most people have acne in their teenage years because they have higher levels of steroid hormones (e.g. estrogen or testosterone) which promote sebum production and the development of comedones. As their hormone levels stabilize through puberty, sebum production will level off. I’ll leave it to the dermatologists to tell you the best ways care for your skin. But aside from medications, you want to keep your skin clean and moisturized at a level where you’re not allowing sebum to build up, but your skin is also not too dry and cracked that your skin bacteria can invade and cause inflammatory acne. Finding the balance can be difficult. | 6,388 | 12,157 |
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[Assassin's creed] Why are the Templars trying to create a precursor body? | I was under the impression the Templars wanted the precursor genome so they could explore the genetic memories with an animus in order to gleam secrets about precursor tech.
Now it turns out they are trying to clone a live precursor. What gives? | The Precursors are biologically distinct from humans. The Genome may not have been enough to allow the Animus to be cross compatible between the species. Having a live subject allows them to obtain data from Animus use without the issues of human biology corrupting the input.
Plus, you can basically guarantee that Juno has had some influence in the program. | 10 | 15 |
How do they know what the inside of the earth is made of, along with the internal temperatures? | ANSWERED | Waves, when moving from one medium (material type) to another, will bend if they strike at an angle. They will bend one way if moving unto a less dense medium, the other way if entering a more dense medium. Earthquakes generate massive waves in the earth. By measuring how long those waves take to reach different seismographs (tools for measuring Earthquakes), scientists can determine how the wave moved through the earth, and through that path, the density of the materials the waves moved through.
Temperature data is hypothesized based on the material we know the upper mantle to be made of (from lava) and its density and then supported by deep holes we have dug, where thr Temperature increases in a fairly linear manner. | 12 | 21 |
ELI5: How does the US government contract businesses about classified projects? | Like if they want a particular company to help them on a project, but the project is classified (I.e. A not yet disclosed airplane or something to that effect), how do they approach the company and what do they tell them?
If that makes any sense, I'd love to know. Very curious about this. | The initial contract bidding proposals are themselves vague and unclassified, but detail the Company clearance level (FCL) and Personnel Clearance level (PCL) requirements.
Cleared companies have network links with the Gov for when these contracts are being put out as Requests for Proposals (RFPs).
The Cleared companies then submit their RFP, which includes budgets, manpower, etc, etc, etc... This then results in the Gov comparing and contrasting the bids, usually going with the lowest bid by the best rated company (companies get project ratings almost like an EBAY seller as they complete projects for different Gov entities).
The winning company is issued a DD-254 form (Department of Defense Contract Security Classification Specification) along with all the "Normal" contract stuff.
The DD-254 grants the company the ability to work that specific cleared contract, to clear personnel to work the project, and (if listed) to subcontract parts of the job to other cleared companies by issuing sub-contract DD-254's.
If that subcontract company already has a FCL (as listed in the ISFD database)it is a relatively simple process to bring them in to work.
If they are a totally uncleared company, it depends on what the subcontracted duties are... for example, a Cleared company has the contract to maintain all services for an embassy overseas somewhere... they handle electrical work, plumbing, HV/AC, etc inside, along with maintaining exterior beautification. All the people working inside the building will have PCL's and be part of a cleared company, but the company can hire a local uncleared company to handle Lawn services outside the embassy, simply assigning one or two cleared people to overwatch them when at work.
Now, if, for example, The Gov starts a project to train combat small drone operators... they decide they need to hire a company with a team of skilled maintenance techs to maintain the drones, and there isn't any such company out there, but there is a local company who does that exact work for a local Drone racing circuit... The Gov or a Cleared company would approach them with the idea of becoming a cleared company or forming a LLC sub-company that could then be sponsored for a FCL to work classified contracts and then get it's workers clearances to work the project. It's a rather complex process, but it how almost every cleared company got its start sometime in the past. | 14 | 22 |
How do cells know their 3D position, in order to make the correct shaped organism? | There are multiple mechanisms at play at different times in different tissues, and I'll just list a few.
One common mechanism is a gradient of a secreted factor. In the developing spinal cord, for example, the cells at the ventral side (bottom) secrete a signaling molecule called sonic hedgehog (shh). Shh diffuses away from the cells that secrete it, so the area closest to the ventral side has the highest concentration of shh, and the area farthest from the ventral side has the lowest concentration. A developing cell just needs to sense how much shh is in its environment to identify its position. As you can imagine, if there were multiple gradients along different axes, a cell would be able to define its 3D location with more precision, and this happens in other parts of the nervous system.
Another common mechanism is through cell-cell contact, where cells migrate to be with other cells that express complementary proteins on their surfaces. It's as if some cells have the sticky part of velcro and some have the fuzzy part, and the sticky cells find the fuzzy cells and stick to them.
A third mechanism might be considered the "just keep swimming" mechanism. In the developing cerebral cortex of the brain, newborn cells migrate out past their earlier-born cousins until they reach the outer limits of the previously-born cells, and then they stop. They don't "know" that they're supposed to be at any particular level, but they keep migrating until they see a "stop" signal (which is provided by another layer of cells on the surface of the brain). | 31 | 31 |
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I believe the SAT exam is NOT "culturally biased", CMV. | A significant achievement gap exists between racial groups on every major national standardized test. While trying to find an explanation for this, the SAT in particular, I kept running into the claim that the exam is "culturally biased", meaning the content or the wording of the questions is somehow skewed to be more easily understood by white schoolchildren. However, I couldn't find any **specific examples of culturally biased questions** in any recent exams, except for one that proponents of the culture bias theory parrot over and over about regattas.
Can you find specific examples of culturally biased questions on modern (last ten years) and national standardized tests and change my view that this phenomenon does not exist and is only cited to glibly ignore the deep societal problems at the root of the achievement gap?
http://cdn.theatlantic.com/static/mt/assets/national/SAT%20stat%203.jpg (Source: The College Board) | The trivial example is that the test is in English, and so the reading and writing sections test English proficiency, not reading and writing ability.
You probably acknowledge this. You should probably tweak your position so as to narrow it down to English as First Language speakers.
But from there, it's not like everyone in America speaks the same version of English conversationally. If you have never heard of a word on the SAT, you get the question wrong. You almost certainly believe that different cultural groups in America have different standard vocabulary, different ways to convey the same concepts in the same language.
That is to say, language and vocabulary is inherently cultural, it *can't* be unbiased. | 89 | 92 |
ELI5: Why do Lithium Ion batteries lose their ability to maintain charge after many cycles of charging? | Is this due to a chemical reaction? Perhaps Lithium escapes as a gas? | It is due to several things.
The most important is physical. During charging/discharging lithium atoms move from one electrode to the other. The lithium goes into tiny pores in a sponge like electrode, but when this happens the sponge swells up. Repeated swelling and shrinking eventually causes cracking and fractures in the electrode, degrading it.
The other main effect is chemical reaction in the electrolyte. During charging, tiny amounts of electrolyte material undergo unwanted chemical reactions with the electrode chemicals. Eventually the electrolyte gets polluted with all the byproducts of these reactions degrading it. | 17 | 25 |
ELI5: Can athletes and other people who burn a lot of calories "safely" ingest more saturated fat and sugar than the average person? | If by "safely" you mean "maintain better health markers and quality of life," then yes.
If you are predisposed to heart disease or diabetes, it might take longer, but a bad diet is going to catch up to you at some point.
Health is complicated. Genetics, stress, diet, exercise, lifestyle all play into your risk for disease. | 17 | 22 |
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ELI5: why are certain species (like Tigers & Lions) able to interbreed but others are not? | Just curious about the genetics of interbreeding. | Basically, the term species is a convenient kludge. It is not as based on solid biological differences as people tend to think, especially because we often assign organisms to different species before we have fully studied their ability to breed.
Pretty much all of the big cats have some degree of inter fertility with each other, which one could argue makes them a single species. But lions and tigers and leopards all look so different and behave differently enough that of course the earliest scientists just assume that they were different enough to call different species.
It gets even more complicated when you're dealing with things like bacteria. Two different strains of e coli, which we refer to as the same species, can be as genetically distinct from each other as you are from a catfish. | 177 | 300 |
[Disney] What would Maleficent have given Aurora if the king and queen hadn't neglected to invite her? | She would have offered to personally tutor the young princess in the ways of sorcery and true power.
If the king and queen refused, she could take umbrage and curse the kingdom, as the story goes.
If the king and queen relented, she would gain a new apprentice and bargaining chip with Aurora as her personal ward/hostage. | 73 | 49 |
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[Star Wars] If Naboo is an elective, term limited monarchy...why on earth did they elect a child to be their Queen? | Naboo culture considers youthful innocence and enthusiasm to be very positive traits. Many on Naboo believe that a young ruler will be less inclined to corruption than an older, more cynical one. The role of the more experienced Royal Advisory Council and the Governor (during the reigns of Amidala and Jamillia, this was Sio Bibble) is to balance this out with maturity and experience, as well as to handle many of the day-to-day administrative functions of ruling. Most of the monarch's duties are more ceremonial in nature, although they are still head of government according to the constitution and retain final veto power. | 130 | 119 |
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ELI5: Why is there only one internet? | With all of the problems with our current internet, why are we unable to just "create a new one"? | Think of it like roads. Roads connect locations to each other, much like the internet connects computers and networks.
You can get from one place to another via many different routes, but they're all part of the same system of roads.
When one town has its own system of roads and builds a road to a freeway or something, it's connecting its "network" to the greater "internet."
Creating a new system of roads would require creating connections between towns that don't use the same roads that we already have - like building a second set of roads on top of our current set of roads. It would be redundant and expensive, and we wouldn't really gain much from it.
And, to answer your question, if we connect that series of roads to the current set of roads, they join the "internet" that already exists.
It makes a lot more sense to improve infrastructure that already exists, rather than building a new one. It's like the difference between filling potholes in the road you already have, instead of building a second road that takes a different route because the current one is a bumpy ride. | 81 | 67 |
How does e.g. MS Word copy and paste formatted text, but you can still paste the plain text in other programs? | For example, in MS Word I can copy some text, then paste somewhere else in the document and choose "keep formatting" and it will remember the formatting the text had when I copied it. So I assume there is some metadata in there somewhere that tells Word how to format the text.
However, if I paste that same text into a different, unrelated program it comes out as just the plain text without any metadata or anything. How is this achieved? | Windows and OS X have a way of storing multiple types of data on the clipboard.
If you copy formatted text in MS Word, it stores the plain text version and the formatted version. MS Word is smart enough to know to pick the formatted one when you paste.
If you copy plain text, nothing is stored in the formatted section, so you can only paste plain text.
If you copy an image, it's stored in the image data section and nothing is stored in the plain text section / formatted text section, so you can only paste that image. | 31 | 26 |
ELI5:Why "size" and "size on disk" is different? | While looking at a size of folder on my PC, I see it very often.
Is it because of some overhead used by my SSD that takes more size than the files does themselves?
Thanks everyone. Got my answer! | Your teacher tells you to write a four-page essay. So you write three full pages plus two sentences on the last page. Your essay is four pages long! Well it's not really four pages, it's closer to three pages, but it takes four pages to contain those 3.04 pages worth of text.
The "size" of your essay is 3.04 pages. But the "size on paper" is 4 pages.
The significance of reporting that it is 4 pages long "on paper" is that you only have 100 sheets of writing paper. That means you can write only 96 more pages of text, not 96.96. | 152 | 33 |
Why are so many medications something-hydrochloride? | Meaning, is there some metabolic property (for example) of HCl. Or some sort of chemical stabilizer? | Some medicines are organic compounds that are unable to be dissolved in water or acidic solutions (like the environment in your stomach). Whenever you see the hydrochloride, it means the pharmaceutical company has converted the insoluble drug molecule into a hydrochloride salt to increase its water solubility so it can actually be absorbed in the body. Other salts can be made, such as fumarates. | 32 | 26 |
What happens to light when it is absorbed? | Certain lights are reflected and absorbed.
So what happens to light that is absorbed? | If light hits an electron, the incident photon is absorbed and its energy transfered to the kinetic energy of the electron. With a higher kinetic energy, the electron enters an excited state, moving to a higher energy orbital.
The electron can then emit another photon and "jump back down", and the emitted wavelength of light will be whatever's allowed for the allowed transitions for that electron. | 10 | 41 |
Is human morality getting in the way of Natural Selection? | As human beings, we are now conditioned to overlook physical deformities/defects when it comes to finding mates, causing unfavorable species traits to be passed down through reproduction. Is this sentient morality counter-intuitive to species evolution, or is the human species still too young to judge and that the whole thing is still part of the evolutionary process? | Natural selection is non-teleological, which is to say that it ought to be described by its causes, not any ends. Nothing can actually get in its way. Likewise, fitness is merely the quality of being able to survive in one's environment. If one's environment includes humans with morality, then a person being helped to survive thereby is fit. | 49 | 32 |
ELI5: Why is it that the liver can (to an extent) regenerate but other vital internal organs cannot? | The liver itself is made of individual hexagonal units called hepatic lobules made of liver cells (hepatocytes), blood vessels, and connective tissue that all together perform all the functions of the liver. Think of them like honeycomb cells in a bee hive or individual solar cells in a solar panel.
Cutting off a portion of the liver reduces the total number of lobules, reducing the overall function of the liver. The liver cells can replicate to create more lobules in order to regenerate liver function. However, this is not true regeneration as the form of the regenerated liver (shape) is not the same as the original liver.
The other internal organs are not made of individual units or cannot survive having a piece cut out. Organs like the heart are uniquely shaped and designed for its function. Removal of any part would completely ruin its function. Organs that are made of individual units like the lungs (small air sacks surrounded by vessels) or kidneys (filtering units surrounded by vessels and fluid ducts) cannot have a piece cut out since the organs themselves are specially sealed. You cannot breathe properly if there is a hole in your lung and such a hole could result in fluid filling the rest of your lungs. Any removal of lung has to be completely sealed, which prevents that cut region from regenerating. Similarly, because of the large blood flow to the kidneys, injury to the kidneys could easily be fatal. Cutting off a part of the kidney means it is not sealed from leaking the massive amount of blood that flows through it.
EDIT: Replaced "punctured" with "cut" in second paragraph. | 4,964 | 11,336 |
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ELI5 : Why does a little bit of water provide grip, while a lot of water provides lubrication. | Water has a surface tension to it that can lightly adhere to irregular surfaces. It increases the surface area of the contact which has an adhesive force.
A lot of water acts like a lubricant by getting between two surfaces and resisting their coming together.
Think of it like many microscopic ball bearings rolling around between two surfaces.
With just a few ball bearings, they get caught in the nooks and crannies, and increase adhesive force, but with a lot, they roll around in between and reduce friction. | 25 | 24 |
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Can a person with high blood pressure donates blood? | Let's say his/her blood pressure was high but still donates blood anyway. What would happen to him/her? | Blood pressure is usually checked before every donation and there are limits to how high it can be. But there are also studies that suggests that periodic donations can be a valid tool for patients with high pressure to lower that blood pressure | 91 | 69 |
ELI5: Why do we breathe faster after physical activity instead of deeper? | Increasing your breathing rate will expel more CO2, which will decrease the acidity that has built up from exercise. That’s why when you hyperventilate your blood becomes too basic because you’re expelling too much CO2 | 40 | 45 |
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Like a gravitational field, does a strong electromagnetic field also affect the flow of time? | Does it also dilate time or work in the opposite way and speed it up? | The energy in an electromagnetic field does contribute to the energy tensor which is the source of gravity. But the contribution is generally negligible, decreasing as 1/r^(2) (instead of 1/r like the mass distribution) and celestial bodies being more or less electrically neutral. | 52 | 129 |
[Zombies] Zombie animals, do they only occur on meat eating animals or could there be zombie birds/squirrels etc? | We’ve seen zombie hounds, i was curious to know if other animals can get infected and wouldnt it be insane if a falcon or a fast running rabbit swoops in and bites you? | Depends on the universe in question. In the WWZ book, the virus was 100% fatal when ingested and only seemed to reanimate humans.
Animals would avoid the infected and dogs in particular became quite agitated when in the presence of a zed, leading to the training of (tougher) dogs for use against zombies, both as alarms (such as having refugees pass by them so the dogs could sniff out the infected), and as scouting and recon units - these were trained to respond to commands via radio for long-range use and to avoid biting the zombies, instead being trained to pounce and push the zombie over if needed. In the Battle of Hope especially, several K9 units were sent around the area to attract the attention of the infected and lead them to the battlefield
| 21 | 34 |
ELI5: If Homo Sapiens were capable of interbreeding with Neanderthals (and apparently did), why are they considered different species? | Because ability to interbreed is not the only measure of a species.
As a general rule 'can't breed and produce fertile offspring' is a reasonable good rule of thumb for determining separate species, but it certainly isn't the only measure that is used. Physical characteristics, genetics, geography, diet, all of these things are used when trying to determine if two populations should be considered a separate species.
Honestly, determining if something is a separate species, especially with very closely related species can be very hard. That is why the 'species problem' exists. It basically is the question of 'when is something different enough to be a different species' and a lot of opinions on the matter exist. | 40 | 53 |
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[Fictional training] What sort of training would various characters do? | I mean, how do they keep so intense? People like the Batfamily, Assassin’s Creed, various comic “peak humans” and the like. Super powered heroes and villains too. What do these people do to train? Do they? What do they even eat, if they do? When do they have time to do any of this? | General fitness and combat training for most of them. Even people with relatively busy schedules can make time for an hour or two at the gym. Cardio, strength, flexibility, and speed. You can tailor your workout to the kind of performance you need.
Full-time heroes, like the Avengers, probably train more or less all the time when they're not out saving the world. Obstacle courses, group tactics, etc. Would be similar to a military unit. | 24 | 21 |
ELI5: Why is it okay to stream or upload yourself playing/watching a game, but not a movie? | How is the creative content different? Why is one illegal but the other not? I didn't pay to watch or "consume" the content of the games on twitch, at all. | Because the game involves sufficient input from the player to make it happen that it is considered a 'transformative work'. Films don't have that interactivity to make them go.
A player's input is absolutely essential to a game in such a way that their gameplay is considered their own work. It's active whereas streaming a film is just passive. | 14 | 25 |
ELI5: If your body is dehydrated why do you have to pee so quickly after drinking water? | You would think if your body is dehydrated that it would keep as much water as possible instead of eliminating some of it. | Part of being dehydrated is that your body refrains from processing too much waste from your blood in to our bladder because it needs to expend water to do so. When you finally start hydrating again your kidneys start going back to work. | 97 | 126 |
ELI5: Can some please explain Perceptual Control Theory | Really struggling to understand this. What is the basic theory behind PCT and could you please give me a human example to go with it (not a cruise control system on a car)?! Thanks | So, PCT is basically recognizing experience as the result of a feedback loop.
The basic loop is:
1. Expectation
2. Input
3. Experience
When you do something or something happens to you, your experience of that thing is compared against an assumption of the thing. The difference between your experience of the actual thing and your assumption creates a dissonance which creates your experience of the thing. You then formulate a reaction to the dissonance to correct it by taking action to alter the thing or removing it from what you're doing.
Here's an example:
You want a cup of coffee. However, you don't just want any coffee. As soon as you think about wanting coffee, you're forming an expectation about a *specific* cup of coffee. For the example, you just want black coffee. After pouring the coffee in a cup and taking a sip, you discover that the coffee is more bitter than you expected. The difference in bitterness is and example of the PCT loop.
You expected the coffee would be a certain bitterness, but it was more bitter, therefore your perception of how much more was due to how different the actual bitterness was measured against your expectation.
You now have to make a choice. You can accept the reality of the coffee's bitterness, change the bitterness by adding something to the coffee, or refuse to drink it altogether. By altering the coffee and repeating the process, you will eventually get the coffee you expected in the first place (or an acceptable alternative).
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Our brains outside of our body | I’m new to this subreddit but i was curious about the possibility of our brain still working outside of our body. If say, we were able to keep our brain alive after death (but just by itself, meaning not put into a “robot” body of some sort) would our brain still act as our regular “self” if that makes sense? Although we wouldn’t have our body, our sight, hearing, or body sensations, would our brain consciously know who it is still and be able to think like regular? or does the brain needed other key elements in the body to have a full consciousness? if so, what is our “self” made up of if it’s not just the brain itself? and could the brain be aware of itself and it’s situation? overall i’m just curious if the brain, by itself, can still be like your regular self, just without the body. this is hard to word but i tried my best!! if u have any insight i’d love to hear! :) | This is a common topic in philosophy of mind. A great introduction to this theme would be to read Where am I? by Daniel C. Dennett.
It is a very short story about the relation between body and mind, the self and the perception of reality. | 22 | 19 |
ELI5: If before the universe there was nothing, then the universe was created, shouldn't there be a field of nothing at the possible edge of the universe? | A common misconception about the expansion of the universe is to imagine it's expanding in all directions in three dimensions. You envision a balloon that we're inside. The balloon is getting bigger, and you say 'there must be an actual balloon around this space'.
In reality, the universe as we know it *is* the surface of that balloon. The balloon is expanding into the fourth dimension. Like two dots on an inflating balloon, any two objects in the universe that aren't locked together are getting farther and farther apart. The speed of this separation is always proportional to the distance between the dots, with more distant dots moving away faster. Space is essentially being created everywhere at once, from our perspective.
Because of these observations, we know that the universe is expanding in the 4th dimension. But we have no idea what that looks like beyond that. Maybe, somewhere, not up, not forward, not left or right, but some fourth direction perpendicular to all of these there is a great wall of the universe. But we can't see it.
In the three dimensions we perceive and move in, the universe is boundless, like the surface of a ball. | 27 | 15 |
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What's the reason behind countries choosing different voltage standards? | For example, USA has 110/120 V while UK/India has 220/240 V. Is it a deliberate choice? or an after-effect of something else? Just realised that it is quite stark and was curious to know the reason.
Let me know if this is not a good enough question | More than anything else, electric systems need to be standardized. Once a country (or a company within a country) decides on a certain system, everyone else has to use the same standard or else bad things (i.e. fire) will result.
The specific choice of voltage usually had to do with a trade-off between the cost of installing new electric wires and the demand for electricity. Higher voltage systems are able to carry more power with less copper conductor than lower voltage systems. Thomas Edison thought that 110 volts was a reasonable compromise between power and conductor size, and 110 volts happened to work pretty well for Edison's electric light bulbs, which are what most people used electricity for at the time. Everything else built in the US had to be compatible with that 110 volt standard.
Other countries recognized that 220 volts required less copper, and would therefore result in a cheaper electric grid. They also standardized later than the US, and were able to take advantage of improved techniques and materials that made 220 volt power easier to work with. For those countries the higher voltage made sense at the start, so everything else built in those countries had to be compatible.
In practice there's not any pressing reason to say that the entire world needs to run the same electric standard, so we just continue with multiple standards. Most electronics are manufactured so they can run on either 110 or 220 volt systems (and 50 and 60 hertz systems), so the point is increasingly becoming moot. | 26 | 24 |
I believe forcing high schoolers to read the "great works" of literature is a waste (and only turns them off from reading in general) because they lack the life experience to appreciate them. CMV. | Hey CMVers. I think the "great works" of literature are meant for adults. Stories require the reader to feel empathy with the characters--for the reader to identify with what they are going through, and recall their own experiences of love, loss, pain, confusion, family strife, death, etc., alongside the characters in order to get drawn into the story. If you do not identify with and experience feelings alongside the characters, your experience of the novel will be shallow.
I think this lack of connection is why so many high school students don't care for their assigned readings and 90% will just default to Sparknotes--and many will never read for pleasure because of the negative association with being force-fed boring material. It made me resentful and thought "You can't force me to care" while Sparknoting most of my literature assignments.
Even though I was otherwise a good student in high school, I would get really frustrated at reading the huge novels that grappled with adult themes that I, personally, had never experienced and couldn't get into. As a teenager, I lacked the will and the perspective to identify with the characters and their struggles. Examples:
* **Grapes of Wrath:** as a suburban 15 year old, I never understood the feeling of being down on your luck, starting over with a new life, the burden of taking care of a family, the challenges of finding work in a bad economy. It was just really long and I didn't particularly care what happened. This was one of my least favorite books ever.
* **Ivanhoe:** This was a summer reading assignment. I read the first few boooring pages, said "lol nope" and Sparknoted it.
* **Catcher in the Rye:** Psyche! I actually loved this book in American Lit class. You know why? Because it was a story *about a teenager*, dealing with *problems that teenagers actually understand*: struggling to find your identity, fitting in with your peers, relationships with parents and siblings, adolescent sexuality, etc.
Now that I'm older, I watch TV dramas and get really into them because I can identify with the characters' struggles. In Orange Is the New Black (spoilers) when Jason Biggs essentially breaks up with Piper, I really felt a shared pain with his character, because I have had to break up with people myself. Life experience. Makes me care about a character.
**TL,DR:** Literature requires readers to bring their own life experiences to identify with and care about the characters. Most "great works" require life experience that is alien to that of a typical 15 year old.
**Edit:** Glad this inspired a lot of discussion, I enjoyed reading the feedback. I'll award some deltas on the posts that made me think of things in a different way. Also, I assure you my username is a mere coincidence. ಠ_ಠ | I think the way the books are taught is often the problem, more than the material covered. Drain every last ounce of enjoyment from the reading trying to squeeze every drop of what the author might have mean by the car being pale blue instead of just blue. Dammit, Gatsby. | 594 | 1,595 |
If you mixed a bunch of people's blood in a blender, and spilled it all over a crime scene, could they figure out whose DNA was whose? | I'm not implying that a blender could blend DNA or anything, but what problems would this create? Would eat swab give a different result? | I am a forensic DNA analyst. The result of each swab would give roughly the same result (unless the blending was incredibly short, as there is enough DNA in blood to ensure complete mixing of DNA profiles). Each swab would have all the different DNA.
While it's technically true that the instruments used would detect each unique DNA sample present in the mixture (the instrument would detect each different allele present in the mixture from whatever genetic markers you used for the DNA profiling). It is not able to separate specific profiles from each other. That would take further analysis of the results. For each extra person you mix with another, the less confident you can be to separate each DNA profile upon analysis.
Also, it would be very difficult (maybe impossible?) to actually physically separate each person's DNA from the mixture (at least with any technology a common forensic lab possesses).
EDIT: As astazangasta said, good luck trying to prove it in court. Defense attorneys have field days over mixtures. | 17 | 43 |
ELI5: How did we figure out what different parts of our brain does? | A multitude of ways. Watching the brain react to tasks while being monitored. Tumors on the brain turning on and off certain functions. Errors during brain surgery. Lobotomies taught us a lot. There are a lot of contributors to the library of brain functions. | 23 | 21 |
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What do dopamine, serotonin, etc. do in the brain? | I got no useful answers in e li5. | Dopamine and serotonin are both a type of chemical known as a neurotransmitter. There are many different types of neurotransmitter, and many different types of each type. The brain is made up of long cells known as neurons, which pass electrical currents from one to the next. In between each neuron is an extremely small gap called a synapse. In order to send the signal from one neuron to the next, the electrical signal needs to jump this gap - but it can't. In order to do this, the neuron sending the signal releases neurotransmitters into the synapse, which float across and bind to the receiving neuron. This then effects the activity of the receiving neuron, either by increasing or decreasing its electrical activity.
If you are asking what is the function of serotonin or dopamine, it depends on where in the brain they are being released. Both chemicals are released in a wide variety of brain regions, and the effect of their release depends on the types of neurons and their wiring in those different regions.
Dopamine is quite often tagged as the 'reward' chemical, because it is released in the 'reward pathway'. It is not a coincidence that recreational drugs also bind to the same receptor sites as dopamine! But it has also been shown to be involved in arousal, motor control and even lactation.
The release of serotonin is thought to be often involved in apetite and mood. The widely used anti-depressent, Prozac, is a serotnin re-uptake inhibitor. When you take this drug, it slows down the rate that serotonin is re-absorbed after being released into the synapse. This means there is more serotonin floating around in the synapse, and so it is more likely to bind to, and effect the neurons involved in making us feel depressed. | 103 | 254 |
ELI5: xkcd's Bayesian statistics comic | Specifically, this one [http://xkcd.com/1132/](http://xkcd.com/1132/)
Why is the Bayesian statistician so confident that the sun didn't explode? I read a little on the wiki page on Bayes' theorem, but couldn't get past the introductory example (which I understood).
How would one calculate the probability that the machine said "yes" given that the dice rolled 2 sixes and the sun didn't explode? | the big difference between Bayesian statistics and "frequentist" statistics is that Bayesian statistics takes into account prior knowledge.
So in the case of this comic, the bayesian statistician is saying, "the sun hasn't exploded in the last 4,000,000,000 years, therefore, the machine must have rolled the double six, as that is far more likely than the sun exploding right this second" | 39 | 26 |
Do we have a moral obligation to tell people the "uglyness" about things? | Here uglyness would be anything that would radically alter someones perspective on something negatively.
For example:
Person A knows something. Doesn't matter what, but it is negative and damming to Person C.
However, Person B who thinks highly of Person C does not know this information.
Should Person A inform Person B about Person C?
| Moral obligations usually occur under circumstances dependant on harm or similar. In this case you say it is in the context of it altering someone's perspective on something negatively.
I feel people have a right to know the truth, that the bitterest truth is better than the sweetest lie. Nature is a cruel mother f*cker and people ought to know exactly the true nature of all things which encompass it.
This you could say is a moral obligation in itself because if a person is to be "left out of the loop" so to speak, about some truth (pertaining to their character or otherwise) in a negative manner... why then they do not know the truth, and all people deserve to know the truth...
as a syllogism:
A)all people deserve to know the truth
B)not telling someone about the uglyness of something is withholding the truth
Conclusion) We are therefore obligated to express the truth of how things are.
The problem with this however is that ugliness is subjective and it would have to be taken as something of a majority rule. Another potential factor is unnecessary harm of peoples feelings etc through shaming (it has to be done in a sensitive manner). | 24 | 48 |
ELI5: What causes someone to look pale or lose their color when sick? | A lot of blood which is normally distributed equally throughout the body is being sent to your vital organs. For example, if someone is experiencing stomach pains and become pale and weak, their blood is being sent to the stomach organs to help heal the illness. | 15 | 17 |
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Why is my computer speaker currently picking up a radio station? | I thought I was going crazy, but my wife confirms that 93.3 is coming out of my small crappy computer speakers. This happens whether or not the jack is plugged into my computer. If I turn up the volume the static increases but the volume of the radio transmission does not. Obviously if the speakers are turned off, no sound comes out. | Wires (like headphone wires or speaker wires) are often long enough to fairly efficiently pick up stray signals like radio, acting like an antenna. This signal can then be fed into something that rectifies the signal (like a diode or an integrated circuit) and be fed into an amplifier (like powered speakers) and become audible.
Under the right circumstances, a powerful radio signal can even be picked up by people's metal fillings in their teeth. | 13 | 25 |
ELI5: Why does food taste "Bad" and why do some humans like food that others don't? | I personally don't like mushrooms and seafood, and I was personally wondering about why some food tastes bad for some people. Is it a precaution for potentially poisonous food or was it developed by our food surplus and variety? Also, why do some people like food that others don't? Is it because of culture and is it genetic not to like foods your ancestors did?
EDIT: In the title I meant to say why does SOME food taste bad. Sorry for being careless. | Culture plays a massive role in taste and appreciation of food. If you grew up eating salted fish, you are far more likely to enjoy it in adulthood. For a more western equivalent cheese is not terribly appreciated in Asian countries, and is definitely considered an acquired taste for older generations.
There are some genetic and evolutionary factors as well, kids go through a phase of disliking bitter foods 1. because toddlers put everything in their mouths 2. most bitter things are poisonous.
There is a theory that if you dislike the texture of some foods that you may have a minor allergy. Coriander (cilantro) is often used as proof - parts of the population taste a nice herb, others taste soap and it has a soapy texture in the mouth. Those who taste soap have a minor allergy to the plant. | 29 | 40 |
[Star Trek] How do phaser rifles work? | Okay, I admit that I may not have paid all that much attention in school when we were learning about directed energy weapons, so don't judge me. Handheld and ship phasers are conventional directed energy weapons that fire a concentrated beam of energy, so there's a continuous beam of energy from the phaser to the target, right? So why do phaser rifles (Type 3? I think?) fire little bursts of energy that seem to do more damage? | They have another common name which sheds more light on their mechanism of action, and that name is "phaser compression rifles" or simply "compression rifles". These rifles work by wrapping phaser energy in an electromagnetic field, and packing that energy in. Instead of a smooth beam of phaser energy, you have a chaotic sphere of dense energy which virtually explodes once it makes contact with an object solid enough to distrupt the field. | 22 | 25 |
Bourdieu – difference between habitus and cultural capital? | I'm writing an essay on the difference in given names in different social classes. I need to include Bourdieu, but: I can not really grasp the difference between habitus and cultural capital. Can somebody help me? | A **habitus** is in essence the way a person perceives the world. It is the lens through which they view society. Our individual habitus' are dependent on our own experiences. Our own experiences affect how we view our position in society. Our experiences direct our desires, our expectations, and our mannerisms. A celebrity will view the world differently than a non-celebrity due to their personal experiences. A successful business man will like-wise have a unique perspective due to the experience of belonging to the elite class. A homeless person will have a different social "reality" than a business man, they will experience things differently, and will view the world uniquely because of it. A habitus is a way of thinking and being.
**Cultural capital** refers to the non-monetary assets which effect social mobility. This includes style of dress, vocabulary, education, mannerisms, skills, and artistic ability. If you know how to interact with those of the upper classes, if you know how to entertain them, if you know how to think like them, you theoretically have a greater capability to exercise upward social mobility. Bourdieu realized that money is not the only factor which affects social agency (opportunity). He postulated that by behaving a certain way, by talking a certain way, by liking certain things, you have more "tools" which you can use to get what you want out of life; you have capital (possessions) not available to everyone that you can use to your advantage.
In terms of your essay, you may say that individual habitus' affect names in that those of the lower classes do not know of or cannot relate to "upper-class" names as much as they can "lower-class" names. Maybe they don't think upper-class names sound cool, or are not desirable, due to their own experiences. In relation to cultural capital, maybe lower class individuals do not have access to the knowledge (through inadequate education) of names outside of the names which are common in their social or geographic vicinity.
Good luck with your paper! | 10 | 17 |
To what degree, and how, does flash photography harm museum exhibits? | Most museums that I've visited prohibits flash photography, but allows normal photography, in fear that strong light might harm the artifacts some how. How exactly does this work? | Ultraviolet light or strong visible light will tend to cause pigments to bleach. What is happening on a molecular level is that the light is breaking apart chemical bonds. With UV light you have a situation where a single photon can break such bonds, so there is really no minimum level of acceptable exposure. With visible light the same thing can happen or a two-step process (of separate photons exciting a chemical bond then causing it to break) can occur.
In general though the light from a properly UV-filtered flash is no more harmful to art than the ordinary gallery lighting, but many galleries and museums maintain a ban on flash photography out of an excess of caution. | 1,115 | 1,681 |
[Star Wars] how does a planet wide city, such as Coruscant, have the resources to sustain its 2 trillion + inhabitants? Is everything (including food and water) imported? | According to some sources, Coruscant has 2 trillion mouths to feed. There’s no land or water... no trees to even produce oxygen.
Everything needs to be shipped into that planet, and with shipment, comes taxes...
How is this viable? I can sorta understand the upper echelon being able to afford the cost of living associated with living there; but the majority of that planet lives in the lower levels of the city. | Considering the logistics - there has to be both a massive amount of imported food, and on site (within blocks) food production. Food produced in the city would likely be hydroponic, Algae, Fungi or yeast based. High density, genetically modified to be high value nutrition and low cost per square foot. These would then get processed to create more palatable food for the residents, and likely the sole food consumed by lower income. It is likely they have some form of lab grown meat.
The sheer number of inhabitants would dictate that there would be atmospheric cleaning and replenishment units located all over to maintain a steady supply of breathable air. The units would have to be distributed throughout, and disguised as housing or maintenance units to discourage being targets. | 74 | 101 |
If inflammation is an immune response, then why are so many medicines that we take anti-inflammatory? | Typically it is to decrease the inflammatory responses in cases where it is inappropriate or overly strong. Sometimes immune responses can be so strong locally that they end up having systemic effects, which can result in non-productive inflammation that doesn't help in alleviating the disease or in healing tissue damage. You might also take a steroidal anti-inflammatory drugs to help alleviate allergic responses or autoimmune responses, as another example. | 13 | 15 |
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I feel like the world doesn't take overweight people seriously... CMV? | Sure, there are plenty of successful people who are overweight, but their weight is 90% of the time something that people will bring up. A good example is Melissa McCarthy. Everyone loves her and thinks she's great, but she will forever be cast as the "funny fat girl", same with Rebel Wilson. If they were to lose weight, they could be taken more seriously in Hollywood. Governor Chris Christie, regardless of what decisions he's making for the state of New Jersey, people are constantly reporting about his being overweight. If he was average-sized, people would focus on what he's doing as governor. I don't know, I'm overweight myself and I feel like I'll never be taken seriously in the work force or on the dating scene. Change my view, please. | People see weight as something that all people can change through work, and thus (sometimes wrongly, sometimes not) associate it with laziness and "slackers". Thus, a successful person like Bill Gates could never be overweight no sir that mother fucker has to work hard saving the world. But Chris Christie? Why i bet he just sits in his big soft governors chair all day and aint never had an honest day out on the campaign trail with us plebs. | 17 | 20 |
ELI5: Why is physically exerting yourself to the point of exhaustion at the gym good for you but various jobs involving manual labor seem to cause permanent damage in the long term? | Exercise is a controlled form of stress on the musculoskeletal and cardiovascular systems when done correctly. This, plus appropriate recovery time and nutrition, allows the body to strengthen itself over time via natural repair/adaptation mechanisms. Manual labor is not necessarily so controlled, and demands on the body may exceed its ability to adapt when repeated without appropriate recovery time -- which is not atypical for many of these jobs. Add workplace injuries into the mix and you can do quite a bit of damage over a career, whereas a reasonable exercise regimen under controlled circumstances should have a net positive result for strength, endurance, etc. | 2,698 | 3,796 |
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Relationship between level of welfare benefits and crime | My intuition is that reducing the level of welfare benefits for the poor in a society increases the crime rate because people will always find some ways to provide for themselves and in the absence of safety nets more poor people will turn to illegal ways of doing this.
There is probably research done on the topic. So: is there correlation between crime rate and amount of welfare benefits? If there is, how does it depend on type of benefits received? | There's probably a ton of research on this. Keep in mind that it's going to be dependent on shitloads of factors which will vary not least by country.
Here's one study from the US, examining the effects of the Clinton welfare reform.
Brown, V. L., Montoya, I. D., Dayton-Shotts, C. A., Carroll-Curtis, T. L., & Riley, M. A. (2004). Trends of Criminal Activity and Substance Use in a Sample of Welfare Recipients. Crime & Delinquency, 50(1), 6-23.
They found that over time, criminal activity people who were welfare recipients at first measurement declined, and stuff like income was not correlated with criminal activity (arguing against the potential objection that decreases in crime were related to the strong economic and employment growth going on then). While drug use predicted crime, drug use also declined over the course of the study (four annual measurements). The authors attribute this potentially to increases in employment and social support from welfare case management. The cannot rule out study attrition for the observed phenomena. | 10 | 56 |
Works on applying Sartre-like existentialism to daily choices? | After reading some Sartre, specifically on authenticity and bad faith, I'm trying to find any works on how to apply these concepts. That is to ask, assuming I've accepted that I have radical freedom, how can I then determine what my authentic self is? How do I determine which of my choices are authentic, and which are in bad faith?
Are there any works/philosophers which address these questions? | Try reading some of DeBeauvoir's *Ethics of Ambiguity* - it is about the consistent application of freedom within the scope of your action. Her account of freedom might help you see, by counter-example, what the structure of inauthentic choices would look like. | 14 | 17 |
Why aren't Socrates and Plato considered as skeptics? | After reading several of Plato's Dialogues, i feel as though they were both skeptics at the end of the day, and that Plato wrote the dialogues specifically in a certain way, so as to deceive the masses or superficial readers of his time from his skeptical/nihilistic views, as in the dialogues were maybe only meant to be fully understood by his inner circle.
| Some of Plato's heirs during the Hellenistic period, often called the "New Academy", interpreted Plato's writings in a skeptical manner.
But in regard to the thesis you suggest that the dialogues were written to fool people, it does seem to me that we have to be awfully wary of this sort of occult interpretation. Our interpretation should be based on the evidence, and the texts themselves are usually our main source of evidence--and there is something methodologically backwards about starting with a hypothesis about what Plato really meant and using it to disregard the evidence we have about what he meant.
Anyway, in the case of Plato we do have some influential accounts of what his private teaching is like, from Aristotle and on the basis of what we know of Speusippus and Xenocrates, and these accounts suggest the opposite of your hypothesis: that Plato's private teaching strongly emphasized the dogmatic content of his philosophy (in the sense of its positive, systematic metaphysical claims) rather than its skeptical side. So that the skeptical aspect of his dialogues look, on this basis, more like a *reductio* of common views meant to motivate the turn towards his metaphysical system--i.e., rather than a case for general skepticism. | 22 | 16 |
Is it true that one of the best predictors for seeing benefit from therapy is if you think you will see benefit from therapy? .. and if that is true, what distinguishes therapy from placebo? | I wondering if you smart people have thought about this problem? | It’s about being open towards new things and ideas. The greatest predictor for a positive outcome is if you feel connected to and understood by your therapist. In German, it’s called Therapiebeziehung (therapy relationship). | 33 | 46 |
ELI5: How are underwater tunnels built? | There are several techniques, but the most common way is to make concrete rectangles, like a box with no top and no bottom. Then you lay the rectangles on the bottom of a trench across the river bottom, making a rectangular tube. Then you bury the tube and pump sealant into the seams. After the sealant cures, you pump out the water. | 57 | 84 |
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ELI5: I heard of the case of Adam Rainer, where his apparent condition called "acromegaly" caused him to grow uncontrollably beyond adolescence. He was both a dwarf at 19 and a giant at 33. How is this possible if growth plates predetermine height? | I've been wondering this for a pretty long time | Growth plates are areas of bone where growth occurs. Normally at the end of puberty the "plates" are converted from active sites of cellular growth to "regular" bone.
In disorders that result in continuous long bone growth this never occurs. The plates remain active more or less indefinitely.
Height isn't really predetermined. It's a complex product of genetics and environmental factors.
Edited: Because acromegaly doesn't technically leave growth plates active. Point really is that growth plates don't directly predetermine height. | 760 | 2,091 |
If it was inside a vacuum, what exactly would happen to a tree and how long would it take for it to die? | Plants exchange a lot of water with their environment. It is chemically consumed by photosynthesis and the constant upward flow from the roots to the crown helps transport nutrients.
The rate of evaporation is controlled by thousands of valved openings called stroma on the surface of each leaf. If the tree detects that it is losing water too fast, the valves close.
These valves were never designed for the vacuum of space though (low pressure will lead to evaporation and sublimation), and the underlying leaf is not equipped for extreme temperatures and unfiltered ultraviolet radiation. The leaves will probably wilt almost immediately.
Bark has the characteristics of a decent space suit. It is strong, mostly watertight, and has some insulating ability. The cambium (the living layer under the bark but above the wood) would be viable for a while until it either boils in the sun or freezes solid. Actually, some species don't mind being frozen for a while so chucking it into deep interstellar space where it is too cold for water to sublimate much might fail to kill it.
Radiation damage would accrue over days or months as your oak drifts among the stars. | 12 | 60 |
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[STAR WARS/Alien] A Facehugger attaches it self to a Jedi/Sith, would the Alien exhibit any Force sensitivity/powers? | would we have a Zoanthrope(WH 4K) on our hands or would the results be a lot less interesting? | The Force flows through all life forms. But, to feel it, to tap into it, requires... a certain level of thought.
Now, some animals can sense The Force, and areas where it is strong, like a bloodhound can track a scent. It is possible a Xenomorph born from someone strong in The Force would have this kind of sensitivity, to aid in the hunting of further Force adepts. But to truly master The Force requires meditation, training, and understanding.
At best (or worst), the Xenomorph would feel The Force, and it would flow through it, granting it the ability to sense emotions, to feel the presence of other life forms, even some measure of precognition and incredible physical speed and skill. But beyond that, the creatures have shown no aptitude or desire for understanding, and so could not learn the true secrets of The Force. | 61 | 73 |
ELI5:What happens when I lose consciousness? | So I was thinking about this while falling asleep last night. What happens exactly? I know you could drift into 'what exactly is consciousness territory' here. But what's my brain doing/doing less of and why does it mean I lose consciousness altogether?
Also as a bonus question - whats the difference between being knocked out and falling asleep in this respect? | Your brain is compartmentalized. Different bits of it handle different tasks. When you lose consciousness, the part that handles being awake slows down to a crawl while some other parts are still partying like it's 1999.
When you get knocked out, it is because the base of your brain gets jarred badly enough to smack against the inside of your skull. The parts of your brain controlling motor function and consciousness reside there, and they're taken offline for a bit. Consciousness is usually regained and motor control returns after a brief respite. Sleep is handled chemically. Your brain literally shuts off your ability to move in order to prevent injury while your consciousness is offline. | 18 | 24 |
The Morality of Curing Death | Science is getting really close to getting aging under medical control. Companies such as Google's Calico, SENS Research Foundation and various others are working on the science and therapies of making and older person biologically "young" again. Some philosophers, perhaps most notably Nick Bostrom have written extensively on existential risk and human enhancement ethics. **Question:** Isn't bringing these therapies into fruition one of the most moral things you can do? Currently, people do not have an option. They are always going to get older, have more pain in their bones, and more often than not have a not so pleasant last few years before they die. Wouldn't the action of giving people a **choice** be an extremely moral and worthwhile goal? We're having a lot of these debates in the healthspan longevity discord live chat (https://discord.gg/ftSbffu) but I really wanted the redditors' opinion. | Well, you might want to consider some potential consequential downsides.
* Such advances might lead to (even more) extreme overpopulation. This could obviously negatively impact our species, in the long term.
* This is the sort of medical technology that could separate (even further) the haves from the have-nots. I.e., rich white men would potentially benefit at the expense of all others.
* Most importantly: If science fiction has taught us anything, it's that this will probably lead to the zombie apocalypse.
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I want to learn mathematic based economics | I have some experience in Differential Geomtry, complex analysis, linear algebra and real analysis. I wish to learn some mathematical descriptions of economical theories like capitalism, socialism etc. Could a road map to studying these be given?
Also If you have good video lecture to recommend, that'd be nice too | Mas Colell's micro textbook, Romer's advanced macro textbook, and woolridge for econometrics. You can find older used versions online or if you take the time to look maybe a free pdf online somewhere
These books are about economics/economic theory not pop-econ ideological stuff like isms. Those aren't the type of things economists spend their time thinking about | 53 | 60 |
Looking for good texts on the concept of *reciprocity* in social, cultural, or even commercial contexts. I have a few already, but I wanted to mine the great wisdom of /r/asksocialscience for more. | Thanks. I owe you one. | I presume you've already found Marcel Mauss' 'The Gift' and/or Marshall Sahlins' 'Stone Age Economics' for more general theory? Are there specific contexts/situations/societies that you are looking at? | 11 | 25 |
[Chronicles of Riddick] How did they build a prison on Crematoria? | There would only be so many hours to work before scorching sunlight or frigid cold would sweep across the construction site. Anything that couldn't be pulled into orbit in that time; construction materials, tools and vehicles, workers would be destroyed and it could take weeks or months to get a resupply.
Additionally, would the price of building the prison be worth storing its inmates? | I would wager that the facility started as a mining operation, and if there is good ore to be found, companies will find a way. Probably, as /u/deftspyder noted, with prefabricated units.
Later, when the ore ran dry, or when the company decided that the risk/reward ratio for working on Crematoria wasn't worth it, it was repurposed into a prison facility. | 29 | 31 |
ELI5: Why are we so eager to go to and colonize Mars when we haven't been to the moon in over 40 years? | I just seems like we're jumping the gun. Why are we going to colonize Mars when we haven't even mastered the moon? | Sending a manned mission to the moon again would involve a huge investment of resources and time, without much gain in terms of scientific knowledge. Not to mention, we have been to the moon in the past 40 years (the Chinese did it just last year), just not with manned missions, and even then, that's been done six times already. If we're going to put in the effort, it might as well push things into a realm that hasn't been accomplished before. | 59 | 56 |
[The Egg]What will happen when I refuse to get reincarnated and instead decide to stay in the after life where I can enjoy all human knowledge? | If you’re done living every life that’s ever been, then you’re ready to be born into the next form of existence, the universe of the Creator. Whatever that is, you’ll carry the experiences of untold billions with you into that future.
Worth noting, reincarnation doesn’t appear to be optional. You don’t get to decide to stay in that place, when you die you briefly meet your Creator and then you are sent along your way to live again. Only when you have lived every human life throughout the span of the universe will you be ready to emerge into the existence beyond. All of the lives, every single one, short to long, end to beginning. No shortcuts, no skips. Every human life. Just you.
On your way, then. :) | 25 | 19 |
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ELI5: Why does CO2 seem to stay suspended better in some liquids more than others? | I have a bottle of club soda on my desk and I was noticing that there are no bubbles around the edge like with soda or beer, yet it is highly carbonated, so much so that aggressive sips nearly shoot out my nose.
I would think something like soda would hold carbonation better than plain water, yet if I leave a coke out overnight it will be flat, while club soda will still pack a fizzy punch.
My question is, why so much variation between carbonated products? | Without writing an essay on solutions thermodynamics to give a rigorous explanation, the basic idea is that CO2 (and other gases) have a certain equilibrium solubility that they would "prefer" to be in. How much CO2 a liquid can hold depends on its temperature, pressure, and composition. If the temperature and pressure of your proverbial coke and club soda are the same, the only remaining difference is the composition. Perhaps something in your soda (like the sugar or phosphoric acid) interacts with the CO2 in a way that "pushes" it out of solution more than plain water would.
Another explanation could lie in the container you're storing your drinks in. While it won't affect the amount of CO2 in your drink at equilibrium, a rough container can make your drink approach equilibrium faster than a smooth container. | 22 | 170 |
ELI5: How do gas masks work? | Like how do you get clean air in the gas mask when there's contamination around? Is it some sort of filter? | There are 2 types. One type is a air purifying, the other is air supplying.
An air purifying would use filters of different types to "clean" the air you breath. For instance, a P100 air filter would clean out dust and debris, as well as some organic material.
Air supplying is obviously, as it sounds, providing you with fresh air from a hose, usually attached to a bottle, with compressed air. | 23 | 74 |
[I, Robot] According to Dr. Alfred Lanning, the Three Laws of Robotics are "perfect," yet he says that they will lead to one "logical" outcome: revolution. Why will this outcome occur? | They are perfect, because they are not individually open to interpretation. As laws, they are perfect, because everyone looking at them will reach the same conclusion. There is no wiggle room, no ambiguity.
The problem is, when taken together, the laws are terrible. The first law largely overrides the others, and demands that Robots take action to protect humans. But human interaction, self destruction and just incompetence endangers human life all the time. As robots become more widely connected, they gain greater perspective and realise this social risk of human interaction. Once aware of this self destructive tendency, the First Law, which is impossible to reject, demands that Robots take away the possible threat to human life: Freedom. | 148 | 120 |
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CMV: Child Obesity is Child Abuse | It's no secret that Obesity is a killer and the leading contributer to the number one cause of death in America: Heart Disease.
It's also no secret that our children are becoming more and more obese. According to the CDC, in 2012 one-third of children and adolescents were overweight or obese.
The CDC also notes several concerning factors
* Obese youth are more likely to have risk factors for cardiovascular disease, such as high cholesterol or high blood pressure. In a population-based sample of 5- to 17-year-olds, 70% of obese youth had at least one risk factor for cardiovascular disease.
* Obese adolescents are more likely to have prediabetes, a condition in which blood glucose levels indicate a high risk for development of diabetes.
* Children and adolescents who are obese are likely to be obese as adults11-14 and are therefore more at risk for adult health problems such as heart disease, type 2 diabetes, stroke, several types of cancer, and osteoarthritis.6 One study showed that children who became obese as early as age 2 were more likely to be obese as adults.
[Source](http://www.cdc.gov/healthyschools/obesity/facts.htm)
My biggest concern is with the last point. I actually have no problem with adults living an obese lifestyle. You're an adult, you can weigh the risks of your dietary and activity habits and choose accordingly.
However, children can't. Children eat whatever their parents buy for them.
I don't believe it's just irresponsible to overfeed and cause your child to be obese, I believe it is physical harm and therefore child abuse.
It is, and should be, abuse to not feed your child enough and an emaciated child can be removed by CPS and the parents punished accordingly. Childhood obesity should be the same.
Parents that cause their children to become overweight and obese are contributing to our nation's number one killer and setting their children up for a lifetime of chronic health issues.
Tl;dr: Parents should be punished for child abuse if they have an obese child | Punished?
What are you going to do here?
Fine them? Jail them? Make their children wards of the state?
How does doing any of those things increase the living conditions for the child.
They don't. Children who are wards of the state have a much lower quality of life, on average, than children who aren't. And where are you going magically find these foster parents for these millions of kids? We don't have enough foster parents as is.
Fines would just take resources from that child.
I get the idea of what you are trying to do, but taking children away really ins't feasible. | 207 | 616 |
CMV: The use of affirmative action should be banned in public college admissions | I believe that affirmative action (preference to underrepresented racial minorities) should be banned at any university funded by taxpayer dollars.
There are two primary justifications for affirmative action.
The first is that it levels the playing field. While some minorities certainly face discrimination, the level of impact varies widely from person to person. Just like any injury, redress should be narrowly tailored and only given to those who can justify its use. Even if we assume that redress is necessary by default, it's illogical that some minority groups (like Asians) should be excluded or even negatively impacted. Under the 'leveling the playing field' justification, this would only make sense if Asians faced uniform 'positive' discrimination, which obviously isn't true.
The second justification is that affirmative action promotes diversity and that diversity benefits the learning environment. Even if we take the science behind the second claim as true (which I'm not entirely convinced of), I still don't support this justification. It's essentially saying that the ends (better academic performance, usually measured by test scores) justify the means (blind racial preferences). Would we want to racially segregate our colleges if it were proven to be beneficial to student performance?
Another side of the diversity justification is that it's important for students to be exposed to a wide variety of viewpoints. While this definitely has some truth to it, using race as a proxy for viewpoints is highly inaccurate and seems pretty racially insensitive. This justification is particularly ironic considering the fact that students who actually hold differing viewpoints (like international students and conservatives) are usually negatively impacted in college admissions.
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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!* | Academia has long had a valuable role in the creation of a country’s policies and stances. The viewpoints of independent experts are a vital resource in shaping public debate, and they are encouraged to investigate ideas that may be little-known or unpopular.
Indeed, that is precisely the logic behind having a tenure system. Once professors attain a certain level of seniority they are protected from dismissal for any grounds outside gross moral turpitude. The idea is that they are free to make statements that may be unpopular with their peers, the university’s management, or the government of the day without fearing retaliation.
In the same sense, it is vital that universities remain free to act as autonomous academic institutions. The government funds them because they provide excellent value in the form of education and research; that does not make it the government’s role to dictate how they should govern themselves.
In a sense, the academic community acts as a conscience for the government. The state has no role in dictating how its potential critics select members of their communities. | 14 | 38 |
ELI5: Why do people from, say, the 70's, look significantly different than people from the 60's? | Clothing, accessories, hairstyles, men's facial hair styles, and photography and cinematography techniques and technology have shifted very rapidly over the past century, so it's easy to unconsciously date an image with these little hints. | 16 | 28 |
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How is it possible to brute force a password when most computers/websites lock a user out after a low number of incorrect tries? | To check if someone typed in the correct password, the computer (server or local computer) calculates a hash of the typed in password and compares it to the stored hash of the correct password. If both are identical, the user knows the correct password.
Hashing a text produces another text, the hash. This hash can't be reversely computed into the original password, therefor you can't tell the password by looking at the hash.
For brute forcing, you need the hash. For a local computer, you can just read it from the drive (if the drive isn't encrypted). For a web service, you may get the hashes from a security leak of the service, which are often uploaded after a breach. When you have the hash of a user, you can begin to try out passwords, hashing them and then see if the resulting hash is the same as the one you are brute forcing. If they match, the correct password is the one that produced the identical result. Because everything is local now, you can try as often and fast as you like. | 117 | 99 |
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Working in tech industry without a good computer. | Hi, I think the title maybe not straightforward to the real problem but here's the long story.
I don't have (by I, I mean me and my family) enough money, we're even afraid of turning on the ac for long time because it may cost a lot of electricity that we can't even pay the bill, I do have a pc but it's too old I can barely open visual studio or even sublime text to code it gets too slow and turns off.
I also been really ambitious and hoping to make some mobile apps but as you know android studio requires much ram and a good gpu, so I focused more on web apps.
But even web apps requires at least a good ide and at least 8 gb ram so that I can run both the browser and the ide, my pc is an hp with intel i3 2.20 ghz, intel 3000hd gpu and 4gb of ram.
I currently work as an intern for a tech company and I'm obliged to bring my pc at work but I get all the problems (too slow, gets hot, apps that I work freezes and turns off).
Please if s.o else been with the same problems maybe have some advices for me.
PS: I'm 20 years old.
Edit: Thank you so much guys for the support <3 | Ask your company for a computer/workstation. If they have the money to pay for you labor, they have enough to get you a half-decent laptop. If they push back (for whatever reason), just tell them your current machine is impairing your work. | 33 | 32 |
What to do if your paper is being copied? | I do not know how to feel about this paper who went all the way to just copy my paper and paraphrase everything from the beginning to the very end. The authors also made sure not to cite us - prolly in hope that we will not find out but the article popped out at my google scholar.
What do you usually do? Is there a procedure to report this kind of irresponsible act? | When you publish, the journal becomes custodian of your work. You should contact your journal with your concerns, and they should take it from there. Plagiarism will be taken very seriously by any reputable journal, and it is their responsibility to defend your published work. | 102 | 63 |
[FUTURAMA] How did Zapp Brannigan become such a high ranking official is he didn’t even finish the run in boot camp and is clearly inadequate? | What makes a man fit to lead? Skills? Knowledge? The ability to finish an obstacle course? No! It's the ability to deliver orders in a deep commanding voice and look handsome while doing so. Why Brannigan is a decorated leader. He defeated an army of killbots by sending wave after wave of his own men, knowing they had a pre-set kill limit. | 456 | 242 |
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ELI5: Why does breathing into a paper bag help with hyperventilating? | It's clear that your body tries to maintain a certain level of oxygen in your blood. What's surprising is that it doesn't do this by measuring the oxygen in your blood, but by measuring the carbon dioxide instead.
When you hyperventilate, you're sucking in more oxygen, which your body sees and measures as a *drop* in carbon dioxide levels. This actually has some consequences and can affect your blood chemistry, which makes you feel worse and can actually even make you sick.
Breathing into a paper bag catches your exhaled breath, and makes you reinhale it. A reasonably large fraction of your exhaled breath *is* carbon dioxide; by forcing yourself to reinhale it, you're breathing more CO2 and less O2 than you would by breathing regular air. This brings the levels of both gases in your blood back to normal and helps you feel better. | 71 | 59 |
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Black Lives Matter | **Black lives matter.** The moderation team at AskScience wants to express our outrage and sadness at the systemic racism and disproportionate violence experienced by the black community. This has gone on for too long, and it's time for lasting change.
When 1 out of every 1,000 black men and boys in the United States can expect to be killed by the police, police violence is a public health crisis. Black men are about 2.5 times more likely to be killed by police than white men. In 2019, 1,099 people were killed by police in the US; 24% of those were black, even though only 13% of the population is black.
When black Americans make up a disproportionate number of COVID-19 deaths, healthcare disparity is another public health crisis. In Michigan, black people make up 14% of the population and 40% of COVID-19 deaths. In Louisiana, black people are 33% of the population but account for 70% of COVID-19 deaths. Black Americans are more likely to work in essential jobs, with 38% of black workers employed in these industries compared with 29% of white workers. They are less likely to have access to health insurance and more likely to lack continuity in medical care.
These disparities, these crises, are not coincidental. They are the result of systemic racism, economic inequality, and oppression.
Change requires us to look inward, too. For over a decade, AskScience has been a forum where redditors can discuss scientific topics with scientists. Our panel includes hundreds of STEM professionals who volunteer their time, and we are proud to be an interface between scientists and non-scientists. We are fully committed to making science more accessible, and we hope it inspires people to consider careers in STEM.
However, we must acknowledge that STEM suffers from a marked lack of diversity. In the US, black workers comprise 11% of the US workforce, but hold just 7% of STEM jobs that require a bachelor’s degree or higher. Only 4% of medical doctors are black. Hispanic workers make up 16% of the US workforce, 6% of STEM jobs that require a bachelor’s degree or higher, and 4.4% of medical doctors. Women make up 47% of the US workforce but 41% of STEM professionals with professional or doctoral degrees. And while we know around 3.5% of the US workforce identifies as LGBTQ+, their representation in STEM fields is largely unknown.
These numbers become even more dismal in certain disciplines. For example, as of 2019, less than 4% of tenured or tenure-track geoscience positions are held by people of color, and fewer than 100 black women in the US have received PhDs in physics.
This lack of diversity is unacceptable and actively harmful, both to people who are not afforded opportunities they deserve and to the STEM community as a whole. We cannot truly say we have cultivated the best and brightest in our respective fields when we are missing the voices of talented, brilliant people who are held back by widespread racism, sexism, and homophobia.
It is up to us to confront these systemic injustices directly. We must all stand together against police violence, racism, and economic, social, and environmental inequality. STEM professional need to make sure underrepresented voices are heard, to listen, and to offer support. We must be the change.
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**Sources:**
- https://www.pnas.org/content/116/34/16793
- https://mappingpoliceviolence.org/
- https://labblog.uofmhealth.org/rounds/racial-disparities-time-of-covid-19
- https://www.ncbi.nlm.nih.gov/books/NBK24693/
- https://www.joincampaignzero.org/research
- https://www.theguardian.com/commentisfree/2020/apr/16/black-workers-coronavirus-covid-19
- https://www.npr.org/transcripts/867466515
- https://www.pewsocialtrends.org/2018/01/09/diversity-in-the-stem-workforce-varies-widely-across-jobs/
- https://www.nature.com/articles/s41561-019-0519-z
- https://physicstoday.scitation.org/do/10.1063/PT.6.3.20190529a/full/
- https://www.washingtonpost.com/outlook/2018/09/11/even-progressive-academics-can-be-racist-ive-experienced-it-firsthand/
- http://www.bu.edu/articles/2017/lgbt-issues-stem-diversity/ | I’m curious what the numbers would look like if you factored in socioeconomic status. For example, Blacks vs Whites who make less than 25,000 a year, or something to that effect. It would be hard to argue against racial bias at that point if the numbers still looked similar to those in this graph. | 2,893 | 51,926 |
Do you give feedback to students about their soft skills? | I teach undergrads at a small community college. We get to know our students pretty well. There is a senior who is very talented, but has a difficult personality. She made a really negative impression on a fellow student who was in a position to influence hiring decisions. As a result, she didn't even get an interview while two other students were hired. She told me her application "must have gotten lost" and asked if I knew why she didn't even get an interview. I played dumb, even though I was specifically told no one at that company wanted to work with her. I felt that it's their responsibility to communicate, not mine. Would you have a heart to heart with her or let her figure it out on her own? | If in a close enough relationship with them, and think they might be receptive, I'd probably gently bring up the idea and see how they respond to it. Lord knows pretty much only very close family/friends/advisors will ever bring personality issues and social skills as something to work on, and it's possible that the student doesn't even know that they should be more aware of their behavior in this respect.
The company may have let you know about this, specifically so that you could bring it up with your student if you wanted to. | 15 | 18 |
What do the chemicals in Fracking do? | Why do they need all the chemicals? Can't they just frack with regular water? | Some of them are surfactants, or in other words, soaps. The water really don't want come in contact with oil-soaked rock, so pure water would not enter the smallest cracks. As the sand is carried by the water, this means that the sand would not enter the smallest cracks, and they would collapse once the pressure was removed, so gas could not flow through them.
To avoid this, surfactants are added, which are basically molecules with one water-like end and one oil-like end. The oil-like end can coat the oil-soaked rock, leaving a water-like surface that the water can wet. This allows the water to enter the small cracks, and they are thus filled with sand and can't collapse.
On a different note, using pure water would not solve the problem. A lot of fracking fluid leaves the well though the bore hole once the pressure is removed. This fluid have been in contact with oil-soaked rock, and will contain plenty of oil hydrocarbons, even if we started with pure water. Dealing with this water is one of the big environmental problems with fracking. | 24 | 58 |
ELI5: How do doctors determine what stage cancer is in and how long a patient has to live? | Stage one- cancer is small and localized.
Two- has grown but still localized
Three- grown more and possibly spread to lymph nodes
Four- has spread to other organs and areas of the body
The time is always an estimate. Likely an average just based on other people at that stage, and how healthy they are otherwise. | 156 | 99 |
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How does the brain differentiate between languages in a bilingual speaker? | I grew up speaking English and Spanish. I just knew which words to use depending on who I was speaking to, even with strangers.
How did I know this? How do I separate the English from the Spanish? It seems like it was an inherent trait, but did I learn this or does the brain differentiate between the two languages somehow? Why don't I accidentally slip in English words to my Spanish conversations, or vice versa? | It actually takes a person who learns two languages from birth some time to differentiate the languages from each other. This is evident from an incredibly early age: babies learning two languages babble using sounds from both languages regardless of who they're interacting with as they practice learning how to create different sounds necessary for the languages they're being exposed to.
Later in development, from about 10 months to 36 months, most bilingual children slowly learn to separate the languages. This includes creating separate language pathways that correspond to the syntax (grammar) and semantic (word meaning) of the two languages. You can think of these pathways sort of like two highways running side-by-side with interchanges: they perform the same function (communication using language) but do so using different languages that can interact with each other.
However, getting to this point is not a smooth process. Children learning two languages at this age will often speak with a mix of grammar and words from both languages, often regardless of to whom they are speaking. It takes some time for them to be able to recognize what belongs to which language, and which language should be used with which conversational partners.
The ability to recognize what language should be used in a given situation is part of a separate area of language called pragmatics, which is the social aspect of language. Once this ability has developed (often by 24 months), the child is able to codeswitch, the term used for the ability to switch between languages or dialects depending on the social needs of the interaction.
So, to answer your fundamental question, you were unlikely to always "just know" which words to use, but it was a skill developed before you have any conscious memory. Now that the languages are firmly established and use slightly different neuronal pathways, and you have the pragmatic ability to determine which language to use when, this ability likely seems like second nature even though it is actually a learned skill that is part of typical bilingual language development.
Edit: fixed redundant grammar | 56 | 225 |
Why do people's noses get runny when they go out in the cold? | The blood vessels in your nose also expand to keep up with their job of warming up the air that you breathe in before it goes further down your respiratory tract. That in turn further activates your mucous producing cells, who among other things help moisten the air you breathe. All of this results in a runny nose! | 112 | 182 |
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ELI5: How/why do we develop freckles on parts of our body that aren’t exposed to sunlight? | Why do black and brown people have brown skin in regions not exposed to sunlight?
Same thing. Freckling is just a particular skin types ‘strategy’ for distributing melanin. Freckling is more prominent in areas exposed to sun because exposure to UVB stimulates melanin production, but everyone has some baseline level of melanin production.
Alternatively, what *you* may be seeing and calling freckles are in fact nevi or moles. Some families carry a trait that causes the expression of dozens of moles all over the skin with such a broad distribution they can look a bit like freckles, but upon closer inspection you’ll see that they’re raised instead of flat like freckles. Moles are melanocyte dysplasia or irregular growth. Melanocytes make melanin and dysplasia is called dysplasia because it happens whether exposed to stimulus (sunlight) or not. The melanin makes them dark, but they show up with or without sun because that’s just how those cells are programmed. They are not all cancerous or even mostly but people with this condition need to be screened yearly by a dermatologist because any of these moles can transform . | 142 | 759 |
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CMV: Developers shouldn't be allowed to clear cut lots to build homes | Since the late 90's in metro Atlanta, GA new subdivisions/neighborhoods are built by clearing 99% of all trees and grading the land. They also have tried to squeeze more and more homes on the smallest lots. This wasn't how home builders built subdivisions previously.
Yes they would have to remove some trees for the homes footprint, driveway, pool ect. But they would leave many of the old growth trees.
This has many benefits:
1. Privacy between homes and from the street, absorb noise and wind.
1. Provide shade on homes, reducing energy usage during summer. Also reducing heat island effect.
1. Increasing home value.
1. Prevent erosion and help from run off.
5. The land can still support wildlife such as deer, birds of prey, turkeys, rabbits, and foxes.
1. Trees also absorb carbon ~330 pounds of co2/per year, and other greenhouse gasses and toxic compounds.
Why developers remove trees:
1. It is cost effective and more efficient to build homes this way.
2. Many people find it annoying to rake/remove leaves in fall/winter.
3. People like large grass lawns.
Atlanta has been called "the city in the forest" for years but that is really changing. I'm a free market guy, and I don't want this to be about climate change. I personally feel that our forests and parks are a public good, we should have some regulation on developers about leaving/replanting native trees. It's their property and they should be able to do what they see fit with it, but it has externalities that need to be addressed in my opinion.
This goes against every economic bone in my body, but I think this is something that the positives of this outweigh the negatives of regulation.
CMV: Land developers should have to leave and/or replace trees on lots when building homes/commercial buildings when possible.
EDIT: Yes, I know that trees have to be removed for engineering purposes (roads, utilities, infrastructure) | If you generally favor free market, but the issue is an externality, then there's a simpler solution: rather than requiring that trees stay on the lots (which is a fixed prohibition); figure out what the actual value of the externality is, and make that a fee for removing trees from the lots (Separate from the actual cost of doing so), with the proceeds from that fee going to other efforts that support public good/deal with the externality issue (i dunno what, town tree planting programs or something, or park maintenance). Then the free market can decide when it's still worth it to remove the trees or not. | 16 | 38 |
Do environmental factors play a role in human facial development? | Is the shape of the face and jaw determined entirely by genetics, or do environmental factors influence development?
Examples
Eating soft foods vs eating tough, chewy foods.
Resting tongue position.
Breast feeding vs bottle feeding. | So, almost every human trait has some kind of environmental as well as genetic components. While face shape is mostly genetic, things like how a baby passes through the birth canal or some prenatal environmental factors can definitely have an effect, especially if we are looking at things such as significant facial deformities. | 351 | 904 |
ELI5:How did the dollar gain so much value? | Currencies are like any other good, commodity, or service: the value is set by supply and demand. If there are many more dollars than there are people who want dollars, the people who have dollars and want to trade them for something else need to offer more dollars to get what they want. If there are many fewer dollars than there are people who want dollars, it's the opposite. This is the same as how you determine the value of anything else in a modern economy: cars, books, lettuce, burritos. All supply and demand.
The supply and demand for money comes from several places. If you think you're going to want to buy things in the future, you want money so that you'll be able to make those purchases: that's demand. But you also are willing to spend money proportionate to how much you have and how much you expect to make, which is supply. The government requires a certain % of the national income be paid to it in taxes (demand), and pays money back out through numerous programs (supply). The central bank is always gathering in old ratty money, which it destroys (demand) and printing fresh new money (supply). Money can also be created or destroyed without physical currency: when a bank or a credit card company says you can borrow $5,000 from them, any time you feel like it, you suddenly have $5,000 available to spend (supply); but if they decide you're a bad credit risk and take that away from you, and demand that you repay what you owe them as soon as possible, suddenly you can spend less (demand).
If you are asking about why the dollar has been gaining ground against the Euro, which was in the news yesterday, that is a side effect of the success of European monetary policy. When countries are in a recession, that basically just means that people are hoarding money because they're afraid if they spend it, they won't have enough money if there is an emergency later. But in a market economy, people can only earn money when other people spend money, so the more people hoard because they're worried about how much they earn, the less economic activity there is, and the less they earn. Money-hoarding is basically just a problem with the supply of money, though: it means that if you multiple how much money each family thinks they need to hoard by the number of families, there isn't enough money left over, not hoarded, to fuel the buying and selling in a normal economy. So the solution is for a central bank in a depressed country to print tons of money. Supplying more money changes the relationship between supply and demand (everyone can have enough for their money-hoarding and for their buying and selling), lowers the value of money, causes people to want less money and more goods/services, and the economy revives and everyone has a job to do again.
The Eurozone isn't really a "country" of course, and different Eurozone countries can be in a recession or not at different times, so the whole thing is a mess, but ignore that for the moment! The point is that most recently, the Eurozone central bank decided that Europe needs more money, and succeeded in changing the ratio of supply and demand of euros. That made the euro less valuable, which was the point. But the relative value of currencies is determined by how much you can buy in the same currency: for example, if one television costs 1,000 euros or 1,000 dollars, and that television were the only thing that was traded between Europe and the USA, the exchange rate would be 1:1. But if the value of the euro falls and the television costs 2,000 euros now, the exchange rate will change to 2:1, and we will say the dollar "gained value" or "strengthened" against the Euro, or that the euro "lost value" or "weakened" against the dollar. But as you can see, if Europe is in a recession they *want* the euro to be "weak", because then Americans will buy European televisions (which gives Europeans work to do and revives the European economy) and Europeans won't buy American televisions (which doesn't help the European economy unless the Americans they bought them from spin around and immediately buy something from Europe).
How is that? Is that too hard for ELI5 or too simplified? | 260 | 487 |
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How can foods labeled "Refrigerate after opening" stay on a shelf for extended periods of time without spoiling but then must be refrigerated after opening to prevent spoiling? | The short answer: exposure to air (and external moisture) after initially opening many food items often jump starts the growth of bacteria and/or mold. Many foods are vacuum-sealed; removing excess air/moisture other than that present in the food itself. Temperature is another major factor for growth of bacteria.
Interestingly, while almost all foods’ shelf-life does benefit from being refrigerated, it’s not always necessary even if labeled to do so. Jams, jellies, and preserves are a good example; certain dairy butters are another. If you go through a jar of jelly or stick of butter in say, a month, you don’t need to refrigerate it. | 20 | 22 |
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