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

[User]
Could someone explain how FTL violates causality?

I've done the wiki reading but it still doesn't make intuitive sense to me. Obviously reverse time travel does because of things like the Grandfather paradox, but I can't seem to grasp why FTL / instantaneous transmission breaks causality.

[Assistant]
So Alice and Bob get fed up with each other and decide they're going to have a duel with tachyon pistols. The rules are thus: Each duelist will board his or her superadvanced spaceship and, on the count of three, accelerate away from each other for ten seconds. They will then turn (without stopping, that's an important technicality), and fire their tachyon pistols at each other.

Alice, filled to the brim with loathing for Bob, boards her spaceship and waits for the count. One  two three and she's off at some substantial fraction of speed of light. She counts down ten seconds, turns and fires at Bob.

But since Bob and Alice have been receding from each other at high speed, Bob is time dilated in Alice's frame of reference. So when her clock says ten seconds have elapsed, only five seconds have elapsed for Bob. When she fires her magic instantaneous tachyon pistol, it hits Bob's spaceship when his clock reads five seconds.

Enraged that Alice fired early, Bob turns and shoots right back at her. But since they've been receding from each other at high speed, Alice is time-dilated in Bob's frame. So when he fires at the instant his clock reads five seconds, only two and a half seconds have elapsed for Alice. Bob's aim is better than Alice's, so his shot hits her spaceship and kills her  seven-and-a-half seconds before she fired the shot that caused Bob to shoot her back.

Faster-than-light anything and causality cannot coexist.


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

[User] Which would cause worse inflation, inserting lots of money into one industry, or inserting the same large amount across the economy?

[Assistant]
It depends entirely on how the money is "inserted."

If, say, the government just bought a bunch of the output from an industry, gave incentives or vouchers for that industry, or something like that, then prices for that sector would increase. The impact of that on inflation would depend on what industry it was. So if it was housing, then it would have a hugely outsized impact on increasing inflation, but if it was Christmas trees or something menial like that then there wouldn't be much of an impact on inflation at all.

If the government "inserted" money in a similar way across the whole economy, then there would be a more even impact on the price level across the economy, which would definitely increase inflation, although again, depending on what industry we are comparing it to, the comparable impact on inflation is pretty ambiguous.

That said, if they "inserted" money by making investments in productive pursuits or alleviating supply chain constraints, say by expanding ports, improving transport capacity, or something like that, then they could actually reduce inflation by bringing the cost of producing and distributing things down.

Wish there was a more straightforward answer, but really, the answer depends on asking several more "what-ifs."


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

[User] ELI5:What will happen to the world-wide economy if America were isolated from the rest of the world?

[Assistant]
Imagine your school allows the sale of candy between students. This rich kid absolutely LOVES candy and the parents are all too happy to give the kid money because they have a ton of it. He literally is buying up 15-20% of the candy by himself. With all this money, more and more students get into selling candy because they see their buddies making all this money! The candy market is booming!

All of a sudden, the kid moves into 6th grade and in to a new building. Now there is so much candy that ISN'T being bought. The kids selling candy had bought so much because they were able to sell so fast. Kids were using their candy profits to go buy video games, lunch food, playing cards etc.

Now in order to get rid of the loads of candy they bought, they have to sell it for cheaper... and cheaper... Now less and less kids decide to sell candy because there is so much uncertainty. They're not sure if they could sell a piece of candy for .10 let alone a dollar. And since there isn't money being made in candy sales - these kids aren't buying playing cards off each other, they're not going to the movies... It may takes years for the candy market to recover and all the other things the candy sellers used to buy with their extra money will also suffer.


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

[User] Is it possible for the moon of one planet to have satellite of its own?

[Assistant] Gravity does not have rules about what is allowed to orbit what.  Also the phrase "moon " is just a label for a body that is orbiting something that is also orbiting a star.  So yes, it is possible.  Bear in mind that orbits are not stable like an eternal clockwork mechanism, so given enough time things will either collide or escape each other's gravitatonal influence.


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

[User]
[Civil War Spoilers] Don't know if this is the right subreddit to ask this but, in the airport scene?

Why doesn't Tony's side just destroy the airplane that Caps team was trying to get to, wouldn't cap just say "ok, we don't have a reason to fight now"? At least the "criminals" wouldn't be able to escape so easily.

[Assistant]
That's the best tactic in retrospect.

**Tony:** Ross gave me 36 hours to bring you in.  That was 24 hours ago. / You're gonna turn Barnes over and you're gonna come with us.  NOW! Because it's us!  We're surrounded by JSOC guys, with no compunction about being impolite.

A flight from Germany to Washington, D.C. is about 10 to 11 hours commercial.

Arguably Tony needed the Quinjet to transport Steve to the New Avengers Facility (in upstate NY) or Washington, in time to fulfill his pledge to Ross, otherwise Steve risks getting killed by JSOC... or spreading the conflict beyond the airport because Steve wasn't going to stop (as recognized by Natasha, though the causalities *she* could foresee would have been mitigated if she stopped Steve *instead* of letting him go, so that decision doesn't make much sense either).

Not a very good reason, but there you go.


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

[User]
[LOTR] Let's say during the middle of the War of the Ring, Sauron just up and dies. Would Saruman at his peak have been able to conquer Middle Earth?

Did Saruman, before his army and Isengard infrastructure get completely wrecked by a bunch of trees, possess the strength to militarily take over the Free Peoples of Middle Earth?

Would his powers of persuasion have helped him to do so, or were they already deteriorating by the time of his war against the Rohirrim?

[Assistant]
No, Saruman could not have conquered all of Middle Earth. He wasn't even able to conquer Rohan.

He has mass-production technology capable of producing both Uruk-hai and the weapons with which to arm them, but he doesn't have enough raw resources or a sufficiently large industrial base to create and supply an army large enough to conquer all of Middle Earth.

At the Battle of the Hornburg, he was able to deploy 10,000 Uruk-hai, 5,000 Orcs and another 2000 Dunlandings (the tribal hill-folk that he persuaded to rise up against Rohan and raid villages in its territory). 17,000 soldiers in total.

If we assume that he was expecting to wipe Rohan out in one fell swoop and wasn't expecting any sort of immediate retaliation, then we can conclude that those 17,000 troops represented the majority of the soldiers available to him.

He clearly kept enough Orcs to keep running his production machinery and a small garrison force to ward off random raiders, but not a full-on "reserve army", because he ends up trapped in his own tower once the Ents rise up and wipe out his garrison. If he had more troops to call upon, he would have done so at that moment in order to free himself.

Someone who wants to conquer all of Middle Earth needs a force capable of destroying the combined forces of Gondor, Rohan, the Dwarf clans, and the few small groups of Elves that decide to stay in Middle Earth and fight alongside the younger races instead of going to the Undying Lands.

17,000 soldiers isn't enough to overcome all those armies. Sauron had 45,000 soldiers at the Battle of the Pelannor Fields, and that wasn't enough to take Minas Tirith.

At the Battle of the Black Gate, which was happening at the very moment that Frodo and Sam were making their way up Mount Doom to throw in the ring, Sauron deployed a combined force of 60,000 soldiers to face Aragorn's force of 10,000.

Saruman was a potent regional-level threat to Rohan (or he would have been if he hadn't chosen to fight them at the one location where they actually stood a chance of winning, although even then he was on track to win a Pyrrhic victory through strength of numbers before Gandalf returned with the Rohirrim), but he would get absolutely crushed if he attempted to take on all of Middle Earth.


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

[User]
Why don't wounds inflicted while taking a poop get infected?

Seriously, I don't understand this. from time to time, I'll have a spot of blood on the TP after a particularly uncomfortable poop, but I've never had an infected wound. It's not like the area is in any way clean, we don't bandage it or apply disinfectants, so what gives? Why are most wounds so prone to infection while the dirtiest location a wound could find seemingly never infects its wounds?

[Assistant]
wounds typically get infected in places that do not have very good blood flow - these places are like seldom policed areas of the city where hooligans (bacteria) can have fun.

there is a lot of blood flow in your rectum - and all of it dumps into the liver - the detoxification center of your body. The combination of these two makes it hard for an infection to grow.


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

[User]
ELI5: How does entropy prove why time only goes forwards?

In a college class today we watched a clip in which Brian Cox said "entropy is the reason time only goes forwards". how?

[Assistant]
Think about burning a piece of toast.  Can you unburn the toast?  No.  Why not?  Because we didnt change the toast into a new thing called burnt toast, we just burned up part of the toast.  The way our universe works, so far as we can tell, this only goes one way.  Once you burnt the toast you cant make it back the way it was.  Even if you had a way or rebuilding it, it wouldnt be the exact same toast.  Even if you found a way to rebuild it with the exact same stuff and it was the same toast (impossible as far as we know) then you would have needed to spend lots and lots of energy to do that, which means we still lost something, right?  Not quite.

We didnt lose anything, really we didnt even lose anything when we burn the toast.  We just converted what was toast into other things.  The universe didnt lose anything, it still has the same amount of stuff it had before.  We see it as loss because the heat and burnt crumbs arent as useful to us.  The universe doesnt care for toast, its not picky at all, it just wants to keep all its stuff.  So its not that stuff disappears, it just gets turned into less complicated stuff by breaking it down into its most basic parts, including just plain old forms of energy like heat and light.

This may not seem like a big deal, but stretch it out of millions and billions and trillions of years and it starts adding up.  Eventually everything gets less complicated, which means eventually everything becomes the same thing.  To put this in human terms, everything dies.  When we see this happening we call it time passing.

Time and Entropy are twisted together, one has to be that way because other is.  Break one and you break the other.


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

[User] [Power Rangers] Are there any Power Rangers who dont get their power from the Morphin Grid?

[Assistant]
While plenty of series don't mention the Grid, and no series has ever specified that every Ranger ever uses it, it's pretty heavily implied and is treated as *the* power source. the Retro Rangers from Once a Ranger had about as diverse a power set as you can get, with Dino Powers, Ninja Powers, Police Powers, and Mystic Powers, and it was still stated that they all used the grid.

We have Grid Battleforce which has a vault full of past Ranger stuff from every series.

Teams that are specifically stated to use the grid are Mighty Morphin, Dino Thunder, Ninja Storm, SPD, Mystic Force, Overdrive, Jungle Fury, Dino Charge, Ninja Steel, Beast Morphers, and Dino Fury, leaving Alien Rangers, Zeo, Turbo, In Space, Lost Galaxy, Lightspeed, Time Force, Wild Force, RPM, Samurai, and Megaforce without specific mentions. But, whenever some comic crossover happens dealing with the Grid, and someone from one of those teams shows up, they never specify that they don't use the Grid even when it would be relevant information, and RPM's bio-field was implied to be the same thing.


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

[User]
ELI5: Do urban poor black youth have a harder time moving up than poor immigrant asian youth? Why?

When observing Asian immigrants (Chinese, Korean, Indian, Pakistani, etc), I see a lot of children of really poor immigrants who came here with nothing and worked as dishwashers, clerks, janitors, and other very difficult jobs, while having language problems (not knowing English [well]) - ending up with their kids being pharmacists, doctors, lawyers, engineers, and moving the entire family up and out of poverty.

I get the sense that although this happens with African-American poor urban youth as well, it doesn't seem to be happening at the relative rate that one might expect if one knows English, already has an established network, and has had their family in the U.S. for many generations, but are faced with the same economic situations as the immigrants (unstable or low income).

Is there a reason why African-Americans poor urban youth aren't able to succeed at the relative rates of Asian immigrant poor urban youth? The latter's parents don't know the language, how the school system works, or how college works, and yet, seem to show a relatively higher rate of success.

Is it primarily discrimination? Is it that neighborhood violence has a greater role in holding back AA youth, but not Asian youth? Something related to family structures?

There must be a few key factors that make these two groups with the same economic conditions, but often not the same socio-geographic conditions different.

NOTE: Please no racist answers about biology or genetics. If that's what you have in mind, there are other forums for you filled with people who marry their sisters.

[Assistant]
Well, that's a very broad claim, but i think i get your meaning.

One factor that you don't seem to acknowledge is the cultural differences. A poor immigrant left their country for a reason. They came here to either succeed themselves, or give their children a better life. They are likely to have hope, otherwise they wouldn't have come to the U.S.  and they are likely to instill that hope in their children and to teach them the value of hard work.

A person born into poverty in the U.S., regardless of their race, whose family has been here a couple generations is probably more likely to live in an environment that has all the trappings of American poor culture, which include drug abuse, physical and psychological abuse, a distrust and general disdain for education, and probably most importantly a deep, pervasive sense of hopelessness. Their parents couldn't succeed, and neither could their grandparents, so why should they?

There are more environmental factors to consider as well, like the overall attitude of greed and self centeredness, the need for instant gratification, and the idea that everyone can be a famous "xxxxx" that are all pretty prevalent in American culture, so if your family is American, your me likely to be exposed to that.

Tl;DR: It has nothing to do with race, but culture.


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

[User]
[Star Wars] How do blasters work in terms of ammunition?

Looking at the Star Wars movies, we NEVER see anyone reloading or even saying they need a new weapon.

Is the ammo capacity infinite or what?

[Assistant]
Not infinite, but pretty fucking good. It's part of why blasters are so popular on all but the most backwater planets. Rifles like the commonplace Stormtrooper E-11 got a whopping 100 shots on a single power pack, more powerful plasma cartridge got a ludicrous 500 shots!

That's a massive amount of firepower in a lightweight cartridge! Good luck even bringing that much ammo in slugthrower cartridges.


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

[User] ELI5: Why does coca cola taste so much better in a glass bottle as opposed to plastic bottles and soda fountains?

[Assistant] Glass is far less permeable than plastic, so glass bottles will have that fresher fizz, and cans probably impart some metallic/metal oxide flavour. Basically glass tastes best because it has the perfect fizz, and the least altered taste.


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

[User]
Why do the rings of planets only exist in one plane?

I was watching a show today about space, and they were taking a look at Saturn. It showed the rings as only existing in one plane so that when looking directly at the side of the ring, it was like looking at the thin side of a piece of paper. Why is that? Do all planets with rings behave like that? Is there some physicsy reason for this?

[Assistant]
Conservation of angular momentum. The initial gas/dust cloud had some rotation and with it at net angular momentum. As gas radiates away energy it has to collapse to a lower energy state, but it also has to conserve angular momentum. A disk is the lowest energy state, while being able to have the same angular momentum. We see this phenomena not only in rings around planets, but planets around stars and stars/gas in galaxies.

Edit: Some believe Saturn's rings are not from Saturns initial formation but are a result of a moon getting too close. Basically the part of the moon towards the Saturn feels a stronger pull than the outer part, ripping the moon apart and scattering its remains into a ring system.


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

[User]
cmv: Ice cream or popsicles in a cup are far more practical than on a stick or cone

So, I love ice cream and frozen treats, and living in currently 100-degree weather makes them even better. However, I absolutely hate when someone gives me a popsicle or ice cream and it's on a stick. This is the worst way to serve frozen treats due to their impractical nature.

Here are some of the points why:

* Rushed/messy eating - when you are eating something frozen on a stick it will be exposed directly to the sun/environment and start melting. This causes you to quickly lick it up and have both messy hands and mouths. This also makes you less likely to savor it as you can when it's in a cup. In a cup, you can easily scoop it up and eat it at your own pace without worrying that it will melt nearly as fast. Only one part of it is exposed directly and so won't get as warm. Toppings are easy to heat and mix around as well.
* The Stick Problem - When eating a frozen treat on a stick, you won't run into the sticking problem right away but when you're near the end, you have to figure out how to get the last precious bites. Are you going to eat it from the side? Well, the other side falls off. Are you going to get it from the top? Good luck having a stick in the back of your throat making you gag. How about the bottom? Well to turn it the other way you have to get your hands dirty on the stick. You just don't have this problem with a cup.
* Walking around - Well you might say that you can walk around with a cone or a stick. Well for the reasons mentioned before, it is still very hard. You cant walk around easily since you have to eat it fast, and accidentally getting it on your shirt is too easy to do. Also, you have to hold it upright at all times. With the cup, you can hold it by your side, rest the spoon inside and set it down when you need to (especially when it has a cap on it too)

The only thing that I can understand is wanting the flavor/texture of a cone but at most ice cream shops you can request a cone on top and dip it instead. Pictures might be a reason as well, but unless you're at some very famous shop, does it make sense to put yourself through the trouble to look cute? Also, you might say accessibility ie their arent always the same flavors in cup and stick form but in my experience there almost always are the basic flavors specifically at ice cream shops or Costco.  I'm willing to change my view if you can show me that it is easier to eat things on a stick/cone or there are solutions that I can easily do while not being at home or needing many supplies.

Change My View!

Edit - taking a quick break for schoolwork be back in an hour

Edit 2:  So I'm seeing really good arguments and although my view isn't completely changed (I still feel the general cons outweigh the pros) I can concede that there are good points

1. The waste involved - not only for the environment since most materials involved arent eco-friendly but just carrying a cup around, in general, is annoying if there arent any trash bins around
2. homemade popsicles- while specific, the process of making homemade items is much easier using popsicle sticks rather than cups. There's a big difference in eating something you made yourself and something a company tested do that it's easily consumable

Other points I'm seeing:

1. the chocolate lined cones and while i would say it can be used to be less messy, it alters the taste and usually costs more as well so i can only see it working if you don't mind the flavors mixing or if you have specifically chocolate ice cream
2. How fast is my ice cream/ popsicle dripping that its such a problem? While I believe that my points stand in perfect weather (ie 73 F) its become more annoying to me now that its summer and it was 105 F just yesterday. I've lived in both environments for extended periods of time so I believe my points still stand

I will probably be answering more later but for now Thanks to everyone in this Summer cmv!

[Assistant] You can eat a popsicle on a stick with one hand. Much better for those on-the-go businessmen that can't spare the time to sit down at a desk and use both hands for just one task. You can eat a popsicle and write a memo, or push an elevator button, or drive a car.


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

[User]
Would flames be shorter/taller under higher/lower gravity?

If I had a bio dome on the moon and made a bonfire would the flames be taller because of the lower gravity? Would you see a clear difference? What about on a huge planet? Or the sun? Does a bio dome  bonfire on the sun have short little flames?

[Assistant]
[I've been involved in several research projects studying just this phenomena on NASA's DC-9 "Vomit Comet", and on the STS)  Buoyancy is what causes this "elongated" effect on flames on earth.  Combustion flames in micro-gravity form beautiful spherical structures and fuel burns at a lower rate.  On Mars or the Moon, you'd be somewhere between what you see on Earth and what you see in microgravity.  Thus:  less buoyancy means less vigorous convective transport=shorter flames and slower combustion.  The oxygen-deprived flame will also burn at a lower temperature, further reducing the convection as well.
edit: Of course this assumes a similar atmosphere to account for the possibility of combustion, which isn't present on either the Moon or Mars.  Let's say you were in a space station with an Earth-like atmosphere for this experiment.


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

[User] ELI5: If hard liquor like gin, vodka and whiskey are said to have no sugar or carbs, how does it impact your insulin levels and weight? Is the former just incorrect?

[Assistant]
Between fermentation & distilation, there should be virtually zero carbs in hard alcohol.  The body, however, breaks down alcohol for energy and *that* is what causes problems for diabetics & weight gain.

A shot of vodka is roughly 100 calories.  If you eat "normally" (ie - all you "need") and then have a few drinks every night, those calories add up over time.


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

[User]
Since gravity according to Einstein is a property of the curvature of space, is there a need for this force to have a corresponding boson?

At the Origins Project presentation at ASU, David Gross brought up the figure of 10^19 GeV as the energy to search for the gravaton. My thought process was that if gravity is the result of the curvature of space itself, does it need a carrier boson (the fabled gravaton)? Would the lack of such a particle require any significant revisions to such theories as the Standard Model and Supersymmetry?

[Assistant]
There's a really interesting proof - by Feynman and some others, IIRC - showing that if you start off with a theory of massless bosons with spin 2 (i.e., twice the spin of a photon) running around and interacting on a *flat* spacetime background, that theory turns out to look *exactly* like Einstein's theory of gravity as the curvature of spacetime.

In other words, those bosons have no choice but to look, on aggregate, like they're describing the curvature of spacetime, and because of their interactions with matter, that matter will *also* act as if it's living in a curved spacetime. This is pretty damn impressive, as is the fact that the theory that comes out of this is uniquely the one that Einstein came up with for completely different reasons.

So while you can have gravity-as-spacetime-curvature without gravitons, the two are pretty naturally linked (you can't have gravitons without spacetime curvature). This link is thought to occur physically through *quantum mechanics*. Every particle in the standard model is described at the non-quantum level in terms of fields, rather than particles. Fields are mathematical objects which have different values at different points in space and time - you might be familiar with the electric and magnetic fields, which are examples of this. Gravity is also a theory of a field, in this case the gravitational field, which describes how much and in which direction spacetime is curved at any given place.

Now, when you apply the rules of quantum mechanics to a theory of fields, then energetic excitations of those fields arise, and some of those excitations have exactly the right properties to be identified as particles. So when you have quantum theory in the mix, fields lead to particles.

We can do this process for every known field in the Standard Model. For example, quantizing the electric and magnetic fields leads to photons, or particles of light. However, we still don't know how to do it for gravity. While it's conceivable that whatever new physics we need in order to do this will require us to drop the fields -> particles picture, it seems most likely that quantizing gravity will lead to gravitons just like quantizing the electric and magnetic fields led to photons.


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

[User] ELI5: Why is the flu seasonal? Does it take vacation the rest of the year?

[Assistant] The flu thrives when there is less ventilation/fresh air circulating. For most folks, this happens when it is colder out & people are more apt to be inside. Flu season is in different months in the southern hemisphere, so it doesn't take a break, just infects during the coldest months.


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

[User]
Why do Microsoft and other software companies care which internet browser people use if the software is free?

After reading that in Windows 8 non-IE browsers will be intentionally slowed down, it made me think - why does anyone care what software we are using if we use it for free anyway?  I am sure I am missing something.

[Assistant]
There are several important reasons, but it mostly comes down to peoples browser having a potentially large impact on what they do online, which *does* have money involved. In particular, it affects what money-making online applications they might use, such as the search engine, with IE defaulting to Microsoft's Bing and google being popular elsewhere. Since many people never change their browser's default settings, that's a lot of indirect money tied up in browser choice.

There are also deeper reasons along the same vein. For instance, google's Chrome originally had a superb javascript engine, which its competitors have now raced to catch up with. This all benefits google, as their business is tied up with complex web applications, but these applications need fast, optimised browsers to be usable.


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

[User] ELI5: Why turning your phone sideways takes a wider angle shot. Isn't the camera the same size no matter what angle its on?

[Assistant]
A camera has two main parts:

- A circular glass called a lens, which focuses light.
- A rectangular light catcher, called a sensor.

The first is a circle and so the angle does not change. The second is a rectangle. When you flip your phone sideways, you flip the rectangle sideways, too.


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

[User] ELI5: When we lose our voice, like during a cold, what actually happens to our vocal cords?

[Assistant] Generally when you lose your voice the reason is your vocal chords are inflammed. Inflammation = swelling. When the vocal chords are swollen they become a different shape & that alters the sound that they make (or don't make if it's bad enough) when you try to talk because the way they move the air is different.


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

[User] Why is my current cold "a cold in the nose", whilst others are "in the head/chest/throat"? Is the infection localised there, or is it that different cold viruses exhibit different symptoms?

[Assistant]
There are certainly countless different viral strains, whose infectivity may range from asymptomatic to severe. Especially with the common cold. It also mutates all the time so new "mixes" of different phenotypes are always transpiring around you.

The infection might very well be more localized, but most likely due to differences in the virus' own capacity to infect different tissues/wreak havoc, and not due to some sort of bad luck that "got it stuck to only infecting a certain location". AFAIK, rhinoviruses (common cold) have the respiratory tract as their pathogenic route of entry. This may be due to the specific molecular mechanism of pathogenesis in those tissues (tissue specificity), or due to much simpler things like how the virus "likes" colder temperatures than the human body so it is able to be successful only in the airways that are constantly being cooled by breathing.

Viruses are so tiny that, as a general rule, their infectivity and area of infection are much more tied to the actual capabilities of the virus and natural selection allowing it to proliferate and infect whereas another cannot. A localized infection is certainly a thing, but it's not usually because a virus failed to infect those parts, but that it just can't.


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

[User]
[MCU] Where is my Daughter?

Five years ago some Madman from space killed half of all life. I was on a Flight to NY with my daughter when it happened. My daughter vanished alongside with little less than the half of the people on the plane. Fortunatly both Pilots survived so we landed safely though we all had panic. I needed 3 years till i could sleep without waking up searching and mourning for my daughter. I am still in therapy. Then a while ago the avengers managed to bring back everyone and with the sacrifice of this Tony guy were able to stop this violet Madman before he could kill everyone (half of them again). But i don't know if my daughter came back. No one knows for sure what happened with the people on planes. Some say they reappeard where they disappeared, some say they appeared somewhere safe. The people that know (if there are any) don't say anything. I just want to see my daughter again. Does anyone knows for sure what happened with the people on that airplanes. I want to know what happened with her, even if you just have bad news. It's better than don't know for the rest of my life.

[Assistant]
Good news is that your daughter is almost certainly fine.

Bad news is that you'll need to do a little leg work to find her.

When The Avengers undid the damage caused by Thanos, they added in a stipulation that anything that comes back will do so in a safe place. People on ships will end up on a nearby shore, anyone in an elevator would appear on the bottom floor (or on the nearby street if the building was demolished) and your daughter would more than likely end up either at the one of the airports or in a nearby town.

Your biggest hurdle right now is going to be logistics. Billions of people have returned and undoubtable a lot of them are going to be displaced so many families are going to be in your situation.

Hold off on calling around and instead try and focus on narrowing down where she'll be. She'd either show up at the departure or arrival airports or possibly near one of the towns under the flight path. Once you've gotten a general idea of where she could be, check online and see if any of the local governments or larger agencies have set up a contact line. Don't worry, you'll see her soon!


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

[User]
Does light leave a trace or a signature on objects?

For example can you tell how much light was in a room if it is completely dark with some kind of device to measure the energy left by the light on the solid walls? How long will the signature remain?

[Assistant] Light excites the outer electrons of atoms to higher energy states. Additionally it transfers energy in the form of heat. So you would probably be able to pick up different thermal signatures in a room that had light shining in it versus one that didn't. In both cases the amount of time that the "signature" remained would depend on the heat conductance and material properties of the molecules.


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

[User]
If world is spining with the force from the begining, shouldn't impact of asteroids coming from reverse angle slow the spin of the world?

Tittle.

[Assistant] the rotational energy of the Earth is huge. It's absolutely massive. That's because the Earth is very massive. Usual impacts are absolutely negligible. Only impacts with planetoid-sized objects, such as the impact that formed the moon, are able to change the angular momentum significantly.


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

[User]
CMV: If a news headline quotes someone stating something, the vast majority of the time they should use the word "said".

Basically, my view is that the word "said" is the most neutral word to use in this situation. Other words carry certain implications, and thus are more likely to be misleading. Consider the following three hypothetical headlines:

"Government insider claims *policy X* has been a failure"

"Government insider says *policy X* has been a failure"

"Government insider admits *policy X* has been a failure"

At least in my view, the first headline suggests that we should be sceptical of what the government insider has stated, whilst the third suggests that what the government insider has stated is a statement of fact. And there are other words which carry similar implications- words like "alleges" also suggest to me a degree of scepticism about just what the person is alleging, whilst words like "reveals" suggest that what the person is discussing is a matter of certain fact which they have now disclosed.

"Says/said" in my view is the best word to use for a news report, because it carries the least baggage and is the least likely to unduly influence the view of the reader/viewer.

[Assistant]
Let's assume that the role of the media is to report this kind of thing as accurately and completely as possible.

The use of the word "admits" communicates more than the word "said", assuming it is used accurately.

Why wouldn't you simply hold the view that media should report things accurately, rather than requiring them to report things in less detail so that important nuance is left out?


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

[User] [MCU] Why couldn't Doctor Strange defeat Thanos the exact same way he defeated Dormammu?

[Assistant]
He tried. He tried 14,000,605 different ways of defeating the Mad Titan, and what we saw in *Infinity War* was, to quote him, "the only way".

We saw that Thanos was able to defeat Strange's Mirror Real trap using the *Power* Stone, not the Space Stone, so it stands to reason that Strange saw Thanos defeating his time-loop trick in a similar manner.

Thanos had four of the six Stones at that point... he was already the most powerful being in the universe. Strange is a powerful sorcerer, but sorcery wasn't going to be enough to defeat the Titan. Instead, Strange used his greatest weapon: his mind.


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

[User]
[MCU] Why didn't Stark use Nanotech in Spider-Man: Homecoming?

At the end of Homecoming we see Tony offering Peter the Iron-Spider suit, which, as we seen in Infinity War, uses Nanotech similar to that of the Bleeding Edge armour.

If this tech was available to offer to Peter at the end of Homecoming, why wouldn't Tony use this much more Portable suit throughout Homecoming?

[Assistant] Probably because Iron Man Mark L was not completely ready yet. The Liberty Island Ferry Incident devolved almost immediately and hence Stark opted to use a more proven suit (Mark XLVII) rather than a prototype. By end of Homecoming however, it's plausible that he worked out the kinks enough to create the Iron Spider suit for Parker.


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

[User] ELI5: Why is riding the clutch in a car bad, but on a dirtbike it is highly recommended?

[Assistant]
Different types of clutches.  A car has a single plate dry clutch.  Its simple, light, durable, but doesnt tolerate a lot of heat.  A bike typically has a multiplate wet clutch. That means the clutch plates live in an oil bath, and can shed heat super easily.  You can slip the clutch in a bike all day long.

Now, this isnt universal.  There are some cars with multiplate clutches and some bikes with dry clutches, but in both cases those are usually specialized race instances.


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

[User] ELI5 What is happening in a hibernating animal's body while they're resting over winter? Do they actually sleep or is some other process happening?

[Assistant] Yes, they go into a form of sleep. The animal's body temperature, heartbeat, and metabolism are reduced, this is why they store fat by feeding heavily to see them through the winter. A similar process, done by animals in hot climates trying to escape droughts or extreme heat is called aestivation.


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

[User]
If the moon were pear-shaped, which end would face the earth?

Would it be the small end because it has "extra" mass ("outside" the sphere) or the big end because it has the center of gravity?

[Assistant]
Either orientation would be stable.

In a frame of reference rotating with the center of gravity (CG) of the moon, there will be a gravitational force inward and a centrifugal "force" outward.  Gravity will be stronger than centrifugal force for any parts of the moon closer to Earth than the CG, and vice versa for parts of the moon farther from the Earth than the CG.  The net effect is to pull mass that's far from the Earth even farther, and mass that's close to the Earth even closer.

That means that if you put the pear's long axis at a 45 degree angle to the Earth-Moon line, there will be a torque turning it to align with the Earth-moon line.  To a good first approximation, these tidal forces are symmetric.  If you start with the pear fat end out, it will stay that way.  If you start with it skinny end out, it will stay that way.


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

[User] ELI5: What's the purpose of water towers and why are they built so high up?

[Assistant]
They store and provide pressure for water.

You know how you can be on the second floor of your house, turn on the faucet, and the water comes pouring out?  You don't have a pump in your basement forcing the water up, instead, you have a water tower forcing the water down via gravity.  Since your second floor is at a lower elevation than the water tower, you have positive water pressure.  If you're higher than the tower, you'd need mechanical assistance to bring the water to your floor.

*edit:
The water is pumped up to the tower, but by nature of its size, and storage capacity, the pumps can be run when electricity demand is low.


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

[User]
What is the speed of electricity?

We know the speed of sound. We know the speed of light. Do we know the speed of electricity? It appears instant, but it can't be the speed flight because electrons have mass and therefore can't reach that speed. (right?)

I know many factors go into current and voltage and all that, so let's just assume basic, household electricity: 120 volts, 14 gauge solid copper wire, distance of 20 feet (switch to ceiling light).

How fast does the electricity move from the switch to the light?

[Assistant]
The "speed of electricity" is essentially the rate at which polarization (the electrical alignment of atoms) can pass through a material. This is related to the speed of light in a material. Note that this is much faster than the speed that electrons move, in the same way that if you turn on a hose the water comes out the far end much sooner than it takes for water to get all the way through.

For a coaxial cable, it's about 2/3 the speed of light.


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

[User]
[Final Destination 2]How does hiding in a mental hospital keep you from dying?

couldn't a  plane or an asteroid still hit the building and kill you? couldn't you just die of something like a random aneurysm?

[Assistant] Hiding puts the game of Death on pause, and lets Death use that piece for it's later machinations - your number is gonna come up regardless so there's no great big hurry. Death clearly also has a preference for the melodramatic, making something as mundane as an aneurysm unlikely to be used - but getting a plane or an asteroid to hit the building is likely to cause other casualties, which goes against The Great Design.


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

[User] ELI5: When filling up the car with petrol, how come you can see shadows of the fuel gases, it not actually see the gases with the naked eye?

[Assistant] Pretty sure the vapors are colorless but it they have a different density than air, which causes light to warp as it passes through them. Im guessing if you got your head down there and really tried to look directly through the vapors, youd see distortion similar to a heat shimmer.


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

[User]
How do springs continue to apply pressure over years?

I repair classic record players, and I've always been amazed that the internal springs can still do their job, even on a 40 year old player. It always seems like they should be much more stretched out than they are, and while I have to replace or rejuvenate some, the majority still work perfectly. How is this possible?

[Assistant]
Materials have what is called an elastic limit.

It is essentially the amount of deformation that a material under force can undergo such that when the force is removed, the material will return to original shape/position/size.

As long as you dont exceed this limit, it will continue to bounce back.  If you go beyond this you will cause plastic deformation, which happens when you stretch out a spring too far and it doesnt go back.


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

[User]
[One Piece] If a bounty hunter SOMEHOW managed to capture one of the Four Emperors and collect their bounty, what would the economic impact be?

So suppose the unthinkable happens: some crazy strong bounty hunters manage to take down the crew of an Emperor. How does the World Government pay them? Does the WG have a few billion berries lying around? What happens now that these bounty hunters have what is basically a small nations GDP in their bank accounts?

[Assistant]
Seeing as how the World Government regularly increases the bounties on the stronger pirates by millions (or billions) and they have the resources to construct massive sea fortresses and also have the backing of the celestial dragons, They can afford to easily pay off the bounty of a whole emperor crew without excessively damaging their accounts.

It honestly depends on how much monetary support do they get from the celestial dragons. If they're allowed to use their money freely, then the world government can easily pay off the bounties of 4 emperors and their crews.


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

[User]
As it's believed we have survived due to our intelligence more than physical strength, why are the most intelligent not considered as attractive potential partners as those who have proven physical prowess?

I would have thought Intelligence is a more powerful sexual selection factor as it's how are species has survived but the top minds aren't considered as desirable as the top sportsmen and women.

[Assistant]
Among the many problems of your statement, are the arguments over the definitions of "intelligence."

Women consistently rate "sense of humor" high among what makes a man attractive, including over pure physical attractiveness.  Some have argued that in order to "be funny" to others, requires a combination of knowledge, social awareness, and timing, i.e. "intelligence."

But whether different groups of people consider that intelligence vs. say, the ability to do a calculus equation, is dependent upon social factors, i.e. who gets to control what counts as intelligence.

The other problem of your question, is what constitutes "survival."  Cockroaches for example have existed far longer than humans and likely will long after humanity.  If humans manage to successfully kill ourselves through nuclear war, can we truly argue that our peak population blip in the geologic time of our planet is a success?  Do we consider dinosaurs successes?


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

[User]
[Star Wars] Why would Luke have turned to the dark side had he killed Palpatine, but Vader turned to the light side when he did so?

Palpatine had to die either way in order for the Empire to collapse, so what difference does it make by whose hand?

[Assistant]
Striking him down in anger vs getting rid of him out of love (for his son), sacrifice (being electrocuted) and because it was the right thing to do.

The emperor goaded Luke into attacking him out of pure hatred and disgust, which is how the Dark Side manifests itself.


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

[User] ELI5 why it goes vitamin A to E, then jumps to K. What happened to F to J?

[Assistant]
Most of them were renamed upon being grouped into the B Vitamin group; for example vitamin G was the old name for riboflavin, which later became known as vitamin B2.

Vitamin F was different: It was the old name for essential fatty acids, which were considered vitamins at the time of their discovery but have since been reclassified as fats.


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

[User] ELI5: What's the thing in berry juices (specifically cranberry) that make your tongue feel dry as an aftertaste sorta effect?

[Assistant]
Proanthocyanidin is a bitter chemical found in cranberry juice. Its also thought to be the reason in which we use CJ as a solution for urinary tract infections.

Because of its bitter and acidic taste, it was believed that it provided an acidic environment in the urine, which didnt allow for bacterial growth. It wasnt until recently that we know it actually causes the bacteria to lose grip on the side wall of the tract, causing them to be expelled in the urine more easily.

In the end, its bitter because its filled with proanthocyanidins.


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

[User]
[Star Wars] In what way did Obi Wan become more powerful than Vader could possibly imagine?

I get that as a Jedi ghost he could pretty much be wherever he wanted, but it really seems to me like Luke & co. were much more able to affect the world given their material existence.  Obi Wan nudged Luke along all of twice (to my recollection), and in both cases he probably could have done so over a radio while also being able to help out in other ways due to not being dead.

[Assistant] Obi-Wan was what we call a "bullshit artist", from a certain point of view. He became more powerful than Vader could possibly imagine, "from a certain point of view". In other words he was lying his sandy white ass off.


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

[User]
Why does your computer screen look 'liquidy' when you apply pressure to it (i.e. pressing your fingernail against your pc monitor)?

wow thanks for all the responses! very interesting comments and im never unimpressed by technology!

[Assistant]
Because it *is* liquidy.  The screen uses something called a "liquid crystal", which is a layer of a special liquid sandwiched between two pieces of glass or plastic (or one piece of glass and one piece of plastic).

This liquid is what forms the image, by changing how it interacts with polarized light depending on the electric field applied.


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

[User]
ELI5: Women are more likely to attempt suicide, but men are more likely to succeed. Why?

Are women more likely to attempt it because they're more likely to be sexually abused, or is there another reason? Are men more likely to succeed solely because they're more likely to use guns, or are men actually more intent on dying when they do try even if they try less often?

[Assistant]
Women are more likely because they didn't succeed the first time. Repeat attempts are a large part of this phenomenon. Men succeed more because they choose more violent methods with higher mortality rates.

I've heard it said that it's because women consider the clean up and whatnot more than men that they choose less bloody methods. Not sure how true this is though.


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

[User]
[Call of Duty] Why did a traditional ground war occur in Modern Warfare 2 and 3 instead of nuclear warfare?

Title. I'm confused as to why they didn't nuke America, or why America didn't nuke Russia when they invaded the US, or why they didn't nuke the Russian fleet attacking New York, etc.

[Assistant] Same reason you don't use a flamethrower to kill the weeds in your yard. Dropping a nuke is for the absolute last resort where defeat is the only option left to you so you decide to take everyone else with you. Using a nuke on a fleet or on home soil is not only inviting retaliation from the opposite country in the form of nuclear annihilation but also destroying anything you or your people could possibly use. Even if you nuke dc it'd be decades before you could safely return to it after somehow surviving the war. And a nuke at sea will poison the ocean for decades killing off untold millions of fish and marine life causing an ecological and economic collapse of anyone depending on those waters.


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

[User] If silver is the best conductor of any metal, why do we most often use gold?

[Assistant] Silver is not as resistant to corrosion and it "tarnishes" - the corroded material/tarnish are not as conductive.  Gold is remarkable in that it does not tarnish and does not corrode under most circumstances.


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

[User]
ELI5: Why is Google Fiber so hard to get into new cities?

Everyone, including me, hates Comcast. So why is it so hard to get Google Fiber into cities?

[Assistant] Google doesn't really want to be in the ISP business. They are making noise about Fiber because they want there to be demand for high-speed Internet service, so that the ISPs will actually provide the service to consumers.


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

[User]
CMV: People who believe that capitalism has no significant downsides are just as foolishly naive as the communists they love to ridicule

Here's one of the most common pro-capitalist arguments I hear:

guy A and guy B each start a business, let's say they're both grocery stores and are competitors. In the beginning they both charge similar prices and get roughly the same amount of customers.

But then guy A takes the customers for granted and starts charging 125% of what he originally was. Unsurprisingly, he loses most of his customers to guy B's store. Guy A's business fails because of his greed, the end.

In another timeline, guy A decides to undercut his competition and charge 90% of what he originally was. Now guy B loses most of his customers and guy A's business gets more profit, as although they make less money from each individual sale they get more sales in total.

Simple, right? In this hypothetical situation, it is in the best interest of the vendor to charge less and they will get more profits.

But the world in this argument is far, far away from reality. Here's a more realistic example:

This more scenario starts the same as the last one, but it's more complex as it's grounded in reality.

Guy A undercuts guy B's prices, but this time he's greedy and instead of taking that 10% out of the profit he takes it out of his employees' salaries.

At first some of his employees leave for guy B's company, but after some time guy B's company fails due to the lack of customers and they end up crawling back to his now larger store.

Now A-mart (as I'll call it from now on) is growing and needs employees, and at the moment it is the only place that will hire most people. It becomes a franchise and opens locations all over the country.

Its routine in each new town it arrives in is: open a large new store > hire a bunch of employees > undercut local businesses' prices > now they're the only grocery store to buy from and work for > customers are stuck supporting an unethical business and the employees have nowhere else to work.

Now that they're the only store around, they can adjust their prices so that whenever there isn't competition they raise their prices, and whenever there is they undercut them, causing them to fail.

Free market won't save you if there's a huge corporation whose prices are impossible to beat because of their predatory business model.

The government won't help either. Since A-mart is such a huge business, they now have hundreds of millions of dollars to invest in lobbying. They bribe politicians into letting them keep their monopoly which thrives off everything an ethical company isn't.

And then there's the whole issue of monopolizing life-saving drugs and procedures that there aren't any generic alternatives for, but that deserves a post of its own.

**tl;dr: the "if there's a bad business free market will make sure that a better one will beat it" argument is foolish, naive, and doesn't account for factors such as lobbying, paying employees less than they deserve, and predatory pricing to stamp out competition**

[Assistant]
Lobbying, paying employees less than they deserve, predatory pricing. OK let's look at these in turn.

Lobbying. That's not capitalism. Once the government is involved, by definition it's no longer a free market. Beseeching the government to regulate (code for "rig") the market you have a state controlled market not a free market.

Paying employees less than they deserve. Wfat does that mean? If a Wal-Mart employee is paid 12 dollars an hour, is that less than they deserve? If so what is the right amount, and how did you determine that? If Deontay Wilder gets paid 15 million dollars for a big fight, is that more than he deserves? You get paid what you are worth. Simple as that.

Predatory pricing. Oh scary words. "Predatory" pricing. Not "low prices" not "competitive prices" but predatory prices. Does the winner eat the loser? No. It's called being competitive and trying to attract customers. "Predatory" pricing is a nonsense term it doesn't even make sense.


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

[User] ELI5 why do we smell rain coming/ what makes up the smell that is "rain"?

[Assistant] The smell is mostly geosmin, which is released from soil bacteria when rain hits them. They produce the chemical as part of their metabolism, and once they get damaged it's kicked up into the air and people smell it. It has such a strong, nice smell because it's a sign of fresh water in an area so people and many other things need to be able to find it quickly.


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

[User]
ELI5: How does dubbing work in live-action movies?

Suppose you're shooting a movie. The actors do their work, and you also record their voices while they're acting. Additional audio stuff like music and sound effects is added later.

But now suppose you want to dub the movie in another language. You can't just slap music and stuff onto the project, but you (somehow) need to remove the voices of the original actors and then slap those of the new voice actors onto the film. Except if you cut that out, you'd also have to cut out all environmental noise, etc. And if you do that, you'd basically have to recreate every single sound required.

So how exactly does this work? Are movies shot with and without sound simultaneously? Or is there some technological means to separate the sound from the image?

[Assistant]
MOST of the environmental sound in most movies is in fact added in later by foley artists.

Not always the case for every movie or even every scene, but quite often its added later. Even background birds, traffic, etc.  You try to isolate the actors.  Sometimes you have to get them to dub their lines in the same language if theres a noisy scene, or theres something that couldnt be cut around in editing.


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

[User]
[D&D] Do the civilized and semi-civilized races share a common anatomical arrangement?

Hearts left of center between two lungs, etc?

[Assistant]
Follow up questions:

* Are racial differences explained by differences in biology? Do Dwarves have redundant livers explaining their constitution? Do Elves have unique visual cortex explaining their resistance to hypnotism and illusions?

* Humans ability to interbreed with Elves and Orcs suggest a common ancestry? With Elves & Drow more distant to Orcs than to humans explaining their inability to produce offspring?


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

[User] [Star Trek] When USS Voyager got back to Earth, if the Doctor wanted to resign from Starfleet, would he have to apply for Federation citizenship as a new species?

[Assistant]
The Doctor explicitly does not have rights as an individual so can't resign from Starfleet. In *Author, Author* the court found that he met the criteria to be the author of his holonovel, and thus had creative control over its publication, but didn't see it necessary to address the matter of his personhood (as it wasn't relevant to the case at hand).

Now if it did go for judgment, he'd most likely win. The precedent has already been set with Data in *The Measure of a Man,* which while there are slight differences in the details, the premise is the same.

He'd need to go to court to have the right to resign.

Citizenship is an entirely separate issue, but he'd be looking for individual citizenship based on his personal circumstances, not Federation membership for his species. The former is a far more manageable goal.


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

[User]
I don't think the American government is of the people anymore. CMV

To my understanding, the government of the United States was designed so that any natural born citizen had a workable shot at political aspirations.  Obviously not just anyone can be an elected official, candidates need to be intelligent, tactful, good with people; but given that you were capable, anything was possible.  My disillusionment begins here.  Money runs everything.  If you don't have money, or friends with money, you have no real hope for political success.  A caste of leaders has formed, strictly reserved for the upper echelon of society.  The one alternative, the third party platform, is almost always viewed as radical, or crazy.  I will admit that this is in part due to the astronomical expense of campaigning, which leads me to my next point.  Even once elected, lobbyists and rich benefactors get an uneven say in what happens behind closed doors.  If that's the case, then the government is no longer of the people.  Instead it's an exclusive club that sits up on Capitol Hill and metes out judgement and legislation, successfully dooming "The Great American Experiment".  Please CMV.

EDIT:
There is a ton of interesting viewpoints below that I would have never thought of on my own.  I will definitely read through them all as soon as I'm out of class for the day.

[Assistant]
Here's the thing: the US isn't an actual democracy.  It's a representative republic.  It's an important distinction.

The Founding Fathers didn't trust the average US citizen at the time of its inception to be able to pick the right people or make the right decisions- this is why we have the electoral college.  Technically, when you vote for President, you don't actually vote for a President- you vote to install certain people who will then vote for that President.

Our government was never supposed to work with the common man being the representative that was chosen to create legislation or enforce the executive branch.  The system they designed was made to allow the more intellectual and capable citizens hold those roles- but also ensure those same people were answerable to the general populace for the decisions they make.

The government is "of the people," not because the average man will be a legislator, but because the legislator has no choice but to represent the will of at least his majority of constituents in order to remain their representative.  The public's will is still enforced, but it's diluted through the (hopefully) more intelligent and qualified individual representing them.


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

[User]
ELI5:Why doesn't scar tissue heal?

I've read how after five years have passed you are a completely different person on the atomic scale. The atoms that comprise your being are, apparently, completely different. Yet your scars and injuries remain: why is that? Has the DNA information to reproduce the original structure been lost and all that remains is the information for propagating the wounds?

[Assistant]
Your skin is composed of several layers.  The very bottom layer (stratum basale) contains the epidermal stem cells which divide and grow to form new skin cells.  If you get a shallow cut above this layer, the stem cells are able to patch up the area and your skin will heal without a scar.  If the cut is deep and goes below this layer, a different cell type patches up the damage.  This cell type is called a fibroblast.  Fibroblasts are more concerned about fixing the damage than they are about how it looks, so they lay down fibrous tissue and seal up the wound.

Think of it like trying to fix a hole in your boat.  If the damage is kind of small, maybe you'll use a sealant and try to patch it up nicely.  If however there's water rushing into the boat, you grab a roll of duct tape and get to work without thinking twice about what the boat will look like.


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

[User]
ELI5: Why does our body seem like it's exhausted when we oversleep?

Why do we need sleep in the first place?

[Assistant]
REM cycles. You oversleep, and your body's internal clock (regulates daily processes) gets screwed up so it rolls over to the next cycle and thinks you need to sleep.

We need sleep to give our bodies time to repair without need for action, so they can do it freely and easily. Studies have shown that we can also solve problems we were thinking up the day before during sleep. It's basically a system repair daily to make sure we're good to go for tomorrow.


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

[User]
[X-men] What does Cyclops see?

Sorry if this has been asked before. I hear his eyes are somewhat openings into another dimension, but what does he see? I don't think he's blind, but does he just see everything in red, or what?

[Assistant]
He sees everything in a red filter, thanks to the ruby quartz.

When it's off, even if his powers are active, he can see normally. (Jean once held them back with telekinetic shields, and he could see her in color perfectly.)


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

[User] [General] Aspiring mecha-designer here! What are some flaws you've seen in mecha design and how could I go about improving them?

[Assistant]
They often appear rather top-heavy with their shoulder mounted missile launchers and such, address this by strapping more dakka to the knees!

Oh, and make their legs have really sharp bits that will cut through anything used to try and trip them.

Another flaw is bipedal locomotion is stupidly complicated for something with a very limited mission profile, give them jet-packs and tank-track roller-blades on the feet!


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

[User] ELI5: Why do we get jealous and how can we overcome it?

[Assistant] You get jealous when you invest your own self-worth in another person. So if that other person is not paying attention to you, it makes you feel like you are somehow being cheated. Overcome it by recognizing your own self is not dependent on what others choose to do.


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

[User]
[The Suicide Squad] How does this character's power work? (Spoilers)

Not sure what all counts as a spoiler so I'll just spoiler everything to be safe.

>!How do Ratcatcher 2's powers work? Obviously she uses the light to summon the rats, but how does she command them? At one point she has rats gnaw the wires to the security cameras at Jotunheim. How did she direct that? Does she use the light somehow or does she have some kind of psychic bond with the rats?!<

[Assistant] the light is a byproduct (read: visual cue) of something else going on. She's using the rod to mentally command the rats, and light is just what we see. The rats aren't getting commands from the light. we just can't see the actual mind-controlling effect.


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

[User]
How is HIV so effective at evading the immune system, despite it only having ~9,000 base pairs and 9 genes in its genome?

This seems pretty crazy to me. How can a virus be so effective with such little data?

[Assistant]
HIV is a retrovirus meaning it takes its RNA genome and uses your cells to convert it to DNA and then integrates that DNA into your cells genome. It is really difficult to get rid of something that integrates into the genome like that, really our best defense at that point is to destroy the cell. Our immune system relies on immune cells called T cells to help do this, unfortunately HIV happens to infect a subset of T cells so the immune system is ultimately weakening itself. In addition to this retroviruses are prone to mutation which allows HIV to rapidly alter its antigens further evading our immune system.

That is also why it is so difficult to cure HIV. We have very effective antiretroviral drugs that can get levels of the virus so low they are undetectable, but its genome is still present in the bone marrow and if the drugs were stopped it would come back.

*Edit: More generally viruses can get away with small genomes because they use existing machinery in cells. Rather than carry instructions for a whole factory they just need to carry instructions for one product, the virus. Viruses are still quite complex, they can quickly take over protein production and some can counter intracellular defenses or even force the host cell into stages of the cell cycle that benefit the virus.*


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

[User]
ELI5: Why there are no sky-colored birds?

Why they don't mimetize with the sky?

[Assistant] For the most part, birds are safe in the air (the exception being from some birds of prey which usually strike from above, not below). Birds are vulnerable when on the ground, so it makes more sense to blend in with their usually terrestrial habitat than the sky. Or they are brightly colored to attract a mate, simply building spending most of their time in remote, hard-to-reach areas where few predators can reach them.


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

[User]
ELI5:Why do countries like the US and Canada have civilian flights available to Ebola infected countries like Liberia?

I was surprised to learn that the first Ebola case came from a passenger who simply flew from Liberia to Dallas. Shouldn't they have stringent testing or guidelines before allowing someone to board a plane from an area so infected? I feel like allowing someone to board just because they don't have a fever is a terrible idea. Couldn't they be carrying the disease on their clothes?

[Assistant]
>  Shouldn't they have stringent testing or guidelines before allowing someone to board a plane from an area so infected?

They do, they check for a fever. This is really all that is required at this point because only an infected AND symptomatic person can spread the disease. You can have the disease and not be infectious.

>  Couldn't they be carrying the disease on their clothes?

No, absolutely not. The virus is contained within bodily fluids (blood, saliva). It cannot be airborne (e.g. sneezing, coughing). It cannot survive outside the human body on surfaces (e.g. door handles, armrests). Therefore the risk of transmission from one person to another, even on a plane is extremely low.

This man became symptomatic AFTER he left the plane and airport. Thus there is no risk to anyone who travelled with him. Everyone (friends, family) who he came into contact with during those two days while was symptomatic are being tested. He is already in quarantine. The situation is controlled.

> Why do countries like the US and Canada have civilian flights available to Ebola infected countries like Liberia?

Because these are major hubs for getting into and out of Africa. A lot of passengers probably aren't even staying in the region but are taking flights elsewhere. The risk to airline passengers at this point in time is very low. The outbreak is really confined at this point to locals and health professionals working on the ground in affected areas.


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

[User]
[Marvel] Mr. Fantastic has used his intellect to save the multiverse. Sue Storm could cut off the oxygen to my brain with little effort. The Human Torch once took over the Negative Zone single-handedly. Why should I be impressed by the Thing?

He can take a punch from the Hulk? So can many superheroes. That's not impressive these days.

[Assistant]
I would say Thing's biggest feat involves his battle with The Champion, one of the elders of the universe, who said he'd destroy the earth if he lost.

Naturally, Grimm had no chance whatsoever. But even beaten to a pulp and having to crawl along the floor with his arms, he kept challenging The Champion to go again, to the point the Champion realised that while he could swat Ben like a bug, he could never *defeat* him, and gave him the win.

He's the moral core of the group, and one of the most determined and dedicated heroes in the MU. That's what's impressive about him, not his powers.


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

[User]
[Star Wars] ELI5 or CMV on why Jedi Knight recruitment is not just child exploitation?

So I live on this little town on this backwater planet where nothing much happens. Except last week when these two dudes in robes who up at my neighbors house. They're welcomed inside and a couple of hours later, they walk out with their son, load him into a speeder and drive off! Its a small town and sure enough within hours everyone knows that their son has been taken to be trained as a Jedi

Now I've read up on these Jedi since then and I know that they like to recruit as early as possible. The child taken is denied any further contact with his family and will spend his entire life training to be some kind of superhero or something. Even if he fails he's not coming back and becomes some sort of indentured servant.

And yet when asked, the kid's mom was absolutely beaming with joy when she told us! A four year old kid who's just out of his diapers is taken away at an age where he has no consent and forced to become a supersoldier and she's proud!? How or Why do we put up with this? How can the Republic allow this? Its child exploitation!

[Assistant]
Force users are dangerous. The jedi train force sensitive children to be emotionally well balanced and benign.

It kinda helps with the whole not doing date rape by mind trick when they're teenagers or crushing a coworkers larynx when you miss out on that promotion.

It helps that the parents can say no to the Jedi.


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

[User]
[Alien Universe] Are the stasis chambers used to conserve consumables (air, water, food) or because of the peculiar nature of their FTL tech?

I used to own (or maybe I still have it in some box somewhere) a book that was written with an in-universe perspective about colonial marine technology. It also had anecdotes relating to the xenomorphs. In it I seem to recall a description of the FTL drive such that while it did indeed propel the vehicles faster than light it had the side-effect of time-expansion for everything inside the vehicle. Thus the 33LY journey to reach LV-426 only takes a reasonable 3 weeks but on board the ship and crew experiences much more than 3 weeks (I do not recall the time expansion ratio).

Is that canon or is the more reasonable rationale of consumables conservation canon.

In the former, the crew needs to go into stasis so that they can survive the effects of accelerated time while traveling FTL while in the latter the crew needs to go into stasis so that the ship only provides minimal life support and they can conserve food, air, and water for when the crew is awake and active.

[Assistant]
I think it's for conservation of resources and crew comfort.

Deep space missions provide pretty minimalist accommodations.  Spending several weeks in close quarters when there are no active duties to perform is a recipe for disaster.  You don't want everyone to succumb to *space madness*.


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

[User] ELI5: Why does diesel in a petrol engine do so much damage?

[Assistant] The flammability is different, the liquid characteristics are different, and it is a huge amount of work to replace all the components that are contaminated when you put in the wrong fuel, either way.


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

[User]
[Night Gallery: The Devil Is Not Mocked] Why does Count Dracula give a shit about the Nazis?

I mean, Dracula is pretty evil. He's not exactly an ally of the persecuted classes in Nazi Germany. Since when does he care about the plight of the Jews?

Seems to me a chap like Dracula would get along pretty well with the Nazis, especially Mengele.

Why's he working with the resistance when he could easily just take people the Nazis considered undesirables and eat them, flying under the radar?

The Nazis were pretty into occultism, it's not like they're not going to figure it out when a hundred men turn up dead drained of blood, and the next battalion is going to roll in with silver bullets.

[Assistant]
Dracula gives a shit because the Nazis rolled up in his homeland and started swinging their dicks around. That's *his* turf they're jackbooting around on. That's *his* lunch they're trying to load into cattle cars. He doesn't give a shit about humans, regardless of nation or creed, but when those humans try to shove him around they're playing with fire.

The Nazis fucked around, and then they found out.


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

[User] ELI5: How is it, if I am standing on top of a train, and I jump, I will land (or more likely fall) on a further back part of the train. But if I am inside the train and jump, I land on the exact same spot as I was standing on before?

[Assistant]
Because on top of the train youll be subject to loads of wind resistance. And as you jump it'll be pushing you back.

Inside the train there is no resistance acting upon you so you land where you jumped.


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

[User]
[Star Wars: The Force Unleashed] What made Starkiller so powerful?

The guy was able to kill numerous powerful opponents, such as: Darth Vader, Darth Sidious, Shaak Ti, Boba Fett and etc..

Him beating Ti and Boba I can buy, but Vader and the Emperor?

How????

Also, let's not forget he literally was able to use the force to destroy a goddamn Imperial Star Destroyer.

What even is this guy?

[Assistant]
I dont know if there is an explicit, in-universe answer that explains it, but Ill posit a few theories:

- He is the son of a Jedi master. The Skywalkers have numbed people to this fact, but thats exceedingly rare. Remember, most Jedi dont breed. That gave Starkiller a genetic advantage.
- He was trained by the literal chosen one from childhood.
- He then received training from Rahm Kota afterward. This made him well-versed in both the light and dark sides of the force, but in the opposite order of most Sith. Typically, a Jedi starts in the light and then falls, losing touch with the light and embracing the darkness. But by starting with the dark side and then slowly getting lighter, he gets the best of both worlds: the emotion of the dark and the restraint of the light.


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

[User]
Is it possible to measure spaghettiness of code?

Is it possible to measure spaghettiness of code?

[Assistant] There might be a quite fitting measure... Cyclomatic complexity, it measures the lineary indepent paths in a module. It either is calculated  depending on the binary splitting paths with an if or with all nodes and edges in a module. If it is high there are many states in a module and thus it is quite spagettish. So all in all it captures a small part of spagettiness...


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

[User] why is it wrong to eat a dog but acceptable to eat a chicken?

[Assistant] Well, you are assuming that it is true that it is wrong to eat a dog and acceptable to eat a chicken. It is true that some cultures _consider_ it permissible to eat chickens but not dogs, but this does not make it true. Many philosophers will say it is unacceptable to eat dogs or chickens. There have been philosophers who would have considered it morally acceptable to eat both dogs and chickens (Descartes, maybe but maybe not Kant). There are a few philosophers who will say it is wrong to eat dogs and not wrong to eat chickens. These philosophers might appeal to the moral relationship we have with dogs that has been developed over centuries of living together in a certain way that we do not have with chickens (a view like this is implied by Cora Diamonds Eating Meat and Eating People although she believes it is wrong to eat dogs and it is wrong to eat chickens).


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

[User] [Harry Potter] How was Rita Skeeter able to publish outright lies with so little consequence in a (somewhat) reputable paper?

[Assistant]
Can you name another newspaper other than the Daily Prophet?

The Prophet has something of a monopoly in the wizarding newspaper sector.  That means they can do whatever they like, and write whatever they like, and the only consequences they would suffer would be whatever they decide to inflict upon themselves.


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

[User] [Star Wars] Following on from the discussion about teaching Vapaad style to Anakin, what if he had originally been found by and paired with Mace Windu from the beginning? How might be have developed differently as his Padawan instead?

[Assistant]
Mace's distrust and barely concealed contempt was damaging enough to young Anakin when he was merely a lofty, rarely encountered Council member.

Being raised by Mace would've fucked Anakin up worse. Mace is the worst *possible* Jedi to raise Anakin actually because Mace can sense anomalies in the Force; clusters of importance to fate, and his sensing of Anakin's importance filled him with paranoia. You know who are taught by paranoid masters? Sith.

By the original trilogy Anakin-as-Vader was a Lawful Evil foil to the Emperor's Neutral Evil. Dangerous to be around, but predictable. Raised by Mace, Palpatine would've had him much, much sooner and raised him in his own image. He'd be an absolute force of nature, barely sane if at all, and all the worse because the duel on Mustafar wouldn't have occurred and he would have access to all of the Force potential he was born to.

The suit was what tempered Anakin into the Vader we meet later. It was a brutally hard lesson that brought a short, shocking stop to his career as the complete deranged, drunk on power lunatic he was on Mustafar. Due to his new state he had to learn to control himself, because he was physically and spiritually crippled and needed far more discipline to achieve the things he could do as naturally as breathe previously. Without the lessons the suit forced, he'd have been Mustafar Vader on steroids *all the time* and Palpatine would have encouraged it.

Perhaps Yoda or most of the rest of the Council could've raised Anakin better than Obi-Wan, who didn't seem able to rein him in and even indulged Anakin a lot. One of the older Masters who have had experience with difficult, emotionally tumultuous apprentices would have been ideal - Yoda, for example, who taught Mace.

But the Council were too busy condemning Obi-Wan's stubbornness in honoring his fallen Master's last wish, making a point of disapproving through their coldness too a child who had just lost his mother, and that combined with Obi-Wans inappropriateness as a guardian and teacher for a child of Anakin's nature led to the prequels as we saw them.


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

[User] Can you gain more weight than the weight of the food consumed?

[Assistant]
I think you're taking some rules of thumb and extrapolating out as if they were established facts, I.e. that 3500 kcal surplus over TDEE definitively translates to one pound of weight gain. That's more of a guide than a hard and fast rule -- eating 3500 calories worth of olive oil is going to be processed differently from 3500 calories of bread in your body.

That being said, conservation of mass means that you can't eat a half pound of food and gain a pound of mass. Where would it come from?

EDIT: Certainly happy about the discussion this is generating but people seem to be missing OP's point that this is a) not about water storage in fat cells and b) not about your body's theoretical ability to gain weight, but literally just the question, can you eat ONLY a half pound of food and gain a pound of weight? There is no serious argument to be made that this is possible -- compounds added to your mass from breathing air will not contribute half a pound.


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

[User] ELI5: I understand that color is added to NASA photos, and why, but why can't the telescopes take true-color images? Are we just not there yet?

[Assistant] They can, but true color isn't always as useful or interesting. A lot of colors would be varying shades of grey and maybe some slight color changes towards red or blue, but nothing like what you see in the ones adjusted to show chemical composition. We can take pictures of our own solar system's planets in true color because there are things to see, but stars will be much more similar to each other.


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

[User]
ELI5: How do cardiologists get past the ribs and operate on the heart?

Do they have to break them and join them back after the operation?

[Assistant]
It's not pretty, but there is a tool designed for this. It's called a rib spreader, and it does exactly what it sounds like. For an open heart surgery, they will actually break the ribs to get access. That's what makes recovery from something like that so hard. You're not just dealing with surface trauma, you're also dealing with multiple broken bones. Standing up or even sitting upright is out of question, sometimes for months.

Source: I've have two open heart surgeries.


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

[User]
[Naruto] Why is there 1, and only 1, girl on each ninja team?

Where are the teams with two girls? Or for that matter, where are the teams with zero girls?

It appears this tradition of exactly 1 girl to 2 boys ratio has been going on for at least four ninja generations. Is there a reason for this?

[Assistant]
The village is essentially an entire population centre dedicated to mercenary work. That combined with it usually being stuck in the middle of violent conflicts means they have high ninja turnover from death/injuries and need plenty of kids to sustain them.

It's not that women are forbidden from becoming soldiers, but men can do the deed and go out for more missions, while women will be out of comission for a few months. Giving birth is a great honour, esspecially given the fanatical devotion each resident gives to their village.

Not to mention the high tax benefits and support systems the village would have in place to reward that devotion.


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

[User]
CMV: Holding firearm manufacturers financially liable for crimes is complete nonsense

I don't see how it makes any sense at all. Do we hold doctors or pharmaceutical companies liable for the \~60,000 Americans that die from their drugs every year (\~6 times more than gun murders btw)? Car companies for the 40,000 car accidents?

There's also the consideration of where is the line for which a gun murder is liable for the company. What if someone is beaten to death with a gun instead of shot, is the manufacture liable for that? They were murdered with a gun, does it matter how that was achieved? If we do, then what's the difference between a gun and a baseball bat or a golf club. Are we suing sports equipment companies now?

The actual effect of this would be to either drive companies out of business and thus indirectly banning guns by drying up supply, or to continue the racist and classist origins and legacy of gun control laws by driving up the price beyond what many poor and minority communities can afford, even as their high crime neighborhoods pose a grave threat to their wellbeing.

I simply can not see any logic or merit behind such a decision, but you're welcome to change my mind.

[Assistant]
>Do we hold doctors or pharmaceutical companies liable for the \~60,000 Americans that die from their drugs every year (\~6 times more than gun murders btw)?

Yes - look up the Purdue Pharma lawsuit.


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

[User]
Why didn't Alan Shepard's Mercury flight lose radio contact during reentry like the Apollo flights?

I'm watching "From the Earth to the Moon" and it seems like Shepard has radio contact the whole time. I haven't been able to find anything that refutes this. Only thing I could think of is that he didn't fly nearly as high as the Apollo flights.

[Assistant] Shepard's first flight was sub-orbital. The speeds are much lower and the kinetic energy involved is far, far lower (kinetic energy scales with the square of speed). Re-entry at those speeds is much milder and doesn't involve the creation of a "plasma sheath" which requires special thermal protection materials and which also blocks out radio communications.


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

[User] If Pangea existed ~225 million years ago (as we understand it) and the continents began drifting apart, is there any observable measurement of the continents drifting/merging back together?

[Assistant]
Pangaea wasn't the original continent, it was just the most recent supercontinent. There have been lots of cycles of continents breaking up and coming back together - India (with Madagascar for the first bit) was an island continent like Australia from about 140 million years ago until it collided with Asia some time around 50 million years ago.

Using GPS (and other things) we can see how the modern tectonic plates are moving, and from present motions and our knowledge of what drives plates we can make guesses at how the continents might be configured in the future.


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

[User]
[Star Wars] Why does it seem like it's incredibly easy to bring a Sith, who has committed multiple atrocities back to the Light side of the Force?

Luke didn't do anything special for Vader other than talk to him and say that there was good in him.

All Han did was appear to Ben and tell him it's okay.

Dooku simply did what all Sith do and betray Ventress.

[Assistant]
It's not very easy. They have to want it.

Vader was a tormented soul who thought he had no choice left but to be a Sith, and his son changed his mind.

Ventress was basically screwed over by everyone she met, except for the Jedi.

>!Ben's struggle between light and dark is like one of the biggest themes of the entire Sequel trilogy.!<


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

[User]
ELI5: Why is driving (or passengering) so tiring?

My kids spent most of the day on a long car ride and came home exhausted. Which I get, because I'm the same way. Driving is more tiring, but even riding for such a long time takes a real physical toll.

Why? I'm just sitting there after all, and if I'm not driving I don't even have to pay attention. Why do I feel physically drained after a long drive?

[Assistant]
Even as a passenger,  you're not really just sitting like you would at your desk.

In a car your body constantly has to make micro adjustments to keep you upright, if you let yourself go completely, you move around your seat a lot even with a seatbelt.

So all those micro adjustments that happen in a lot of places in your body (back, neck, etc) wear you down slowly and you don't really notice it until it's 2 hours in and you are exhausted.


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

[User]
[MCU] How reasonable was Thanos?

He may not be the sanest bloke around, but his demeanor and way of speech gave out a reasonable presence. Would you dare to come to his encampment politely then proceed to have a decent conversation?

[Assistant]
The Thanos we met in *Infinity War* was madness masquerading as rational, and so far up his own ass that he couldn't see how irreparably flawed his own plan was.

He was right about the state of the universe, about too few resources and too many many people fighting over them. And he was even right about the ability of the Infinity Stones to fix this issue.

But his plan to end half of *all* life, to cull the birds and the trees along with the men that would harvest them, made no sense, and he refused to listen to anyone who argued otherwise. The greatest minds on Titan couldn't convince him that he was wrong, and he took their resistance as a personal insult.

The Thanos we meet in *What If* was different, but we don't know if that's due to something in that Thanos' mindset, or if it was due to the eloquence of that universe's T'Challa. For whatever reason, though, that Thanos *was* rational, and *was* able to see the madness in his plan.

The Thanos of *Endgame*, however, the Thanos that saw his goals accomplished and realized that the sun did not, in fact, rise on a grateful universe, was fully, irredeemably mad. He believed the universe owned him gratitude, and when he was confronted with mere mortals that had the audacity to not only deny him his glory, but actively fight back, he decided to strip the universe to atoms and rebuild it in his own image.

That is not the response of a sane man.

It would appear that, at least in most cases, Thanos is a madman with a calm veneer. He is intelligent, well-spoken, and often calm, but at the very core, he is a megalomaniac with delusions of grandeur, as well as a madman who managed to steal enough power to inflict his will on the universe.


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

[User]
Can gravity set up concentration gradients in a solution?

If we take a perfectly mixed salt solution and leave it at rest indefinitely so the only mixing process is molecular diffusion, will the solution remain perfectly mixed or will the force of gravity set up a (small) vertical concentration gradient?

[Assistant]
At ordinary temperatures, "regular" gravity is not enough to set up a concentration gradient, as diffusion processes greatly overwhelm the effect of gravity.

However, if you subject solutions to high "artificial" gravity (i.e. in an ultracentrifuge at 450,000 *g*) you can set up small concentration gradients. This technique is called density-gradient ultracentrifugation and was used historically to make some key discoveries in molecular biology. The centrifugation medium is usually a concentrated solution of cesium chloride or of sucrose.


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

[User]
Why don't they use jet engines for the first stage of rockets?

I just learnt about specific impulse and how the specific impulse of jet engines is much higher because they don't have to carry their own oxygen. And that made me think; why don't they use jet engines for the first stage, when there's still oxygen around? Wouldn't that be much more efficient?

[Assistant]
Some of the problems:

Jets are only efficient at a specific designed air pressure and density. This is bad for vertical movement, where those parameters constantly change.

A rocket will quickly leave all altitudes where there's enough oxygen to burn. This means that the first stage would barely be used, which is a horribly inefficient thing to do.

Air consists primarily of nitrogen, so you need to separate the oxygen from the rest of the air - while in flight.

To get enough specific impulse from oxygen, you need to liquify it first, otherwise it's density is far too low to carry enough momentum. That means you need *a lot* of oxygen, which is difficult to come by if you fly very slowly (which you *do* at launch).

All of that under very cold conditions, which makes the processes even more complicated. For example your heat exchangers might freeze.

Tackling all these problems usually makes the rocket way heavier than just taking the oxygen and a normal rocket engine with you. It's also expensive as hell, considering your tech will be lost after one use. Unless you are SpaceX that is.


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

[User] ELI5: Throughout our lives, how much food goes into our lungs and how is it disposed of?

[Assistant] Hopefully not very much at all. If food were to make it all the way into the lungs your body would attempt to violently remove it via coughing. Particles that couldn't be removed that way would slowly be pushed out of the lungs by tiny hairs called "cilia". Millions of those tiny flapping tendrils create a flow of mucus up and out of the lungs to be coughed up.