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

[User]
How do Computer Algebra Systems, like Wolfram Alpha, solve algebraic problems?

I've been working with mathematica and maple a lot over the last week, and I still don't understand how computers can interpret and solve algebraic equations, yielding closed form solutions.

[Assistant]
It represents the equations and has rules for how to manipulate them.

For example, if you tell it "expand (x + 2)(x+3)" then it might:

1. Parse the expression into a tree representation

        multiply
          add
            symbol("x")
            number(2)
         add
           symbol("x")
           number(3)

2. Notice that this tree has an add underneath a multiply and apply the distribution rule:

        add
          multiply
            add
              symbol("x")
              number(2)
            symbol("x")
          multiply
            add
              symbol("x")
              number(2)
            number(3)

3. There's a still an add underneath a multiply. Do it again!

        add
          add
            multiply
              symbol("x")
              symbol("x")
            multiply
              number(2)
              symbol("x")
          multiply
            add
              symbol("x")
              number(2)
            number(3)

4. Man, so much distribution to do.

        add
          add
            multiply
              symbol("x")
              symbol("x")
            multiply
              number(2)
              symbol("x")
          add
            multiply
              symbol("x")
              number(3)
            multiply
              number(2)
              number(3)

5. Finally, now we can try some other rules. Oh hey, adds under adds can be flattened:

        add
          multiply
            symbol("x")
            symbol("x")
          multiply
            number(2)
            symbol("x")
          multiply
            symbol("x")
            number(3)
          multiply
            number(2)
            number(3)

6. Oh, and one of the multiplications can be computed:

        add
          multiply
            symbol("x")
            symbol("x")
          multiply
            number(2)
            symbol("x")
          multiply
            symbol("x")
            number(3)
          number(6)

7. And there are multiplies under an add that have a common term except for some numbers, so we can group those and add the numbers:

        add
          multiply
            symbol("x")
            symbol("x")
          multiply
            number(5)
            symbol("x")
          number(6)

8. Oh, and multiply something by itself is just squaring it:

        add
          square
            symbol("x")
          multiply
            number(5)
            symbol("x")
          number(6)

9. Hmm... can't see much else to do. Better make it pretty and print it:

        x^2 + 5x + 6

In summary, computer algebra systems work by applying known-to-be-good operations to a tree representation. Sometimes they will try many different combinations of operations and return the one that worked the best, sometimes they'll fall back to doing approximations, and sometimes they don't work simply because the right rewriting rule hasn't been added yet.


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

[User]
Why do we prefer to sleep in the dark?

I've always wondered this.

[Assistant]
Humans are evolutionarily adapted to sleep at night (when it is dark) and be active during the day (when it is light).  Chemicals that make you sleepy build up in your brain over the day until you go to sleep at night and your brain gets rid of them all.

There is another chemical as well which wakes you up and stimulates you.  It is triggered by bright light (especially blue coloured light) that historically would be only from the Sun (i.e. it's day time and you need to be active not sleeping).  Artificial lighting simulates sunlight which in turn signals to your body that it is day time and not time to sleep.


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

[User]
ELI5; How do Gatling guns/miniguns have such reliable accuracy?

With the very manner of how they fire bullets, guns like the M134 and GAU-8 for example must create a large amount of centrifugal force, which is still in motion while the bullets are traveling down the barrel. How do they fire accurately rather than with a spray area, as a result of centrifugals upon barrel exit?

[Assistant]
> must create a large amount of centrifugal force

They don't for the simple fact that the bullets/shells are travelling at really high speeds so they spend almost 0 time in the barrel and so are barely affected by the fact that the barrel is rotating.


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

[User]
Do we know how long dinosaurs lived?

I'm talking about each individual dinosaur, not the time period. Did T-Rex live for 10, 50, or 100 years? Do we have this information?

[Assistant]
Yes, we do. For some.

Or at least we have an idea.

Animals tend to grow seasonally, with more growth in warmer weather and less in colder weather. This results in what are called "lines of arrested growth" or "LAGs" for short. As an analogy, you can think of them sort of like tree rings for animals.

Now, for some dinosaurs, we can make a cross-section of their bones and count their LAGs (note, this does not always work for a variety of reasons including bone reworking through life and such). From this we can estimate age-at-death.

For example, "Sue," a large and very complete specimen of *Tyrannosaurus rex* currently on display at the Chicago Field Museum is estimated to have been ~35 years old when it (despite the name, the sex is not known) croaked. And "Sue" was an *old* tyrannosaur, practically geriatric.

From bone histology and LAGs we can also make inferences of how fast dinosaurs (and other animals) grew. For many even very large dinosaurs, the answer is surprisingly fast, reaching adult size in often <10 years.


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

[User]
ELI5: Why is a small amount of inflation considered "good" for an economy?

I mean, it's pretty obvious why large amounts of inflation are bad. But it's much less intuitive why some amount of inflation is considered "good." Does that help money move around somehow? Or are people more motivated to spend because the value of their savings diminish over time?

[Assistant]
Small amounts of inflation are good for the economy because it encourages investment. If you have a large sum of cash, it's losing value every day (slowly, but it's still happening). If you want to make the most out of your money, you'll recognize that you need to to put into an investment fund of some sort so your stored cash doesn't lose value. Or you'll want to buy something with it, since given more time, the same item will be more expensive. Investments and purchases are needed to keep the economy churning.

If deflation is occurring, then it's a good idea for you to sit on your big pile of money Scrooge McDuck style since it's because it's worth more every day. If everyone does this, the economy stagnates.


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

[User]
What is the difference between "targeted relief" painkillers and the generic painkillers?

I saw an advert for Nurofen period pain targeted relief pain killers and I wondered what the difference was between that specific Nurofen tablet and the other plain version? From my knowledge, isn't there some sort of molecule in the tablet that will bind to a receptor in the brain to alleviate pain? How is the tablet specifically targeting, in this case, period pains? Does it also purposefully interact with the female reproductive system?

Similarly for headaches and other problems, if I took a tablet to alleviate headache pain, would that help at all with say a sore throat?

[Assistant]
That's actually pretty controversial. Nurofen is just ibuprofen. Ibuprofen doesn't do anything specific for pain or discomfort associated with menstruation.

But the thing is, ibuprofen *has* been demonstrated to relieve pain associated with menstruation  just the same way it relieves most other types of pain. So it's entirely truthful for the makers of Nurofen to advertise that their product is for relief from menstrual pain. Because it works fine for that.

No, there's no molecule in the tablet that binds to any receptors in the brain. Ibuprofen works by deactivating an enzyme called *cyclooxygenase* which is a precursor to hormones called *prostaglandins.* Prostaglandins are part of the body's inflammatory response; that response causes discomfort in varying degrees. Inhibiting the body's production of prostaglandins reduces the body's inflammatory response, which almost as a side-effect relieves the pain associated with inflammation.

Basically the mechanism of all NSAIDs non-steroidal anti-inflammatory drugs like aspirin and ibuprofen is largely the same. The differences between them are pretty subtle. So yes, taking an ibuprofen (or aspirin, or naproxen, or any of the other zillion drugs in that class) will help relieve a sore throat. It isn't the *best* way to relieve a sore throat; other medications are better at relieving pain, but they come with various interactions and possible side-effects. So the various NSAIDs with their anti-inflammatory properties remain the best overall way to relieve minor pain.


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

[User]
ELI5: How much of a cold or flu virus do you have to be exposed to in order to catch it?

As I sit on a train home from work in Australian winter, half the carriage is coughing and sneezing. My understanding is that, generally, cold/flu viruses spread either through the air and being inhaled into the nose/lungs, or by being left on a surface by contact and subsequently picked up by new contact and then passed to the eyes/ears/nose by hand. Ive read articles about how a single uncovered cough or sneeze can spread a whole heap of virus into the air.

When the virus is bloody everywhere in a container like a bus or train or plane, I cant see  how the majority of people arent getting at least some degree of exposure to it. So why dont the majority of people actually contract it and become sick? Ruling out pre-existing immunity to that particular virus, what determines who does or doesnt contract a cold/flu when they are exposed to it?

Is it the amount of virus which enters the body? The strength of our immune system? Id love to know!

[Assistant]
In terms of "how much of a virus do you need" - we don't really know, in most cases. Some viruses, such as influenza or adenoviruses, only require 10 particles to cause infection. It depends on how the virus infects (it is harder to get infect through the skin than it is to be taken in as someone breathes, for example).

For "why does x person get infected over y person" - it relies on a couple of different factors, all of which are different depending on the virus and the individual person being infected:

1. If you've been exposed to the virus before, your body will have built up what is known as "immunological memory" - it has immune cells stored away from the last infection, which can prevent a second infection from building up (so effectively that you may not even know you have had a repeat infection!)
2. How contagious the virus is. Some viruses are heavy, and when in the air, can't spread well, so don't infect many people. In contrast, the most contagious virus - measles - is an extremely light particle, and can float in a room for hours after it an infected individual has been there. The letter R is used to mark how many people an infected person will infect - for measles, every person infected will infect 17 others, on average. So if the virus is extremely contagious, a lot of people are likely to get it. If not, then only an unlucky few will.
3. Personal immunity. Just like everyone has different DNA, we all have cells and receptors for things in the body to bind to. This is really diverse, even between family members. Some people have receptors for one virus or bacterium to bind to, but others do not. This is why, even between siblings and parents, some people get sick from a certain pathogen, but others don't. In essence, it can come down to luck.
4. Health. A healthy individual may have a better functioning immune system, allowing a more rapid and effective assault on a viral infection. Others who are "immunocompromised" (such as AIDS sufferers) or more elderly don't have this same functionality, so cannot so easily get rid of an infection. This is why people so often get secondary illnesses in hospitals (as well as the fact that there are many sick people concentrated in a small area) - they are already unwell, and don't have the capacity to fight off further infection.
5. Personal hygiene. One of the single biggest factors for preventing viral infection (which most effectively spreads through bodily fluids released from a cough/sneeze) is washing your hands. If someone with the flu touches the button to open the train door, then you touch that some button, and then your mouth/nose/eyes/opening... you see where this is going.

When you think that a cough can release hundreds of thousands of these particles, and a sneeze millions, you can see how this could be common! But our immune system has a number of very effective techniques to prevent viruses from entry in the first place (the skin, mucous, chemicals in bodily fluids), and prevents a huge number of foreign pathogens infecting us every day.


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

[User]
If half of the matter falling in to a black hole during Hawking Radiation emission are anti particles and half are their particle counterparts, why does it cause the black hole to shrink?

Why aren't the effects of particles and anti particles netted out?

[Assistant]
There is a variety of misleading information in this thread.

To begin with, you are correct: the absorption of particles or antiparticles would increase the mass of a black hole.

Next: this whole description you are referencing is a description of one way of calculating the existence of Hawking radiation, but you should not take the description of the calculation to be a physical description of what happens (and, in fact, there are other ways of doing the calculation).

To expand: There are physical particles in nature -- things we are familiar with, like electrons and photons and so on.  In certain approaches to particle theory calculations, there are separate entities called virtual particles.  Virtual particles are NOT physical particles; there is no way to observe them.  One way we know they are not physical is that there are ways of doing particle physics that do not use virtual particles at all!

Hawking radiation occurs because quantum mechanics allows for states that start out as just a black hole and end up as a slightly smaller black hole plus an outgoing particle.  The way Hawking first showed this is with the creation of a real particle/virtual particle pair near the event horizon, with the virtual particle getting absorbed, and the black hole decreasing its mass.  You can also show this without virtual particles but using tunneling ( la Parikh and Wilczek).

Trying to think too literally about the virtual particle calculation is problematic because you can wind up trying to reason about non-physical objects as if they are physical.


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

[User]
Is time quantized ?

We know that energy is quantized by the Planck constant.

There is such things also for time, or time is continuous ?

[Assistant] We don't know.  We have no evidence of any discontinuity in time down to about 10^(-28) seconds.  If time is not continuous, it will show up at shorter scales.  It may also be that time is not a fundamental construct, and only emerges as an effective notion.


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

[User] ELI5: When you make red hot metal hotter, why does it become white hot, rather than blue hot?

[Assistant]
Color temperatures go red->orange->yellow->white->blue.

It could become blue hot if you mad it much much hotter. But in practice you can't make iron hot enough to be blue hot.

6500 K is "standard white" (color of sunlight).

You'd need to make it around 8000 K hot to be blue.
Iron **boils** at around 3000 K.
Even tungsten boils at around 5700 K.

So any metal you could be heating up would boil away before it became blue hot.


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

[User]
If men are obligated to recognize any children they have, should't they have a say in abortion?

So this question popped up in a debate I had with a friend of mine about feminism. He was arguing for the rights of men and he asked me if forced fatherhood is fair when a man impregnates a woman and she decides to keep the child but he doesn't want it considering that he doesn't have a say over abortion.

I have never thought this question before, but it seemed fair to me that if you must bear the consequences of supporting a child, you must have as much control as possible to its birth, the same control as the woman who bears it, while at the same time respecting the bodily autonomy of women.

It seems like an ethically delicate subject that is complicated.

What are some philosophical thoughts about this?

[Assistant] With the way this is framed this isn't an abortion issue, but rather a child support issue. If the man does not want the child and the consequences of supporting it, then it is possible for the child to be born while still not forcing him to have to support it. The issue isn't so much, "should men have a say in abortion if they don't want the child but have to support it", the issue is more "should people have to support a child that they do not want?"


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

[User]
ELI5:Why don't we like the taste of everything that's edible?

I mean from a survival view point it would be more logical to like everything; because it equals more food, which means more chances of survival.

[Assistant]
Edible things have different nutritional values.

Early humans who thought everything was delicious spent their days eating dirt and grass.  This was fun but did not provide the nutrients their bodies required so those people died off.

Early humans who thought meat and fruit were delicious were extra motivated to gather those foods instead of eating grass, and they received the nutrients they needed to thrive.


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

[User] What does the term Linear Independence represent graphically? And what are the implications of two things being Linearly Independent?

[Assistant]
Two vectors are linearly independent if they are not parallel.

Three vectors are linearly independent if they don't all lie in the same 2D plane.

Four vectors are linearly independent if they don't all lie in the same 3D "hyperplane."

...


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

[User]
ELI5: How does the International Space Station have enough oxygen for all the astronauts?

How does NASA calculate the amount required? What happens in case of a leak? Do they refuel it every trip there? If that is true how come we can't setup multiple ISSs on the way to reach further into space?

[Assistant]
**How does NASA calculate the amount required?**
Decades of research by the Russians and Americans (Skylab / Salyut)

**What happens in case of a leak?**
They generate it on board from water and backup solid candles, also the ISS is pretty air tight. It has to be.

**how come we can't setup multiple ISSs on the way to reach further into space?**
It would be hugely inefficient to have multiple stations in Earth Orbit, one big one would do.  Better off with things like Lunar bases.


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

[User]
How is it that radiation suits protect people?

Maybe this is TV magic and I don't know what a real suit looks like but it seems like people become immune to radiation when they put on these thin plastic suits. How is it that radiation can be so dangerous and yet so easily dealt with.

[Assistant]
The radiation suits you typically see don't block a lot of radiation. To understand their purpose, you first need to know what happens in a nuclear incident or any other situation where radiation exposure is a risk.

Essentially, radiation is emitted by unstable particles that decay (the radioactive material). Normally, we like to keep these particles contained, but after, for example, an explosion, these particles can be spread all around or even be airborne for some time after the event.

When you enter an affected area unprotected, the amount of radiation you'll take in during your presence is only a small part of the problem. The larger issue comes from particles that end up in your clothes, on your skin or even in your lungs after you breathe them in. These particles cause a continuous exposure to radiation even after you leave the affected area. Especially ingested particles are dangerous, as the radiation emitted by those can directly affect your internal bits, whereas radiation originating outside of your body still has to pass through your skin and muscle tissue (though it can already do damage there).

So the main purpose of a radiation suit is to avoid taking too much radioactive material with you.


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

[User] Why is zero multiplied by infinity not defined as zero?

[Assistant]
Infinity isn't a number (you can't point to it on a number line), and since both things that you're multiplying have to be actual numbers, you can't multiply anything by infinity.  In general, infinity is not a valid term to use in any "normal" math.

What you *can* do is take the **limit** of "0 * x" as x approaches infinity, and the solution to that limit is zero.


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

[User]
ELI5: Why is Africa always in a state of peril?

Maybe that title is a little imperfect, but I know how valuable Land and resources are, and I think Africa has a lot of that, but it always seems to be unevolved and always in disarray. Also , I know a little about most countries and continents, but not very much about Africa, why was it left out of my education. Thanks in advanced.

[Assistant]
Plus, the continent is really fragmented.  The entire continent has almost no quality natural harbors (one in South Africa, a few on the Mediterranean, and that's it.) The coastlines tend to be rather jagged cliffs, which made it hard to catch up to commerce, back in the day.
Many small rivers bisecting the land, large savannahs and desert divide the continent. Africa is a continent with dozens and dozens and dozens of different cultures, heritages, and languages, and many of these groups have been historically at odds with their neighbors.
All of this really prevented Africa's ability to keep up with Europe and the Western world. Plus, ya know, slave trade.
All those historical divisions between peoples haven't gone away, and modern weaponry has only made old hatreds much bloodier.  There are just so many different cultures that it's hard for a single nation to unify, much less a continent.


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

[User] Why does Bacillus thuringiensis produce a protein that is toxic to Lepidoptera? What does Bt need to kill caterpillars for?

[Assistant] *B. thuringiensis* can be present on basically any surface in a caterpillars environment, including those it eats. Delta endotoxins paralyse the insect digestive system causing it to starve to death, providing a delicious substrate for a primarily saprotrophic bacterium.


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

[User] ELI5: Why do dogs lick people?

[Assistant]
There could be several reasons.

 * To show submission to someone they recognize as dominant over them

 * To show intimacy with something else, which they learned from their mothers while young

 * To gather information about you through sweat and other things your skin secretes

 * You might taste really good

Licking also releases endorphins, which are chemicals in brains that make you feel good, so the dogs benefit even if they only lick due to instinct.


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

[User] Is there any evidence of a liberal media bias in the united States? If so can anyone tell me why?

[Assistant]
Here is the most highly cited journal article that directly addresses your question.

Watts, Domke, Shah, & Fan (1999). Elite cues and media bias in presidential campaigns - Explaining public perceptions of a liberal press. Communication Research 26(2)

Abstract: Public perception of a biased news media, particularly media biased in a liberal direction, has increased over the past 3 presidential elections. To examine what might be influencing this public opinion, the authors look at shifts in public perception of media bias, press coverage of the topic of media bias, and the balance in valence coverage of presidential candidates-all during the 1988, 1992, and 1996 presidential elections. Their results suggest that the rise in public perception that news media are liberally biased is not the result of bias in valence news coverage of the candidates, but, rather, due to increasing news self-coverage that focuses on the general topic of bias in news content. Furthermore, the increased claims of media bias come primarily from conservative elites who have proclaimed a liberal bias that is viewed as including the entire media industry.

Now you need to decide whether you trust liberal academics to tell you the truth. Oops. You're in an epistemological quagmire.


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

[User]
When you donate blood, are you accelerating the depletion of valuable stem cells you will need as you age?

I was just thinking about this when I saw the blood bus today. I know blood cells come from marrow. Could losing a large amount of blood on a semi-regular basis deplete the stores you need to make more red and white blood cells in the future?

[Assistant]
Red blood cells are manufactured in the bone marrow and are replaced every 100-120 days. Outside of some chronic disease, you have a infinite ability to manufacture them.

White blood cells, or leukocytes (there are 5 different kinds), are also manufactured in the bone marrow and are replaced every few days. You also have an infinite ability to produce them, absent some chronic disease.

Giving blood does not deplete your ability to manufacture either type of blood cell. You are safe to give blood, as long as you don't have a disease that affects your ability to produce either type of blood cell.


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

[User]
ELI5: Private equity or hedge funds that buy successful brands and drive them to bankruptcy within a few years. What do they gain by doing this?

Just thinking about JCrew, Toys R Us, Payless, Sears, Neiman Marcus and more were all bought out by funds seemingly trying to bankrupt them. Isn't the point of buying a business trying to get them to succeed?

[Assistant]
This isn't always the case but when that's the plan, it goes as follows:

    - Borrow money and buyout the company.

    - Have the company massively go into debt and use the money to pay yourself an enormous dividend.

    - Use the dividend to pay back the money you (not the company) borrowed.

    - The company is way over leveraged, defaults on the debt and declares bankruptcy.

Here's where it gets interesting, the bankrupt company now sells off it's assets (brand name, plant, etc.) and defaults on its union contracts, pension obligations (which screws the retirees and the taxpayer funded PBGC), etc. The corporate lenders are now basically the owners of a new unencumbered company with a much higher profit margin. Hostess Bakeries is a good example of this.


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

[User]
Where does body heat originate?

I've been wrapping my brain around this and the best I can do is that the metabolizing of proteins and sugars during digestion must create energy that provides heat for the bloodstream to carry around. Is this correct?

If so, I'm thinking that blood gets warm near the digestive system but this doesn't make too much sense when you think that body heat doesn't drop during periods of fasting.

Can someone shed some light on this matter?

[Assistant] Heat is a byproduct of inefficient conversion of energy. In most living organisms' cases the this takes form in the conversion of the chemical energy in metabolic substrates like carbohydrate, fatty acids and amino acids to the phosphodiester bond of ATP. This process is inherently inefficient due to several factors such as proton leaks from the mitochondria and inefficient transfer of electrons to carriers. Additionally, some organisms have developed proteins that are responsible for regulated uncoupling of the electron transport chain, known as uncoupling proteins (UCPs). Brown fat is very rich in these UCPs and this tissue is activated when the body must produce greater amounts of heat, such as severe cold challenges. So, though some heat is produced in the digestive processes, the majority of heat produced by the body is by the inherent inefficiency of energy metabolism in each and every cell.


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

[User] ELI5: Why do my teeth hurt when my drink is too cold?

[Assistant] The nerves in your mouth become numbed by the cold like if you put an ice pack on a bruise, but since your teeth are more important than a bruise your body freaks out and thinks that something bad happened because it is no longer receiving a signal from your numbed teeth so it tells you that it hurts so you will figure out what is wrong and fix it.


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

[User]
[Endgame] (spoilers) How did Thanos know

.

.

,

,

,

,

,

,

,

How did he know how to use the Pym Particles? He was only able to go into the future because he got them from the Avengers in the past, correct? via the past Nebula?

[Assistant] Thanos was able to access all of 2023 Nebula's memories. She may have learned quite a bit working with Banner and Stark. Additionally, he likely has access to some of the best minds and technology in the galaxy. Also, there wasn't necessarily a 1:1 correlation between elapsed time for 2014 continuum and the 2023 continuum, so he could have had more time to figure things out. Lastly, 2014 Nebula used Stark's time machine to bring Thanos. His ship literally was shrunk to the scale required for the Quantum Realm and spit out at the Avengers compound. He may not have been able to travel in the QR and traverse time without Stark's equipment.


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

[User] [Harry potter] why are wizards and witches auch elitist and racists?

[Assistant]
In the past their people, a distinct minority in the human population, were heavily persecuted. This was during the medieval era. Despite being powerful, they still struggled to survive.

As a result, the wizards and witches isolated themselves, forming their own ethnic (for the lack of a better term,) enclaves, preserving their own culture. Their 'racism' as you call it is arguably justified. If they suddenly reappeared, there would be mass chaos on a civilizational scale. A tiny group of people with no apparent limit to their abilities living alongside normal humans? It would be the equivalent to finding out that lizardmen exist.

The elitism that exists is possibly just a natural result of that massive difference in power. A group of people with genetic superiority over another group in a way that is obvious and evident would naturally breed that kind of ideal. Just look at the slur mudblood for example.


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

[User]
Why does earth rotate ?

Why does earth rotate ?

[Assistant] Planets form out of a protoplanetary disk, which is a collection of material thats all orbiting the sun. This disk has some net angular momentum vector, usually pointing in the same direction as the angular moment vector of the solar system. Since angular momentum is conserved, when the disk coalesces into a planet, it will rotate in the same direction, but faster because the effective radius is now smaller.


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

[User] [the Silmarillion] Why did the Valar ask Eru to intervene against Ar-Pharazon's fleet instead of dealing with it themselves?

[Assistant]
Because Men are children of Eru. Despite the fact that they were afraid that Numenor could ruin Valinor, they asked Eru because they did not want to directly kill humans or indeed any child of Ilvatar by their own hands. It was basically a problem with too much ramifications.

Also, remember that Eru didn't just kill Ar-Pharazon and his fleet, he sunk the island and then turned the world round. Perhaps not actually beyond the Valar's combined power, but something they did not want responsibility for - something they did not want to get 'wrong'.

So in the end they asked Eru because he was the creator of everything, they knew that what Eru did would be the correct punishment or judgement depending on how you want to look at it. Rather than them doing it and somehow they screw it up and cause even more damage down the line.


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

[User] [DBZ] So if almost dying makes a Saiyan double in strength, why wasn't future Gohan on a self harming sensu bean craze to stop the androids?

[Assistant] The problem with abusing that ability is that there's a high risk of accidentally killing yourself. The only time it's worth the risk is when you have an incredibly short time to become powerful enough to defeat an opponent who would be impossible to defeat otherwise and retreat is not an option, like with the fight against Frieza.


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

[User]
ELI5: Why is there such a wide gap in the intelligence of homo sapiens and every other organism?

The answer I've been given was basically: GOD. I'm not convinced.....

[Assistant]
Chimpanzees are actually pretty close to us. But here's the thing. Once we reached a certain level of intelligence, we adopted a way of life centered around intelligence -- notably the use of language, tools, and complex civilizations. Suddenly being intelligent was *even more valuable* because our societies were designed around it.

Once society started rewarding intelligence, people with higher intelligence were *even more likely* to survive and reproduce. A self-reinforcing cycle was born.


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

[User]
Is it more energy efficient to leave the heater on low when nobody is home, or to heat it up from cold when you get back?

So this morning as I was the first to walk back into my freezing office after the holiday, I was reminded of an argument I used to have with my roommate when I lived in a drafty old house in upstate New York.  We would both leave the house for one to two weeks every Christmas, turning the thermostat down to something like 5C while we were away, and when we returned we would have to run the furnace full blast for about three days to get the house up to 22C again.  I would always suggest that it would be better leave the thermostat on something in the middle while were gone, like 15C, but he thought it was a waste of energy.  I argued that it took just as much energy to run the furnace continually for those three days when we returned than it did to maintain a modest temperature while we were away.  In reality, I have no idea, but I just hated those three days of feeling cold.

Obviously, this depends on lots of factors, like how cold it is outside and how long we are gone.  But in general, ignoring issues like pipes freezing, does it use more energy to maintain a moderate temperature for a long time and then heat it up for a short time, or to let something cool way down and then heat it up all the way?

[Assistant]
The amount of heat lost by an object to the environment is proportional to the temperature difference between the environment and the object.

So if the object is at 20C, while the environment is at freezing (0C), then the rate of heat loss will be twice as high than if the object was at 10C.

If you keep heating the house while you're away, you keep the temperature higher and the total heat loss during your away time will be higher. Whereas if you turn the thermostat down very low, the rate of heat loss will gradually slow down as the house becomes colder and colder.

The total amount of energy you consume during this absence and the reheating that follows will be equal to the amount lost. In the case where you keep heating your house, this energy loss will be higher than in the case where you don't heat your house at every point in time (except for the initial period where the temperature drops from the starting point to your "something in the middle" value, in which case the energy loss is equal in both cases).

So from basic physics, it will be more efficient to turn the heater down as much as possible (without risk of freezing pipes) and heat it back up upon return. To overcome the discomfort of returning to a cold home, consider a smart thermostat that can be programmed to reach the desired temperature when you return (and will start to heat before you get back). Some can even "learn" how long it takes to heat up your house specifically with repeated use, so that they start at the exact right time.


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

[User]
Is the galaxy a mostly flat plane like its depicted in pictures? If so, why?

In most artistic depictions of the Milky Way galaxy, its illustrated as a roughly flat 2 dimensional plane. What I was wondering is if thats really the case, or if solar bodies revolve  above (relative to said 2D plane) and below the center of the Milky Way?

[Assistant] To add some numbers to the good answers here: our galaxy has some thickness to it, but its wider than it is thick by a factor of 10-50 depending on how you measure.  Roughly the same relative thickness as a thin-crust pizza.


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

[User]
[MCU] Which timeline would be the least unpleasant to live in had one of the villains succeeded in their goal?

For example:.

If Obadiah Stane killed Tony Stark at the end of Iron Man 1, would the long term repercussions have been better or worse than if the Project Insight helicarriers had successfully launched during Winter Soldier? Or if Ronan the Accuser had killed the Guardians of the Galaxy and purged Xandar with the Power Stone? Or if Darren Cross had killed Scott Lang and sold Pym Particles to HYDRA? Or if Hela killed Thor and continued her conquest of the universe?

Which timeline in which the villain wins in an MCU film would be the LEAST bad?

[Assistant]
*Spider-Man: Homecoming*.

If Spider-Man hadn't stopped Toomes, he would've sold a few more weapons to street criminals in New York.  Maybe there would've been a few more robberies before the Avengers or SHIELD stepped in.


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

[User]
ELI5: How can someone call a phone number they heard on the radio and get "80% of their IRS debt completely gone!"

Are you in debt with the IRS? Do you have $20,000 or more in back taxes? Call this number for IRS relief!

[Assistant]
Some of these businesses are scams, but some are legal and just charge for a service that anyone has access to.

For instance, people in a lot of debt to the IRS can make an "offer in compromise." They agree to pay a good chunk of their debt within a set time, based on their income and assets, and the IRS does not collect the rest of the debt. This is something the IRS does because a partially collected tax debt is better than nothing.

Companies like these might do something like charge you up front to submit the application for an offer in compromise, even though that's something you can do yourself, if you knew about it.


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

[User]
Can butterflies remember being caterpillars?

During the metamorphosis of insects it seems their cellular structure is completely reorganised. How much of the memory of the individual survives this? For example, if you "trained" a caterpillar or conditioned it to respond in a certain way would the resulting imago remember this conditioning?

[Assistant] Yes, and it's actually quite amazing that it happens at all. The caterpillar's body breaks down to reorganize into it's adult form yet does retain memories. This was discovered using your example, conditioning. Caterpillars were conditioned to avoid a scent and remembered it as adults. However, it seems events are more likely to be remembered in older caterpillars than younger ones.


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

[User] ELI5: What does it mean to sing a song in a particular key?

[Assistant]
**First and Foremost: The vast majority of people saying this have no idea what it means! Especially Singers.**

Notes are Frequencies. Doubling a Frequency results in a Note that sounds "kinda the same but higher", which is why it is treated as a higher version of a lower note. Example: 440Hz is an A, but so is 880, 1760 and even 220 and 110 or 55. The same Note but higher or lower is called an Octave, which you might have heard before.

Between two Notes of the same Name we divide the space into 12 Notes equally spaced called A A# B C C# D D# E F F# G G# cycling back to the A. We might also call them A Bb B C Db D Eb E F Gb G Ab, but that's a whole nother can of worms. We didn't always use the 12 tone equal temperament system, but that's how we do it now, because that way the most amount of notes appear, that sound good, "when played together with each other". It's just the most practical. The distance from one note to another is called an *Interval* with a specific name depending on how large the interval is. You might have heard about thirds, fifths, Seconds, Octaves etc.

Now, when you pick any Note as your Basis for any music (We call this our *root note*) we have to look at the intervals from the root to the other 11 possible Notes in our western System. If we just play them all, then it will sound really confused, so we gotta pick some of them. A group of picked notes to be played is called a "Scale". The A Minor Scale is A B C D E F G, the B Minor Scale is B C# D E F# G A, the A Major Scale is A B C# D E F# G#, the A Locrian Scale is A Bb C D Eb F G A and there are countless others.

After you got a "Scale" you want to base a song around you can say that this is the "Key your song is in" with the Root Note of the Scale beeing the "Key Center". If you now write a Melody in lets say A Minor you might go: A -> B -> D -> C -> E -> G -> A (Higher Octave) and have other Notes as chords to support the Melody. But you might Run into a Problem, because your Singer can sing the E, but not the G and high A requested, because it's too high. One Option would be to play every Note a whole Octave lower, with all the notes staying the same in name, but that just might sound way too low as a whole, so we have to change the Key.

For this example i said the E is the Note the Singer can still sing, so we move the highest Note in Question down to an E, which is 5 notes (Look at the full 12 Note-names here, not just the scale). A -> B -> D -> C -> E -> G -> A becomes E -> F# -> A -> G -> B -> D -> E (Higher Octave), which our Singer can likely sing. Congratulations, we have now changed the Melody to be in E Minor instead of A Minor. All the Instruments, Chords etc. have to also be played in the new Key.

*PS: Aside from Singers, Guitars (and other instruments) are also easier to play in certain Keys (A Minor, C Major, G Major, E Minor, E Major) than others (F# Major or Bb Minor). Piano is easiest on C Major / A Minor, because it's all the white Keys.*


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

[User]
ELI5: Why do we give North Korea humanitarian aid instead of forcing them to give up?

So, why? Why doesn't everybody just cut off them completely, forcing their government to "surrender" as it were, open their borders and join the rest of the world.

I mean, their situation ain't exactly been improving over the years [while giving humanitarian aid].

[Assistant]
If North Korea were to collapse, it would be the closest thing we've experienced to a refugee crisis from another planet. North Koreans are forced to live in a completely different reality, and China has absolutely zero interest in integrating them into Chinese society.

Providing humanitarian aid is a preventative measure against a collapse that would be extremely expensive for all parties involved. The US, China, South Korea, and Russia would replace living next to a hermit state with living next to Somalia.


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

[User]
[Pokmon] Why do some pokmon not evolve? (Only have one "form"). And, is there any advantage to that? Or is it all disadvantage. Examples would be nice too.

In each generation there are pokmon that do not have an evolution. I'm thinking of pokemon like Taurus. Is there any in-game explanation for why some species don't evolve? (Bar them adding an evolution in a later game.) Also, for this question, I'm not counting mega-evolutions because I think those are really more akin to injecting a massive dose of steroids or PCP into a pokemon.

[Assistant]
Why are humans born looking like small adults? Frogs are born as tadpoles, that turn into frogs as they get older, but humans never change form. Why is that?

Answer that, and you'll find your answer.


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

[User] ELI5: Why, sometimes, you dislike a song at first, but after hearing it a few more times you begin to like it.

[Assistant]
Music is all about patterns and repetition, but just simple repetition is boring, so there is also change. So music sits on the boundary between predictable/boring, and chaotic/incomprehensible. This is something you will notice in almost all music, that it sets up a pattern, and then changes it before it becomes predictable. The music builds expectations and then either fulfills those expectations or doesn't, depending on the effect the composer is trying to achieve. Establish the pattern then break the pattern, change it into something else - familiar, recognisable, but different. The next verse is the tune you know but with new words. Then the chorus uses different chords, or the same chords but a different rhythm, or a different order, or the same thing with a new instrument, or a different melody over the same chords. Some things predictable, some things unexpected.

Point being, much of the effect of music relies on expectations, so it really makes a difference whether you know the song or not. Some songs that you end up liking the most once you know them you don't like at first because they violate your expectations in ways you don't like. But once you know what's coming, you can enjoy the changes without being thrown by them.


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

[User] ELI5: Why are fights between players allowed in the NHL when it is very strongly prohibited in just about every other sport?

[Assistant] It's just part of the game. The refs do stop fights when they go to the ground or when it gets out of hand to prevent any real injuries occuring. The players aren't really fighting to hurt eachother. It's more to show the other team that certain things won't be tolerated. It can be strategic or just because emotions are running high, but players rarely get any real injuries from a fight.


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

[User] ELI5: Why can't I swallow twice in quick succession, without it being difficult?

[Assistant] It's because swallowing starts a chain reaction of muscle movements in the throat all the way down the digestive tract called peristalsis.  So the top muscles in the throat have to wait until the adjacent muscles are ready to start again.  It's like trying to start a "wave" at a sporting event when the person next to you is still standing up.  It just doesnt work.


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

[User]
Why do people keep dreaming about their old friends/relatives even though they're no longer in touch?

I keep dreaming about my childhood friend for years. I have not seen the guy for at least 6 years and even before that we went to different high schools, so we weren't in touch since elementary school. I finished university and still have dreams about him once a month. I don't consciously think about him, I don't wonder what he's doing but I keep seeing him in my dreams. It started to freak me out. Is there a particular name for this in psychology? Why do I keep seeing him?

[Assistant]
Because the stories of our dreams, are compiled from our memories, worries, concerns, etc.. **The only thing your brain has to use as content matter for dreams is what's already there.**

If you've seen it, experienced, or have ever thought about it, it's a possible inclusion.

Then, the more you worry about it, the more it is top of mind, the more you will often see it.

It's just how our mind works. Dreams are nothing more than stories that our brain puts together while you are experiencing random neural firing (think of those firings like a sleep release of sorts).....

...and what the brain pulls for content can be random or something you've thought about, but it can certainly pull from memories many years passed.


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

[User] ELI5: After eating spicy food, why does breathing-in cool my mouth, but breathing-out burns it more?

[Assistant] most spicy foods work by activating a receptor that reflects heat. Imagine if there is a thumb print machine and the thumb that opens it is heat, the spicy food has capsaicin which also has the same thumb print. Basically activating the sensor. When you breath in, the air in ambient which your body is used to. But when you breath out it comes out around 30 degrees C. Which is going to trigger the censor which is partially opened by spicy foods.


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

[User]
ELI5: how did radiation destroy machines in Chernobyl?

I remember hearing that everything from cameras to trucks stopped working because of the radiation, what's up with that?

[Assistant]
You heard something wrong about the trucks then, those certainly didn't stop working. There's a graveyard of them because the metal became irradiated, it's not so much "they don't work" as they're now unsafe to be around because they are radioactive from induced radiation.

Only more sensitive stuff breaks - film in mechanical cameras gets exposed by radiation and semiconductor based things glitch out and over time degrade to malfunction permanently.


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

[User]
In animals like octopuses and cuttlefish that die shortly after mating, what is it that kills them?

In documentaries about cephalopods, sometimes footage is shown of octopuses and cuttlefish post-mating indicating that they die shortly afterwards. They usually look very disheveled, with their skin peeling off it looks as though they are literally disintegrating. What causes this, is it some sort of super fast aging process?

[Assistant]
The trait you're looking for is called semelparity. A classic example is a marsupial mouse, which basically fucks its way into the grave. As it enters the mating season it starts producing a huge amount of the stress hormones adrenaline (epinephrine) and cortisol. These make fat stores more available for energy, reduce hunger, reduce pain, reduce fatigue, and kill the immune system in order to maximise the number of times it can mate in this one season.

It will continue to have sex without eating, barely sleeping, until it is ridden with diseases (fur hanging off etc.), has no fat remaining and has been digesting its muscles for energy, and is completely exhausted.


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

[User] ELI5: Do trees have a life span, or will they continue to grow if not damaged or diseased?

[Assistant]
**Edited to correct stuff.**

Many trees can live for an exceptionally long time. The oldest known trees are over 5,000 years old.

Trees are an interesting case because, as they grow older, they also grow *faster*. This basically means that the older they get, theyre simply more and more likely to die of a disease or other event. Also, when a tree gets old, it has trouble protecting most of its inner heartwood and/or exterior. This means it cannot fight damage as well as when it was younger.

The most common way a tree would die of old age would be through this process:
> Woody plants heal through by compartmentalizing the damage, sealing it off from the rest of the plant. This is called CODIT. This process happens in four steps, called walls. The process happens like this:

>Wall 1: The tree blocks the transport tubes surrounding the wound, thereby preventing the wound/infection from spreading further.

>Wall 2: The tree then builds a ring around the wound or infection to prevent it from spreading inward. This acts as a barrier providing further protection.

>Wall 3: The tree then sections the wound laterally. This prevents the infection or wound from spreading circularly, keeping it from spreading left or right.

>Wall 4: As the trunk grows, the trees new growth rings seal off the infection or wound. This prevents it from spreading outward into the new growth.

>When a tree gets extremely old, it begins to lose this ability to compartmentalize and eventually causes the tree to die. Trees that still have leaves on them but their trunks are completely hollow is an example of wall 4 beginning to fail. Unless the wall 4 step has succeeded just in the nick of time, the tree will soon die.

Hopefully this makes sense? It might not be exactly what you were hoping for.


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

[User]
[Terminator 2] How do we clean up this mess?

So some idiots just crashed a tanker full of liquid nitrogen into the foundry where I work. Ive hit the alarm and my colleagues and I have escaped from the spill, but thats about 40,000 litres of liquid nitrogen sloshing around in there. Who do we call to handle that much liquid nitrogen and how will they go about cleaning up the mess? Do I even have a job to go to tomorrow or will the plant be closed indefinitely?

[Assistant]
You don't have to worry about cleaning the nitrogen up. Its going to warm up pretty quickly and boil off into nitrogen gas once it reaches a balmy 320 F (yes minus 320).  Then dissipate into the atmosphere which is 78% nitrogen anyway.

The only clean up is the tanker itself and the physical damage done.  There will be a few days of inspections to make sure the cold didn't damage pipes and tanks that are meant to hold other substances at pressure. Some of them might have to be replaced as the intense cold could have made them brittle.


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

[User]
ELI5: How do electronics with battery indicators "know" how much battery they have left?

My phone has a battery icon that shows a visual representation and a percentage of battery remaining. How does it tell how full the battery is?

[Assistant]
Batteries voltage changes slightly as they discharge. A simple way is just to measure this voltage (like a battery tester). Smarter batteries, like laptop batteries, have micro-controllers built into them that allow the device to communicate with the battery. Charge is measured in Coulombs and battery capacity can be measured by counting Coulombs. Amps, are just the number of Coulombs per second flowing, so smarter batteries can measure the current flowing out of a device and integrate this to get the amount of charge flowing into or out of a battery. Current is usually measured with a small resistor and a voltage meter using Ohm's law (Voltage = Current \* resistance)

Smart batteries will also report battery degradation over time etc, so a 100% charge on an old battery might only be 80% of the original capacity.

Better ELI5:

A Coulomb (charge) counter would act like a water meter that can measure water flowing into or out of a storage tank. By keeping track of the net water in the tank, and you know the total size of the tank, you know the percentage.

A more simple method is to measure voltage. This would be like capping the spigot on a tank with a PSI gauge and reading how much pressure was at the bottom of the tank and therefore you can calculate the water depth and estimate the remaining capacity.


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

[User]
If the story of Adam and Eve were true, how fast would the population have to grow in order to reach 7 billion people in 6,000 years?

I'm an atheist* who ~~believes evolution is real~~ accepts evolution as fact. I'm just curious what the math would look like for my question.

Edit:

1.) Thank you for help everyone. This wasn't designed to be a religious debate. I just thought it was an interesting story problem for math that I don't understand.

2.) I'm getting a lot of comments and messages about how the Bible doesn't state that the Earth is 6000 years old. I grew up in a fundamentalist Christian religion which taught Young Earth Creationism. I understand that every Christian sect is different, so no need for the apologetics.

Note: Atheism is a conclusion one arrives at when they value reason and evidence. I don't believe in, or have faith in, atheism. Faith is pretending to know things you don't know.

[Assistant]
6000 years is roughly 300 generations. Using the premise that 2*x^3"00=7000000000, this gives a rate of 1.076 per person per generation.

Put in human terms,  we multiply that by 2 to get the average fertility rate of 2.15, meaning each woman would need to have 2.15 children on average to attain this rate. The current global fertility rate is 2.36 and dropping, for context.

This of course ignores infant mortality, which was likely high at most periods of history and could bump this number up considerably.


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

[User] [X-Men, Marvel Comics] How dire does a situation have to get for Charles Xavier to go out on the field with the X-Men.

[Assistant]
I don't know if it necessarily needs to be a dire situation, just one that requires his specific skills. It doesn't have to be a fight, sometimes it can be some kind of diplomacy or communication. Sometimes the X-Men need to appear as a united front, and for that it can help to have the guy who runs the whole thing.

Otherwise, if he really needed to, he's probably powerful enough to assist the X-Men in skirmishes from the school, using Cerebro if he needs it.


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

[User] ELI5: Why can't news stations (CNN, NBC, CBS) sue the President for defamation when he calls them fake news or says they don't cover certain stories?

[Assistant]
First, it would be a poor public relations move -- it would make the media look petty and thin-skinned to attempt to sue the President over negative tweets. This would likely damage, rather than help, the media's credibility. This would play directly into the President's strategy of marginalizing and denigrating the media, and thus not be to the media organization's benefit.

Second, to win a claim of defamation, the person or organization filing the claim (the plaintiff) has to prove that there has to be some harm or injury done to the plaintiff by the defendant's defamatory statements. That would potentially be difficult for the media to quantify, and, if they did, then again they would be playing into the President's strategy of marginalizing and denigrating the media, painting themselves as having been weakened or harmed by mean tweets.


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

[User] ELI5: What "sins" did Jesus "die for" exactly? What would have supposedly happened to us if he didn't? (Serious)

[Assistant]
Christians believe that after Adam ate from the tree of knowledge of good and evil, that all humanity was fallen and carried a sin nature, even the most innocent of babies carries this with them (passed from father to their children).  It's this nature that causes sin to be tempting.  The only way to pay for sins is via blood sacrifice (thus the reason Hebrew law required all sorts of animal sacrifice).  The best analogy I've heard for a sin nature is bamboo which grows sprouts rapidly and spreads widely.  The sprouts can be cut but the root remains and spreads.

Jesus being born with God as his father, lacked this sin nature and offered a way to undo the curse brought on by Adam's sin.  Because he didn't succomb to temptation, and lead a sinless life, his death becomes an eternal sacrifice for all who accept it.  By becoming a Christian, Christains believe that they have the keys to victory over sin (not that they'll remove the root, but can machete the top effectively, and eventually the root will wither and sprouts will be less frequent).

That's not really ELI5, but if you have questions I'll try to explain more clearly.


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

[User] [Dragon Ball Z] How did Vegeta keep his sanity after becoming Majin?

[Assistant]
Saiyans have a tremendous will, and Vegeta's will is extreme even by Saiyan standards. He's extremely focused on one thing: defeating his enemies. He's also extremely arrogant, and there was a part of him that just wouldn't let himself be controlled by an _inferior_ like that.

He allowed himself to be controlled when it served his desire to test Goku, and the stakes were manageable, and kept his willpower and ki in reserve until the moment breaking free was a necessity. Babidi really never had a prayer of keeping him under his spell indefinitely. This is a Saiyan warrior _price_ we're talking about here.


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

[User] If you break your bones to a point you need metal rods and bolts, after the bone heals do the metal implants make your bones more sturdy & less susceptible to breakage?

[Assistant]
Nope. The metal won't break, so it is technically more sturdy there... but the attachment points through the bone weaken them quite a bit, leaving weaker points. To some degree time can fix that.

Modern implants get better and better but thin bones won't become stronger after drilling holes through them. They can even split, then you're further from home.

Implants with specific surface structures and eg bone matrix proteins are interesting research topics!


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

[User]
If Helium is so scarce, why are Helium balloons so common?

Also, if we stopped using it in balloons, would that make much of a difference in the long term?

[Assistant]
It's not scarce yet, but the alarm is because there is only just so much in the earth and it is being used up fast, often just released into the air, where it relatively quickly floats to the top of the atmosphere and gradually gets propelled by the solar wind away from earth.

It's somewhat controversial as to exactly when we'll run out of accessible helium.

> if we stopped using it in balloons, would that make much of a difference in the long term?

No, that's not a large usage. It's the amount being thrown away to the atmosphere that is really large.

It has critical and irreplaceable use in physics and engineering and medical applications, so everyone should note that it's definitely not the party balloons that make this an important topic.


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

[User] [Cuphead] If Cuphead's soul belongs to the devil, then why does his ghost float upwards, with a halo?

[Assistant] He still needs to be judged. There's a Tom and Jerry episode where Tom dies and goes to heaven, only when he gets there the guy at the gate looks over his paperwork and gives Tom the bad news. Everyone's an angel until they're evaluated.


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

[User] ELIF: What does the phrase "corporations are people" mean and why is it significant?

[Assistant] "Corporations are people" is a legal fiction (that's not a derogatory term, it's just the name we use for the concept).  What that means is that it's something that isn't technically true, but legally we pretend it's true because it makes things easier.  We do this so that we can apply existing laws to new scenarios that may not have existed when the original laws were created.  We allow corporations to "be people" legally so we can treat that as such for the purpose of enforcing contracts, and so that they can sue and be sued as if the were a person.  More recently corporate personhood has been a political issue because of recent court cases involving corporations rights with respect to political speech.


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

[User]
ELI5 how a jet engine works

I don't understand how jet engines work. It's awkward when I'm around people that are talking about jet engines - I just have to come up with an excuse to leave or just guess how they work.
Thanks for your help, webernet!

[Assistant]
A gas turbine engine is a tube designed to take that air from the front (the intake), add fuel, burn it and the blow it out the back at a greater rate than it was sucked in, the result being called thrust.

In it's very simplest form it is a tube with 3 stages, with each stage performing a task, and each stage from front to back being part of a continuous stream of air that end up with it being ejected out the rear:

**Stage 1.**  Compressor - This is a fan, or set of fans, all stacked up together.  This is spun (we'll come back to what spins it later) and in doing so acts like a fan in your house, blowing the air in a certain direction, rearward.  Due to the fact that there are a number of fans all stacked up and acting in the same direction on the air, the force of these fans squashes the air up, compressing it many times over.  The air continues to move backward towards the next stage.

**Stage 2.**  Combustion Chamber - The compressed air is now passed onto a chamber where fuel is continuously being injected and ignited with spark plugs.  You might ask how the fire isn't put out by the fast moving air, the reason is that the way the air mixes and the ratio of fuel to air means that it's perfect conditions for combustion.

In the process of being burned the air is suddenly charged with a huge amount of energy that is bursting to get out somewhere.  Because the fans at the front are still furiously pushing the air backwards, the air takes the path of least resistance into the 3rd stage.

**Stage 3.**  Turbine - This is very similar to the first stage, but whereas stage 1 (the compressor) is like a huge desk-fan, stage 3 (the turbine) acts like a windmill.  It is designed to be spun up by the hot expanding and high-energy air from the combustion chamber.

Here's the clever part... Because the compressor and the turbine both sit in this tube at opposite ends, we connect the turbine (being spun by the hot air) to the compressor.  The hot air has so much energy it can spin up the turbine, in turn spinning up the compressor **and** still have enough energy to produce thrust out of the back.


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

[User]
What kinds of acids could damage a jacuzzi?

Are there any with innocuous household uses?

[Assistant]
Chemist - There are lots of acids that could damage a jacuzzi, depending on what it's made of.  There are specific interactions to watch out for, but as a general rule, higher concentrations cause more damage. Perhaps you could specify what you are doing?

There are a number of acids that you can get for household use: vinegar (acetic acid), muriatic acid (HCl), battery acid (H2SO4), and many rust removers (usually phosphoric acid). Plastics and glass generally tolerate acids in low concentrations well, but plastics shouldn't be used with nitric acid, because it is a strong oxidizer. Metal components will react with strong acids like HCl and H2SO4. And if your jacuzzi is made of stone/marble, avoid acetic acid.


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

[User]
ELI5: Why is the unit circle divided into increments of 90 degrees (90, 180, 270, 360) and not based on 100?

I'm just genuinely curious as to why we separate it like that?

For example, 100 degrees would be the same as 90 based on 100 system and 400 degrees would be 360.

[Assistant]
The Sumerians started with a base 6 numbering system. They studied circles for things like navigation and came up with 36 degrees for a circle (in base six, 36 is 100). Later the Greeks decided they wanted more degrees, but found the divisibly of 36 useful.  Since they lacked the decimal point, they chose to make a circle 360 degrees.

The divisibility remains useful and that's how we all learned it, so it remains.


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

[User]
ELI5: What happanes to someone with only 1 citizenship who has that citizenship revoked?

Edit: For the people who say I should watch "The Terminal",

I already have, and I liked it.

[Assistant]
They are considered "stateless." Countries will likely grant him certain residency statuses or asylum after they consider what exactly caused his citizenship to be revoked.

Statelessness due to political conflict and ethnic discrimination, particularly in central Africa, is actually a significant issue that burdens surrounding countries with refugees and illegal migrants.


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

[User]
ELI5: Why do we have  to raise breast cancer awareness?

I'm all for preventing breast cancer, but I'm pretty sure most people are aware of it by now. It's not some unknown problem that nobody knows about.

[Assistant] Women still die all the time because they ignored a painful lump in their breast until it was too late.  Having a breast removed is sucky, but it's way better than being dead.  The awareness is to encourage these women to get to their doctor before it's too late.


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

[User]
[Lord of the Rings] Do the Uruk-Hai inherently know how to fight skillfully?

In the Two Towers, the Uruk Hai bred to attack Helm's Deep know battle formations, can wield crossbows, use siege engines, and are able to duel trained elves to the point where they can pretty much slaughter them.

Were they taught how to do all that, or do they have some sort of inherent knowledge about how to fight as soon as they're born? It doesn't look like they'd get much training or instruction in, given the amount of time they had before they were expected to take over Rohan.

[Assistant] Sounds like "Movie Version".  IIRC, there are a couple really short scenes in the movies that show them doing some form of practice against each other... usually in the scenes showing them being bred.


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

[User] [Overwatch] Since Reaper can see (and eat) souls and both Bastion and Zenyata drop soul orbs, does this mean that Zenyata is right and the robots DO have souls?

[Assistant] It's unknown what exactly reaper absorbs. Outside of gameplay, there is little to suggest that he has any connection to the supernatural. So until the lore surrounding reaper is further explained, there is no clear answer.


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

[User]
[Avatar the Last Airbender] How does Toph "see" attacks coming at her?

She can only see things if they're connected to the ground right? so how does she effectively dodge/counterattack a rock flying at her?

[Assistant]
Though the vibrations in the ground, she can track where her opponents are standing and get a clue as to which earthbending move they're using against her, since she primarily fought against earthbenders and they heavily rely on footwork and solid contact with the ground. Similarly, she'd be able to hear and feel where a pillar of stone or a thrown rock is being torn from the surface and dodge it.

She can also hear their breathing, so she can predict when a big move is coming. Long years of practice have allowed her to recognize which breath means which attack is coming. The other elements are harder for her to track due to sheer inexperience, but there are some telltale clues. Water and fire make a lot of noise when bent. And fire also gives off a lot of heat, which she can feel coming her way. Breathing is also much more important to a firebender than any other, so they probably light up like a beacon before every attack for someone trained to listen for it.

Again, most of her experience was fighting against Earthbenders, especially earthbenders who greatly telegraphed their moves for the best show in their wrestling ring. So she was able to learn how to predict and respond to all kinds of attacks.


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

[User]
ELI5: If a computer only takes an input of 0s and 1s how does it know to expect an image as supposed to text?

I get that any symbol is usually 8 characters in binary and that pixels colors in an image range from 0-255 with 255 being 11111111 using binary But how does it actually determine to either look for a letter or a colored image by just using strings of 1s and 0s if that makes sense.

[Assistant]
It doesn't. You can interpret the same binary data multiple ways. It's up to the program that's running what it does with the data, which is why you can open binary files in Notepad.

However, if the program is expecting data of a certain structure, it may fail if it sees data that doesn't fit that structure. A BMP file, for example, should begin with a header that specifies the width and height of the image and then the image data. If there isn't enough image data for the image size given in the header, a BMP loader will fail and report that the file isn't valid.

Many file types begin with a "magic number" that serves to identify the file format. An ELF executable file, for example, begins with the bytes 0x7F454c46.


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

[User] ELI5:why are the noses of rocket, shuttles, planes, missile(...) half spheres instead of spikes?

[Assistant]
Blunt noses are fine if not preferable at low speeds because the airflow can start to move out of the way before it hits the aircraft. The air in front of the craft pushes on the air further ahead to allow for a smooth transition.

Supersonic travel does not have this. The air is 'notified' of the oncoming plane right as the plane comes up on it because pressure waves cannot travel out ahead of the plane. This makes pointier designs better in this region.

At very *very* high speed, a blunted nose forces the shockwave to form farther in front of the vehicle, protecting it from the heating of the air that forms at the shock.


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

[User]
[Mass Effect] If the Reapers have been exterminating the Milky Way's sentient life every 50K years, what is the sentient life situation in other galaxies?

I'm assuming the situation in the Milky Way is quite abnormal.  If the reapers are millions and millions of years old, what level of advancement are sentient life forms in other galaxies at?

[Assistant]
The Reapers do not travel outside the Milky Way (except for their hiding spot), because it would probably take them more than one cycle to arrive. There will be a few stable civilisations in the other galaxies, which will be old enough to wipe the void with the Reapers.

However, nearby galaxies like the Magellanic clouds probably get harvested too.


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

[User]
All philosophy is situation?

After reading Victor Frankl's "Man's Search For Meaning" it struck me that the philosophy that came out of the book seemed very much as response to his situation, and that is it no surprise that he didn't adopt a philosophy of something like Utilitarianism instead. This got me to thinking that most if not all philosophy in general comes in response to the world at large or a particular topic of concern at the time of the philosophy's creation and to the author's situation.

So my question, is there any branch of philosophy that basically says there is no real philosophical rules, but rather any number of valid approaches exist depending on your environment or circumstances. I would call something like this "situational philosophy", and i theory your philosophy of life could change as often as your circumstances change.

Apologies if this questions is unclear.

[Assistant] You might be interested in *moral particularism* \-- the view that there are no authoritative ethical principles, and that moral judgment consists of nothing more than deliberation about particular cases.


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

[User]
Why does humidity kill static electricity?

When I take off a fleece coat in dry winter you can hear it crackle with electricity but in the humid summer it doesn't. What is it about humidity that kills the static?

[Assistant]
Static electricity on clothes comes from electrons separated (by friction of putting it on for example) from their original molecules. The separated electron acts as a negative charge, while the left behind molecule now has net positive charge. This local charge surplusses and deficits are what makes up "static electrity".
As fleece sweaters are typically made of synthetic materials that are bad conductors of electricity, these separated electrons can not move on the surface of the sweater to reunite with their molecules and thus are kept separated. This makes the static electricity stay on the sweater.

If you now introduce very humid air around the sweater, some of the water will condense into the sweater, improving the conductivity of its surface (if even by the smallest amount). Now the separated electrons can move around the surface and reunite with a molecule that is missing and electron, evening out the electric field at that point. This makes the static electricity disappear from your sweater.


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

[User] [The X Files] How much did Mulder and Scully make? What kind of performance reviews did they receive? Are they collecting a pension now?

[Assistant]
In todays money, FBI agents make 50k or so starting. This is about 25k 30 years ago. Its a government job, so good benefits including a pension are part of the package.

Mulder was top of his class at quantico iirc. Scully was recruited as an MD. So Im guessing they got something like too starting pay, so maybe more like 30k in 1991, or 60k today. As seasoned/senior agents, they could make more, like twice as much. Id guess Mulder probably didnt get too many raises, but Scully might have.

Realistically, they have comfortable middle class retirements, but arent wealthy.

Mulder lived in a tiny apartment, so maybe he saved up, but he also just as likely spent his money trying to find the truth.


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

[User] ELI5: why do things like metal and lava turn red when they are are hot?

[Assistant]
It is  thermal radiation. The thermal radiation that everything emits depending on temperature.

Glowing orange red is the lowest temperature that emit visible light. The hotter it gets the whiter it gets and even hotter it will look blue.

The light from a incandescent light bulb and the sun is black-body radiation but it is whiter at the temperature is hotter.

Thermal radiation it emitted at all temperatures but it has to be over approximate 798 K (525 C, 977 F)  to be visible. At lower temperature it is only infrared light and not visible.

The heat you feel radiate from hot object at lower temperature is thermal radiation but in infrared. But with special camera often called Forward looking infrared (FLIR) in militery application you can see the thermal radiation  from a human.


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

[User]
If we existed on the planet found orbiting Alpha Centauri, would we be able to detect the Sun's planets with our same technology?

Obviously it would be too hot to exist on, I'm just trying to grasp what sorts of planets we are able to discover at this time.

[Assistant]
There are two primary methods for detecting planets, the transit technique and the radial velocity technique. The transit technique looks for dimming of the parent star as the planet crosses in front of it. This technique works very well for large planets (e.g. Jupiter) but is sensitive enough to detect even Earth-size planets. However, it requires continuous monitoring of the star (otherwise you'll miss the short-lived transit event), it requires detecting at least 3 transits to be certain that you're seeing the same planet in orbit, and it requires that the alignment between the orbit and the line of sight to the star be within a narrow range. This last requirement is a big problem as it means that only a fraction of a percent of planets in Earth-like orbits would be detectable, all of the others would have orbits which don't pass in front of their parent star relative to our view. On the other hand, the technique works just fine if all you want to do is get a better handle on the statistical probability of planets of various types.

So if we were looking at a clone of our own Solar System out in the galaxy we might be able to detect Venus and Earth but the chances of that would be about 1 in 300 or so.

The radial velocity technique is a bit different, it looks at the "forward" and "backward" motion of the parent star relative to us over time. If a planet is orbiting the star it will tug on the star a slight amount and force it to move back and forth as the planet orbits around the star. The bigger and closer the planet the larger the amount of movement in the star. Right now we could detect Jupiter around a star, but we'd have to observe the star (not continuously fortunately, just intermittently) for at least an entire orbit: 12 years. Also, if the relative angle of the orbit is nearly perpendicular to our line of sight then the motions of the star will be up/down and left/right instead of back/forward so we won't be able to see them with the radial velocity technique, and with the current level of sensitivity of such instruments that translates into roughly 10-20% of the potential orbital inclinations.

**tl;dr** There's about a 90% chance we'd be able to detect Jupiter, though it would take at least a decade of observations, and there's about a 0.3% chance we'd be able to detect Venus or Earth.

Although the technology is improving fairly rapidly so what we'll be able to detect in another decade will likely be different.


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

[User] [Zombies] In modern stories where zombies/walkers are treated like purely scientific carnivorous animals, why aren't the zombies all starving to death within a year because their prey is being driven extinct?

[Assistant]
This happens in 28 Days/Weeks Later. Humanity still ends up ruined, but the zombies do starve given enough time. Humans take weeks to starve, records are pretty sketchy here as most of the "longest without eating" claims are religious figures claiming supernatural assistance.

Lets say 45 days is the limit with no food. Zombies don't sleep, so lets assume the disperse radially from the center of the outbreak. 5 kph is the average walking speed, 24 hr per day times 5 kph times 45 days gives us 5400 km. Lets round down to 5000km for meandering. That's how far a zombie could travel with no food. For reference, NYC to LA is ~4400km, well within that range.

So draw a 5000 km circle around a city you want to say is infected and the draw 5000 km circles around every circle  population center in that circle. You'll quickly see that the barrier to zombies isn't starvation, it's just oceans and us killing them.

You could hide. Find a bunker, wait 6-8 months. Keep in mind though, that every new infection basically resets your timer for when all zombies will have starved by 45 days. You could be in that bunker a very long time.


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

[User]
[Harry Potter] What's the point of the sorting hat if it puts you in the house you want anyway?

Like can't they just let the kids pick which house they want in a secret vote or something so they don't get peer pressured?

Also, how did the hat start talking? Like is it an actual wizard that was trapped in the hat, did Dumbledore create it himself or did he just find it already talking?

[Assistant]
The hat doesn't put you in the house you personally want to be in, after all, Hermione had more of a preference for Ravenclaw before she was sorted. What it does do is look into your heart to see what kind of a person you are. Harry's desire to not be in Slytherin showed the hat that despite Harry's great potential to use the traits associated with Slytherin, he didn't want to be that kind of person. It was that selflessness of preferring to be a good person than a successful one that told the hat that he deserved to be part of Gryffindor.

As for how the hat started talking, the legend goes that when the founding wizards of Hogwarts decided to split the school into the houses, Godric Gryffindor enchanted his hat to do the sorting based on the criteria the founders set, and it sorted new students ever since.


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

[User]
[The Expanse] How is Mars able to stand any sort of chance against Earth?

Earth has several billions of people, and the economy that comes with that. I dont know what the population of Mars is, but if they have to live in habitats, it cant come close to Earths. There just isnt enough collective physical and mental manpower on Mars to keep up with Earth both logistically and technologically.

[Assistant]
Earth has a population of 30 billion, however most of the population lives on "basic" assistance, essentially struggling below the poverty line.

Mars has a population of 9 billion and their entire culture is near militarized towards their goal of terraforming the planet - they look upon the people of Earth as weak, suckling off of basic and living weak and papered lives compared to the struggle they endure.

Earth actually lags behind Mars technologically, in the early days all the best scientists, industrialists and entrepreneurs went to Mars. Earth has more ships, but they're older and far less advanced, case in point, a state of the art Martian Corvette was able to cripple an Earth Battleship.

But dem dusters and dirters down da well got noting on Beltalowda.


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

[User]
Are there any philosophers who speak about the preference of death over an afterlife?

Has there been any philosophers who have objected to the heaven/hell dichotomy preferring eternal destruction of the self over a continued existence in another realm?

[Assistant]
In Plato's *Apology*, Socrates argues that we have nothing to fear from death because both an afterlife and oblivion are desirable states.

Schopenhauer, taking a cue from Indian philosophy and religion, believes both in a cycle of endless reincarnation and that this process of reincarnation is a bad thing; he sometimes explicitly describes the end result of the process of escaping this cycle, which he holds as the highest ethical and philosophical goal, as if it were the literal cessation of all existence. But he's very ambiguous about this, and eventually goes on to say that we can only really be sure that this cessation would be "nothingness" relative to the perspective we have while we are here trapped in the cycle.


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

[User] ELI5:Is there a specific reason why our forearms and calves have two bones instead of one?

[Assistant] It allows them to rotate axially, for example turning your hands from palm down to palm up. Imagine you had one big bone in your forearm - how the heck would that work? You would have to twist the bone itself, and spiral fractures are no fun. Instead, the two bones just shift around each other.


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

[User] [Star Wars] How can one rogue apprentice destroy all the new Jedi with Luke Skywalker being around?

[Assistant]
By being the apprentice Luke loved best.

Ben Solo was Luke's nephew. Luke would have known him from the day he was born. With no family of his own, Luke would have loved him like his own son.

When Ben turned on Luke, it would have been shattering. Heart-breaking. Luke would have hesitated. He would have tried to talk. He would have tried to beg. He would have done anything he could think of to stave off the moment when he would have to kill his own nephew.

And then, by the time he realised he was out of options, it was too late.


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

[User]
[WH40K] There is enough evidence to convince the Imperium beyond reasonable doubt that the EoM would come back within a millenia if the Golden Throne were destroyed. Would they be able to afford to do this?

If they go through with it, what's the holding pattern while Big E regenerates/reincarnates and makes himself known again?

[Assistant] No, the Imperium can't afford even minute interruption in the work of Astronomicon beacon, let alone millenia, and God-Emperor and his Golden Throne are integral parts of the beacon. Without it, Astronomicon would go out and ships won't be able to safely navigate the Warp, basically starting another dark age and needing to reconquer everything all over again. There's nothing short of Plot Induced Stupidity that can convince High Lords of Terra to take God Emperor off life support, and Lord Guilliman would probably slap your head off if you suggest it in his presence.


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

[User]
CMV: mocking or distorting academic meaning of important terms is heavily contributing to post truth world we live in

I see all the time people completely disregarding what important concepts actually mean and putting popular understanding (many times shaped as propaganda) as a more valid definition.

Good example is happening in CMV right now in discussing USSR where word communism is used a lot. Popular mocking phrase in USA/internet/reddit is - "not real communism" (usually with weird caps) when people try to say that USSR doesn't represent it.

The thing is... Even the county itself was called Socialist. By definition of Government type/Economic system it was Totalitarian/ central planning socialism or even central planning state capitalism. By no definition of communism was Soviet Union even close to it or try to claim to be. Communist Russia was literally invented as a propaganda name and yet people still seem to mock anyone who points out the flaw of directly linking the two.

There are many more examples like this, like US definitely not being a free market economy or whataboutism being frequently confused with precedent (one is an unrelated point to deflect blame, other is a related/equivalent action brought as an example). Or my favorite "just a theory" said by people who clearly try to mean hypothesis from context.

Using incorrect or pop understanding of words instead of academic meaning on important subjects is detrimental to discussions.

[Assistant]
On the issue of the USSR "not being communism" because they called themselves socialist... you have to be very careful about taking a country at its own word about what it says it is, versus how it actually functions in practise. For example; North Korea calls itself "The People's Republic of Korea". So, taken at face value we must assume that N.Korea is a wonderfully democratic republic system, yes? Well, obviously not, it's an authoritarian hereditary dictatorship. Another example; Germany in the 1940's was run by the "National Socialist Party", but was far from truly socialist and in fact persecuted and hated socialists particularly Marxists and Leninists, they hated and rejected the idea of social welfare instead believing in social darwinism (e.g. life unworthy of life), banned trade unions...; so in reality Nazi Germany was just another form of Fascist Dictatorship.

Examining the USSR under Stalin in particular, it was certainly a corrupt communist dictatorship. Wealth and property was owned and dictated by the State not the People, wealth was seized and redistributed (often in a corrupt manner), and the the economy (particularly manufacturing sectors) were nationalised in pushes for industrial revolution to compete with the West during the Cold War.

*Also, if we are going to take them at face value- the ruling political party of Russia from the early 1900's through to the dissolution of the USSR in the 90's was the CPSU (Communist Party of the Soviet Union).*


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

[User]
CMV: Cancelling student debt seems like a terrible idea

Obviously, student debt is a huge issue for many Americans who are stuck managing it for years if not decades but I feel like the core of the issue can solved in so many other ways other than cancelling the debt as a whole and that taking this route would not only be unnecessary but also unfair.

Why are we so hyper focused on student debt cancellation when the core of the issue comes from uncontrolled tuition and rent increases. If anything, cancelling student debt just signals that these institutions can do whatever they want on that front with no fear. On top of that coming from a poor family growing up in an upper middle class region. The majority of people I saw taking up student debt absolutely took on more than they needed to. I graduated from a class of around 1,000 people. Of those 1,000 people around 80% of them went for higher education, yet only 50 of them went to state university. I knew people that were in hundreds of thousands of dollars of debt for shit like an English major. My family worked hard to get to where we are, my parents never had any luxuries, the amount of times we ate out can be counted on one hand. Despite that I still commuted and worked every year from HS to college. My parents dont have much but theyre proud that they were able to provide that for us. The idea that someone else can just be handed that when 1, they couldve avoided more than half of the debt they took on and 2, didnt nearly sacrifice as much is bullshit.

[Assistant]
I imagine that most people who want student debt cancellation also want the increased price of education to go away, either via free college or something else.

Also, "I suffered so other people should suffer too' is the worst reason to write laws.


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

[User]
[MCU] How does Captain America age?

He goes into the ice and comes out without aging a single bit. Then he gets sent back in time and seemingly aged normally, him being an old man at the end of Endgame. Does he age slowly because of the super serum?

[Assistant] He was 39 when he went back in time, if we assume he went back to that point at the end of WWII (1945) and lived till Endgame in (assuming 2019), he'd be 113. It's not an impossible age for a normal human, he was just very healthy for his age due to the super soldier serum, probably a couple decades younger physically compared to his real age.


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

[User]
Why is escape velocity so high?

Why is the escape velocity for earth 11.2 km/s? Can someone explain why it needs to be such a high speed? Why can't a vehicle just travel at a steady 1 km/h until is out of reach of the planet's gravity?

[Assistant] It can, it would just need to be thrusting the whole time. Escape velocity is the speed you need to escape without adding any more energy - just coasting. That is why escape velocity depends on altitude - the higher up you are, the less speed you need to go the rest of the way.