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[Fallout] What was the actual point of the Vaults? | The US at large knew the world was most likely going to go down in a nuclear hellstorm, but, rather than have Vault-Tec build a bunch of safe shelters, so a good chunk could survive the initial bombs, they went with saying that, then using the Apature style, basically if humanity somehow hadn't survived the initial blasts outside of the vaults, all that would be left is whatever "control" vaults, or the few vaults that had stupid tests that weren't deadly/mutagenic/brainwashing to insanity ,contained, because some morons at Vault-Tec decided to use them for SCIENCE! instead of what they were actual meant for.
So what was, as said, the point? it's clear, so far at least, that there is nobody left to Collect the data. | While many of the vaults have experiments running, the majority where "safe" tests and not expected to last for centuries. In addition there was a number of control vaults, and vaults specific for certain groups ment to survive the war.
Vault-tech's "plan" isn't coherent as it is a company run by many people with conflicting desires and obligations; but the long and short of it is to build test vaults to fund and do testing for the actual goal of leaving earth with the survivors of the actual vaults (who collected and researched that data from the test vaults and the wasteland).
Unfortunately they took too long and the war started earlier then they expected and was too disruptive to their infrastructure. Many of the actual vaults became groups like the enclave, but others would continue until their discovery centuries later, mostly by the master his supermutant armies | 34 | 24 |
ELI5: How does exercise boost energy levels? | Regular exercise makes your muscles and your heart stronger. When you're stronger, it takes less effort to finish your regular day-to-day tasks. This makes it seem like you have more energy leftover after doing your regular tasks. This goes for intentional physical activities as well as just being alive (I.e. having a beating heart).
It may help to think of this in reverse. If you're in great shape, you get used to doing a lot during the day. If you were suddenly out of shape, you'd have difficulty keeping up with your former, fit self. | 4,854 | 9,703 |
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What causes us to 'auto-breathe', and why do we have to consciously take breaths when we think about it? | Unconscious breathing is regulated by the brain stem by monitoring the pH of the blood. Too much carbon dioxide, causes a disruption in the equilibrium causing some carbon dioxide to react with the water in blood creating carbonic acid, which lowers the pH and increases your breathing rate to expel more carbon dioxide. Lactic acid generated by extensive muscle use also decreases pH causing increased breathing rate. The actual process is actually pretty complicated and there are multiple pH chemoreceptors around your body (brain stem, near the carotid artery, along the aortic arch). These chemoreceptors then send the appropriate signals along nerves to the diaphragm, the muscle that expands and contracts your lung cavity.
In terms of conscious control, it's the same as with any other muscle in your body. | 16 | 16 |
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Are electrons running through electrical wires bound to any atoms? Or are they just free-flowing? | High school chemistry taught me that electrons exist as part of the "shell" of an atom. Whenever we spoke about electricity in physics class, I always got confused; how can these electrons just be flowing by themselves? Do they not need some sort of atom to exist within? | Electronic orbitals get a little more complicated when you are dealing with a solid rather than a single atom. High school chemistry only really taught you about isolated atoms. The lower electrons bound closer to the atom's nuclei are indeed fixed there. These do not contribute to electrical effects. It's the valence, or outer electrons, that come into play with electricity.
 
When you throw a whole bunch of atoms together, the atomic orbitals you learnt in chemistry no longer exist. Because of the pauli exclusion principle (the reason why in chemistry two electrons can't share the same orbital) two electrons cannot hold the same state within the solid. This leads to what are known as electronic bands, rather than orbitals.
 
Basically, when you throw two of the same atom together the valence electron states cannot overlap. This leads to two new states very close to the isolated atom energy level, but slightly off and not overlapping. Throw a few billion billion billion atoms together and you basically get a continuous bands of allowed energy levels. The bands are really made up of a lot of discrete possible states of energy and momentum that electrons can uniquely hold, but we treat them as a band. These bands really aren't localised to an atom, their wave function is more so for the composite solid.
 
Now just like an isolated atom has higher unfilled orbitals that an electron can be moved up into by addition of energy without being totally ionized from the atom, there are higher unfilled bands in solids that electrons can move up to given energy without being ionized. These higher unfilled bands have lots of empty states to any electrons that move up into them, so they facilitate electrons moving around. Which is what electricity is. So in electricity the electrons aren't bound to any specific atom, but they aren't ionized and totally free. They are just in a higher energy level, with a lot of very close by empty energy levels, which allow them to move between them freely.
 
In metals the valence band, the band with all the bound electrons that aren't free to move, overlaps the conduction band, the band of mostly empty states where electrons can freely move. This means in metals it takes basically zero energy to get electrons to hop up into the conduction band where they can move about. Simply applying a voltage is all it takes to get lots of electrons to move.
 
In insulators the story is a little different. The valance band, where electrons are at rest, and the conduction band above that have a high energy gap. That means it takes a lot of energy to move an electron up. Very few electrons are free to conduct because of this, so they are poor conductors. The only way to make them really conduct is a very high voltage, which will give the electrons so much energy they will be pulled away.
 
Lastly there is semiconductors, which are the basis of electronics and computers. These are the same deal as insulator, but the energy gap is much smaller. This means at room temperatures, the thermal energy is enough to cause a useful amount of electrons to jump the gap into the conduction band. As well as the electrons that move up to the conduction band being able to conduct electricity, the empty space they left behind in the valance band allows other electrons that aren't moved up to fill their place. In essence, this empty place constantly being filled by electrons appears to move, so we actually treat it as a positive particle known as a *hole* that conducts electricity too. We can alter this energy gap with impurities, which is crucial to making electronics fucntion. Other things can cause the electrons to jump this gap, such as visible light photons giving them the energy. This is the basis behind solar-cells. | 11 | 26 |
ELI5: why is it that so many animals have their brains in their head, rather than anywhere else in their body? | Simply, the speed of transmitting information from the senses to the brain and back encourages a central nervous system that is focused on the primary sense gathering organs. Eyes, Ears, Nose.
From there it's an evolutionary advantage having those in an optimal position to gather data, or a head. Different species have different locations of not only their heads, but also their sense organs. Fish and horses for example have eyes on the sides of their heads, while most mammals have forward facing eyes. That's a bit of an aside, but it does go to show that their are evolutionary advantages to different configurations. | 57 | 34 |
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[Death Note] If you're a human who is immune to heart attacks... | Should the death note be ineffective against you? I mean,I'm aware you can make the person die in other ways by detailing it,but if you're immune to the default kill,it seems like you should be immune to the note altogether.. | How would you be immune to your heart failing? It's a muscle that relies on a great many things to go right. A slight blockage, inflammation, tear, or electrical disruption is all it takes to bring the whole system crashing down. | 58 | 34 |
Where does bubble gum flavor come from? | Flavoring chemicals, likely esters and aldehydes, possibly with actual fruit oils or extracts. Exact recipes are hard to come by, but basically it's a combination of things that smell/taste somewhat fruity, without mimicking any particular food. | 68 | 196 |
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ELI5: Why does memory come in specific sizes? (i.e.8 GB, 16 GB, 32 GB, 64 GB, etc)? | Sorry if it's a newb question, I just want to know.
And memory is in the ones on SD cards, MicroSD cards, harddrives, etc.
Thanks! | Memory takes more than just the physical space. You also have some sort of controller which takes read and write request and applies them to the memory. This controller handles the address of the memory you want to access.
Every byte must be accessible, so they need an address.
You controller will handle a certain amount of bit for an address.
If your physical memory is just 2 bytes, 1 bit of address will be enough. The first byte could be addressed with a 0 and the second with a 1.
If you now add a bit to your address you can address 4 different bytes as:
* 00
* 01
* 10
* 11
If you add another bit to the address you can already access 8 bytes. This is exponentioal growth with 2^x where x is the amount of bits available.
At 30 bit of address you can access up to 1gb of memory. With 31 you can access 2gb of memory... etc. Since every bit you process for addresses doubles the possible access space you get those 1,2,4,8... numbers.
Now why waste valuable address space by not having the possible physical amount? You would also have to handle the possiblity, that the computer will send you an address which will still use only as many bits as your memory expects but at the same time lies outside of the physical memory. That sort of exception has to be handled aswell. Every non 2^x value needs his own controller which knows the max limit for his address space. It is easy to generally just ignore additional bits after a certain one (for example you can just ignore the last bits and start from the beginning). This isn't so easy to do when you have to check if it is bigger than a specific 1-0 sequence.
That specificly built controller is probably more expensive for the manufacturer than just build in a bit more of memory especially since more memory will also sell better. | 49 | 74 |
[General] What exactly does "Selling Your Soul" to a particular deity entale? | so I sold me soul to a deity. What does this mean? Do I have to do everything they say? Do I go to their domain when I die? Bonus question: what can one usually get in return from selling their soul? | For good, firm detail on the contractual ins & outs of the negotiation process, read Christopher Marlowe's play *Doctor Faustus* or, if you've got the intellectual stamina for it, Goethe's novel *Faust*.
Preferably while listening to the incredible krautrock band Faust. | 31 | 69 |
Is it legal/valid to assign variables to infinite sums? | My dad who studied math involving infinity in college claims that you can't go assigning infinite sums to variables willy nilly, for example saying g = the sum to infinity of 1-1+1-1+1-1... is illegal, as the sum doesn't converge.
Have maths changed since the time of his studies (~30 years ago)? Has his mind ripened, so he's plain wrong? Where is the line drawn to where you can assign sums to variables? | You can be as formal as you need to on a whiteboard, provided you know what is necessary to make your argument formal. If you introduce a variable equal to a sum whose convergence you don't want to address now, the convergence becomes a hidden assumption which, if false, tanks your whole argument. Your dad saw this and decided not to even listen to whatever you were going to say about "g."
Give him a fist bump for me. | 47 | 59 |
Why don't dogs recognize their reflections? | I would like to point out that humans gain this ability at some point between ages 2 and 5.
There is a common test for this ability, place a dot on someone's forehead, then place them in front of the mirror, if they reach for their own head, then they recognize that they are the same as the person in the mirror. Not very many animals can pass this test. | 27 | 36 |
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How does a wave function change after scattering? | I'm trying to understand scattering theory in QM a little better.
What I'm trying to ask here—in more detail than the title—is how can the wave function be calculated after a scattering event? More specifically in the context of Compton and/or Thomson scattering. | In non-relativistic scattering theory, you just consider an incident plane wave, and an outgoing spherical wave, which has been modified by the interaction potential.
If you assume the incoming particle is moving in the z-direction, you can write the total wavefunction as:
ψ(**r**) = e^(ikz) + ψ*_s_*(**r**),
where e^(ikz) is the incoming particle, and ψ*_s_* is the scattered wave.
The scattered wave can then be written as:
ψ*_s_*(**r**) = f(θ,φ)e^(ikr)/r.
This has the form of an outgoing spherical wave which has been modulated by an angle-dependent factor f. f is called the scattering amplitude, and |f|^(2) ends up being the differential cross section.
To find what this function actually looks like, you just solve the time-independent Schrodinger equation for whatever potential is mediating the scattering.
To treat something like Compton scattering, you don't really want to use non-relativistic QM, but rather QFT. In QFT, you don't generally work with wavefunctions anymore, but you can still calculate S-matrix elements and cross sections. A common way to do this is using time-dependent perturbation theory, and Feynman diagrams. | 566 | 2,065 |
ELI5: We’re always taught to never pull a sharp object such as a knife out of someone who is stabbed. How exactly do medical professionals pull it out then? Would they have to pull it out the same way anyway? | It's all about setting and training.
An untrained bystander with no medical equipment pulls a knife out of a stab wound, the knife is no longer keeping the blood in and the victim will bleed out faster.
A surgical team with medical equipment pulls it out and can get the veins sewn together and close the wound before the victim bleeds out.
That being said it is still risky even for trained professionals. They have to act quickly to avoid killing their patient. | 106 | 33 |
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ELI5:after losing some blood, the body starts replacing that blood, how does it know that it has already finished replacing that lost blood so it could stop making more? | Special cells in the kidneys, called peritubular cells, sense that the level of oxygen in the blood has decreased (due to the loss of red cells) and start secreting a protein called erythropoietin. This passes through the bloodstream until it reaches the bone marrow (the soft fatty tissue inside the bone cavities).
The bone marrow produces stem cells, the building blocks that the body uses to make the different blood cells – red cells, white cells and platelets. The erythropoietin sends a message to the stem cells telling more of them to develop into red blood cells, rather than white cells or platelets.
Your body makes about 2 million new red cells every second, so it doesn't take long to build up stores of them again.
What about your white cells and platelets? A number of other messenger proteins also stimulate the production of these cells in the bone marrow, and over the next few days levels return to normal. | 515 | 1,408 |
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How is it that we know an electron's mass but not it's size? | http://www.reddit.com/r/IAmA/comments/mateq/i_am_neil_degrasse_tyson_ama/c2zg74j
Following Neil deGrass Tyson's great AMA, how come we can measure the mass of a particle yet can't measure it's size? | Imagine two cars take the same turn at the same speed. The heavier car is going to turn more widely through that turn. Well we can use electric and magnetic fields to measure the mass of charged particles by measuring how much they turn through the field at a given speed.
But how do you measure the size of a thing? On every day scales you put a ruler beside it and see where the edges of the thing line up to the ruler you have. For smaller things, we shine light on it and then pass that light through lenses to magnify the image of the light. But this process is limited by the fact that light has a finite wavelength. And you can't really measure smaller than the wavelength of light.
So in particle physics what we do is go to smaller and smaller wavelength *probes*. Imagine you had a statue in a room and you wanted to measure it. But your only tools are a variety of balls from sports that you can bounce off the statue and look at how they 'scatter'. First you could bounce basketballs, and these would tell you maybe you have some kind of columnar object in the center. Then you go to baseballs, and you get some structure about arms and maybe a neck. Then you go to golf balls, then bbs, each smaller ball telling you more fine detail of the structure.
So how do we get small wavelengths in physics? Well, wavelength of a particle is inversely proportional to its momentum. So small wavelengths need high momentum probes. So we build particle accelerators to ramp up electrons or other particles to very very high energy (and thus very high momentum). Then we use these particles to scatter off of other things and look at how they scatter off to determine its structure. We were able to "see" the quarks in a proton by scattering electrons off of protons at very high energies.
Well it turns out that even at the highest energies we're able to probe at, the electron is smaller than that size. The present version of the theory treats all the fundamental particles (quarks, electrons, neutrinos and the like) as being "point" particles, having no intrinsic volume or size, and we haven't seen any evidence to indicate that they do have a size. | 153 | 37 |
ELI5: How can scientists create measuring tools more accurate than the tools we already have? Doesn't the accuracy of new tools depend on the accuracy of the tools used to make it? | There are methods for creating accurate without already having an accurate thing.
Like finding the mid-point between two points. Attach a pencil to a string and attach a string to a needle that you stick at point A. As long as the string is more than half the distance to the second point, you can can draw a large arc with it.
Then repeat the process from the other point. There will be two points at which the arcs intersect. If you draw a line between those points and draw another line between the two original points, you will have accurately determined the mid-point using "in-accurate" tools.
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Eli5: How does a single cell multiply into exact copies of itself yet somehow knows to start building into different body parts? They are all in the same environment with the same DNA yet behave differently. | Each cell has all the DNA, however based on external signals the cell activates certain enzymes that read specific DNA to become whichever organ.
Theoretically, you can introduce a reading enzyme from a liver cell to a heart cell and that enzyme will read the heart cell DNA to make liver stuff. | 15 | 25 |
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ELI5:Why are all "As Seen on TV" commercials so similar to each other? | These companies carefully study what works -- even trying different versions of an ad to see what brings in more orders.
What you see now is the optimal format -- the one that brings in the most orders -- so everyone tries to use it. | 12 | 23 |
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Why are copper and silver so effective against bacteria, fungi, and viruses? | /r/science submission [here] (http://www.reddit.com/r/science/comments/1omy0l/researchers_have_discovered_that_copper_and/)
[Recent paper in PLOSone] (http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0075017)
What do copper (and silver) do to have such a broad ranging antimicrobial effect?
There are a lot of potential mechanism listed on the [wiki page for the antimicrobial properties of copper] (http://en.wikipedia.org/wiki/Antimicrobial_properties_of_copper), and it seems to be a developing knowledge area.
Larger life forms don't seem to be as affected by these metals, why is that? Any recent developments in the literature on the issue? | Engineer here that works with copper silver disinfection systems in hot water loops.
We use a method known as copper silver ionization, which adds charge to copper and silver ions. The positive charge of the ions attracts it to the negative wall of a bacteria. Copper weakens the wall which effectively allow silver to come in and cause cell death. Both are okay on their own, but together their effectiveness is much greater.
You can almost think of it like an american football offensive team, with copper being the linemen, and silver being the running back. Alone they can only function just alright, but together they are extremely powerful.
We fight Legionella, Pseudomonas, and other waterborne pathogens this way.
EDIT: added football analogy | 83 | 392 |
Is sociological privilege distinguishable from a persecution complex? | Social injustices occur, for sure. One of the main arguments I hear about privilege is that the majority simply cannot experience or understand it, and need to take the notions of their privilege on good faith from the underprivileged minority. This got me thinking though: how can we (either the majority of the minority) tell the difference between an actual, existing privilege, and from an illusion of one, born from a minority with a persecution complex?
It seems to me that in both cases, a main tenet proposed is that the majority is blind to the privilege. Whether this is a real or perceived privilege is what I'm not sure how to tell. Certainly both can cause social injustice. So, for example.
Take an actual privilege case. A cop pulls over a car, notices the driver is black, and is stricter with his check than if it had been a white person he pulls over. Because this person is black, he's more open to scrutiny.
An example of illusory privilege may be a black person getting pulled over by a cop, and perceiving it as a persecution because he's black. Subconsciously, this affects his language and body language, albeit subtly, and the cop can pick up on it, and feel threatened and do a stricter check. Because the black driver perceived a threat that wasn't there, a threat manifested itself and actually occurred. In this instance, it's a self fulfilling prophecy.
I was wondering how--if at all--sociologists are able to distinguish between the two. Does it even matter? I suspect they'd warrant different resolutions, but maybe they don't. | First, two issues:
One is that you seem to be trying to analyze this primarily (or totally) from an individual level of analysis. Individuals can "have privilege" in the sense that they as individuals accrue advantages due to privilege but privileges are ultimately social in nature - the individual accrues the advantages because of their membership in some social group or category.
Two is that you seem to be confusing privilege with discrimination. Being pulled over because of your race is discrimination. Not being concerned about whether you were pulled over because of your race is privilege.
Second, sure, responding to being pulled over with nervousness or hostility because of perception you were singled out because of your race might explain some amount of disparate treatment of racial minorities (to continue the focus of your examples). However, it's not really a paranoia/persecution complex if they're really out to get you. We know that the driving force of discrimination isn't minority paranoia because there is a significant amount of evidence that can clearly show us it is not. For example, studies that look at the percentage of drivers of different races who break the law and then comparing the percentage of drivers of different races who are pulled over (see, for example, Lamberth's Driving While Black study). Racial groups aren't being pulled over at different rates because of differences in driving styles/behaviors - they're being pulled over because of differences in physical appearance. | 16 | 18 |
Does a photon have to be absorbed in order for it to have been created in the first place? | Inspired by this: http://www.reddit.com/r/askscience/comments/of8pf/when_a_photon_leaves_a_star_what_are_the_odds/c3gtsbc
I say that a photon can be emitted if it is not absorbed. yel02 disagrees with me.
I did a quick google search but didn't find an answer. It seems obvious to me that photons don't care about whether or not some mass is there to hit but I'm more than open to a good explanation as to why I'm wrong. | A little bit about quantum mechanics that's important to understand:
The real physical object is the wave function. A particle is only the manifestation of the wave function when it gets collapsed (when you observe it).
Therefore, the wave function of the photon exists regardless of wheter it is observed or not ( being absorbed is being observed ). The photon itself only exists when the wave function is collapsed, hence when it gets absorbed. | 29 | 70 |
Are there ocean dead zones where there is little or no life activity? If so why do they exist? | Absolutely.
Consider a typical oceanic water column of about 3.5 km. The overwhelming majority of living critters are found within the photic zone, which ends at an average depth of about 200 m. Within this zone, all of the necessities of life are present: an energy source and nutriments. However, light from the sun cannot reach beyond this 200 m zone, so biological productivity decreases abruptly. Still 3.3 km to go.
Some critters will spend part of the day below the photic zone and have a daily vertical migration to get to rich food sources from the surface, before retreating to deeper waters where the likelyhood of predation is reduced. A lot of these daily migrators are plankton sized, and stay within a few hundred meter of the photic zone.
Below this, life is scarce. It is not quite a dead zone in the formal sense of the word, but the combined presence of some of the more basic necessities of life (nutriments and an energy source) is not there. Consider this a biological desert. The main source of food is dead organic matter (mostly plankton) raining down from the surface. This may be degraded by bacteria on the way down, which may take a few days. Significant food resources, such as whale falls, are scarce and just "passing through".
Next stop is the ocean floor, 3.5 km down. Here is the final resting stop for that rain of organic matter from the surface. This allows for the (relative) concentration of this organic matter in a single locale. There is more life here than in the intervening 3 km between here and the surface. The food chain for the most part depends of this rain of dead plankton; this is the land of bottom feeders and detritivores, with a few predators which pick upon the benthos.
Very locally, you'll find extraordinarily lush oases of life tightly clustered around hydrothermal vents. These are exceptional, and constitute a parrallel food chain where the input of energy is not from the sun (no matter how far removed) but from chemical energy transported by the Earths heat transfer system. A lot of these critters depend on symbiotic relationships with specialised bacteria and archea, and live off methane, sulphate, sulphuric acid, or some other energy source.
So, in retrospect, you'll find that most of the water column, from a few hundred meters of the photic zone to the ocean floor, is pretty much a biological desert with little biological productivity. | 25 | 15 |
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CMV: Hiring a Real Estate Buyer's Agent Will Cost you More Than Purchasing a Home Without a Buyer's Agent | I hear repeatedly that I should hire a realtor to represent me when purchasing a home. I hear that a buyer's agent will work hard for me and will help me get the best deal possible on my home purchase. My logic says that this isn't true.
Given that a buyer's agent will make 2.5% to 3% of the home's price in commission. **Isn't the buyer's agent incentivized to get the buyer to pay more for the home instead of less since this will increase the commission? And so wouldn't hiring a buyer's agent be detrimental to me getting the best deal on a home purchase?**
Please change my view! Thanks!
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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!* | An agent will know all the ins and outs of the industry and you don't know any of them. It's in their best interest to get you a house you like as quickly as possible and to get it for you at a price you like. This serves a couple of goals. The first is the faster she gets you a house you like the sooner she can pick up another client. This means that instead of you spending a lot of time searching she will find houses that fit your requirements in a timely manner. Realtors also rely heavily on word of mouth. If one isn't working to get you a good deal word will get around. Not to mention the fact that you can refuse to buy a house if your realtor isn't getting you the deal you want. | 14 | 20 |
ELI5: How do allergies develop in kids? | Basically, the body encounters something it hasn't encountered before. It usually is a foreign protein. The body encounters it and thinks that it is something bad that is trying to harm the person. The body then creates an immune response to protect the body. The next time the body encounters this allergen it reacts as if it is trying to harm the body, leading to an allergic response. This often means massive release of histamine which can cause swelling of the lips, tongue, throat, and gut in the case of a serious anaphylactic reaction.
​
Source: Am doctor. | 24 | 42 |
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Eli5: Why do we study Limits in Calculus? | Calculus, both integral and differential calculus, is based upon limits. We don't actually reach our answers but we get infinitely close to it. You can't calculate instantaneous rate of change (the value of the derivative) without using two infinitely close points. Well, you *do*, but not without using limits to derive that ability. The rules of differentiation can be derived (no pun intended) by taking the limit as delta approaches zero blahblahblah you know the rest. Similarly, when calculating area, you're actually calculating the sum of an infinite number of rectangles. As you approach an infinite number of rectangles, you approach the actual area under a curve. | 17 | 16 |
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Could a cosmic ray set off ammunition or explosives? | I've read about how cosmic rays can cause errors in computers.
I've also read about how they can damage genetic information.
This got me to thinking.
Could a cosmic ray set off the primer in a cartridge, resulting in a bullet firing unintentionally?
Or could a cosmic ray unexpectedly cause explosives to detonate?
I'm guessing it would come down to the amount of energy a cosmic ray could potentially deposit and how it interacts with something it passes through. But I don't know much about either of those things. | You may have read that cosmic rays have very high energies. That's true, but incomplete: they have very high energies *for such a small particle*.
They can cause errors in computers because transistors have been scaled down to microscopic levels, so the ionization caused by cosmic rays is meaningful at that scale. They can damage genetic information because the DNA molecule is storing information at scale of a few atoms, so if ionization breaks the molecular bonds then atoms may recombine in weird ways.
But at a macroscopic level their energy is negligible.
Ok, there's an exception to that. There are some *ultra high energy* cosmic rays where a subatomic particle may have an energy equivalent to a fast baseball. That's really a lot, but at the same time, higher energy particles traverse matter almost unaffected, depositing only a very small part of their energy.
So no, they can't cause a bullet to fire and they can't detonate an explosive.
> the amount of energy a cosmic ray could potentially deposit
Lower energy cosmic rays are the ones that deposit more energy in matter proportionally to the distance they travel, and it is negligible at a human scale.
> how it interacts with something it passes through.
Matter is made of atoms, and atoms are full of electrons. When it passes through it kicks electrons off their atoms. This may cause weird recombination and modify molecules such as DNA. It can also collide with an atomic nucleus moving it out of its place - it implies something for highly sensitive electronics but not much for humans.
Also note that these things about errors in computers and damage to DNA are mostly a concern in outer space, but fortunately on Earth we're protected by the atmosphere. The radiation level we receive on the surface is low enough to say we don't have to worry about it.
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CMV: Yoga is beneficial for the mind and body. It should be a part of school gym classes. | Hear me out—I’ve gotten a lot of people saying that advice from yogis is bunk, and that it’s a lot of “woo-woo.”
I got into a discussion on another thread about how yoga releases fixation in the joints and prevents them from fusing over time. I am an acrobat and I experience the same pleasant popping sensations in my joints when warming up for aerial work.
Here’s my view. Yoga is a 5,000 to 10,000 year old art, depending on what source you look at. Old yogis remain mobile and flexible well beyond an age that would leave most sedentary people practically bedridden. Medical science may disagree with the *mechanisms* for why yoga works, but the results have been proven. It increases mobility and strength, reduces stress and mind wandering, and can fight depression and even chronic pain.
Gym classes in the US are poorly regulated, and include competitive games that [teach kids about winning ](https://slate.com/technology/2013/05/reform-physical-education-gym-class-shouldnt-require-team-sports.html) instead of being active and healthy. On top of that, the methods taught for stretching and warming up are in direct conflict with what health professionals recommend.
TL;DR — Yoga isn’t woowoo. It’s supported by medical science and it’s a time-tested tradition. It should replace *some* of things that exist in gym classes, like static stretches and even competitive sports that cause injury and stress. | Yoga is intrinsically tied to Hinduism (or at the very least Dharmic religions). Keeping it in a curriculum, however mild, would violate the strict secularism that has been a feature of public schools.
OTOH Whitewashing away the Hindu aspects would be indirectly denigrating the Hindu culture. Sure it is fashionable amongst a bunch of people including many self hating hindus to whitewash away this connection, but is that the unconscious bias you want to embed in children? | 12 | 29 |
Why can water undergo electrolysis despite being covalently bonded? | Ask my chemistry teacher, she had no clue. | With two hydrogens on one side and one oxygen on the other, water is a polar molecule. This makes it a great solvent and also allows you to divert a running tap using a statically charged rod. By applying charge across the water, you pull apart the molecule.
The ions then travel through the water to the electrodes and donate/acquire an electron, bonding to similar atoms in their elemental form and bubbling out as a gas.
TL;DR there is a charge differential across the water molecule. | 33 | 176 |
The element Oganesson has the highest proton count of any element , what is stopping us from artificially adding a proton to it to see what new element we have created? | I know that adding new protons to an element has been done before but that it is very expensive and usually produces a radioactive element but surely it would be worth the cost and risk to see what goes beyond the Oganesson? | All of the nuclides which are easy to produce using currently existing facilities have been produced already. Given the way that Oganesson has been produced so far, it's not easy to just shoot another proton at it (or shoot it at a hydrogen-rich target) and measure the reaction products. The superheavy nuclides we've discovered have lifetimes on the order of milliseconds or so, which *is* long enough to run experiments with. But it would be very technically challenging to do the experiment you're suggesting.
These superheavy experiments run for a month or so at a time and hope to see *a few* events where a new element was produced. They are typically produced using low-energy fusion reactions. So you would either have to slow down the superheavy nucleus and bombard it with protons, or you have to speed up the superheavy nucleus and shoot it at a plastic target and hope it picks up a proton. These kinds of experiments can be done in principle; this is often how radioactive beam experiments are done. But if you get a few counts a month of the original superheavy nuclide, and there's a very small probability of proton capture, the experiment would take way too long to see any valid events.
There is no existing facility that could perform an experiment like that in a reasonable amount of time. You'd be much better off just trying to produce element 119 directly in the fusion reaction with some different combination of beam and target. | 34 | 32 |
Are modern encryption techniques (like 256-bit SSL encryption) more complicated than ciphers used in WWII (e.g. Enigma)? By how much? | I understand the *basics* behind encryption of messages, and thanks to a recent analogy posted (I think) on reddit, also understand the basics behind how one-way hashes are created (but cannot easily be reversed).
How do modern encryption techniques compare to those used by the English/German militaries in WWII? Are new encryption techniques simply iterations on existing methods (linear improvement), or completely disruptive changes that alter the fundamentals of encryption? | SSL relies on a mathematical technique that was unknown to militaries until the seventies.
That specific technique was public key encryption, and the first (known, declassified) instance of a military using PKI was in the 70s in the UK, at the GCHQ in 1972. Diffie and Hellman also discovered the same technique as the GCHQ in 1976, but their work was out in the public domain, so it was used in a non military context immediately after.
What's interesting is that the idea of "easy to compute, hard to invert" had been thought of in the context of cryptography and number factoring sometime in the late 1800s, but it was never theorized that the two could be logically combined.
SSL relies on the RSA algorithm, which was invented in 1977 and again, in private by a mathematician in the employ of the GCHQ in 1973.
At the very minimum the public key infrastructure of SSL would've been something unknown to militaries in the 40s, whose keying systems were essentially just moving the keying information down from location to location. With Diffie Hellman key exchange, you can generate a shared secret over an insecure channel, and with RSA, you can encrypt messages with public keys that are distributed beforehand (in practice, you just encrypt the session key with RSA, and then use a standard block cipher). Being able to not have to physically move your key around is a sea change from the 40s: captured key books were a common source of Enigma cracks.
Block ciphers would've probably been more familiar to mathematicians of the 40s, but the first known (unclassified) example of a modern block cipher was with IBM's Lucifer in 1971. As you can see, almost all modern cryptography is now based on math that was developed in the 70s. That's not very surprising given that all modern crypto now relies on computers instead of electromechanical devices and scramblers which were de rigeur during the 40s, 50s and 60s. | 215 | 280 |
Given that many universities are facing financial hardship what should we expect the higher-ed landscape to look like in the future? | Hampshire College is now considering a merger to stay afloat.
Are partnerships going to become a common practice? | We should expect things that absorb resources but don’t contribute to the bottom line to be excised, and not just academic departments. You’ll know things have gotten really really bad when it’s been a decade or so without any new sports facilities being built or majorly renovated. | 32 | 38 |
ELI5: Could some Canadian companies actually benefit from a drop in the value of the Canadian dollar? | I was shopping around for computer parts, and it looks like it could actually be cheaper for me to buy from NCIX (Canadian company) rather than a US based company.
If the Canadian dollar dropped low enough to where Americans were ordering from Canadian companies rather than US companies, would this extra business actually benefit Canadian companies despite the currency not being as valuable as before? | Absolutely, falling value of currency can definitely help companies which seek to do international business. In fact some countries, like China, purposely keep their currency value low, so that their companies are more competitive. | 29 | 52 |
[Bioshock] What were the requirements for living in Rapture? We're people banished? And could outsiders possibly move there? | You needed an invitation, which required you to be one of the best in your chosen line of work.
No, people weren't banished. They were locked up or executed though depending on the severity of their crimes. | 25 | 27 |
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Why is nature comprehensible to us? | I went from a physics program straight to a philosophy graduate program and so likely missed out on the relevant literature, but I can't seem to find it on the SEP. So as to make my question more precise, it was motivated by the following two sentiments:
> It is precisely the common features of all experiences, such as characterize everything we encounter, which are the primary and most profound occasion for astonishment; indeed, one might almost say that it is the fact that anything is experienced and encountered at all. (Schrodinger)
and,
> One may say the eternal mystery of the world is its comprehensibility. (Einstein)
That is, we find enough reason to be astonished that, say, abelian gauge theories like quantum electrodynamics offer so precise a framework for predicting and interpreting the time evolution of natural systems. But that we are able to come to this knowledge at all, or even to knowledge of the ordinary objects of experience, seems even stranger. Are there philosophers who approach this question in any manner?
| what is "nature"? what is not nature?
Kant divides our cognition into sensibility (providing access to experiences) and understanding (or intelligence related to those experiences). the phenomenologists and Merleau Ponty particularly collapsed these two, arguing that all comprehension of the world is subject to the perceptual process that creates a "lifeworld" of lived experience for the individual.
"nature" is interesting to consider in that context, because we can ask what is natural and what isn't? philosophy of science (Kuhn and Midgley for instance) has done a lot of work to critique whiggish, objectivist accounts of sciences as providing progressively improving and pure descriptors of nature, and instead argues that the products of science (the sort of sense-experience we get from it) are both convenient and perfectly natural human constructs.
science and technology are constantly redefining what we perceive as "natural," whether in the social sense or the "natural sciences" sense, since they are involved with expanding the scope and nuance of our lifeworld. as we articulate the natural world via science or "conquer" nature via technology, we pacify its raw strangeness, subjectifying what is otherwise incomprehensible. so comprehension also has to do with power. a pheonomenologist like Dylan Trigg might argue that nature in-and-of-itself is a horrifying abstraction beyond our comprehension, so this is why we invent our own means of interpreting it (think Bowker and Star's work on classification or Foucualt's The Order of Things) | 14 | 32 |
ELI5: If my headphones have only 4 connections, how can it play stereo sound, have a microphone and three buttons (vol. up/down and pause)? | This is the one: http://www.amazon.com/Samsung-3-5mm-Stereo-Headset-Galaxy/dp/B00F9G20LM/ | By multiplexing- this simple multiplexing circuit uses a different value of resistor for each of the buttons. The processor on the receiving end takes different actions depending on the resistance it reads down the wire. Press button one and a 200 ohm resistor is connected across the multiplex lines, press button two and a 470 ohm resistor is connected across the multiplex lines, etc.
Less ELI5: This is technically done by using a reference voltage to measure the voltage drop across a pair of resistors, but that's a bit more that is needed to explain. | 19 | 47 |
How does the body react to food after prolonged food deprivation. Will eating even a normal portion of food cause stomach aches or other adverse reactions? | Food stimulates the pancreas to produce a hormone called insulin. This hormone has various functions, including lipogenesis (creation of fat) and glycogenesis (storage of sugar in the form of glycogen). Some resources are needed in order to make these processes happen, but a prolonged period of fasting depletes the body of them. So, in the end, the cells “pull” too much of those minerals from the blood, causing low phosphate presence in blood (hypophosphatemia), low potassium (hypokalemia), and others. That usually leads to various cardiac and neurological problems.
This is referred to as refeeding syndrome, and has been documented for a long time throughout history. | 12 | 16 |
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If 128 people pick a number between 1 and 64, what's the probability each number gets picked at least once? | The # of ways to pick should be equal to the # of onto functions from the set of people to the set of integers 1 to 64. This requires applying inclusion-exclusion.
The prob. is then that # divided by the total # of functions 64^128.
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It seems that the # of onto functions can be calculated with the help of the Stirling numbers of the second kind: 64! * S(128,64) | 14 | 29 |
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ELI5: Definition of a parsec for an amateur astronomer | 3.26 light-years or the distance of an object where the orbit of the Earth around the sun creates a visual **P**arallax of one **ar**c**sec**ond
Parallax is the difference in apparent position of an object viewed from two different spots like how an object shifts a bit when you look out just your left eye is just your right eye. You can measure the difference in the angle when seen from both spots to determine the parallax angle. The smaller this angle the further away an object is(this is how we tell distance with our eyes at short to medium range)
For a Parsec, these two measurements are opposite sides of the sun, exactly 2 AU(Earth's orbital diameter) apart. If you can set the angle difference between these two measurements to be 1 arc second then they're focused on an object 1 Parsec away (~3.26 ly) | 27 | 26 |
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Why can humans cross their eyes but not do the opposite? Make them look outward. | You can cross your eyes because that's the action required to look at an object which is very close to you. You can see this by focusing on your finger and moving it towards your face; you'll end up with crossed eyes.
However, no matter how far away an object is, you'll only ever need both eyes pointing in exactly the same direction; you'll never need them pointing apart, and so there's no reason to be able to do that. | 41 | 31 |
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ELI5: What does the "ion" button on fans do? | I mean, I was told that it ionizes the air (whatever that means?), but does it actually have any benefits of turning it on? | The benefit is that ions help to remove dust from the air.
The air purifier releases negatively-charged ions into the air. Dust is positively charged, so the dust and ions attract each other. This operates on the same principle that makes CRT screens attract dust -- the screen has a negative charge from electrons hitting it.
Once enough ions attach to a dust particle, the whole thing becomes heavy enough to fall to a table or other surface. Then you wipe the dust off the surface. | 28 | 44 |
CMV: The universe is completely deterministic and thus we have no free will. | I can see that all atoms behave according to physical laws. Given any small system and enough information about said system, for example a box with 10 atoms in it with every atom's position, velocity, and acceleration at t = 0, we can say what their state will be at t > 0. I see no difference to this and our bodies and the larger universe around us. We are made of atoms and behave according to the same laws that govern every physical body in the universe. Furthermore, this means that any choices you think you make on a day to day basis are simply based off of a combination of your genetics (which you have no control over) and your life experiences leading up to the present (which you have no control over either) - meaning that you have no free will.
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This isn't true because of quantum effects. Under the hidden variables model you might be right but quantum effects really could be random. Of course the macro events might be deterministic but this premise is wrong.
Also free will is irrelevant. It is impossible to both determine what people will do in the future with perfect accuracy and make decisions that will effect that person with perfect accuracy. If your prediction effects how you will interact with the person then your simulation must be a part of the prediction which will create an infinite loop. Thus as far as we are concerned you do have free will. | 78 | 83 |
ELI5: Why don't sharks last long in captivity? | Sharks aren't the most robust fish species, and size, diet and activity effect the health of all fish species. Sand tiger sharks and species of cat shark are often kept in aquariums because of their size. Another contributing factor is the build up of waste and size stunting in a tank rather than an entire ocean. | 18 | 32 |
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How big has a object to be, that it would cast a shadow on the moon, visual from earth? | Humans can discern objects that are about one arcminute (one sixtieth of a degree) in apparent size. The moon's apparent size is about 30 arcminutes, and actual size just under 3500 km. So, an object that would case a shadow with an apparent size of 1 arcminute would have to be almost 60 km wide. | 24 | 17 |
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New Postdoc supervisor says I can do whatever I want and I'm lost | Hello, I know this sounds strange, in theory, anyone would like to be in this position but I just finished my PhD, applied for this role based on the description given thinking it would be similar to my PhD, having a good idea where it's going and what the deliverables are then zig zagging my way to them while learning new things.
But this is my first week and they just gave me an office and left, I was confused and didn't know what to do for a few days then finally spoke to the supervisor and he just said I can do whatever I want and that he is very busy most of the time, this is in France by the way, the description mentioned working on a project to validate an exisisting design and create an optimized chip for it, but the supervisor said that task is trivial and better stuited for an engineer and that I can use the time for something more interesting.
So I found my self wondering where did the funding come from and what was it for exactly? how are they going to keep track of my work or progress for the duration of the contract, I find my self worried I'd be lost and not do much, I tend to lean towards slacking these days because of how burnt out I felt from the PhD, there is also the worry that by the end I wouldn't have much to show for whatever next position I go for.
Any insights from people who are experienced or just have advice in general? | A good starting point would probably to be to get up to speed on the work your PI and the group/lab has been doing so far, so that you can start to think of where you might fit in. It would at least give you a sense of direction if he won't. | 37 | 20 |
ELI5: What is collective bargaining and why do people hate Scott Walker? | Collective bargaining is where legally a group of workers can join together to negotiate or renegotiate their employment with their employer. Normally you don't have a lot of pressure to make your employer pay you more, if you can get every worker together and threaten to all stop workign if you don't get paid more, you probably will.
Scott Walker thought being able to do this ended up costing the state a lot of money (state employees wanted more pay and negotiated as a group to get it), and he was instrumental in having laws changed to make some of those actions difficult/impossible. People who benefit from those laws are upset they changed. | 24 | 39 |
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ELI5: why are the rhyming words in poem stanzas give a sense of satisfaction when read? | The human brain likes solving things, and rewards it's self for doing a good job.
The brain is also particularly optimized to spot patterns so that the unfamiliar can be spotted and quickly processed. Examples are all the faces of Jesus in toast & pieces of wood.
Poetry you get the build up "oh, a pattern!" as far as your reading & oration skills are on par to connect that there is indeed a pattern, and you did find it! Good job, your brain has rewarded you. | 20 | 31 |
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CMV: Males wearing suits to look more professional (including ties, handkerchiefs and other accessories) is largely based on historical social constructs that will be deprecated in a few decades, as there's no real usefulness. | From a usefulness perspective clothes serve the purpose of warmness and protection from nudity. There are also many complex secondary purposes such as personal expression and impression. For centuries clothing became simpler and simpler, and garments that once were considered inferior such as jeans are now the norm. There's no good reason why this trend won't continue in the future.
Suits will be the first to go. Suits are traditionally chosen when one wants to seem "professional", as they tend to be forgiving on body imperfections such as weight and periphery. However nowadays it seems less and less important to dress to impress, and there are other attires that are just as, if not more, comfortable.
Also, accessories such as ties don't serve any particular purpose, other than to add style and color to the attire. There are also other ways to do that without a double windsor knot, that will be simpler and more effective. | The whole idea of "professionalism" itself is a social construct.
I mean, what you are saying is that there is no natural property inherent to suits that are "professional" you are ignoring that professionalism itself is nothing that can be inherent to anything, as it is just as made up as suits. | 21 | 17 |
ELI5: Blood types | Imagine there are different colours of blood. You have yellow blood, blue blood, green blood, and clear blood.
It's okay to give a person with blue blood some blood from another person with blue blood, because the colours won't get mixed up. However, if you give a person with blue blood some blood from a yellow blooded person, the colours get destroyed and the blood doesn't work anymore.
You can give clear blood to anybody, because it doesn't affect the colour of the recipient's blood when it mixes. This also means that people with clear blood can only get blood from other clear blooded people.
Conversely, people with green blood can receive blood from anybody, as their blood has components of blue and yellow in it.
| 257 | 256 |
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Why does sexual fetishism exist and, moreover, why are some fetishes more common than others? | I just finished a Human Sexuality class, and our professor showed us studies in which fetishism developed due to early sexual experiences, many times including trauma, stress, or punishment. However, fetishism varies case by case.
In one case, a man with a shoe fetish described how as a child, his parents were hyper vigilant about knowing where he was and what he was doing every second of the day. He was caught masturbating a couple of times and punished harshly. From there on out, every time he wanted to masturbate, he would hide under his bed and do it as quickly as possible. From under the bed, all he could see were shoes. Every time he masturbated under the threat of being caught and severely punished, he would get under the bed, and his view was always shoes.
Thus was born his shoe fetish.
| 34 | 82 |
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[Star Wars] How long do the effects from a Jedi Mind Trick last? | I heard about a Jedi during the Old Republic who used his Force powers to tell a guy to stop selling death sticks and go home to rethink his life. Would this guy actually turn away from selling these drugs for good or just until he realizes he doesn't have any other skill sets? | It varies widely, depending on the power of the Jedi, how subtle or obvious the mind trick is, how strong-willed the target is, and whether other people will confront the target with contrary evidence. For example, there are lots of protocol and astromech droids in the galaxy, and they all look pretty similar. It could easily be weeks or months before a stormtrooper facepalms and pisses his pants in fear of Vader finding out what happened. The death stick guy is quite likely in the grip of a serious physical addiction himself, and his introspection will likely last until the withdrawal cravings hit. | 57 | 69 |
Is the spiciness of peppers intended to persuade or dissuade animals from eating them? | "The seeds of Capsicum plants are dispersed predominantly by birds: in birds, the TRPV1 channel does not respond to capsaicin or related chemicals in birds (avian vs mammalian TRPV1 show functional diversity and selective sensitivity). This is advantageous to the plant, as chili pepper seeds consumed by birds pass through the digestive tract and can germinate later, whereas mammals have molar teeth which destroy such seeds and prevent them from germinating. Thus, natural selection may have led to increasing capsaicin production because it makes the plant less likely to be eaten by animals that do not help it reproduce."
Source: Tewksbury, J. J.; Nabhan, G. P. (2001). "Seed dispersal. Directed deterrence by capsaicin in chilies". Nature 412 (6845): 403–404. | 112 | 78 |
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ELI5 what is Gauge Symmetry? | Imagine you're trying to measure the length of a piece of string using a ruler. You place one end of the string at one end of the ruler, and the other end reaches the 10cm mark. However, you could also put the first end of the string at 10cm, and the other end at 20cm, and work out the difference. You still get 10cm, as the place you start measuring from does not affect the result. This means that the length of the string exhibits gauge symmetry, as it's unaffected by moving the scale that you're using to measure it. | 30 | 31 |
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ELI5 how ivy, poison ivy, Virginia creeper, any other fast growing vine or plant, don't take over an entire area and destroy a forest? | Every living creature has a limit of size produced by the physics of their biology. While the capillary effect can transfer water very long distances with minimal resistance, the transfer of nutrients becomes a different story.
If you wanted to transfer supplies a long distance, it requires resources just to maintain the route, so your need to carry resources for maintaining the route along the way and the evolutionary infrastructure isn't quite capable of that. Especially since they're competing for resources to grow further in the process. | 18 | 34 |
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ELI5: Why does your skin 'dent in' when wearing e.g. a too tight wrist band or bra strap or rubber band? | What happens to the cells? What process allows them to bound back in place and is there any damages? Why does it get reddish? | There is water in three places in your body: in your blood, in your cells, and between your cells. There is an equilibrium between these three, and one of the large determinants of where that equilibrium sits is physical ("hydrostatic") pressure. When you compress the tissue for a while, you increase the pressure and force some of the cellular and tissue fluids into the blood to be carried off, leaving a dent. When you take the pressure away, the fluid comes back to restore the normal balance. | 226 | 202 |
would it be possible that firing unproductive workers would actually shrink the economy at a macro level? | let's say that a worker's marginal cost (their wage) is higher than their marginal revenue product, making them a net burden to the firm. in this case evidently an unproductive worker like this would be harmful to the firm and negative to the firm's production, and thus a firm would likely let go of this worker, which theoretically should be beneficial to the economy at first glace because the worker took in more than they actually produced.
however, by letting go of this worker, they would also lose their wages and would lose wealth. as such, at a macro level, having unemployed workers (even if they are unemployed for good reason) might be negative to the economy at a macro level because aggregate demand would decrease to some extent due to the loss of wealth.
so, would it be possible that laying off unproductive workers would still be bad for the economy at an aggregate level due to this shift in aggregate demand? or would this effect be negated somehow? | If the worker requires a wage above their MPL, it must be because their opportunity cost of working that job is high. If they didn’t have better work to be doing (or feared the consequences of a layoff), they wouldn’t require such a high wage to do that job. So firing them is probably better for all parties in the long run.
In the short run, the frictions that make it hard for workers to immediately match to a new job would cause problems. (One worker probably has little impact on the macroeconomy, as opposed to massive nationwide layoffs) That said, such frictions make workers more willing to stay at their current job for a lower wage, so for a given wage level, the presence of short run costs means the long run gains are likely to be larger. | 22 | 57 |
CMV: People identify too much with being either an introvert or an extrovert | I think most people are sometimes one and sometimes the other. Identifying too strongly as an introvert means that you miss out on things. Identifying too strongly as an extrovert makes you loud and obnoxious.
The issue partially stems from people confusing being socially anxious or lacking social confidence with being an introvert. An introvert has no problem talking to people and can be a likeable person but likes to spend time on their own often. A socially anxious person is afraid of social interaction and feels panicked during social situations. The former is not a problem but the latter is. | How does *identifying* as an introvert or extrovert actually affect your behavior? Don't people define themselves as introverts/extroverts *based on* their behavior? Or are you saying people arbitrarily pick a label and then act accordingly? | 19 | 156 |
If I shine a laser pointer north and another south, from the perspective of the photons traveling north, wouldn't the photons traveling south be traveling twice the speed of light? How does this not violate the constant speed of light? | Velocities don't add linearly, they add in such a way that the speed of light is constant in all reference frames. In the case of two photons, the velocity of one in the frame of the other is (c+c)/(1+c^2 /c^2 )=c | 59 | 35 |
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What did Camus mean by "there are truths, but no truth"? | I'm reading through The Myth of Sisyphus, and in it Camus says,
>Of whom and of what indeed can I say: “I know that!” This heart within me I can feel, and I judge that it exists. This world I can touch, and I likewise judge that it exists. There ends all my knowledge, and the rest is construction. For if I try to seize this self of which I feel sure, if I try to define and to summarize it, it is nothing but water slipping through my fingers. I can sketch one by one all the aspects it is able to assume, all those likewise that have been attributed to it, this upbringing, this origin, this ardor or these silences, this nobility or this vileness. But aspects cannot be added up. This very heart which is mine will forever remain indefinable to me. Between the certainty I have of my existence and the content I try to give to that assurance, the gap will never be filled. Forever I shall be a stranger to myself. In psychology as in logic, there are truths but no truth.
What does he mean by the last phrase? | There are groups of properties or aspects which are truths, however we cannot sum them up to form a truth. There will for Camus always be parts of the equation which we cannot know, which are as well to numerous, such that we can only construct a partial equation. X+Y+?+?=? | 12 | 34 |
What determines a material's heat capacity? Why is water's so high? | This question came to me at 1:30AM in bed thinking about *why* we actually boil stuff in water: it has high heat capacity so it spreads the heat evenly and stays hot after we turn off the heat (or put out the fire)
But yeah water seems like an unassuming molecule if that makes sense, what makes it able to take in so much energy before changing temperature? | Heat capacity is heat energy being stored in
(i) molecular or atomic movement
(ii) molecular vibrations, rotations etc
(iii) breaking bonds
​
As others have noted most liquids just have (i) and (ii) to contribute. Water and ammonia can store energy by revesibly breaking hydrogen bonds as well. | 19 | 15 |
[Star Wars] Mon Calamari vision | Do Mon Calamari have binocular vision and if so, what is the binocular field of view? Do they have difficulty looking forward? | There are plenty of images where both of their eyes can clearly be seen from a point somewhere in front of them, so it seems perfectly reasonable that they would be able to see any of those points with binocular vision - indeed it seems highly likely that the evolutionary advantage of their externally positioned eyes was precisely that they did allow for binocular vision. From an evolutionary perspective, they would seem quite vulnerable, and so a disadvantage, without *some* over-riding advantage.
It is likely that their range of binocular vision is significantly less that for Humans, but probably greater than such successful predators as the Tyrannosaurus Rex from Earth for example.
It is more than likely that they have a much wider peripheral vision, of course. | 18 | 57 |
ELI5: How do antiviruses first discover malware? | If someone creates a new piece of malware, like a botnet or virus, how does the antivirus company find the malware in the first place, so that they can include it in their AV database. Obviously it's pretty simple to detect things that completely wreck your system, but how do they discover the more covert stuff? | first, with signatures: they compare the suspicious file to a database of known viruses, and see if it matches. this only works with viruses that have already been discovered.
second, with heuristics: they examine the behavior of the file or process and see if it's doing anything suspicious. if a process is sending a packet over the internet every time you hit a key on your keyboard, it's probably a keylogger; by monitoring communications patterns and memory access patterns, some viruses make themselves known even if they've never been seen before. heuristic detection is extremely unreliable.
most of the time antiviruses rely on signatures. this is why you have to constantly update new virus definitions from your antivirus provider; they employ full-time security researchers whose job it is to browse the web, gather and identify new viruses, and determine how to detect and remove them. | 10 | 15 |
Eli5: Why do Children that have gone missing for days, weeks or longer think they've only been gone for much less time? What happens to the human psyche under high stress situation, especially that of children? | u/Novembergirl83 has provided a pretty thorough explanation, although there are some more aspects at play - especially since you are referring to children in particular.
To really ELI5-ify it: To a child, time is *weird*. Young children in particular (<10 years old) don't have the best sense of time passing. For them, time is set by their routine. It's *breakfast* time, it's *bus* time, it's *class* time, it's *lunch* time, etc. It's *Monday*, so we have PE today. It's *Tuesday*, so grumpy old Miss Grumblebottom will be teaching us (ew). The regular events act as timestamps to identify when the irregular events happened (e.g. Monday is PE, so this happened on Monday!).
Take all of that away, and their 'tether' to time is gone. You see it in summer holidays, most frequently. Time flits by, things happen, but there's no order, no routine. Ask any child what they did on a specific day in their holidays, and 9 times out of 10 they'll just kinda stare blankly and think, because it all kinda blurs together into a haze of memories. Oh, they can tell you everything that they *did*, but without a specific daily routine, without a weekly schedule, they don't really have any ability to order and sort those memories since they have no regular event to act as a "bookmark".
Happens to adults, too. All those memes that you've seen about 2020 having 31 days in January, 29 in February, 546 in March, etc? There's a grain of truth there. Strip out routine and we have trouble telling the days apart.
Now throw in a healthy dose of fear/excitement/hunger/adventure/terror/exhaustion and their ability to sort events gets even worse. Everything is new, everything is irregular. They don't have a need to track the day, so that falls to the wayside. Days and nights blur together like a really shitty summer holiday. | 116 | 109 |
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[Star Wars]What kind of food can allow the more than 30,000 crew members of the Star Destroyer to live in the Star Destroyer for 2 years? | There are more than 30,000 crew members in the Star Destroyer, and the consumables they carry can allow them to survive in space for 2 years. If it is conventional food, the daily consumption is very large and takes up a lot of space. Although the Star Destroyer is very large, the building occupies a large part of the entire Star Destroyer, so the place for food storage will not be very large. The food that can provide the crew members to live in space for 2 years should not be ordinary food. Then, what kind of food can make more than 30,000 crew members of the Star Destroyer live in the Star Destroyer for 2 years? | They use rations and nutrient packs in addition to smaller standard food storage that needs to replenished regularly. The ration packs are the size of a cigarette pack but can feed a human adult for a week easily if not comfortably. The packs have a shelf life of a few decades but have been known to survive for longer in optimal conditions though no one will eat them if given an alternative choice. They're cheap and contain the bare minimum of nutrition in a compact size. With appropriate rationing a few thousand pounds of packs could feed several thousand personnel without taking up more than a cargo container or three in the ships hold. | 235 | 212 |
[HP] Why do wizards not fix most physical disabilites/problems | When Hermione went to the nurse to have her teeth fixed the implication was that it was fairly easily done. So long as it hasn't been curse off they can reattach limbs relatively easily, but they can't fix Harry or Dumbledores sight issues? | The healing spells function by accelerating and enhancing the bodies natural healing properties, an astigmatism isn't something the body gets better from overtime.
Next; "why not just fix his eyesight without a healing spell?" well permanent physical alteration of someone is one of the hardest spells imaginable, well maybe not when it comes to cursing limbs or eyes off people, but the good kind, and certainly not the kind that would be worth doing just to save anyone from the minor inconvenience of wearing glasses.
Also as a minor point, anything that has been damaged by a curse can't be healed (see Alistar Moody), and as Harry is a [Spoiler:] horcrux he specifically can't be healed. | 13 | 28 |
ELI5: How does something become a commodity and what does that mean for public access to the item - like water, gold etc? | Generally commodities are less expensive than otherwise due to the greater competition between suppliers. If you want gold then any gold will do from anyone who has it, but if you want an iPhone only Apple can produce it.
Of course this doesn't mean that a commodity is inexpensive overall, gold being an example. It just means there aren't any differentiating features between one supplier and another. | 10 | 17 |
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[Mass Effect 2]Why is Shepard solving all of his squadmates issues? | Isn’t there more pressing matters, like the extinction of the galaxy by the reapers? Can’t their daddy/mummy issues wait until after? | Resolving personal deep issues is pretty important in not dying when facing an existential force that wants to wipe out all life. It’s not always like the movies where people are able to overcome their past in the heat of battle to become invincible heroes. Sometimes resolving your life problems can give people a clear head about what they’re fighting for, or at least hope against such terrible odds.
Shepard is experienced with this sort of thing, he knows how to handle even the darkest of scenarios as best he can.
That being said, while the threat is credible throughout, the only really time constraint is your own. The Harvesters seem content to hide behind their relay for now. He should take his time, prepare, research and do whatever he thinks is best as a prior and possibly future hero of the galaxy.
That being said, if by chance most of his crew gets abducted by them if say, Harvesters ambush the Normandy? Then he should haul ass straight through the relay to save them. Who knows how long they’ll have... | 42 | 18 |
ELI5: What makes a scientific study a good one? what are the best practices? | Like, control groups, placebo, whatever. I don't have much knowledge about it.
And how to check when some study seems reliable but it's actually flawed?
Thanks. | It's almost impossible to tell if a study is flawed, unless you are an expert in the topic. Instead you could see if the results have been replicated by other people. By the time you see 3-5 papers published that confirm a result, that's pretty good evidence that the study is true. It's also **super important** to read the actual scientific study, even though it might be really hard to decode, because the "science news coverage" is likely to be wildly different than the actual paper that was published. | 25 | 40 |
ELI5:what is information (referring Black Hole Information Paradox) | i understand the logic behind the conservation of matter and energy, but i just can't grasp my head around why the information about the state of a system needs to also be preserved.
if i take an apple and I dismantle it until it is nothing but protons and electrons, how in the world is the information about its previous state conserved?
i am trying to understand why it is so controversial that matter falls into a black hole and then it irradiates away as hawking radiation (without conserving the information about what that matter was) | Disclaimer: Some simplifications that are not technically true but make it easier to understand the principles.
On a deep level physics doesn't care if time moves forward or backward. Speaking in your apple analogy, it is physically possible to "un-dismantle" an apple and reconstruct it the way it was. Due to entropy it is unrealistically unlikely for something like that to happen, but it's physically possible.
To take this to the next level, if you have the dismantled apple in your hand it is possible to reconstruct how you dismantled it and in which state it used to be before just from looking at where the apple, you and everything involved are *right now*. The movement can sort of be "rewinded", and the rewinding is a process that follows all fundamental laws of physics (it reduces entropy, but again, that's not impossible, only so unlikely that it never happens).
Black holes seem to violate this principle. In standard black holes an electron drops in and photons come out at a later time, but it is not clear what their connection is. On a mathematical level, the process is not reversible: If we take all photons and their times when they exit the black hole we still don't know when and where an electron or something else dropped in.
To put it into an analogy: Let's say some sort of God randomly steals particles from our universe and randomly inserts them at other places. In such a universe we can never say when and where a particle will appear or disappear, and if we look at the universe as it is right now we cannot say what it was like in the past because the God may have stolen particles earlier and from looking at today's universe no trace of them remains. Black holes seem to do a similar thing - they take particles away without going into a state that allows us to trace back that a particle entered at a certain moment. | 21 | 53 |
Why is a Chihuahua and Mastiff the same species but a different 'breed', while a bird with a slightly differently shaped beak from another is a different 'species'? | If we fast-forwarded 5 million years - humanity and all its currently fauna are long-gone. Future paleontologists dig up two skeletons - one is a Chihuahua and one is a Mastiff - massively different size, bone structure, bone density. They wouldn't even hesitate to call these two different species - if they would even considered to be part of the same genus.
Meanwhile, in the present time, ornithologists find a bird that is only unique because it [sings a different song](http://www.bbc.co.uk/news/science-environment-23044469) and it's considered an entire new species? | Assuming we're working under the biological species concept, the answer is gene flow.
Two breeds of dogs may face physical challenges to mating and appear phenotypically very different, but over just a few generations there could be significant gene flow between a Chihuahua and a Mastiff. Hypothetical example that only takes two generations: a Chihuahua/Terrier mix would be perfectly capable of mating with a Dalmatian/Mastiff mix.
Moreover, the dogs would be capable of recognizing each other and would certainly attempt to mate (though probably not successfully). It's important to keep in mind that although dogs look very different from each other, there is usually less than a few hundred years of divergence between most breeds.
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On the other hand, a bird who sings a completely different song is *usually* not recognized as a member of the same species. There isn't going to be any gene flow here (at least in any considerable amount). For example, some flycatchers of the genus *Empidonax* look nearly identical. Willow and Alder flycatchers are impossible to tell apart in the hand, even when using precise measurements with calipers. However, they all have distinctive songs (a species recognition mechanism) and occupy specific niches. An Acadian Flycatcher will not mate with a Willow Flycatcher or an Alder Flycatcher, even though they all look quite alike. There are thousands or millions of years of genetic isolation separating them.
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As far as paleontology goes, a good scientist would almost certainly place a Chihuahua and Mastiff in the same genus based on their anatomy. The bird would be more tricky, as soft tissues and behaviors don't fossilize. This is certainly a limitation, but it doesn't change where we stand on extant species.
(Edited because of a typo.) | 1,932 | 1,595 |
Would LIGO results improve if there were a third branch perpendicular to the existing two? | Yes, you would have increased sensitivity to some waves that do not propagate in the correct orientation to the current setup. However as it would have to be built directly into the ground, or into the sky, that seems unlikely. | 16 | 33 |
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Can better nutrition in a person's 20s make up for poor nutrition in childhood and adolescence ? | During childhood years (8-12) i never had good nutrition. I often ate junk food especially like chips etc. even though i was hungry. In adolescence unfortunately money was tight so i did not eat well either. Now that im my early adult hood, i am making better choices.
Can this improved nutrition, make up for what my body had missed back then ? | Disclaimer: the topic is complicated, and does not lend itself to simple, compact answers. Nor are the citations straightforward, e.g not single topic studies, but lots of fundamental biology & biochemistry, so apologies in advance for lack of citations and nuance.
Two scenarios:
1. Malnutrition resulting in growth consequences. Typically chronically low or insufficient protein intake, exacerbated by insufficient calorie intake. This may result in stunting/failure to reach height potential, delay to or incomplete sexual maturation, fragile bones, and more (i.e. neurological deficits in the extremity, from micronutrient deficiencies)
2. Overnutrition of poor quality. This may result in excess weight, and attendant health/hormonal consequences.
The first type (1) is unfortunately permanent if the malnutrition extended over the majority of the growth phase, I.e. past puberty. This rarely happens in developed countries, where the problem is overwhelmingly of the second (2) sort.
Since heart disease and other diseases of excess take decades to develop, the evidence available suggests ample opportunity to improve outcomes - mainly by losing weight and adopting a diet of medium protein, low saturated fat, high in polyphenol and fiber, e.g. a traditional Mediterranean style diet. There isn't full consensus on whether this "repairs" (reverses) whatever damage has already been done, but there is clear evidence that even with symptomatic heart disease, lifestyle improvement (diet, weight, exercise) is a very effective tool for reducing cardiac events.
In the second (2) case it is also typical for the diet to be rich in macronutrients but poor in micronutrients, the consequences of which may or may not be permanent either. For example, it is now clear that fiber and various phytonutrients like anthocyanins are essential for immune function, and to make a long story shorter, probably are involved in many types of cancer, but are conclusively known to affect bowel cancer. There is evidence that beneficial lifestyle changes can re-normalise abnormal pre-cancerous tissue in the bowels. So that can probably be thought of as limited reversal (but would not be the case once a precancerous polyp has become a malignancy, at which point lifestyle changes will surely improve overall health outcomes and survival, but only medical intervention addresses the actual problem). | 19 | 22 |
AskScience AMA Series: We are climate scientists here to talk about the important individual choices you can make to help mitigate climate change. Ask us anything! | Hi! We are Seth Wynes and Kimberly Nicholas, authors of a recent scientific study that found the four most important choices individuals in industrialized countries can make for the climate are not being talked about by governments and science textbooks. We are joined by Kate Baggaley, a science journalist who wrote about in [this story](http://nbcnews.to/2AjqKSL)
Individual decisions have a huge influence on the amount of greenhouse gas released into the atmosphere, and thus the pace of climate change. Our research of global sustainability in Canada and Sweden, compares how effective 31 lifestyle choices are at reducing emission of carbon dioxide, methane, and other greenhouse gases. The decisions include everything from recycling and dry-hanging clothes, to changing to a plant-based diet and having one fewer child.
The findings show that many of the most commonly adopted strategies are far less effective than the ones we don't ordinarily hear about. Namely, having one fewer child, which would result in an average of 58.6 metric tons of CO2-equivalent (tCO2e) emission reductions for developed countries per year. The next most effective items on the list are living car-free (2.4 tCO2e per year), avoiding air travel (1.6 tCO2e per year) and eating a plant-based diet (0.8 tCO2e per year). Commonly mentioned actions like recycling are much less effective (0.2 tCO2e per year). Given these findings, we say that education should focus on high-impact changes that have a greater potential to reduce emissions, rather than low-impact actions that are the current focus of high school science textbooks and government recommendations.
The research is meant to guide those who want to curb their contribution to the amount of greenhouse gas in the atmosphere, rather than to instruct individuals on the personal decisions they make.
Here are the published findings: [http://iopscience.iop.org/article/10.1088/1748-9326/aa7541/meta](http://iopscience.iop.org/article/10.1088/1748-9326/aa7541/meta)
And here is a write-up on the research, including comments from researcher Seth
Wynes: [NBC News MACH](http://nbcnews.to/2AjqKSL)
-----
Guests:
Seth Wynes, Graduate Student of Geography at the University of British Columbia in Vancouver, currently pursuing a Doctor of Philosophy Degree. He can take questions on the study motivation, design and findings as well as climate change education.
Kim Nicholas, Associate Professor of Sustainability Science at the Lund University Centre for Sustainability Studies (LUCSUS) in Lund, Sweden. She can take questions on the study's sustainability and social or ethical implications.
Kate Baggaley, Master's Degree in Science, Health, and Environmental Reporting from New York University and a Bachelor's Degree in Biology from Vassar College. She can take questions on media and public response to climate and environmental research.
We'll be answering questions starting at 11 AM ET (16 UT). Ask us anything!
-- Edit --
Thank you all for the questions! | how accurate is it that individual choices, while great and all, are a drop in the bucket compared to what industry is doing? shouldn't "voting" and "boycotting/informed spending" be high on this list? | 296 | 4,141 |
What happens to meat when it cooks? | On a molecular level, what happens? | Proteins, which are molecules that generally speaking are specifically folded up chains of amino acids, denature and become tangled. Fat deposits in adipose tissue, and oils and stuff stored in vesicles like liposomes, melt and are released as their containers fail and get squeezed out by the meat shrinking. The meat shrinks probably from a combination of protein denaturation, cell breakdown, and dehydration as water is driven out.
Most meat is muscle tissue with a bit of adipose, and muscle is very enriched in strands of protein involved in motion, so these strands in particular would become disordered. dehydrated, stick together more, etc. At a larger scale, muscle is also a collection of oriented cells that form fibres, and the connective tissue that holds together these fibres made from muscle cells breaks down, making the meat easier to break apart. | 25 | 24 |
If i have a human fingerprint of just the index finger ,can an ai generate the rest of the palm's prints if the AI is trained with a huge dataset of human palms and will it be accurate? | The fingerprints form by how the skin develops in the womb. This is a random process, not unlike how paint can wrinkle. AI works on matching patterns, and random data is the worst for this. Best case is finding some weird population trends e.g. some minor loop variation statistically more likely in men, or a specific whorl is not found in people whose ancestors lived in part of France 20 generations ago, but would not be able to extrapolate the other prints. | 2,279 | 2,582 |
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How stable is the human oral microbiome against disruptions like mouthwash? If I use alcohol mouthwash will my mouth microbiome be back to the same amount and species ratio by my next meal? Several meals? Or never quite the same again? | This varies from person to person, but alcohol based mouthwashes do disrupt the oral microbiome at least in the short term, ranging from days to about a week. Combined with recent studies that cast doubt on the efficacy of those mouthwashes in preventing cavities, it's becoming more typical for salt water rinses to be recommended as an alternative. | 2,464 | 4,820 |
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We've cloned sheep. We've cloned a lot of mice. Some folks want to clone mammoths. How hard is it to clone a tree? | I was reading recently about a species of mahogany that yielded the finest furniture ever made--so fine, in fact, that it went extinct from over-use. With all the recent talk about resurrecting the mammoth, it struck me that bringing back a species of tree, a much simpler organism which has many close extant relatives and a large amount of genetic material available (largely in the form of chairs) seems like it'd be relatively easy. Are there any impediments to cloning plants the way we'd clone animals?
EDIT:
I realize that it's very easy to clone plants by their own mechanisms, and that that's how many food crops are grown. Obviously, this wouldn't work with long-dead wood. | Plants are easy to clone. You just take a cutting of it, shove it in the ground, and boom, clone. Cloning from straight DNA in plants is vastly harder.
Plants are NOT simple organisms, no matter how boring they look. They are just as complex as humans in just about every metric you pick - genome size, number of genes, specialization of cells, etc. In fact, plants can have extremely complex and confusing genetic makeups - redwoods, for instance, have 6 sets of chromosomes, compared to our two.
Further, molecular biology with plants is incredibly difficult. Aside from having complicated genomes, they have big thick cell walls that make a lot of standard techniques difficult. Cloning in animal cells is done by ripping the nucleus out of an egg, and adding the nucleus from a target cell. The very tiny surgery required to do this is a lot harder when you have to deal with a rigid layer of cellulose.
The only reason we've made more progress in genetically engineering plants is because nobody cares if you kill them. Kill one measly human and everyone's all human rights this and mad scientist that. | 208 | 124 |
ELI5: Why do we feel stupid around people we like even if we're not acting or doing anything stupid? | It's because you have a heightened perception of their competence. You laugh at their dumb jokes because you like them, even if the jokes aren't funny if told by someone else. You think that they are incredibly skilled at whatever things they do, even though they would be considered average at best. | 40 | 63 |
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Isn't the free prisoner in allegory of the cave still ignorant? | The prisoner who escapes the cave and now sees his previous truth for the false perception it is, now accepts this new truth as the ultimate truth, why? Shouldn't someone who just learnt that their truth was false be able to consider that any new truth they may learn of may also be false, just as the original shadows were?
There seems to be an implicit assumption that only two states of knowledge exist; ignorance and the philosopher, which seems wrong given that the philosopher cannot verify his new truth is not just another false perception | Regarding the supposed implicit assumption about 'states of knowlege': Plato distinguishes more than two 'states of knowlege' in *The Republic* (509d–511e) through his 'analogy of the divided line', namely *eikasia, pistis, dianoia* and *noesis.* All of these 'states of knowlege' are present in the 'allegory of the cave' as well. | 14 | 15 |
ELI5: I'm laying naked in bed when someone breaks into my house, steals something and leaves. I bolt out after them without any clothes on. Can I get into legal trouble for being nude while chasing a criminal? | Legality is a difficult subject, because the legal system was designed to be at least somewhat subjective. The law itself states whether or not you are legally allowed to do something, but the judicial process, including getting "caught," serves as a way to evaluate whether or not a punishment is actually deserved for the crime. For example, indecent exposure (being naked in public) is technically illegal, yet it is unlikely that an elderly person with mental deficiencies would be punished for running naked from a nursing home in an episode of delerium, even if the law did not have any written exceptions for people who were mentally compromised. They *could* get in trouble for it, but most of the time, no one would try to press charges.
So, while technically you *could* get in trouble for being naked in public in this case, there would have to be other circumstances to warrant most people seeking to punish you for this, like if you happened to run by an elementary school with a bunch of children outside, because then it could be considered exposing oneself to a minor, or something like that. If, while chasing the criminal, a police officer stopped you, and you explained that you were chasing a burglar, it is likely that any police officer with good morals and priorities would just respond, "Well I'll try to catch him, here's a blanket so you can cover up, now go back home and wait there," because your actions were not really "criminal" while still being technically illegal. Hope that makes sense. | 109 | 118 |
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ELI5: Why is modern day camouflage pixelated? | The pixelation softens the edges of the large scale pattern and makes the outlines, and thus the underlying objects, harder to discern. It is also a lot easier to fabricate clothing with pixelated designs which lowers the costs of the clothing.
So basically the Marines believe it to work better than traditional camo designs and it is also cheaper to produce, so that satisfies them on the two most important facets of uniform design. | 16 | 36 |
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[He-Man] Who built Castle Greyskull? | Most versions revolve around a "Council of Elders" that existed in ancient Eternia and who were dedicated to discovering and preserving magical secrets into a Hall of Wisdom. One day they had a vision of a great danger coming (IIRC it would be Hordak trying to invade Eternia and his disciple Skeletor trying to get the magical secrets) and also of a champion who would defend it (He-Man). They then changed the Hall of Wisdom into a "resistant form" which is basically impregnable Castle Grayskull, and concentrated all their magic into an Orb of Power inside the castle. The Castle should be guarded by the Sorceress (which is a title, there have been many Sorceresses through the ages) until the coming of He-Man. | 23 | 19 |
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CMV: The fastest solution to fix the US is to vote every single incumbent out of Congress | I have followed politics heavily since 2000. I was one of the original members of a democratic website despite growing up in a heavy republican home. I have seen nothing but hypocrisy, false promises, pleads for votes that accomplish nothing, and absolute waste on both sides.
I understand this would have consequences where your favorite long term senator or representative would be ousted but honestly I don’t care. How many of us our allowed to fail at our jobs long term and keep them?
I would love if we only elected candidates of whichever party that cared about two things and I don’t care whatever issues they support. One overturn Citizens United and two enact terms/age limits for Congress. I literally am open to the rest being battled out.
This whole cycle of who is in power wins what mid term. Who has what approval rating determines what news cycle. I am over it. The only effective way we, as citizens can efficiently pull this off, is to literally get rid off all of them. Replace them with the same party; I do not care. Just get rid of them all.
Edit 1 - I see the repeated statement saying basically what about having all new people with no experience. This is not true at all. Not every representative and seat is up in every election it is a cycle. Also assuming that every replacement would have zero experience is naive at best. It is a staggered 1/3rd system. I do believe the fastest, peaceful way is to replace the next 1/3 with a new 1/3rd. The committee’s don’t fall apart and there is still experience in the room that just had a massive message sent basically saying start serving us or you are next | Can you cite a precedent for something like this being successful?
Inexperienced legislators will have some tremendous problems. They need to understand the procedural and institutional practices of the legislative branch, need to be able to draft legislation with precise language to avoid unintentional loopholes and need to function in a diplomatic capacity without the benefit of their predecessors’ influence.
I understand the frustration, but tools (in this case legislation) are only as good as those that use them. | 83 | 172 |
Coding Bootcamp Vs. Associates and Beyond | Hello all,
I'm wondering if going to a coding bootcamp would be worth the 11,000 I'd have to drop to get in. Are any of you employers? Or does anyone know from experience, can a 3-6 month bootcamp get me a job in CS fields or will my certificate be laughed at. I know that an associates and definitely a bachelors will give me a great chance of landing a job with all the openings out there. My dilemna is spending 2-4 years to get one. I'm 24 and for some reason I feel like getting an associates/bachelors and starting over my career at 26/28 is too old? I know that's ridiculous but...Anyway, what is the best route to go. What will really land me a job upon completion.
Thanks everyone! | Go for the degree. Gives you much stronger foundation and covers core concepts much deeper. Bootcamps teach you tools/frameworks but they don't focus much on the CS fundamentals. CS programming courses focus on applying the programming concepts to problem solving and the questions are usually difficult; thus to a recruiter you are more likely (based on you passing the course) to be a better problem solver than a bootcamp grad. In the long run the degree will be more beneficial than a bootcamp. And with a degree you can always study further (formally) if you want and go into more complex topics.
Imo it's never too late to start a degree. | 22 | 21 |
[MCU] If you can create a powerful wizard like Dr Strange just by telling him to read books and train, why alien races don't have armies of wizards? | I imagine that funding whole fleet of battleships or army of genetically modified monsters would be a lot more expensive than training 500 wizards that would desintegrate any military force easily, even 20% of Dr Strange power for each would be enough if 100% was able to challenge Thanos with Gauntlet | If it’s as easy as reading books and training, why don’t we have more doctors? Astronauts? Engineers? Potential is not limitless, and if Kamar Taj is any indicator then few people are truly capable of magic. Multiply this across the cosmos and wizards are still going to be incredibly rare. | 829 | 1,119 |
If water boils (i.e. turns to gas) at 212°F how do things ever get dry at room temperature? | To start, there is a distinction between temperature and heat. In a given amount of water, the temperature of water is the *average* energy level amongst all of the molecules of water. However, heat is the *quantity* of energy that the amount of water has in total. As an example, the ocean has a lot more heat than a boiling cup of tea, but the cup of tea has a higher temperature. The quantity of heat in the ocean is greater than the tea, but the average temperature in the cup of tea is greater than the ocean.
At room temperature, the average energy levels in the water is not great enough to cause it to evaporate. However, individual water molecules do not all have the same quantity of heat, and some can gain enough energy to evaporate. This amount of energy is then lost from the source of water (evaporative cooling), but it will soon be replaced from the ambient air (at room temperature). Thus, the average temperature will remain constant, but individual water molecules are capable of evaporating if they gain more energy.
This is also why things will dry faster with higher temperature, even below boiling. The average temperature of the water molecules is higher, and a molecule takes less deviation from the average to gain enough energy to evaporate. | 28 | 29 |
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Difference between a “Psychotherapist” and “Psychologist” | When I look up the question above for myself , the info it gives just seems the same for both. Are these both two different terms to describe the same position? | A psychologist holds a doctorate (PhD or PsyD) in psychology and doesn't necessarily provide psychotherapy to clients, but can do so under the title of psychologist.
A clinical psychologist is traditionally trained as a researcher and practitioner, and may focus on either. Someone who gets a PsyD, also a doctoral degree, focuses on practice, and is a psychologist. A PhD in experimental psychology is a psychologist, though it is very rare for these psychologists to practice or gain licensure, and they normally investigate aspects of psychology that often have nothing to do with treatment.
All others who are licensed to provide psychotherapy are not considered psychologists. They can be officially assigned various titles depending on the nature of their education, location, and work. A licensed clinical social worker can provide psychotherapy. A psychiatrist can earn licensure to practice psychotherapy. A counselor can practice psychotherapy. Anyone who practices is often colloquially referred to as "a therapist", except for psychiatrists, oddly enough. They're often just called psychiatrists. | 22 | 40 |
[TMNT] What would the offspring be like if the turtles fertilized some non-intelligent females of their same species? | In nature a new species can be created when an existing species is divided somehow and the two groups begin to evolve differently. Over time mutations will arise in both populations and once sufficient differences have occurred it will no longer be possible for the two groups to mate and create viable children.
Although that's not exactly what happened here, certainly the four turtles underwent extreme mutations and it seems highly unlikely that they would still be able to produce viable offspring with females of their previous species.
I think that if they mated then the offspring would not be viable enough to come to term and the eggs would abort in early development. It's shame but the four turtles will likely be the first and last of their species and once they are dead their bodies will be stuffed and put on display in the natural history museum. Well that's what I'd do with them anyway. | 128 | 157 |
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CMV: I think cheating in university is acceptable under certain circumstances given the current standards. | I attend a state university somewhere in Texas. I study a STEM major, again somewhere in the sciences. It is a "hard" science (like geology).
It is difficult. It is tough. Despite my university's nearly 90% acceptance rate, the courses still prove unyielding. People routinely fail classes, are forced to retake, need to do prereqs...
Or, they can cheat. They can schmooze. Butter those professors up, why not?
It has become evident to me that the adage "It's not what you know, but who you know" is so true. Nobody in my classes does any work. At all. Our classes remain small in a university bursting past 25k students. Some of my classes have at most 40 students. Word travels *fast*. And you can easily be excluded from the top 50% of the class by not being "in the know".
Several of my peers routinely make top grade because they cheat or access exams from years prior. The latest cheating scandal in my department forced the prof to switch up the test, but I doubt he'll change for the next set of kids. He'll use the same, and next year, the exams will make their rounds, and kids who shouldn't pass will -- including me.
I will admit I have cheated. Sometimes with great success, sometimes not so much. But the point is, I would not be where I am now had I not cheated. Honestly. And this is the case for nearly my entire graduating class. Every single time a lab is assigned, or we get new work, the rally begins. Who can ask so-and-who for their papers? Oh, really? Yeah, I'll just rewrite the entire thing, sure.
Instant A.
And why not? I'm tired of playing goody-two-shoes. When I played fair, at my natural capacity, I made Cs and Ds. Now? I make Bs! Sometimes even a holy A. All because I "network" and create ways of foreseeing answers. All because the guys next to me and the gal on my left doesn't report me ("snitches get stitches" scenario -- and I hate this saying, but it's true, that's how it works).
I still uphold "regular" moral values. I try not to hurt anybody. I try to be the most empathetic person I can. But at the end of the day, what's wrong with a little cheating? You can say I've hurt myself...but really I don't think so. I excel now. And it's wonderful.
As a side note, I will admit to cheating because I dislike my major entirely. I wish I'd not chosen it. I have a passion for literature and English, but alas, these interests can be pursued as hobbies. And the money is elsewhere...
CMV | The purpose of university is not to learn (you can learn these subjects for free without even enrolling). The purpose is to get the credential. Why do you want A's? Because employers prefer to hire employees who obtained good grades. Perhaps because those who get good grades have shown mastery of the subject. In any case, employers value the ability to score high on a test that rigorously tests the subject matter; perhaps they see some correlation between that and the quality of work.
Whenever you cheat, you reduce the correlation. You are undermining the system that allows employers to use grades as a way of predicting future performance. Yes, the harm is dispersed across the whole industry, and of course, you accrue a big benefit from cheating. But we should never think such blatant externalizing of costs is ever acceptable, in the same way we wouldn't think polluting a public river or driving recklessly is acceptable.
Speaking more philosophically, to consider such behavior "acceptable" is to consider such behavior at least not immoral. But morality plays an important role in helping people internalize external costs. The administration of penalties and taxes on externalities is not perfect and morality can fill in the gaps. For example, a society can enact heavy penalties for murdering someone, but the inefficiency of finding and penalizing murderers is not going to deter all murderers. Therefore, it's important to enforce the norm that murder is immoral, which should deter a lot of people from murdering in a situation that is otherwise rational to murder.
So you may think it's rational to cheat and you aren't hurting anyone. First, you are hurting all current and future students, though to a very small degree. Second, it may be rational to you as an individual, but it should not be deemed acceptable. Your very example shows the difficulty in enforcing school policies on cheating, and if cheating were deemed acceptable, everyone would do it and make the entire grade credentialing system worthless. | 30 | 22 |
ELI5: If a magnifying glass will magnify the sun’s rays, then wouldn’t wearing prescription glasses actually be dangerous for our eyes? | If so, does prescription glasses that come with photochromatic or polarised lenses help to combat this? | All lenses focus light, including the lens in your eye. Prescription glasses just move that focal point to where it should be, they don’t collect any more light than your eyes do. That being said - Do you look directly in the sun when you wear glasses (or when you aren’t)? That is dangerous, with or without glasses because sunlight is strong enough to damage your retina permanently. | 68 | 29 |
Is there a way to test plants or flowers if they are edible without eating them ? | RAF edibility test:
>This test is only for plants; don’t try it with mushrooms, which can be deadly without the kind of warning that many plants provide.
>Separate the plant into its various parts—roots, stems, leaves, buds, and flowers. Focus on only one piece of the plant at a time.
>Smell it. A strong, unpleasant odor is a bad sign, as is a musty or rotting odor. Keep a special lookout for pear- or almond-like scents, which can be evidence of cyanide.
>Test for contact poisoning by placing a piece of the plant on your inner elbow or wrist for 8 hours. If your skin burns, itches, feels numb, or breaks out in a rash, wash off your skin and don’t eat the plant.
>If the plant passes the skin test, prepare a small portion the way you plan to eat it (boiling is always a good bet).
Before taking a bite, touch the plant to your lips to test for burning or itching. If there’s no reaction after 15 minutes, take a small bite, chew it, and hold it in your mouth for 15 minutes. If the plant tastes very bitter or soapy, spit it out and wash out your mouth.
>If there’s no reaction in your mouth, swallow the bite and wait 8 hours. If there’s no ill effect, you can assume this part of the plant is edible. Repeat the test for other parts of the plant; some plants have both edible and inedible parts. Starting to feel sick? Time to bring it up.
Edit to add: this is a *survival* guide, with the RAF's intentions being to extend rations and keep you alive until rescue. There are lots of considerations like nutrition that would need to be taken into account for extended survival. | 4,384 | 3,672 |
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ELI5: What is the difference between momentum and inertia? | My 5-year-old really likes vehicles, and we've been talking about rockets and rocket cars and why they're not as agile as regular cars when it comes to turning and maneuverability. They are designed to just go straight, in the case of rocket cars.
I think this is because they have a great deal of forward momentum. But as we talked, I realized I no longer remember much about momentum -- or inertia -- and what the difference is between them.
And one thing I have learned in answering these questions from my son is that you need a rock solid understanding to be able to explain things in a way that promotes good comprehension for a young child. And when you have gaps in your own knowledge of a subject, you will realize it right away.
Anyway, thanks for helping a mom out! | Inertia is an objects resistance to changes in motion. For instance, a heavier object is harder to push around so it has more inertia. Inertia does not change with speed (unless you consider einstein's theories, which can be ignored in daily life) so a certain object always has the same amount of inertia, which means it will always take the same amount of force to accelerate.
Momentum is the total amount of motion of all the parts of the object. Specifically it's the velocity of an object times its mass, in other words, the amount of motion times the amount of stuff. An object with a lot of momentum can push a lot of objects out of the way before it stops, while an object with less momentum can only push a few things out of the way before it stops. (an object with a lot of mass counts as many objects with smaller mass, because it can be thought of as a lot of lighter objects glued together).
A faster object can push more on things (more momentum), but it still takes the same force to change its speed (inertia does not depend on speed). | 18 | 69 |
I don’t understand the value of gold? | So, in terms of the applications of gold as a conductor and it’s value to computing and technology today its appeal is obvious. What I’ve never understood is why it has always been valuable thousand even tens of thousands of years ago. Is it really just a matter of it being considered visually appealing making it initially desirable and then the rarity and difficulty of extraction making it a mark of wealth/power or maybe its relative malleability made it useful? | Lots of metals where used as similar to gold historically. Gold is just the one we typically think of today.
Basically, it is a measurable unit of something that was easy to carry, durable, and you could cut into smaller versions of it self.
Gold was valuable compared to other metals because it was rarer. | 13 | 20 |
ELI5: Why is the autism spectrum so incredibly broad and diverse? | It seems a bit weird to me that a person who is otherwise independent and has a successful career but struggles with relationships and social interactions can have the same diagnosis as a severely disabled non-verbal, self-harming person who still wears diapers and will never be even remotely independent.
Can anyone explain what exactly makes autism so diverse? | Well, the word spectrum in autism spectrum disorder helps account for this. In previous DSMs the term was slightly less broad as there were other diagnoses to count for more mild autism. If you look at the diagnostic criteria, you can see how there are a couple main parts to the diagnosis: impaired social communication and restrictive and repetitive patterns of behavior. This can be a huge range, whether it’s rigidly sticking to a schedule and struggling with eye contact and humor, or being completely nonverbal and unmotivated by social communication and spending hours on rituals. Other diagnoses are like this too, there are certain traits but they can manifest very differently depending on the individual | 12 | 24 |
One of the main reasons so many die from the flu and coronavirus is because of pneumonia. Since we have pneumonia vaccines, why is it not standard procedure to have the public get vaccinated for pneumonia? | Pneumonia isn't a single illness, it's an umbrella term for an infection of the lungs. Pneumonia can be caused by a wide variety of infectious agents: bacteria, viruses, fungi.
Consequently, there is no single "pneumonia vaccine". Vaccines exist that help against some of the causes of pneumonia (for example the flu vaccine), but not all. | 588 | 308 |
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How does one work in industry and do their masters? | As the title suggests, I work for a company where people have completed their masters while working. I'm just curious about how this works. Do I still get paid my 40 hours a week? Do I conduct my research at work or at the school? I assume I have to stay on top of my regular work duties? Any info is appreciated I'd like to start reaching out to the prof I'm interested in working with, but would like some background knowledge beforehand.
I have a bachelors in chemistry and would like to take a masters in engineering. I work at a bio remediation / environmental company. | You need to ask your manager/HR. No one here can tell you how your company works.
Some places have specific agreements with particular universities and others will just contribute towards the fees of a relevant degree. Some places will allow you to dedicate some of your work time to study, other places don't and you have to do it outside of hours. Sometimes you can tailor the research part to link to a project as part of your work, sometimes you have to do research at the university. It depends what master's you do and what your company allows. | 29 | 26 |
ELI5: What is Pragmatism? | I've never exactly been sure of whether or not I'm right about what I think it is. Would a correct example of pragmatism be dealing with something in a more effective manner even if it's not moral or ideal for others or how it'd normal be dealt with? Never could understand its meaning from different things being said by sources. Thanks. | In everyday use, being pragmatic is simply being practical.
For example, you go to a restaurant with a few friends, and you decide to split the bill. Then there's always that guy who starts complaining that he didn't have as many beers as everyone, didn't have the dessert, and so on.
The fair approach would be to get the check, look at what each person had, and divide accordingly. The practical approach is to say "sure Bob, you just pay what you think you had and the rest of us will split the rest. The 4 bucks this will cost you is less annoying than spending the next 15 minutes arguing about who had what, so you take the pragmatic way. If you're the guy who thinks he spent less than everybody, being pragmatic means paying a little extra for the sake of a good time with your friends.
Philosophically, pragmatism is a movement that believes that only actions and their consequences matter. The truth is whatever comes out after the consequences of your actions are known. For instance, arguing if capitalism and socialism is made irrelevant if you can point to the way people live in both types of societies and see that objectively those under one system have a better life than those of the other, however you decide to quantify what a "better" life is.
I don't think that pragmatism needs necessarily be amoral, as your definition suggests. You can be a moral, or ethical person, and still be pragmatic when you take into account the consequences of your actions for all involved. For instance, if you kill your creditor and get away with it, never having to pay your debt, this might seem pragmatic exclusively from your point of view. When you take into account the big picture, though, this is not pragmatic because a life was lost, your community has been deprived of a productive member, an so on. | 53 | 30 |
ELI5: How do companies like Blackrock and Vanguard make money? | By providing investment services. People give them their money, they invest it for them while charging a fee. When people have given you trillions of dollars, the small percentage that you make from fees is still a lot of money. | 37 | 37 |
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CMV: There isn't a single advantage for a language in not having consistent phonemic representations. | In languages like Spanish or Greek there is no uncertainty in how a word is pronounced when you see it written, but in others like English it is really a pain when it comes to pronunciation. It just doesn't make any sense, because literally it doesn't. There are no infallible rules to know who a word it is pronounce.
Just look at the very vowels!! a, e, i, o, u --> ə, iː, aɪ, əʊ, juː
Most of them have 2 sounds instead of one and some of the sounds are repeated. And don't get me started with all the combinations in actual words...
I cannot see any advantage to this mess. | Language does not need to be super productive, advantageous, and optimal. Because it's not just a tool for communication it also carries culture, history, it's in a way an art. And actually there is a logical reason for why every single word is spelled and pronounced the way it is if you understand the rules. Like in English the F or Ph can make the /f/ sound because all words the ph are Greek. C and H make a /ch/ sound unless they are greek then they make a /k/ sound like in \[tech\] or \[scheme\]. Or the ch makes a /sh/ sound if it's a French origin word like \[chef\]. It makes logical sense, it just doesn't have to make sense to you. Millions of English speakers have no problem speaking English and some even like that we use words from different origins or we can use the schwa sound sometimes and other times not in the same word. It's not a mess it's a beautiful web | 45 | 38 |
Is it okay to do a personal/side project in a full-time postdoc position without letting the supervisor know? | I am doing a postdoc in computer science. I kind of lose interests in the project after 1.5 year, but I still keep trying to be productive (2 papers accepted). I was doing a side projectby myself from like half year ago. The side project is not quite relevant to the funded project. The result is interesting and I think it's publishable. I am considering submitting it to a conference without letting him know, as I am concerned that my supervisor would be upset as he might think it's a full-time job and I should not do any other side project. Any advice? thanks | Read your contract. It will probably hinge on how much time it will consume and what you are using. If you're using your supervisors resources (and that can include your university supplied laptop) and/or time they are paying for then you should talk to them. | 80 | 75 |
ELI5:what happens in an acid trip and why? | edit: what happens to your body not what happens | I'll explain starting with the "Why."
Your perception of the world is controlled by your brain which places selective filters on the things we see and hear. Throughout your life you've trained your brain (unknowingly) to do this, and so everything that you perceive is essentially a subset of what you're actually being exposed to. Your brain's ability to do this is what allows our minds to make decisions in a more manageable way. By taking acid, you are, in a way, removing those filters.
[Simply put, you're letting unprocessed information into your mind.]
Now for the "What."
Typically, acid trips run for a duration of up to 12 hours. Primary effects from these trips are mostly visuals accompanied by an overwhelming sense of euphoria. Imaging seeing the world in a completely new way. The way you perceive your environment and your thoughts is totally different (refer back to the 'filters'). Due to these new thoughts, many people will tell you that tripping on acid can be seen as a very religious or spiritual experience.
Hope this helps! | 31 | 32 |
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