[System] Given the following post, respond as if you're commenting on Reddit:

[User] [Halo] Why haven't the UNSC reverse engineered covenant antigrav tech? They must have a whole mountain of ghosts and wraiths that they can use by now?

[Assistant]
They dont really need to. UNSC ground technology was already almost on par with the Covenant early in the war, even discounting the advantage of their plasma weapons, they were holding their own on the ground. Most of the UNSC ground vehicles wouldnt benefit that much from anti grav tech anyway, the warthog is pretty cheap to produce, and the Scorpions are incredibly maneuverable anyway.

TL:DR Its probably a cost-benefit thing as UNSC ground tech is perfectly fine as it is.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
Have atoms ever been observed to quantum tunnel out of a weak chemical bond (Such as hydrogen bonds)?

Bonds are sort of like potential energy wells, so that means they can be quantum tunneled out of, right? I've never heard of this being reported though, so is it just very rare or is it not possible. If not possible, why do you think/know so?

[Assistant] Yes of course. It's easily measured experimentally using the kinetic isotope effect, for example replacing hydrogen with deuterium and measuring the change in rate of reaction/exchange due to the change in mass.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] ELI5 Why is the situation in Somalia always so bad?

[Assistant] Somalia had a civil war in the 1980's and since then has had no unified government. Somalia is ruled by different clans. Somalia is also very very poor. Now when you have a bunch of very poor people ruling themselves they will do pretty much whatever they can to survive, including crime and violence, lots of violence. So take this situation, you have a very poor country with no unified government and the only rules that are in place are made up by crime clan bosses essentially. This means complete chaos in this country.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] [WH40K] Apparently, if you travel through the warp, you can arrive before you even started. Did this actually ever happen?

[Assistant]
Ork Warboss Grizgutz actually led his WAAAGH!!! into the warp and time traveled back to just before he left.

Then he proceeded to kill his past self because he wanted two copies of his favorite Shoota, and destroyed his own WAAAGH!!! in the process.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5: Why can I see in low light so much better than even a high-quality camera?

Cameras seem to perform so much worse in low light than how I perceive a room in person, why is that?

[Assistant]
Night vision in cameras and night vision in eyes aim for the same thing. In both cases, the goal is to widen the dynamic range available to view the environment. However, cameras and eyes work in very different ways. The he camera sets one exposure level for the entire scene, but each minute portion of the retina (the eye's "sensor") sets adaptation level independently. For example, suppose the scene has a small light at night. The camera will meter an entire photo (normally at a number of points) and the resulting average will probably be pretty dark. So the exposure or ISO are pumped up, which means any light in the picture will be over exposed, and noise is added.

On a quick aside, ISO is basically the "volume" of the light hitting the sensor; the circuit amplifies the light hitting it but as you amplify the digital signals interruption from radio waves, heat etc can make light be registered when it isn't even there. thus the random little dots.

 Meanwhile, the eye will measure 120million different points of the environment, sensing the amount of light available in each and exposing it accordingly. You can still over/underexpose, like when you look from a screen to a dark room quickly. So basically, your eye is more sensitive to light than a camera, is performing a HDR style photo (ie varying exposures across the environment), has a decent sized sensor (better than those camera phones), and because of this gets much better results. Current high end SLRs are getting pretty damn close though!


[System] Given the following post, respond as if you're commenting on Reddit:

[User] [Vampires] Can you kill a vampire with the splinters of shattered IKEA furniture? Or does it have to be solid wood? Can you kill it with something else pointy, like a railroad spike?

[Assistant]
Yes... in some cases.

The issue is that "vampire" is more of a *genus* than a singular *species*. Surely you've heard of some vampires that are monstrous and some that are beautiful. Some that have two sharp canines and some that have a mouth full of sharp teeth. Some that can turn into bats and some that remain in a human form and need to take a boat or plane.

There are differences in their appearances and powers, and also differences in their weaknesses. Did you know that there are some vampires that can walk around in sunlight and will survive a wooden stake through the heart? And yet there are some that can't cross bodies of running water.

Because of this, the answer to your question is unfortunately "it depends."

For those kinds of vampires that can be killed by a stake through the heart, that broken piece of IKEA furniture will absolutely work. In these cases usually even a metal rail spike or a kukri knife will also work. And even if they didn't work, if used while the vampire is sleeping they would succeed in pinning the vampire and allowing you to behead them (a much more reliable killing method across several vampire genera).


[System] Given the following post, respond as if you're commenting on Reddit:

[User] Eli5 Why do cars move at all when in drive without the accelerator being used. Im not talking cruise control.

[Assistant] Automatic cars have a torque converter. It's like a fan facing another fan. The first is connected to the engine, the second to the wheels. Provided the engine is on, the wheels experience a bit of force.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5: What happened to Occupy Wall Street?

What happened to Occupy Wall Street?  Is it coming back?  Can anything be done?

[Assistant] It was far too unorganized to actually go anywhere. Too many people going there were just attending because "I hate the big corporations maaannnn! - posted on facebook from ipad" without any definite purpose. They had good intentions, but it was poorly executed and fell apart quickly.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[DC] How much the average person knows about each member of the Justice League?

Do they know Batman is only a human, not a vampire? That Superman is a Kryptonian? That Green Lantern belongs to the Green Lantern Corps etc.

[Assistant]
The Hall of Justice down in Washington DC is actually a tourist attraction open to the public. Schools trips and tours are held there every day, usually hosted by heroes or the actual founding members of the Justice League.

They have pretty decent PR as a team, and most of their key details are public knowledge. Not to mention kids have to write essays about superheroes as historical or sociological figures whenever the subject comes up.

If you're like, 40 and don't much care who your representatives are, you probably also don't care what the hell a Green Lantern Ring is. But if you're well-informed and curious, the information is readily available.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
multiple job applications

I'll be graduating this Spring with a Ph.D. and I found a position at a university which I applied for the other night. However, I was browsing today and I noticed another, better position in the same department of the same university. I don't know how I missed this one before. Should I still apply to this position even though I have already sent in an application to the same department/university? TIA!

[Assistant] Yes. If you are meeting the requirements then its nothing wrong to apply to both. In case they ask why u applied both, just say your profile meeting both the jobs, hence applied. Good luck and all the best for your interview.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[GOTG] Could Groot be taught sign language or how to write?

As Rocket says, Groot's vocabalistics are limited to "I" and "Am" and "Groot" (exclusively in that order), but clearly there is more going on behind that big wooden forehead.

With enough time, would it be possible to teach Groot how to express himself through basic sign language or through writing, or is his species limited in comprehending those things?

[Assistant]
"Hey, Groot! Wanna learn how to write?"

"I AM GROOT."

"Well, uh. Here's some paper. Wanna draw a picture?"

*Groot stares sadly at paper*

"Oh, uh, this was made from a not talking tree. Um. This chalkboard?"

*Groot walks over and draws himself*

"I AM GROOT."


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5: How does soap work?

How does it keep off bacteria/smells?

[Assistant]
Some molecules dissolve in water, and some dissolve in oils or fats. So if you get grease or oil on you (like from your own skin),  water won't do much to get it off, because they won't mix. This grime can harbor bacteria that can make you stink and make you sick.

Soaps basically contain molecules with one end that dissolves in water and one end that dissolves in oils, so that when you lather it up on your skin, it can stick to the grime and at the same time stick to water, so the water can wash the grime away.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] [Zombies]. can cold blooded animals turn into zombies?

[Assistant]
In traditional Haitian Vodou, animals of any sort are not ensoulled and cannot be made into zombies. The particular combination of toxins that produces the highly suggestive zombie-like condition in books like *The Serpent and the Rainbow* doesn't work exactly the same in animals (and even if it did, would require different dosage based on body mass, etc.) In continuities where the condition is caused by a virus, it only works if said virus jumps species, which is easier from mammal to mammal than mammal to reptile or amphibian.

Supernatural curses don't face the same restriction although, again, lack of possession of a soul might be a barrier to transmission - in *Dungeons & Dragons*, this is a non-issue, all you need is a corpse and a *raise dead* spell; other fantasy games have varying requirements, but it's usually not outside the realm of possibility.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] ELI5: how does sleep quality effect mental clarity?

[Assistant]
As you think and operate your brain, electrical signals are passed between the axons and dendrites in your nerves to reinforce pathways.  This process involves chemical reactions, and over the day plaques (the resulting salts) build up on the receptors similar to how they do on a battery as it is used.

At night during one of the phases of sleep, most of your brain turns off and then gets flooded with cleaning fluid that washes away these plaques for disposal.  After getting rinsed, those areas of the brain come back online and can now send and receive and reinforce signals without interference.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] ELI5: how can smartphones manipulate every single pixel on the screen through a thin ribbon cable with a few electrica connections?

[Assistant]
There isn't a single wire for every pixel on the screen. The graphics system will send information about what is on screen in small batches and the display processor takes this and controls what's actually on screen.

To greatly simplify the process, the graphics system may only send a single pixel at a time but it sends one million of these per frame that needs to be drawn. The information is sent left to right, top to bottom. If you have a really fast camera you can actually watch the screen change, pixel by pixel.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[Matrix] Why does it seem Neo lost his godly reality warper powers after the first movie?

Watched the trilogy for the first time not too long ago and found this odd.

First movie: Neo learns the true nature of reality and becomes an omnipotent Buddha who can deflect bullets with a wave of his hands.

Following movies: Neo stills fights his enemies with martial arts instead of turning them into tortillas or something.

What happened here?

[Assistant]
Neo isn't omnipotent, even in the first movie. His main feats are:

- Coming back from the dead
- Fighting an Agent to a standstill
- Stopping bullets with his mind
- Flight
- "Overwriting" Smith

And he displays all of these powers in the subsequent films, often to a superior degree. He can now fight multiple, upgraded Agents and hold off a mob of Smiths. He could stop a few dozen rounds in the first movie, and stopped a hail of gunfire from multiple machine guns in the second and third. He could fly in the first, and flies fast enough to drag vehicles along in his wake in the third. And his final sacrifice is what undoes the Smith virus.

The One isn't omnipotent, he's an escape valve for all of the mounting frustrations of the people who realize that the Matrix isn't quite right. Part of that is the ability to find and exploit loopholes and errors in the Matrix code; his mind can send inputs that the Matrix software interprets as superhuman actions.

As for why he uses martial arts; Neo is faster and more powerful than any handheld weapon. Getting punched by him is worse than getting shot with a gun, *and* its more likely to connect. In his hands, a katana is significantly more lethal than a handgun.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] ELI5: According to data we have discovered 14% of all organisms on earth. Where does this number come from, if the other 86% of haven't been discovered yet (and therefore we don't know if they exist)?

[Assistant]
Statistics like this are created based on looking at what is identified within a group.

Perhaps an easier example.

Let's say people are inspecting defects in a product.  Someone in charge intentionally adds 10 defects.  Then they watch and see what comes through the line, what is discovered by the process.  If people only find 3 of the defects, then they can estimate they're catching 30% of the defects overall, letting 70% of the defects go through.  On the other hand, if all 10 defects are discovered, then they know they're catching all or nearly all of the defects.  The percentage of things they know about should roughly match the percentage of things they don't know about.

It applies to other statistics as well, like crime stats.  They can look at crimes they know happened but weren't reported through official channels, and look at crimes they know about and were reported. Looking at the difference shows about how many crimes go unreported.  It is not exact, but if people are careful about how they create the stats they can be fairly accurate.

For counting species there are several ways it can be done.  One way is like above, to have one group track the number of species in an area and another group figure out how many are new. Another method is a linear regression, figuring out an approximately how many species there should be based on estimates and comparing it to how many have actually been identified.

Also, most of the species that aren't discovered are small things.  We're down to small numbers of new birds and mammals, often they are sub-species that get reclassified as a new species, or they're highly specialized species living in a remote and small geographic area.

It is mostly bugs, fungi, and other small organism that are being discovered in large numbers. These are things that are hard to spot and identify, many only identified because of genetic testing on tiny or microscopic organisms.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
Do other animals get acne?

I was just wondering if it was just a human thing or is it specific to mammals going through adolescence or even do all animals get it?

[Assistant]
Yes, cats get chin acne and "black heads" on their chins. They sometimes will get severe sebaceous zits as well, that fill up with pus.

This usually happens to kitties eating out of plastic dishes. Better to use ceramic, glass, porcelain, or metal food bowls.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
Could someone please explain how government bonds being bought by the Bank of England works please?

I have a few questions and I just cant seem to understand what is going on at the moment. Could someone explain in simple terms:
1. Where does the Bank of England get money from?
2. If its money is linked to the nation, the government, or its ability to print money, then how is buying the governments bonds going to achieve anything?

Im problem being silly for even having to ask this question but if anyone could explain I would appreciate it.

[Assistant]
The Bank of England has the power to create money at will. If they buy bonds, they just credit the former bondholders bank with additional money.

The point of that is buying bonds drives up their demand, which drives up their price. Right now this will be done to stabilise the falling prices of long term bonds.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] If two self-driving cars are on the road next to each other, and their ultrasonic sensors are projecting the same frequency, would the data become muddled? How can the manufacturers account for this?

[Assistant]
I work on the radar version. We use a few techniques to mitigate interference. One simple one is to randomly hop between frequencies. If you have, say, 1kHz of bandwidth that you can split into 1Hz steps, that's 1000 frequencies. If you randomly hop between them, the chances that another sensor will happen to intersect for, say, 5 consecutive transmission periods becomes tiny (10^-15). You were going to average across many transmissions anyway, to average your way through noise and so on, so it's a cheap way to become robust.

By the way, I've heard that manufacturers used to bring their devices to conferences so that everybody could test interference mitigation against one another. Doesn't seem to happen any more, at least for automotive radar.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[Warhammer 40k] When chaos, or some other threat is attacking the imperium, whats stopping them from ignoring everything and just going through the warp all the way to Terra?

Why dont other factions just do what the orks did during the war of the beast and just teleport/ride the warp right up to Terra? Whats stopping them? Are there barriers in the warp preventing them from doing this?

[Assistant]
Logistics mostly. It's a long way to Terra and warp travel is not exactly safe and reliable. While 40K ships are large they still require periodic resupply stops for food/fuel/slaves/souls/whatever. So just heading straight to Terra isn't easy it will take a long time and chances are you'll need to stop off every so often to conquer a nearby planet for supplies.

Plus Terra is VERY heavily defended and leading Chaos forces is a bit like herding cats. It would not be easy for a warlord to put together a force large enough to conquer Terra and actually get it there relatively intact. It would be a bit embarrassing to drop out of warp, broadcast your demands for Terra to surrender and then find out that the beserkers wiped themselves out in gladiator matches, the noise marines all mutated after turning off the gellar fields to "see the pretty lights better", the plague marines all caught some weird disease that turned them into something with far longer arms (but which is quite incapable of drinking recaf) and the Tzeentch sorcerers decided to take a shortcut and got lost.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] ELI5: How come when people experience memory loss they can forget everything and everyone they know, but they still know how to speak?

[Assistant]
There are multiple different types of memory all of which are stored and accessed in different ways in the brain.

Procedural memory, which governs things that are learned through repetition, is one of the strongest, most durable types of memory we have. It's almost impossible to wipe it out without also destroying the brain to the point where the person is no longer really there at all.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5: Why cant we use steam generators for desalination?

Heat up seawater, use the steam to spin the generator, take the steam and condense it. Filter the remainder for usable salt.

[Assistant]
Because how do you heat up the water? Burn a bunch of coal and stuff?

We know a better way to do it, which is to push the water through a special filter that salt molecules can't go through. Still takes loads of energy.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[Doctor Who] Sonic Screwdriver VS Wood. What's up with that?

Why doesn't the Sonic Screwdriver do wood? Why doesn't it work on wood and why isn't there a setting for wood? Even in the 50th Anniversary Special where they *try* to make it work on wood, it takes the Sonic Screwdriver centuries to run the calculations it needs to work on a crappy wooden door in a cell in the Tower of London in the 16th Century, which is even more perculiar when you consider that the Sonic Screwdriver is likely to have more computing power than every computer we currently have on Earth combined.

What the hell is so difficult about getting it to work on wood? What is special about wood that it's more difficult for the Sonic Screwdriver to open a wooden door than it is for the Screwdriver to open a steel reinforced door or break the encryption on a computer or disable a weapon?

[Assistant]
wood is extremely sonically resonant (hence why we make guitars and violins out of it), and has billions of microscopic pores that transfer sonic energy in unpredictable ways. It is also a type of a material that is almost never used on spaceships, space-habitats and by interstellar civilisations, because trees are native to Earth and rare.

It makes wood an unpredictable unknown to any device designed for space technology.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
When a teabag/sugar is put into water heated up by microwave, the reaction is different to water heated up by a boiling kettle. Why?

If you heated water to boiling point by 2 different techniques, the reaction of putting a teabag/sugar into the cup is different.

Technique 1: Mug of water is microwaved to boiling point and then teabag or sugar is put in. In both cases, the water sizzles and turns cloudy, even as you mix it with a teaspoon.

Technique two: Water is boiled in a gas or electric kettle and then poured into a mug. A teabag or sugar is put in. The water remains clear even as you mix it with a teaspoon.

Why is there this difference?

[Assistant]
When water is heated, it can hold less dissolved gas. In a boiling kettle,the agitation causes the excess gas to come out of solution. In the microwave the water heats and becomes supersaturated with gas, even after the water is no longer boiling (<100C). Your introduction of the tea bag provides nucleation points for dissolved gasses to come out of solution (like carbonated water in a chipped or dirty glass).
Edit: corrected to "solution," not suspension.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
What are the physical consequences of skipping breakfast, and why is it so bad?

As the title says, it beeing considered the most important meal of the day, what happens on a biological level and how does that impact the person throughout the day? Like affecting someone's mood and energy, so on. I pull some crazy hours sometime, going to sleep at late night and waking up almost by the end of the morning, so plenty of times, lunch is my breakfast wich I take it isn't very healthy as well.

[Assistant]
Your body relies on your liver for glucose stores when you don't eat. Realistically, a healthy liver contains about 12-16 hours of glucose in it that your body can use during fast- some sources put it closer to 16, some closer to 12. However, after that, your body relies on a process called gluconeogenesis, where your body produces the glucose it needs to supply the brain's and red blood cells' glucose needs.

What does your body break down to make glucose, during gluconeogenesis? The majority of it is amino acids, taken from breaking down your body's muscle (about 60%), and the rest (about 30%) comes from body fat, lactate, and pyruvate from your muscles.

So, the consequences of skipping breakfast and fasting more than 12 hours include: using up your body's glucose reserve and starting up gluconeogenesis, which largely relies on muscle. This isn't so great, since you want your body to to keep muscle; plus gluconeogenesis produces much less glucose than you need to feel perky (it's just trying to keep your brain and RBCs alive) so you feel tired, have less energy to do work, etc.

When you eat breakfast, your body will use that for energy, plus restock your liver for the next night of fasting. Eat breakfast! :)

Edit: this does not mean that with no breakfast, your body is going to start eating itself from the inside out! It simply means that your body is using muscle-derived amino acids as a substrate for gluconeogenesis. You're not going to wake up one day after skipping breakfast for a year and have no muscles left! :) It's simply healthier to have your body use glucose you just ate, rather than go into gluconeogenesis, especially for hormonal reasons (see other comments below).


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
Will the contents of landfills eventually fossilize?

What sort of metamorphosis is possible for our discarded materials over millions of years? What happens to plastic under pressure? Etc.

[Assistant]
Under pressure, landfills are unlikely to have their objects slowly replaced by dissolved calcium.

Whats more likely is that all the plastic in landfills will prevent bacteria from breaking down the contents properly, with the result being a gradual dissolving of all hydrocarbons into oil, just like what happened with early biomass before bacteria evolved that could process lignin.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
How did the British keep the fact that they broke the Enigma code secret?

What statistical formula's did the British and Allied forces use, if any, to decide to take action based on the German deciphered information?

This might get into game theory or statistics, but how could they be sure that the Germans would not 'get wise' and switch their code? How often could they change their behavior before it became suspicious?

P.S. I'm a new redditor and got on the site for askscience, so thanks and keep up the good work!

[Assistant]
This is more a history of science question, but there were a few big factors:

1. The British were extremely successful at keeping the operation a secret, even within their own government. Only the highest commanders were cleared to know the source of the intelligence they received, and they kept it a closely guarded secret, even from their allies and their own officers. They were also extremely successful at both intelligence and counter-intelligence operations, and there was effectively no Axis spy network in Britian. Prominent members of the codebreaking operation were unable and unwilling to divulge their association with the codebreaking group for decades after the war ended, sometimes at great personal expense.

2. Wherever possible, conventional intelligence gathering was used to provide a plausible alternative explanation. For example, Enigma might reveal the presence of an Axis naval convoy, and then Allied reconnaissance planes were sent to independently find and report the convoy on their own. Once these searchers were observed by Axis forces, they provided a cover for the true source of the information. In addition, to go along with the point above, care was taken to prevent Allied forces from guessing that something was up. Multiple search teams would be sent out so it wouldn't appear as though they were getting luckier than they should have been. In another example the British concocted a fictitious spy and fictitious reports from that spy, who was then exposed to the Axis forces via radio traffic so as to provide a plausible explanation for enigma intelligence.

3. The Axis cryptanalyists knew that attacks against Enigma were possible in theory, but thought these attacks were too laborious to achieve in practice. They additionally conducted their own reviews of the Enigma system and found it to be secure. They even decrypted Allied communications and did not find any reason to suspect their device had been broken, because operational security was very tight. In light of that, they looked for alternative explanations of Allied successes and found scapegoats in technology like radar (of course, radar advancements themselves were also significant during the war, so they weren't off the mark so much as measuring effect strength poorly).


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
CMV: Most conspiracy theorists are just borderline narcissists

It seems like the route cause of believing in conspiracy theories is some form of self importance. As in, I am not a sheep, I know the facts, I am smarter than everyone else and one day everyone will see how Im right

This is why things theories such as the Mandela Affect, flat earth, and most political theories exist.  A bunch of people misremembered something, so instead of saying, oh I guess I was wrong they double down and something mustve changed so theyre actually right and everyone else  is wrong.

They also have some main character syndrome. They think that calling a school shooting a false flag is akin to being Katniss Everdeen or something. This is also why there are so many theories related to pedophilia, like Wayfair, Pizzagate, and others. They need to be heros.

[Assistant] I think most people that fall for conspiracy theories are scared. The world is big, complicated and sort of chaotic. That's very scary. Conspiracies tend to make the world less complicated and less chaotic. It's simple because "they're" behind everything. These a clear enemy, with and evil but comprehensive plan.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5: How can the universe be both "infinite" and "expanding"?

Throughout my whole life I've heard that the universe is infinite.  I've also heard that the universe is constantly expanding.  What I don't understand is how it's possible for something to be both infinite and expanding because, to me, the word "expanding" implies that something is finite.

[Assistant]
Imagine a rubber ruler that is infinite in length, that has marks at centimeter intervals in either direction.

This is an infinite ruler, but it can stretch as it is made of rubber.

Now, stretch it. Despite it being infinite the tally marks have moved and are no longer 1cm apart, but a bit further than 1cm. The ruler has expanded, despite being infinite it is now longer than it was before.

That's the general idea behind "expanding universe." it isn't so much that the universe is expanding into something but that the space between two points in the universe are moving apart, the space itself is expanding.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[Iron Man 2] If Ivan Vanko (Whiplash) can miniaturize an arc reactor why hasn't every Tom, Dick and Harry also done so?

In Iron man 2 Ivan uses (large) arc reactor blueprints from his father to do what Tony did *IN A CAVE with a BOX OF SCRAPS* and miniaturize it. If both Tony and Ivan were able to independently do this with minimal resources why is it that well-funded corporations/ governments/ even scientists within Stark Industries, if the blueprints are secret, haven't come up with similar designs? Surely at least 30 smart men = 1 Tony Stark or Vanko?

[Assistant]
Because it's difficult.

Ivan wasn't just some guy.  He is the brainchild of the guy who helped the original Stark figure out the foundation for how arc reactors even work.  Tony proved that the technology is possible, Ivan had access to everything he needed because of his father.

All that was left was filling in some blanks.  Tony guessed them, and Ivan did too.

Most of the world doesn't even know what tolerances you need to contain that thing or why.  We generally don't understand what an arc reactor is or how it works or why.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] [The Elder Scrolls] Did any technological advancement happened between the events of Morrowind and Skyrim?

[Assistant] Some did, but most of it occurred between Morrowind and Oblivion. Between Oblivion and Skyrim there was a demonic invasion and massive civil war that pretty much set everyone on the back foot, development-wise. It doesn't help that Skyrim has always been kind of a backwater, compared to Cyrodil or Summerset for example, and new stuff doesn't get up there very often.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5: Radiocarbon dating is based on the half-life of C14 but how are scientists so sure that the half life of any particular radio isotope doesn't change over long periods of time (hundreds of thousands to millions of years)?

Is it possible that there is some threshold where you would only be able to say "it's older than X"?

OK, this may be more of an explain like I'm 15.

[Assistant] It's also worth noting that there are multiple dating methods that overlap. As an example pulled from thin air, one method has a range of 10-400 years, one that's most accurate at 100-5000 years, one for 300-10000 years.  A sample dated 350 years ago by all 3 methods means the date is fairly well supported.  It also means that the methods are fairly reliable as well.  Now multiply this by hundreds of thousands or maybe even millions of samples, each corroborating together to increase the confidence by some amount.  Over the years, this builds a really high confidence in the methods.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] ELI5: Why does drying laundry on a line leave it wrinkly and feeling crispy?

[Assistant]
The crinkle is from both left over soap and minerals drying and hardening.

When you use tumble dryer, the same hardening happens, but in lots of small spots. On a Line the entire item can harden as one.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
What does "catching a cold" mean biologically?

Is it only due to temperature difference? What are the physiological reactions taking place?

Is it due to an infection? If yes, which organisms and what the temperature has to do with it?

[Assistant] It's an infection by one of a couple of hundred viruses, often one of those called a rhinovirus from the Greek for "nose", that lodge in the nose and throat. The irritation it causes results in swelling, causing the blocked nose sensation, mucus production and a cough as the body tries to rid itself of the source of irritation. One of the automatic responses to infection is to increase body temperature as usually the organisms are more sensitive to higher temperatures than the rest of our body.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
CMV: It isn't injustice to not give non citizens of a country access to things that citizens get

So, this is a little tricky probably as it involves a lot of topics, but the general things still fall under the same umbrella.

I was reading about debates about what to do with Canada's housing bubble. Someone suggested that foreigners, even permanent residents, shouldn't be allowed to own a home. While I think it won't do Canada any good, I do agree that I don't think PR people have the 'right' in the sense that it really isn't immoral to bar them from being home owners. As a citizen, I believe I get the privilege to vote for things that make my life better. Non citizens can still rent, but citizens should get the first pick.

There was also the case of  Rina Sawayama, who is not a British citizen but really wanted British awards. I think it's dumb and I see nothing wrong with her being denied british awards. If she wants to be British so much, she should give up her citizenship of Japan. I have no issue with dual citizenship, but if she or anyone, including myself, have to choose, then yes, I will choose. I don't believe in abusing non citizens, but I think we all agree an award isn't a 'human right' so Rina not getting anything like that is fine with me. (I can somewhat agree if we voted for denying non citizens access to health care, that would be a very tricky debate in which i might tend to agree but even then, I am on the fence)

Similarly, it isn't injustice to kick out illegal immigrants. (This was sort of brought up) If illegals, PR etc get the things citizens get, then what's the point? In some countries, being a citizen through naturalized means means doing more, ie, holding a job for longer, staying longer etc. If illegal immigrants get access to everything I get without paying taxes, why shouldnt' the same be for me. Why is an illegal immigrant in say, Germany, allowed to stay when naturalized germans had to work hard to stay?

I guess in sum, what is the difference between a citizen and non, and what is the 'moral' and 'just' things that citizens should have the privilege of getting?

I know 'moral' and 'just' is grey, and i'll be honest, I dont' really know what i find just other than feeling, so I'm willing to explore it here.

[Assistant] Do you mean all 'things' or just some 'things', like housing rights, awards, and security against deportation? It seems to me at the extreme, there are also 'things' that would be completely unjust to withhold, for example the right to defend yourself in court. If you think your opinion only extends to certain 'things' and not all 'things', can you describe the qualities of a 'thing' that would make it fair/unfair to withhold to non-citizens?


[System] Given the following post, respond as if you're commenting on Reddit:

[User] [FMAB] How does Wrath/Fuhrer Bradley managed to cut a tanks projectile in half? What was his sword made out of?

[Assistant] I suspect that it's not really the sword itself, but his superhuman speed and strength combined with the really preternatural ability of the Ultimate Eye. Perhaps he just "saw" the weakest spot of the projectile with the Ultimate Eye and precisely hit it with the sword so as to cut it in half.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5: How do seeds "know" to start sprouting?

I ask this because I recently bought some flower seeds at a gardening place. The seeds came in a small paper pouch and were all dried up. I followed the instructions on the pouch and the little tiny leaves have just broken through the dirt.
The ones in the pouch still are just chilling out.

How then, did the seeds "know" that it's ok to sprout?

I thought maybe it's the presence of water. But then how would it stop from sprouting in a lake where it will likely not have the proper things to grow?

[Assistant]
Most seeds have to go through a freezing process called stratification befote they will germinate. Stratification prevents the seeds from germinating as soon as they are in the correct conditions (moisture and darkness) but would not have enough time to grow large enough to survive winter. So once the seeds freeze and then thaw, the presence of moisture and darkness allows the seed to germinate. This allows them to sprout at the beginning of a growth season and maximize growth to survive the winter.

Edit: seeds do not always grow in the correct place (as to your question) and that is why seeds are usually distributed in large amounts by the shrub or tree to maximize the chance of a seed successfully growing to full size.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[Ben 10] What would the intended use of the Omnitrix look like?

Azmuth says repeatedly in the series that the Omnitrix was never meant to be a weapon, that it was supposed to instill empathy for other species and let the user walk in the shoes of other aliens. But, what would this look like?

[Assistant]
Pretty much everything's been said already but Azmuth once said that the Omnitrix was essentially a parallel to Noah's Ark- A way to preserve and revive any race that has gone extinct.

An example of this is Cannonbolt. In the episode that form was introduced in, Ben and co have to figure out how to deal with a massive tick-like alien that devours the life of entire planets before it destroys the Earth. One of the worlds this monster had already destroyed was the home planet of Cannonbolt's species- They were not driven entirely extinct, but were nearly wiped out and scattered to other planets. Through the Omnitrix, Ben as Cannonbolt unknowingly avenged that form's homeworld.

Another would be the Highbreed. The Omnitrix held a DNA sample of them, one which still shared the genetic deterioration that plagued the entire species, but was able to divert them from extinction by repairing the DNA of the entire species in one fell swoop, using materials taken from other species.

On the original stated purpose of building empathy for other species- Ben, despite his way of using the Omnitrix in most cases, is a pretty good example of it working as intended. Living as so many different aliens, learning their limitations and capabilities, Ben absolutely has a strong understanding of what it's like to live as so many alien species in different environments. He's been a Vladat burned by daylight, a Tokustar towering over the world, a Galvan struggling in worlds built for giants, hell he literally had kids as a Necrofriggian. He's absolutely got empathy for alien species and an understanding of what it's like to live as them.

Albeit, in most cases he lacks cultural knowledge of most of the Omnitrix' aliens- This is outright addressed in the OS when Ben meets Tetrax. He fights him as Diamondhead and is sternly rebuked by Tetrax for treating his alien forms like costumes, with no real regard for their worth- Tetrax is a proud warrior, but Ben as Diamondhead is a brute and a mockery of his people. Tetrax helped Ben learn what it meant to be a Petropian, and that carries forward throughout the rest of the series and its sequels as Ben continues to unlock more and more of the Omnitrix.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
I'm interested in an academic career in the Humanities (lit or philosophy), but also terrified by the bleak job market. How should I prepare myself?

I'm currently applying to undergrad degree programmes (I have some offers from universities, but not all, yet) and my dream job is being a researcher/lecturer at a university. Unfortunately I've read and heard many terrifying stories about the bleak academic job market for the humanities and how even if you're willing to go to the remotest part of the globe to secure a job, you might not even get one, or you might end up jumping from one adjunct position to another without securing a tenure-track job.

Additionally, I've also heard that getting a PhD in the humanities and failing to get into academia will leave you stranded because you're nearly thirty without any working experience and essentially you'll be jobless and broke.

As I'm not from a rich family, and not particularly confident of my ability to marry a rich person (lol) the future sounds bleak and terrifying. At the same time I don't know if there's anything more important to me than ideas and books--I feel more at home and alive doing coursework than anything else--I'm the kind of person that gets obsessed and will work compulsively, and I also have emotional and mental health issues that make me doubt my ability to find happiness elsewhere. And all of this makes me think my only chance of finding fulfillment is pursuing an academic career.

So I'm not sure what I should do. Should I just go for it? Or find something else to do? Are there people here who've left academia and found fulfilling jobs elsewhere? Any advice would be really appreciated!

[Assistant]
Slow down.

You haven't had any undergrad classes and its not clear if you're good at any of the things you want to do.

Further, there is political maneuvering involved in academia that you may find yourself unable to perform. You may not want to or have the opportunity for career advancement.

Further its not clear if you're undergrad is sufficiently good to do a real job. The opportunities, presented to people at ivy league schools are substantially different from those presented to state school students.

Come in to college with an open mind.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
What investments have done well in Japan since the stock market peak in 1989?

The Japanese stock index, the Nikkei 225, peaked on December 29, 1989 at 38,915.87.  Over 30 years later it is still below the peak at 28,400.  Have any sectors within the Japanese stock market produced a positive return over this same period?  What was the EPS of the Nikkei 225 in 1989 and what is it today?

[Assistant] Interest rates on Japanese treasuries hit 6% in early 1990. If somebody held 30 year bonds your essentially risk-free investment would have nearly sextupled during a period where inflation increased about 15%.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
Why is the pH scale 1 through 14 instead of 1-10 or 1-100?

Goodness, can't edit titles.

The lowest pH is 0 and not 1. So the title should read "Why is the pH scale 0-14 instead of 0-10 or 0-100?".

[Assistant]
pH is defied as -log([ H^+ ]), where [ H^+ ] is the concentration of H^+ ions in mol/L.

Water auto-dissociates into H^+ and OH^-.  The equilibrium equation is:

H_2O <-> H^+ + OH^-

so we can write the equilibrium expression for this as:

K_eq = [ H^+ ] * [ OH^- ]

At 25 deg C, K_eq = 1 x 10^-14.  If H^+ and OH^- are equal, as would be the case at neutral pH, then both would have concentrations of 1 x 10^-7 and this would be equivalent to a pH of 7, so that's where that number comes from.  Given a concentration of OH^- as 1 molar, then we'd get an H^+ concentration of 1 x 10^-14 and a resulting pH of 14.  The converse can be done with an H^+ concentration of 1 molar to show that the pH would be 0 in that case.

Could you have an H^+ concentration of greater than 1 molar?  Yup.  You'd end up with a negative pH in that case, which is perfectly fine.  Same deal with a pH greater than 14.  These situations require a very powerful acid or base, but that's easy to come up with using a concentrated strong acid or base solution.

There's one little cheat above - pH isn't really the negative log of the H^+ concentration, but rather the H^+ ion *activity*.  This is complicated and difficult to measure experimentally, but is actually important when talking about very concentrated acid or base solutions.  In these cases the actual pH isn't terribly accurate or useful, but rather reporting the concentration of the acid itself (ionized or no) is more useful since you rarely care what the pH is in the concentrated acid since you want to know what the pH is going to be when you dilute it.  For most cases pH works fine.

One weird quirk about the dissociation constant of water - like all equilibrium constants it changes with temperature.  That means that if you change the temperature you change the pH scale and what number corresponds to 'neutral' pH.  At high temperatures a neutral pH is actually closer to 6 than 7.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5: How can a absurdly small amount of deadly poison, like Botulinum, kill a human?

I cant understand how a small grain, a speck of toxin can kill a grown adult?

If this has been asked before please redirect me to the post.

[Assistant]
The botulism toxin can do this because it's an enzyme - it cleaves a critical neurotransmitter protein in half, then resets to do it again.

And again

And again

A single molecule can keep dicing up protein and disabling a neuron for hours before it finally degrades.

In that time, you've been unable to breathe because the signal pathway is all locked up.

Compare that to a poison molecule like carbon monoxide that disables a single protein and is then permanently expended.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5: How does an avocado develop nutritional fat in it, while most every other fruit has zero fat?

See title. I can't think of any other fruits with fat in them, or at least a significant amount. What makes the avocado special and how does it do that.

[Assistant]
An average avocado contains 6.7 mg if monounsaturated fatty acids. All plants contain the instructions to make these, but avocados are unique to produce these in the fruit instead of the starch and fiber most plants use to make their fruit edible. (Yes, edible is the goal. Edible fruit means that animals poop out the seeds and distribute the seedlings.)

Avocados belong to a genus of plants called persea, which use fatty acids in their leaves, stems, and seeds to repel water in wet environments and to help survive in hot conditions. Avocados are one of the only species that had figured out that these can be used to make edible fruit.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
Could a human replace solid food with liquid equivalent?

What would be the most optimal diet in such case, and what does it  consist of?

[Assistant]
This is a common occurrence with sick patients who are for whatever reason unable to eat solid foods.  It's called enteral feeding, and there are many different compositions.  This is what Harrison's has to say:

>Standard Enteral Formula
>
>1. Complete dietary products
>  a. Caloric density 1 kcal/mL
>  b. Protein 14% cals, caseinates, soy, lactalbumin
>  c. CHO 60% cals, hydrolyzed corn starch, maltodextrin, sucrose
>  d. Fat 30% cals, corn, soy, safflower oils
>  e. Recommended daily intake of all minerals and vitamins in >1500 kcal/d
>  f. Osmolality (mosmol/kg): 300

There are variants that tailor to specific nutrient needs, but that's the basic idea.  Uptodate has a similar description:

>Standard  The following characteristics are typical of standard enteral nutrition:
>
1.     Isotonic to serum
1.     Caloric density of approximately 1 kcal/mL
1.     Lactose-free
1.     Intact (nonhydrolyzed) protein content of about 40 g/1000 mL
1.     Nonprotein calorie to nitrogen ratio of approximately 150
1.     Mixture of simple and complex carbohydrates
1.     Long-chain fatty acids (although some are now including medium-chain and omega-3 fatty acids)
1.     Essential vitamins, minerals, and micronutrients

>Administration of 18 kcal/kg per day is a reasonable starting point for most critically ill patients. Most patients require additional free water.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] ELI5: Why do I feel less tired in the morning after only sleeping a few hours rather than sleeping a full night (8 hours)?

[Assistant] Sleep cycles are approximately 1.5 hours. So you're better off with 6, 7.5, or 9 hours sleep. 8 hours is a bad amount of time to sleep. The further into the middle of a cycle you are, the more you feel like crap when you wake.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
CMV: "Life is unfair" and "That's the way it is, just accept it" are worthless in discussions about changes in society and laws.

This is probably the go to argument for anyone who can't justify some specific law and custom despite the harm it might bring but also wants to keep it for some reason.

The argument seems to ignore that the world can improve and in fact did, mainly because of people who didn't accept the status quo. That notion seems to be literal toxic defeatism and adds nothing to the discussion.

It was also used through history to justify various institutions (or support indifference to injustice), for instance back during the early 19th century many American politicians "considered slavery immoral but thought it couldn't be changed" leading them to accept (and sometimes even profit from) the institution just like someone who didn't think once about the morality of slavery.

The idea that we should strive towards perfection, even if the final goal is too idealistic, should be our guiding principle because that way we would be able to maximize human happiness and benefit others as much as we can.

EDIT: I noticed many people used counter-examples that discuss how those phrases can be useful in our daily life, I agree with that, that's why I said "are worthless IN discussions about changes in society and laws", doesn't mean they have no uses at all.

[Assistant] Sometimes taking a moment to express toxic defeatism can be cathartic.  For some people, being optimistic and positive in the face of overwhelming challenges is difficult and allowing themselves some time to express that frustration is akin to blowing off steam after work.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[Star Wars] Can ships sit in hyperspace?

My understanding of hyperspace is that it's an alternate dimension that ships punch into through complex mathematical routing and a tangle of relatively poorly-understood technology known as a hyperdrive.

Said alternate dimension has different physical laws which allows for FTL travel along predetermined routes.  However, gravity still trickles into this alternate dimension, as evidenced by the relative dangers of blind jumps--running into a star or planet can be severely day-ruining.  But while gravity persists through hyperspace, not much else does.

My question: could a ship simply drop into hyperspace to escape an enemy vessel, but not go anywhere, and simply enjoy invulnerability for awhile--or is FTL velocity a necessary quality for hyperspace travel?

[Assistant]
well there are two problems, one is that you'd have to run your engines in a way they are very much not designed to do, they'll stall out.  You can make a hyperspace drive that simply puts you into hyperspace, but there's no point because; you are still quite detectable in hyperspace.

objects in hyperspace interact with realspace objects all the time, whether they be the gravity shadow of an uncharted asteroid or the gravitons emitted by an interdictor.

In fact the only reason one can't detect ships at ftl is because they're moving faster than the particles you're using to detect them.  If one simply entered hyperspace without making use of the one real advantage of hyperspace, that it allows one to easily and with very little energy travel at ftl, you would in fact be quite vulnerable.

while you are correct that pretty much only gravity influences through the real/hyper-space gap it influences *quite* strongly.  Also gravity detectors are very very advanced, with an ordinary ship model able to discern human sized objects at a a distance of 1 au, making a sitting hyperspace shadow *very* obvious.  Also it takes less than a gram of realspace mass to knock a megaton of matter out of hyperspace, meaning child throwing a rock could knock a star-destroyer out of hyperspace if it was just sitting around.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[Supernatural] What is it about going to hell spiritually, that changes what you need physically.

Specifically why did Sam and Dean not even need sleep after returning from hell.

[Assistant] Dean required sleep like a normal person, he just had nightmares from the trauma, like PTSD. Sam was a special case because (spoilers) he returned without a soul, which is why he didn't need to sleep. Once he got his soul back he slept again.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] ELI5: So what exactly is the difference between the different tiers of gasoline (e.g. "Regular"and Premium)?

[Assistant]
The only difference is the octane rating (the number on each grade). The higher the rating, the more the gas/air mixture can be compressed before spontaneously exploding.

Higher-performance cars compress their gas/air mixture more, so they need the gas with the higher rating. If your car doesn't need it, there is no advantage to buying the more expensive gas.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[MCU] Did Loki know he would die trying to assassinate Thanos?

The whole scene seemed very final. I'm not sure if this was just cinematic effect or if Loki actually knew he would die trying to kill Thanos. If that were the case, why would he try it anyway?

In addition, Loki is a god of mischief and trickery with thousands of years of experience, was access to powerful illusion magic. You'd think he would come up with a better lie than, "I pledge to you my undying fidelity." And you'd think he would send in a clone to do it instead of going in himself, just in case Thanos saw through the lie.

[Assistant]
At that point Thanos has the space stone, the only source of Bifrost is dead, Thor is captured, and Loki likely doesn't believe he's ever going to get another shot at killing Thanos.  He knows his odds of success aren't high (Thanos just manhandled Thor and Hulk, the two things Loki is most afraid of in the universe), but he appears to sincerely believe he has a shot at killing Thanos.

As for the speech, Loki sweet talked his way into Thanos' good graces once, to the point where he was given an Infinity Stone and an army.  He likely used very similar lines, poking the Mad Titan's ego to get him to let his guard down.  One of Loki's recurring flaws is trying the same trick twice (or apparently dozens of times in Thor's case) and assuming it'll work every time.

Loki could have sent a clone or an illusion, but the chances of success would have been lower and the cost of failure would have been essentially the same.  Loki probably can't survive in the vacuum of space as well as Thor can, and Loki knows how vengeful a person Thanos is.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[The incredibles] If they are gone then what do we do?

Some things that I never understood, in the events of the first movie we have that the superheroes are banned because of some dude that sued Mr. Incredible, for ruining his death? It seems like there are no campaings against suicide in that world. Yeah, that triggered that all the destruction that Mr.I causes came to bite him plus loosing Bon Voyage (which wasnt his fault) thats fair, but do all heroes have to pay for that? I get that they would stop giving him support if the government saw that the cost was in the millions, or the sponsors (if it is like Tiger & Bunny or BNHA) but aganst supervillans I guess damage is expected, not to mention I doubt that all made damage like Mr.I...

Other thing is, in MCU Vision says that their presence causes that others want to challenge them, and makes sense like, ok there are classic bank robbery, police, conflict etc. add super powers criminals will make their superpowers to compete with heroes, or the classic "heroes never helped me so Im gonna make them pay" scenario.

But what happens if you just take super heroes away? Would police officers just be able to face, the sandman? The mandarin? Thanos? I remmeber there was an episode in the powerpuff girls were they got prohibited to use their powers and at the end the people that prohibited the use got attacked by some monster and they didnt have any other option than let them fight, I think the same would apply here.

[Assistant] The Incredibles isn't like Marvel or DC, there's no aliens or magic, there are only those few humans born with superpowers. And there's no Superman or Jean Grey or Homelander, there's no super who's powerful enough to take over the world, the military can defeat any of them. And that's probably why the villains in Incredibles are all tech-based, since they're actually *more* powerful than most supers, either because their tech is physically more powerful or because they can lay low or hide behind money and political power instead of relying on powers. Any super who openly becomes a villain will get shut down immediately by the military. If Mr. Incredible decided to become a bad guy, he'll just get met by a Predator missile.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[Quake 2] why don't they just nuke the fuck out of the Strogg planet?

Instead of bothering with that idiotic ground war/ invasion?

[Assistant] The planet was fortified for just that. Pretty much everything major was in underground bunkers or behind reinforced walls. Plus their defense cannons could probably handle shooting missiles out of the sky.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5: Why is brown such a "default" colour in nature?

Brown seems to be such a default colour for things in nature and in day to life. Why is it so common for things to be or turn this colour in contrast to the vast array of other colours around?

[Assistant] Because brown is a result of mixing pretty much any two/three pigments (try it with red and green). That being said, its also because plants have usually two or three types of pigments and carotenoids are useful and abundant, and carotenoids range from yellows, to oranges and reds. For mammals that need to camouflage, it was useful to mimic the environments that are murky/shadowy especially since most mammals evolved from animals active in the mornings/evenings - hence ones producing melanin hit the jackpot and blended well with murky undefined colours such as varieties of brown.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5: How do they determine statistics like 8 million people in the US have __ disease and another 1 million are undiagnosed?

I work in healthcare and there have been multiple times where Ive seen disease prevalance statistics that include undiagnosed cases. If they have not been diagnosed then where do they get those numbers from?

[Assistant] By reliably measuring rate of infection in smaller populations then extrapolating the results to larger populations, researchers compare the extrapolation against reported cases. The difference between these quantities becomes the assessment of undiagnosed cases, which is always subject to some measure of error.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
Why is the flight duration different when going to a destination and returning from the destination?

I wasn't quite sure how to describe this.

I looked at booking a flight from SEA (Seattle Tacoma, USA) to ICN (Seoul, South Korea). It's a nonstop flight.

SEA -> ICN is 11hr 20min
ICN -> SEA is 10hr 24min

Why is the return flight one hour shorter?

[Assistant] As explained in Tex-Rob's comment this is due to the jet stream. Air that rises in the Florida/Cuba area travels high in the atmosphere and falls at a boundary along a static polar cell that sits on the pole above 60 degrees North. As the tropical air retains some of its original equatorial rotation its fast when it reaches the north. East bound planes are guided into these tailwinds along the boundary polar cell boundary.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[LOTR] Why didn't Sauron breed Uruk-Hai?

He knew what Saruman was up to, so he would have the know-how. Uruk-Hai are superior to orcs in every way: taller, stronger, faster, and most importantly, they can move in sunlight. Why didn't Sauron go with them?

[Assistant]
Two points:

1. All orcs can move in sunlight, most of them just strongly dislike it.
2. Sauron had larger Uruks as well, though the movies make such a big deal out of Saruman's Uruk-hai that you might think Sauron had none.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[LOTR] Why dont royalty ever wear helmets during battles? Aragorn, Boromir, Elrond, Legolas, etc. never use them. Even Theoden ditches his quickly. Is it a cultural thing?

It seems like it would keep them all a lot safer.

[Assistant] Many of the people that you named are leaders who, in addition to actually fighting, are also important for maintaining the morale of their men. They can do a better job of that if they can be clearly identified, which is easier without a helmet. As for Legolas, a helmet might interfere with his archery.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] ELI5: Why does our skin take on the texture or impression of whatever we sleep on, instead of staying elastic and returning to its normal state immediately?

[Assistant] Laying on something long enough to leave a dent causes the fluids in the tissues to be squished into surrounding areas instead. It takes some time for those fluids to find their way back to where they belong.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] When a tadpole becomes a frog, does Aquaman lose the ability to talk to them?

[Assistant]
Prime Aquaman can't "talk" to marine life as marine life generally aren't intelligent enough to talk.

He can only compel them to do things by altering their midbrain.

So if a tadpole has a midbrain, he can control it.  Same goes for a frog.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
Why dont tattoos disappear?

If your skin falls and and replaces itself, how come your layers of skin with the tattoo doesnt fall off?

[Assistant]
The epidermis sheds. That's the upper layer. The dermis, underneath, doesn't shed, and a well-done tattoo is in the dermis. A poorly done tattoo will shed all or bits over time. (I have both well done and poorly done.)

However, sun exposure can fade the color, if not protected.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
CMV: Language That is Prevalent in Academic Articles, and Research Makes Reading The Articles Arduous and Unnecessarily Difficult.

Just For Background:  I am currently getting my masters in Political Science and hope to eventually get my PHD so that I can do research and teach.  This view is mostly focused on Writing in the social sciences, and humanities, because that is the majority of what I read.

I have read many research papers and articles where the language used seems to deliberately complicate a topic that could be explained just as well if written in a style that was more accessible to people.  It's not rare for myself or other students to have to read a section five or six times to understand the argument the author is trying to make, however once we understand the language, the idea itself is relatively simple.

This makes academic research inaccessible or at the very least has a gate-keeping effect to lots of people.  There are many great ideas and quality research that never leave the relatively small sphere of academia in part because of how damn hard it can be to understand what the author is reading unless you have an extremely advanced and sophisticated vocabulary.

I am not arguing that ideas need to be simplified, I just believe that there is no reason to use language that most college educated people would struggle to comprehend without making a real effort to do so, especially when the ideas can be presented in a much more accessible  way.  I believe that using overly-complicated language is very prevalent in academia, specifically social sciences and humanities as that is what I am familiar with.

[Assistant] The purpose of a research paper is not to appeal to a general audience  that is the job of a science communicator. The purpose of a research paper is to show findings and be as precise as humanly possible. The intended audience of a research paper is other researchers, who should be familiar with all these complicated terms. They use all this technical jargon because it makes it easier for them, it does not matter to them that it makes it harder for you.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[Fullmetal Alchemist] So Human Transmutation requires a soul right? What if I kidnap another person and use them as the source for my transmutation? Exchange their soul for the soul of another?

This is Hypothetical, I did not kidnap another person and strapped them into a transmutation circle.

[Assistant]
That's pretty much the concept behind the Philosopher's Stone. Still, without properly having a Philosopher's Stone on you, or turning them into one, it could still be a risk.

The series is a little unclear about what happens when you use a soul as energy without making it into a philosopher's stone. When Ed did it, he used his own soul, which would have fulfilled Truth's requirement, but it seems to me like trying to use someone else's soul as fuel without a philosopher's stone would be Human Transmutation in and of itself,  so just offering up their soul may not be enough for Truth.

You did get that first thing wrong, though. Human transmutation does not require a soul. It requires a price. Ed didn't lose his soul, he lost an arm and a leg. Al didn't lose his soul, he lost his body. Izumi lost her ability to have children (and a good chunk of her other internal organs). Mustang lost his sight.

The only time we see someone use *a soul* that isn't part of a philosopher's stone to perform human transmutation is when Ed heals a lethal wound to his abdomen by using his own soul as the price.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[Cyberpunk2077] why does anyone use cybernetic implants when they are usually used against them?

Hacking is so easy in this game for you or your enemies. It makes watch dogs look like algebra.

Like i would never get a cybernetic implant if i knew my potential enemies had netrunners that could force me to commit suicide with them, make me lose control of my limbs, or even explode. Why does anyone trust and use cyberware when 99% of the time its just used against them? Wouldnt non hackable enemies ALWAYS be more dangerous?

[Assistant]
Cyberware is basically mandatory for most jobs. You think you can be an analyst for arasaka without neural stim and datanet implants? Work at a millitech dock yard without gorilla arms and fatigue reducers? Even prostitutes need implants to meet high end clientele needs.

Sure, you can find the odd 'ganic ripperdoc, but most generally don't have a choice, and they're so culturally normalized that not having implants is seen as weird.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
Why exactly does String Theory require more than four spacetime dimensions?

And are there predictions or ideas of what those extra dimensions actually are and how they... function?

[Assistant] To put it simply, there's a certain equation that has to be solved, and you can put in a variable D for the number of dimensions. You'll find that for all values of D except 26 or 11 (depending on your assumptions), the equation goes to infinity.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
Eli5: How come we don't bleed out during surgery?

I've always wondered how the blood doesn't just keep flowing out of you like say, during knee surgery when they cut you open to expose your knee bones. I've always wondered how this works.

[Assistant]
Blood doesnt wander wherever it wants the body, its largely confined to the circulatory system.  In an ideal world, you just dont cut any of the blood tubes.

Surgical cutting instruments are *extremely* sharp, which lets them cut through tissue very cleanly without tearing open more capillaries than is absolutely necessary.

Surgeons will avoid cutting through larger veins and arteries whenever possible, and can burn or clamp them closed if safe/necessary to do so.

Sometimes this isnt possible, and the patient will require blood transfusion(s) during the operation because a major blood line had to be opened.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[Daredevil] Hows DD get around so quick?

He soundly beats police to crime scenes on atleast 2 occasions..  Did he run there??

[Assistant] He travels over the rooftops using parkour, and Hell's Kitchen is only about 20 blocks wide. Also, he can react to crimes as soon as they happen, while the police have to wait for someone to get out their phone, call the switchboard, and then carefully explain what they saw and where they were.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5; Why is it impossible for me to imagine a completely original human face I've never seen before?

Every face I think of is some combination of other faces I've seen before.

[Assistant]
Because our own definition for a face is based on previous examples. It's like saying "think of a color you've never seen before." How could you? Our experiences dictate the possible configurations.

Of course, if you really wanted to be creative, you could still come up with something new; a person whose nose droops to their belly button, or a mouth that opens in the wrong direction. These are, however, impossible (as far as we know), so they become ridiculous and grotesque. The only way to know a possible face *isn't* ridiculous is to it in real life.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
CMV: Social media has ruined romance.

Romance is defined as a feeling of excitement and mystery associated with love. However, with social media playing an increasingly greater role in our lives, it has changed the course of relationships and romance forever. Social media depersonalizes relationships and sets unrealistic standards for romance.

There is no doubt in my mind that social media has changed the way humans communicate, not just in regards to relationships, but in general. However, people are using media more and more coming to an average of 2 hours and 35 minutes per day.  Yes, social media has increased communication by making connections instantaneous, however, this instantaneity comes at a cost: poorer communication skills. Nothing beats in-person communication: feeling the presence of your significant other near you, looking them in their eyes, and seeing their real-time reactions. Social media has a great capacity for miscommunication and misunderstanding. A text or status update can easily "get lost in translation" of the Internet. When you put a message on a screen, you lose the contextual clues of facial expressions, voice inflection, and body language.

Social media also raises the bar for what we consider to be romantic. On Instagram alone, you'll find over 14 million posts tagged with #CoupleGoals ranging from magical dates, to adventures in foreign countries (#baecations), or video edits of someone's significant other. This media shoves this perfect image of couples in your face, and it innately plants a seed of insecurity within you. Your relationship needs to be just as extravagant as another's, you need to be your bae's #WCW every day, and you have to share every moment of your perfect relationship online. Instead of working on the realities of a relationship, people work on how their relationship looks to the outside world. But at the end of the day, you can't appreciate what you have when you're constantly chasing what appears to be.

The Internet and social media have brought so much to our world, and it's changed the dynamic of social interactions forever, but at what cost? Relationships are harder now because conversations became texting, arguments became phone calls, and feelings became status updates.

[Assistant]
It's all aimed at selling you something, nothing new.
Before social media saturation - and still, many take their idea of romance from TV/Film which is just as stupid and unrealistic. At least online versions are real people albeit exaggerations that are not nearly as happy as they appear.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
CMV: Paying off everybodys student loans is a bad idea

As somebody who just graduated college and payed off all their student loans, I believe that making the taxpayers pay off everybodys student loans is a bad idea.

1. If we could get that money, it would be much better used elsewhere (e.g. improving the quality of public schools especially in poor neighborhoods.)

2. Paying off everyones student loans would not solve the problem in the long term. In fact, colleges would just raise tuition even more if they know the government will pay for it. Tuition is so high right now because its all going to administrative bloat which isnt improving the quality of education. For example, my college employed like 100 diversity officers that get paid six figures. I have no idea what that title means or what their job could possibly entail. Thats just one example, theres just a lot of wasteful spending in general.

3. Not everyone with student loans is a super industrious victim who was let down by the economy and society. There are a lot of people who irresponsibly took out ridiculously high loans to go to out-of-state colleges because they just wanted a change of scenery or  knew too many people going to their in-state school. I know lots of these people.

4. It is not fair to people who worked their asses off to pay off their student loans or made sacrifices to not accrue so much debt in the first place. Im sick of seeing the argument We shouldnt have antibiotics because its not fair to the people who died of diseases or freedom is a slap in the face to people who were slaves or some bullshit variation of that. I cannot believe how many times I have seen this on the front page of reddit and how much people support it. Its so fucking painfully obvious that taking out a loan is not the same as getting a disease. You dont voluntarily sign up to get a disease. When you take out a loan you are fully aware of the consequences. The student loan website walks you through a bunch of shit to make sure you know full-well what you are doing and plan out how you are going to pay it off and stuff.

[Assistant]
1: Eliminating student loan debt would be a pretty efficient sort of economic stimulus. The people holding the lobs will almost certainly spend the extra income on something.

2: Nearly everyone pitching student loan forgiveness also has plans to reform how college gets paid for. The student loan forgiveness would be part of a package deal to reform how people pay for collegenot a one time gift.

3: The fact that some people overspent on a lavish college experience isnt really an argument. So what? It would be impractical to try to go back and determine what was immorally wasteful and what wasnt. The proposals are usually for canceling federal student loan debt, and theres pretty sharp limits on that. The people living it up on borrowed money usually ended up having to dip into other sorts of loans since the yearly limits in the federal loans basically cover tuition.

4: The fact that a student loan forgiveness program wouldnt help everyone equally also isnt really an argument. Its still morally preferable to help many people even if it wont necessarily help everyone in every situation. Youre effectively just saying that some people who already paid off their loans deserve an advantage for having struggled more with burdensome loans. More to the point, the loans were significantly cheaper to pay off many years agothe further back you go the less of a burden the loans were to pay.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] ELI5: When does our brain choose our dominant hand?

[Assistant]
Its not entirely clear exactly what causes someone to be left or right handed, but its probably genetic. So its not really your brain choosing, its just how the chips fall when youre conceived.

The current theory is that basically the left side of your brain handles language and also controls the right arm. So as we developed written language, it became beneficial to basically have the hand you write with be controlled by the part of the brain deciding what to write. So a gene that made people right hand dominant became favorable.

There isnt actually a similar left handed gene. You either have the right handed gene, or a different gene that could wind up going either way. You could have this second gene and still be right handed.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5:How does Kickstarter prevent fraud?

Ive seen now quite a few kickstarters that have been very close to being funded, but missed out by only a small amount. What is there to stop the project organiser from contributing to his own kickstarter? By creating a dummy kickstarter account, using a different account, they could contribute a small amount to push it over the limit and guarantee they get thousands.. They wouldnt lose anything, as they donate to themselves.

Obviously kickstarter must prevent this.. But how?

[Assistant]
But if you need 16 grand for your project, and you get 15 and put in the last grand yourself, thats effectively the same as having just set the bar at 15.

I mean the bar is totally arbitrary, its just the point where you defined "yeah thats enough money to do this" if you decide 15 grand is enough and you can stump the rest yourself, who cares?


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
How long does it take for the body to replenish blood that is lost? And why does it take that long?

I have seen from various websites that for blood to fully replenish it takes 4-6 weeks. What I dont understand is why it takes so long and what variation there is depending on the amount of blood lost I.e. 15% vs 30%?

[Assistant]
Creation of RBC's. Millions of them are being made and dying every second but in more or less equal amount. When you give blood you lose more red cells and the body needs to make more to replace them. 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.The bone marrow produces stem cells, the building blocks that the body uses to make the RBC'S.

Your body makes about 2 million new red cells every second, so it only takes a number of 3-4 weeks to build up stores of them again.

Also a number of other messenger proteins also stimulate the production of WBC and platelets cells in the bone marrow, and over the next few days levels return to normal but quicker than RBC.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[The Witcher] What are the chances of another large scale conjunction of spheres? Would our world be prepared to handle one akin to the first?

I'm especially worried about the amount of monsters that'd be thrust into our world. It's not as if we have many witchers to combat them anymore. What if another sentient race such as humans arrive?

[Assistant]
Everything is cyclical in the world.

Conjunctions birth new populations of magical creatures and energies and the world reacts.

New witcher academies would open as the populace loses their hatred of magic and magic beings as seen in Novigrad during the Witcher 3. Their notions of holy fire and evil magic would wane as their need of witchers overtook their prejudice.

The world of men would wane slightly as large groups of creatures retook some of their most land.

Ages would pass and the world would thin out magical beings and places. Cities would forget that these monsters even existed as they disappear from the world as before.

Witchers, having completed their duty, again become targets of fear and misconception. Their numbers fade and man's numbers rise again.

And then the 3rd conjunction occurs...


[System] Given the following post, respond as if you're commenting on Reddit:

[User] ELI5: Why is it so comfortable to put ones feet up?

[Assistant] Normally your heart must work to pump your blood back up your legs all the way from the bottoms of your feet, lifting it as much as four or five feet upwards if you are standing up. When you put your feet up, and lean back in your chair, your body's circulatory system is much closer to all being on one level plane, and your heart only has to pump the blood back and forth rather than up and down, which is much much easier. Try lifting a large cup of water off of the floor up to your mouth and then putting it down again and then lifting it back up again over and over continuously and see how fast your arms and legs get tired. Basically, when you put your feet up you're reducing the amount of work your heart, the hardest working muscle in your body, has to do, and giving it a nice rest.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5: Why do some websites simply refresh when I hit the back button, not allowing me to actually go back?

Is this intentional? It usually happens with amazon, I've noticed. I'll hit 'back' but it won't take me back at all. If I hold the back button, I'll see the list of previously visited websites, and there will be several identical copies of the page I'm currently on. It's annoying. Why does it happen?

[Assistant] Some sites have a middle page between where you clicked the first link to the page you get to, the middle page has scripts that send info before redirecting you to the page you want to get to, so when you click the back button it sends you to the page that redirected you and not to the page you first clicked the link on.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] If inflation devalues currency why is the dollar so strong vs euro?

[Assistant]
Inflation is not the devaluation of a currency. Its the general rise in prices.

Sounds the same but they are different. Its important because the dollar for example has appreciated significantly in recent months. But the US has also had inflation.

Exchange rates between currencies are more than just the relative inflation rate between the countries. Its a very complex relationship.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] ELI5, Why is Molten Salt(?) Used for heat transfers?

[Assistant]
1. Relatively large heat capacity: on the order of 1 J/gK
2. Relatively dense: on the order of 2 g/cc
3. Very good working range: depending on your choice you get a few hundred degrees of working temperature between "melts" and "boils/otherwise breaks"
4. Relatively cheap
5. It turns out that a LOT of compounds are technically salt

When you're designing a heat transfer system, you want something that can carry a lot of heat per unit volume, that is relatively cheap, and that works over the range of temperatures you need.  Liquids work well (in comparison to gases, which don't usually hold as much heat in a given volume), and if you're looking for a liquid that works at 500C -- pretty much all the results you'll find will be different salts.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] ELI5: If you were to raise a large column of water from the ocean in a top-sealed cylinder with an open bottom in the water (say 300m high), would the water pressure at the bottom of the cylinder be equivalent of a depth of 300m?

[Assistant] You wouldn't be able to keep the water in the cylinder when you raised it. Atmospheric pressure would start pulling a vacuum in the cylinder at about 30 feet, so you would end up with 30 feet of water in your cylinder and the rest empty (or realistically full of water vapor, as the water would be boiling).


[System] Given the following post, respond as if you're commenting on Reddit:

[User] ELI5: Where does the bond money go after bailing someone out and why do you only need to pay 10%?

[Assistant]
The bondsman pays the bond to the court and once you've made all of your court appearances he gets it back.

He charges you the 10% for you borrowing the money until your trial is finished.

Bail isn't a "fee" that you never get back, it's just a cash guarantee that you aren't going to run away.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] [Harry Potter] what is the difference between a spell, charm, jinx, hex, curse, enchantment, etc. Are there specific magical differences for each or are some of them just synonyms?

[Assistant]
A spell is the generic term for any magical ability cast.

Transfiguration is the alteration of the object's form or appearance.

A charm alters an object's inherent qualities i.e. its behaviour and capabilities.

A jinx is minor dark magic; spells whose effects are irritating but amusing, almost playful and of minor inconvenience to the target.

A hex consistently affects the object in a negative manner; has a connotation of dark magic, but more so than a jinx. Major inconvenience to the target.

A Curse is a form of dark magic intended to affect the target in a strongly negative manner.

An Enchantment is a spell that affects an object consistently, altering its inherent qualities permanently instead of temporarily like a charm would.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5: How does Anxiety manifest into causing more health problems?

Aside from other mental health issues, some symptoms I've read about range from muscle weakness to severe heart/organ problems. How can anxiety do so much damage to the body???

[Assistant]
Fear causes your fight or flight response, and anxiety causes a similar response except its a fear of something that isnt real.
If it gets really bad, you become terrified of something that isnt there or even real.
Hormones including the stress hormone cortisol and adrenaline are released at these times, which are meant for short term escape/survival situations.
Adrenaline increases heart rate, blood pressure and use of energy reserves. Cortisol alters immune response, digestion, reproduction and growth processes. Almost all of your body is affected in a way which isnt sustainable long term.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] [Marvel Comics] Why does everyone like Namor again? Didn't he murder quadrillions of billions of billions of people just to protect Atlantis?

[Assistant]
unless there have been some change since last time i saw him, no one likes him.

infact, one of the first things hyperion did after the universe was restored was to go to atlantis, pick up atlantis, throw it against the ground so it was smashed, then decapitate Namor.

So yeah, Namor got his comeuppance.


[System] Given the following post, respond as if you're commenting on Reddit:

[User] [Silmarillion] Why does it seem like so much of Erus plan and the Maiar & Valars time was spent on a single fragile world rather than working on life for multiple planets?

[Assistant] The Ainur (the ones that actually shaped the world) were not omniscient or omnipotent beings capable of creating trillions of planets all at once. They put most of their power into shaping just the one world. And when they shaped that one world they were bound to it until the end.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
CMV: Hitler was a smart leader, and was just a really bad person.

I constantly get into a disagreement with people who feel I am a Hitler sympathizer when I state that I feel that hitler was a smart person. They go on to say that how could I think that, he killed so many people and held such nasty views. That's not the point I'm debating. I feel that he was a very charismatic leader which has been stated in many documentaries and how he had to have been very intelligent to rise to the top during such a rough time in German history. Most of my defense for my thinking is that he was able to take a war torn country and bring it back better than what it was by his leadership. German inflation was crazy high; they were burning money cause it was worthless. They had so many sanctions put on them after the First World War to make it almost impossible to move in Germany. Yet despite all the negatives Hitler was able to bring Germany back to a world powerhouse at the time. Again I'm not saying the man was right in any way, but that he was a smart intelligent leader. Except for trying to invade Russia, he kind of messed up there.

Edit: just wanted to say my view has changed quite a bit thanks to the informative discussion a lot of y'all were able to have. I really appreciated the people talking deeper into the economic and military side of the subject and German view during that time. It gave me a better understanding from people with a lot more knowledge on the subject. I mainly feel like he was just a proficient speaker who came in at the right time and had the right people around him. Again thanks for those of you who were able to understand my thinking and have a civil discussion and not feel I was saying Hitler was right for the things he did.

[Assistant]
Trying to invade Russia, declaring War on the United States, not destroying the British forces at Dunkirk, having absolute paranoid fears about the Jews, valuing political loyalty over technical competence, etc. etc.

There are a lotttt of stupid, stupid things that Hitler did.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5: How does cellular data work?

Ok I get it sends a signal to my device, but how does it know the specific data I want? Also, how does it find my specific phone when I receive calls?

[Assistant]
The cell tower doesn't know what specific data you want, any more than the post office knows what's inside your mail...it just knows it's got a "packet" addressed to you and it delivers it. Your phone is the one making the requests and processing the receipts.

As far as knowing where your phone is, as long as you're connected to your network, you've got an active radio connection to the "nearest" cell tower ("nearest" because it's really the one with the strongest signal, not necessarily physically closest). When someone calls you that request goes into your phone company's network. The network says "Right, which tower is talking to number XYZ?". If you're on the network, one of the towers will say, "Me!" and the cell network routes the call to that tower. Then the tower sends a radio signal to your phone saying, "Call for you." The tower already knows where you are (in a "which antenna" sense) because your phone is always maintaining a connection.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
ELI5:Why is time based on multiples of 60?

60 seconds is a minute, 60 minutes is an hour, why?

[Assistant] The Babylonians used a base 60 number system because of it's prime factorization, it allows 60 to be divisible by a whole bunch of numbers between 1 and 60 and thus it is a very flexible number. Today's society carried over a bunch of their numberings because they were so advanced at the systems for their time: it's also why circles are measured in 360 degrees, etc.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
Why do sunscreens expire?

I would like to understand if it is because of microbial contamination or if the UV-blocking agents are degraded. If the latter is the case... how? Sunscreens are light-protected in their recipients and not usually exposed to high temperatures.

Also, do sunscreens lose 100% of the effect at the expiration date, or do they just lose partial effect (e.g. 75% of effectivity after 1 year, 50% after 2 years,...)?

[Assistant]
Sunscreen works by absorbing light in the UV wavelengths of a spectra. Conjugated ring systems and other compounds with double bonds are good at absorbing energies at this wavelength, hence sunscreens are often made of organic compounds that breakdown with time.

The good news is mineral sunscreens such as zinc oxide may last longer as its inorganic(its in powder form). The bad news is they are emulsified with essential oils or plant oils etc with emulsifiers to help spread the sunscreen better. When they start to breakdown, you are left with a grainy separated mixture that will not adhere to the skin properly.


[System] Given the following post, respond as if you're commenting on Reddit:

[User]
[Star Wars] Is The Force a source of energy that Sith and Jedi are connected to and pull power from, or is it a link to all Force users?

It feels really confusing that we aren't really given much explanation in the movies about how The Force actually functions, and its purpose. Could it be an energy source, or a link of some sort?

[Assistant]
The force is an energy field that binds together everything in the galaxy, even space and time. Its generated by living things and connected to all living things but only certain individuals possess the ability to sense it and do anything tangible with it.

In other words, even non-force users are connected to it and are affected by it but they cant really feel that connection (unless theyre being choked or slammed against a wall, usually).