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

[User]
[Futurama] Why is everyone so cavalier about having their limbs ripped/cut off?

Quite often we have seen Leela and Fry have their arms and legs violently removed. Fry actually ripped Leela's arm clean off of her shoulder when trying to save her from Mars crashing into Earth. After an initial subdued yelp, everyone seems to converse and act normally after having their *freaking limb ripped off* with no indication of shock or pain. What is going on here?

Bonus question: How come these forcibly removed limbs don't bleed?

[Assistant]
> How come these forcibly removed limbs don't bleed?

Since replacing limbs is convenient and inexpensive (see: stores like HandCrafters), the worst part about losing a limb would be going into shock or dying as a result of blood loss. Or, best case scenario, getting blood all over the place.

Therefore, Earthicans voted for a Proposition that would allow the government to put a special chemical into the water supply that causes your body to instantly stop blood loss if you suffer significant damage. It's also what allows corporations to send commercials into your dreams.


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

[User] Why can't animals with gills breathe air?

[Assistant]
Fish gills are very delicate, and have a very large surface area (which makes them work so well). It is completely dependent on being immersed in water to support their weight. Out of the water, the delicate gills will collapse like wet tissue paper, and very little surface area is left exposed, so gases can not be properly exchanged. Therefore, most fish can't survive out of the water for a long time, because oxygen deficiency will catch up with them and they asphyxiate.

If we could find a way to keep the gills supported and moist without being immersed, a fish could survive for a lot longer, but this it isn't physically possible, even in a humid air-filled chamber at zero gravity, considering that the gills would just stick to one another. Water must completely fill the gill chamber to keep everything else in working order.


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

[User]
ELI5:How does an economy crash.

One has been posted five years ago so its pretty old, and I would like a more simplified explanation.

[Assistant]
A crash can ultimately be caused by many different things, but they all have the same effect: money stops circulating.

To over simplify a healthy economy; a baker sells bread, he uses that money to buy flour from a farmer, the farmer uses that money to buy equipment from a factory, the factory uses that money to pay workers, the workers use that money to buy bread.  But if the economy crashes, the factory closes down and so can't pay it's workers.  Then the workers can't afford to buy bread.  Because no one is buying bread, the baker can't afford to buy flour.  The farmer can't afford to buy equipment.  No has money to spend because no one else is spending money.  It's a vicious circle.


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

[User] ELI5: why we cant domesticate wolves or tigers and etc. Even if we raise them from birth?

[Assistant]
Domestication goes further than just raising an animal around humans. Wild animals are wild animals. They have instincts. And, more often than not, that instinct of "feeding, fighting, fornicating" has a higher priority than any superficial or parental bond between them and humans. If you want to domesticate a species, you basically need generations and generations of selective breeding --propagating lineages with more docile temperaments-- to get to a point where those instincts are more manageable.

Also, yeah, a lot of these animals are powerhouses and it's generally ill-advised to keep an animal around your kids when an accidental nip or swipe could mean losing half a face.


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

[User]
How can water molecules be dipolar?

Greetings! I am relatively new to Chemistry and the natural sciences overall, and have a question regarding molecules vs ions.

To   my understanding, molecules are always neutral as they are not the   compound of two charged atoms (+ or -), but rather the fusion of two   neutral atoms. Ions, however, are the other way around, and the more   ions you add (polyatomic ions), it will flip between being neutral or   charged. But, how then, can water (H2O) be dipolar? Perhaps I have   understood the concept of polarity wrong. If the molecules are neutral   as neither the Hydrogen or Oxygen atoms are charged, how can the   water-molecule have two sides? Or is it for this very reason that it has   two sides, simply because it is the fusion of two neutral atoms?

On  a  similar topic, I must also ask the difference between ionic bonding  and  molecular formation ... The ions, of course, attract other charged   atoms (other ions), because the valence-electrons wish to jump over to   differently charged ions since atoms strive to have a full outer shell.   But, molecules do not do this, do they? How are they different? Are  they  simply the combination of two atoms, in which the electrons do not   leave their respective atoms, but rather join together in an "orbital   fusion" in which they can travel freely (until broken up)? This would   make sense since they are not charged, and therefore have no attraction   to leave their own atoms for opposing ones.

I am very thankful for answers! Good day :)

[Assistant]
There's two parts to the answer. First, the molecule is H-O-H as you say. In the simplistic picture of chemical bonds, each hydrogen shares its electron with one from the oxygen to make the bond. But the sharing isn't equal, the  oxygen has eight positively charged  protons against the hydrogen's one. So the negative electrons get more attracted to the oxygen so that has a small negative excess and the hydrogens a small positive one. Like this:-

H^d+ - O^d- - H^d+

So far so good. But the molecule isn't linear, its bent at an angle of 104.5 degrees like a wide V. So the tips of the V have the positive charges and the apex the negative one. So there's a charge dipole running vertically (as drawn like a V) from apex to tip.


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

[User] eli5: if your teeth are attached to your jaw, how do braces move them around with out breaking the teeth away from the sockets in the jaw?

[Assistant] They don't attach directly to the jaw bone, your teeth attach to a ligament (a periodontal ligament) and the ligament attaches to the bone. The bone socket they are in isn't like a super tight plug in socket, it's more like a vague hole they float in that the ligament locks them in place into. So you can pull on a tooth and the ligament can resist and give up resistance on and let the tooth move in certain ways. There is very specific rules on how a tooth can move, but those rules are often similar to the rules of how a tooth could have been out of place in the first place so it works out.


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

[User]
[Harry Potter] Did any of the professors in Hogwarts have families?

Were they away from their families 9 months out of 12 or were they able to return to their families for each night using floo network etc? Or were they all single for one reason or another? No children? Or is there somewhere a guideline saying they only hire single/widowed people?

I know the HP universe is not perfect, I'm just wondering if there's ever anyone teaching in Hogwarts who has a family; and how do they handle this.

[Assistant]
There isn't much information on the marital status of hogwarts professors, but we DO know that Neville Longbottom was married to Hannah Abbot during his time as Herbology Professor. Hannah originally took over as landlady of the leaky cauldron, but then later trained as a healer to become Matron of Hogwarts. There's no certain reason why she would have chosen such a drastic life change, but it isn't impossible she did so to be closer to Neville. What it definitely suggests is that the two didn't see each other often due to the nature of Neville's work.

Another fact is that the majority of Professors during Harry's time at school were single, even excluding the rather... unfortunate DADA professors. This suggests that there might be some extra burden their jobs put on forming relationships, or that the type of person to pursue academic success don't tend to marry as much.

Overall, professors at Hogwarts would be no different from teachers at Muggle Boarding schools. Those tend to either marry within the faculty, or their spouses will live on campus with them, or nearby in town. It could be that due to the ease of travel via wizarding methods, that couples have an easier time apart, but really, each professor will have their own solution. It may very well be that they find they're not suited for a long term, long distance relationship and choose to either pursue romance or their career.


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

[User]
[Avatar: The Last Airbender] What would have changed if Monk Gyatso had left the Air Temple with Aang, and was frozen along with him for the 100 years?

Rewatching The Storm, it seemed like Gyatso had planned to take Aang with him, or at least not leave him alone. What if he had walked in earlier on Aang preparing to leave, and decided to go with him? They would still both be caught in the storm, with the AS freezing them in an iceberg for the hundred years until Sokka and Katara find them.

How would Gyatsos presence not only affect Aang and his friends, but the course of the show as well?

[Assistant]
Aang was already a master airbender, so theres not much in terms of learning how to bend. However, having an older airbender would probably provide the Gaang with 2 things: another master/fighter, and a sort of guide spiritually. If Gyatso chose to fight with the team (not something Im sure he wouldve done), the story might go a lot smoother. For example, in episode 1, Gyatso wouldve whooped the Fire nation soldiers and Zuko. Maybe Gyatso couldve pretended to be the avatar to fool the fire nation for a while, so if he gets captured, Aang has more time.

The other major thing is providing Aang with some comfort from his lost life. Aang would be less upset and attached to the world he came from, and would maybe mature a litter faster with an adult, in that he doesnt become upset as easily, and may even master the elements faster with an anchor who knows how it feels to be in his situation.

Basically, imagine Iroh as an airbender and put him in the gaang, and its pretty similar.


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

[User] ELI5: Wireless charging. No really, Explain like I'm a young child.

[Assistant]
Two very simple ideas govern the whole thing:

1. When an electric current passes through a wire, it creates a magnetic field around it.

2. When a wire is passed through a magnetic field, it induces an electric current within the wire.

The shape of the wire in each case can have an impact, and if you coild the wire up, it increases the effect you see.

The section of the wireless charger you plug into the power source has a coil of wire in it. The power supply gives an alternating current - basically it switches very very quickly (tens to hundreds of times a second): This creates a corresponding switching magnetic field.

By placing another coil of wire within this switching magnetic field, you can induce a switching current in the new coil of wire. A magetic current switching many times is pretty much equivilent to moving a wire through a static magnetic field.

This switching current that's induced can then be rectified and modified (using simple electronic components) to provide a nice stable supply to charge the battery.


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

[User]
I don't think there is anything wrong with cursing. CMV.

So I know most adults don't have a problem with it, but I'm getting a lot of flak from friends and family about cursing and I don't know why. I just don't think there's anything wrong with it. I guess if you're calling someone a bad name (asshole, cunt) or talking about things in a sexually vulgar way it's different, but I really see no reason for profanity to be considered bad. I'm a Christian and all, but I can't find any scriptures against it. I just don't see why there's such a stigma attached to it.

"All this shit is in the way" is the same as "all this stuff is in the way".

"I'm pissed off" is the same as "I'm mad".

"Fuck off" is the same as "get away from me".

"What the hell" is the same as "what the heck".

"Damn you scared me!" is the same as "dang you scared me!".

"I saw her tits" is the same as "I saw her breasts".

So why the hell are we stigmatizing certain words? In most cases they can be used to convey greater emotion or release tension. Change my view.

EDIT: View changed.

[Assistant]
Cursing:Polite Language::Bikini:Business Casual

Essentially, cursing has its place, and there is nothing wrong with it in that place, but there are just as many reasons it is only allowed certain places as why bikinis (or man thongs) are only allowed certain places.


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

[User] [Harry Potter] How Ron Weasley passed whole year of Charms with broken unusable wand and why professor Flitwick didn't exclude him at the begining of the year despite knowing that a broken wand can not be used to perform any magic?

[Assistant]
His wand sorta worked. I'd say it was like random die roll every time he cast a spell. Sometimes it did the thing, other times it backfired or altered the effects a bit.

Most likely he got a really poor grade. He's already a bad student, he's maybe scraping by with an Acceptable... with the want he might get a Poor.


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

[User]
[Edge of Tomorrow] What's the reason behind soldiers wearing the exo suits?

They have no armor, they move slow and I thought they were intended for helping carry heavy loads.

[Assistant] Cage and Rita certainly showed that with extensive training, the exo suits were powerful weapons. In the right hands, they're faster, stronger, and can carry a huge loadout of weapons. The problem is that no one's getting the amount of training they had because they saw Rita doing these things with "minimal" training.


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

[User] Eli5: When encountering dangerous aggressive animals, why is it so that you have to stare some species directly in the eyes while with others you have to break eye contact immediately or it will attack?

[Assistant]
Some animals have the instinct to sneak up on and attack unsuspecting prey and don't want to risk an encounter with an animal that knows it's coming.

Some animals have the instinct to respond to potential threats or rivals directly and perceive you staring it down as aggression toward it that needs to be dealt with.


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

[User]
Given that an Alcubierre warp drive is physically possible, how would the crew experience time in relation to others?

Would time be different from their perspective because they're technically going faster than light? Or would it be the same to those inside as those, say, on Earth due to the warp "bubble" the drive creates?

[Assistant]
Just to focus on the start of your question - current physics doesn't tell us that the Alcubierre Drive is possible. Current physics just doesn't explicitly *forbid* the Alcubierre Drive. These are very, very different things.

There are all sorts of things that aren't forbidden by modern physics but also can't/don't exist, and the Alcubierre Drive is probably one of them. It relies on a form of matter that we have no evidence for, and no reason to suspect it exists anywhere in the universe, and no reason to suspect it can be created.

To answer your question, there is no significant time dilation involved, although you instead have to deal with the implications of faster-than-light travel, including implied time travel and causation paradoxes.


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

[User]
Why are SpaceX landing at sea rather than land?

I'm thinking a land landing would help reduce the risks of weather/waves and the transport to and from the touchdown spot. Why have they chosen a barge rather than a large empty field?

I was thinking it would provide mobility in choosing a landing site, but this has never been a factor before in space travel, and they're launching the rocket from the same place regardless. Besides, there's no time to move the barge post launch I'm guessing.

[Assistant]
As far as i am aware, their launch trajectory from their launch site requires the rocket to fly over the sea in order to deliver the payload to the correct orbit. As such, if you follow the parabolic arc of the booster, it would fall into the sea. Therefore it is considerably more fuel efficient to slow the boosters descent so that it lands on a barge, rather than expend extra fuel to change the direction of the booster, fly it back to land, and then land it there.

That said the first tests of this technology did involve changing direction, flying it back to land and then landing it there. This was done to make sure the tech was viable.

tl;dr Landing the booster on a barge at sea saves a large cost in fuel, rather than expending extra fuel to change its direction and land it on the land.


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

[User]
[BSG] Why was it risky for Admiral Cain to perform a blind jump when the Cylons first attacked?

When Cain recounts the initial surprise attack, and says that she ordered an unplotted jump, Adama calls it a gutsy move. What's the risk, though? Space is mostly empty, so it's not likely that the Pegasus would have reappeared inside a star or planet.

[Assistant]
Space is mostly empty of physical objects, very true. You're probably not going to run into a planet or ship. However, there are other things to consider.

1) You're making a blind jump. How will you know where you are when you get there?  Astrographics bases your location off of known constellations and their relationship to each other. Jumping blindly could put you someplace where you cannot figure out where you are again for a long period of time- if ever. This makes *every subsequent jump* a blind one until you learn your proper location again.

2) Space might be lacking in physical objects, but it is not lacking in energy. Massive radiation fields exist, as do colossal gravity wells around various anomalies in space. Jumping into something like that could spell instant or slow death for the fleet.


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

[User]
ELI5:Why are universities such as Harvard and Oxford so prestigious, yet most Asian countries value education far higher than most western countries? Shouldn't the Asian Universities be more prestigious?

In most Asian countries, they take education super seriously, like people rent out rooms just so they can study more. I'd only assume that they universities are very selective of their students and that the criteria to get in would be equally as selective. But, when looking at the top universities in the world, it seems to indicate that the western universities are better. And also, universities such as Harvard, Oxford and the like seem to be the best universities in the world.

[Assistant] Oxford and Harvard typically place well in any inter-university student competitions that they enter and produce world class research. That's 100's of years of being 1st, 2nd or 3rd so they built up reputations. Consequently they have the most competitive entry requirements now because demand is so high which in turn makes them more prestigious. In turn they get the best students and continue to excel in research and competition.


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

[User] [Spider-Man]. Has there ever been a universe explored in which Aunt May died and Uncle Ben continued to raise Peter Parker? Does it change how Peter views being Spider-Man?

[Assistant]
There's a what if comic with exactly this premise. Uncle Ben is framed for the death of the burglar that killed Aunt May and goes to jail. Without either of them in his life, Peter develops anger issues and is sent to juvie for attacking J. Jonah Jameson and later becomes a bounty hunter of supervillains. He then tries to break Uncle Ben out of jail, but Ben refuses to leave with him, giving him the Great Power, Great Responsibility speech.

Peter turns his life around, becoming more like the Spider-Man we know and love, but Ben becomes his sidekick when he is released on parole.


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

[User] [Star Wars] Is there any particular reason the Force impregnated a human with the Chosen One?

[Assistant]
Which particular bit are you questioning?

Humans are the majority of the population of the Galaxy. Pick a random sentient, they're likely to be a human.

Furthermore, the old EU blames the whole shenanigan on Darth Plagueis the Wise tinkering with the Force. Both the Jedi and the Sith have their concepts of messianic figures.


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

[User]
[MCU] I know who Bruce Banner is, but who is The Hulk?

I'm writing my thesis* on Dr. Banner and his monstrous alter-ego, and I've run into a bit of a dead end. We've all heard the stories, about how he got trapped in a gamma chamber and was inundated with gamma particles in such a way as to not only *not* kill him, but to unlock a transformative effect in which he gains mass, strength and durability, but at the expense of his mind. That's the part I understand.

What I *don't* understand is *who* The Hulk actually is. I understand the theories behind dissociative identity disorder, but is that the answer? Is Banner simply a mutant, and when he changes does his mind just shift in such a way that it engages a personality Banner subconsciously created to control the change?

Or is it more complicated? Banner is a genius and would surely understand DSI, but doesn't seem to acknowledge that the Hulk is another personality, but rather an individual with his own motivations and relationships, and one he is often at odds with. Is the Hulk a person? One who uses Banner's body as a conduit through which they are able to travel? If so, where did they come from?

Hopefully someone knows more about this

*fictional thesis, is this still sort of an RP subreddit?

[Assistant]
You must have been Blipped, because Banner figured this out between 2018 and 2023.

He and the Hulk finally realized and acknowledged that they are the same person.  Now theyre a single entity thats always smart but also always big and green.  Banners new form has his old intellect and morality, and the strength *and confidence* of the Hulk as well.  Hes a lot more sociable these days and eager to please his fans, while he wasnt big on photo ops before the merger.

TL;DR: Theyre the same person, just took a while to embrace it.


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

[User]
I believe that police should be restricted to using rubber bullets, billie clubs, and tazers. CMV.

I see no reason why police should carry a weapon that has the express purpose of killing (or seriously injuring) others at all times.

I don't believe that the threat of being killed should be the incentive for criminals to halt their activity, and I believe the harm that can be inflicted by rubber bullets is more than enough to stop criminals from doing whatever their doing. Especially when you consider that the most of the criminals police deal with do not have guns themselves, so the threat of mutual harm is not necessary.

The British police get by fine without guns at all

Why should they carrie guns and ammo with them at all times?

[Assistant]
I recall an AMA with a police officer a bit back, where he talked about a suspect on PCP, or possibly meth.

Apparently, clubs, tazers, and rubber bullets may as well be marshmallows and pillows when facing down a person on one of those drugs.


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

[User]
How is it that shockwaves can occur in space?

My understanding is that shockwaves need an atmosphere to "shock" or distort.

Referring to the supernova that the Hubble telescope caught that is circling on Reddit.

[Assistant]
Space has gas in it; it's at much lower densities than the atmosphere at sea level on Earth, but it's there all the same.  When shockwaves happen in space, they happen over much larger distances than they do on Earth, and it comes down to the mean free path of the particles.  On Earth, the mean free path of an air molecule is around 100 nanometres; the molecule can only travel 100 nanometres on average before it hits another molecule.  Under these conditions, shockwaves have widths of about 200 nanometres, twice the mean free path length.

In space, mean free path lengths are much longer.  In interstellar space, a typical mean free path might be 1 million kilometres, although it can vary considerably; a particle travels an average of around a million km before it hits another particle, so shockwaves in the interstellar medium should have a width on the order of a couple of million km, very roughly speaking.  More if the mean free path is longer, less if it's shorter, but there's always going to be some distance scale over which a shockwave can form at a given gas density.


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

[User]
ELI5:How do journalists get into conflict areas?

I've seen many in Syria with the rebels, and even one guy who managed to access to Raqaa and IS. (Medyan Dariyah)

[Assistant]
In general they can arrange with rebels to get in and report.

It is not difficult to get in to rebel or IS held areas from the Turkish, Saudi , or Jordanian borders although journalists are not likely to reveal exactly where or how they crossed.

People who report on IS tend to be locals (like in the vice news video), or make a special arrangement with IS. For instance, PBS Frontline got a local a special arrangement with the Taliban to follow and report on them. It is harder with IS since they tend to be harsher to journalists than the Taliban, but you get the idea. You need contacts and connections to report on such groups.


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

[User]
ELI5:The differences between First Degree, Second Degree, and Third Degree Murder

I always hear those terms being used, and never understand what they mean.

[Assistant]
Murder 1 - This is when someone plans on murdering someone. For instance, they buy a gun, they find a place for the body, then carry out the plan. This is also typically the degree of murder given to those who kill during the commission of another crime (also called Felony Murder).

Murder 2 - Murder with no planning.

Murder 3 (aka voluntary manslaughter) - Killing someone during an emotional outburst. For instance, you walk in on your wife stooping another guy. You grab your gun and shoot the other guy. No planning, just a head of the moment stupidity.

Involuntary Manslaughter - Death caused through negligence with no intention of harm. If you're driving drunk and kill someone this is what you may get charged with.


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

[User]
If there isn't an objective truth, where does the authority of a art critic come from?

For the sake of argument we will follow the following premise that there is not an objective truth.

Recently I was wondering this. "If there is no" good taste "or" bad taste "to appreciate art, where does the judgment of an art critic come from?"

[Assistant]
You're asking two questions: first, if there is no objective truth, where does their authority come from, and second, if there is no good taste or bad taste, where does their judgment come from.

With respect to the first, they might be good at articulating compelling points, or good at drawing on knowledge of other works of art, or good at guessing what the typical reader cares about, or good at touching on enough points to cover stuff that most readers will care about, or knowledgeable about the subjective truths of the matter, and so on.

With respect to the second, first of all please note that "no objective truth" does not lead to "there is no good taste or bad taste." There's no *objective* good taste or bad taste, but there could be good taste or bad taste. But in any case, if there somehow weren't good taste or bad taste, judgment could come from basically anywhere! There aren't any standards!


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

[User]
[Back To The Future] Why was Doc Brown stuck in 1885?

In the end, he creates a time travelling flying train, after Marty left? He did that without the deloran. Why didnt he just create that, instead of sending a telegram to marty, how he was stuck? Doesnt make sense.

[Assistant]
He sent the telegram to Marty to keep him from worrying and specified no rescue.  Marty found out Doc would soon be killed and got help from 1950s Doc to come back.

The train took years to build judging by his sons' ages.  Even the ice cube maker looked like a lot of work.


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

[User] ELI5: Why does heat melt some things, but harden or cure others?

[Assistant]
Well, everything is made of tiny molecules and these molecules are always moving around, and go faster and faster as they get hotter. When they get really fast they turn into a liquid and when they get even faster they shoot off away from the rest of the molecules and turn into a gas. Solid, liquid, and gas are the three main stages of matter, and for most material how hot they are determines what stage they are in.

The trick comes when you realize that these three phases come at different temperatures depending on the material. So clay has phyllosilicates and water, phyllosilicates are like a kind of rock, and when you have it mixed with water it's kinda like really good oatmeal, and it's like both a liquid and a solid. You can shape it around when it's like that and make whatever you want. When you heat it up the water, which is already a liquid, turns into a gas and flies away, leaving the rock in whatever form you shaped it into. The rock only turns into liquid when it gets crazy-super-hot, and the oven doesn't go up that high, so only the water evaporates and the clay is left hard.


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

[User] [Jurassic World] Does jurassic world use Isla Nublar AND Isla Sorna? If no, why not?

[Assistant] No, only Isla Nublar. After the events of the Lost World, the Costa Rican government declared Site B a nature preserve and permanently off limits to humans as an environment to allow the dinosaurs to live as close to naturally as possible.


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

[User] ELI5:How do large venues and sporting organizations, which ban lots of people for unruly behavior, actually enforce these bans?

[Assistant] For the most part they aren't actively enforced. But what the ban means, in a legal sense, is a trespass warning. So, if they come back and cause any trouble, they immediately go to jail for trespassing.


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

[User]
Solar System Formation

Why is it that when solar systems form, the mass doesn't just all come together to form one giant ball? In other words, where does the velocity come from to keep the planets from just falling into the sun during formation?

[Assistant]
Imagine a very large, elongated cloud of hydrogen in space. It's slowly falling in on itself due to gravity, but it has no angular momentum, so everything is falling toward the center.

There's a star nearby. Because of the elongation of the cloud, one end of it is nearer to the star than the other end, but it's at some angle to a line from the center of the cloud to the center of the star. The star goes supernova, its shockwave hits the near end of the cloud, which begins to move away from the star. This shockwave hits the other end too, but it's more distant, so the force is less by some 1/r factor.

Since the cloud was already falling in on itself, when you add the falling in velocity to the differential shockwave velocities across the cloud, you get a net rotation of the cloud.

This is just one example, there are probably other ways for there to be an initial rotation.


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

[User]
ELI5 Why our bigger military cargo planes still use propellers when jet engines exist?

I'm assuming it has something to do with fuel or the ability to fly slower? Maybe it's a noise thing? I dunno, but that's why I was hoping to get a little insight into it!

[Assistant]
As others have said, they are turboprop engines, so, basically, a jet engine driving a turbine which drives a propeller.

Why the propeller?

Well, that's because cargo planes needs to go slow, in order to get short take-off and landing, and also to be able to land on improvised fields (you don't want a fast landing on a bumpy field).

The thing is, if you want to go slow, the most efficient propulsion is to create a wide, but slow stream of air, and if you want to go fast, you'll need a narrow, but fast stream. The extreme examples of that are helicopters, which can go very slow (hover) and have a huge rotor, giving a wide, but slow downwash. On the other end, you have aerospike engines, giving an extremely narrow, but fast stream, which are used on rockets.

So, to be efficient at slow speeds, a propeller is better.

Also worth noting is that a modern propeller has very little in common with a propeller from, say, WW2. Computer simulations has increased efficiency a lot.


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

[User]
ELI5: How do CPUs deal with dead transistors?

A CPU has billions of transistors, of which any number of them could be broken or not working - how do they continue functioning without these transistors?

[Assistant]
Welcome to the wonderful world of CPU binning.

Have you ever wondered why Intel doesn't just make i7s?

This is why.

They try to make all i7s, say a 4 core CPU (not anymore but things have changed a little bit from this a 2 years ago because chiplets).

Say a transistor in 1 core runs a little slow, its not broken but it can't run at full speed. Depending on this speed, they may take this down to a lower tier i7 or an i5.

Say the transistor is completely broke. They will disable that core, disable the second worst core, and call it an i3 with 2 cores.

I do want to note that the vast majority of the transistors aren't transistors in the cores, most of the CPU is cache. In which case they just disable the cache block with the faulty cache, and depending on how much cache they have to disable, they might also disable cores and call it an i3.

In theory these cores disabled beside the faulty cores are perfectly good (though if disabling a working core, they will disable the worst working core), in fact back in the day you could re-enable them and use them, but just to keep a consistent and small set of cpu models they will keep a few of them.

Do note that CPUs don't really have transistors dying with use usually. The only errors are usually in the manufacturing process.

But overall they will only throw away CPUs that don't work completely. Everything else can still be sold.


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

[User]
[LOTR] What would happen if the one ring were taken to the undying lands with the elves?

Could Sauron still reach it? The movies made it seem like a VERY exclusive place that only certain people could get to. It doesn't seem very likely that orcs could get to those lands. I realize that this is not a solution to defeating Sauron once and for all, but wouldn't it keep the one ring out of his reach forever?

[Assistant]
> 'Then if the Ring cannot be kept from him for ever by strength,' said Glorfindel, 'two things only remain for us to attempt: to send it over the Sea [to the undying lands], or to destroy it.'
>
'But Gandalf has revealed to us that we cannot destroy it by any craft that we here possess,' said Elrond. 'And they who dwell beyond the Sea would not receive it: for good or ill it belongs to Middle-earth; it is for us who still dwll here to deal with it.'

*The Council of Elrond, The Fellowship of the Ring*


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

[User] Is there a critical mass for a body of water to experience tides? If so, what is it?

[Assistant]
It's not about mass, but span being significant in relation to the size of the Earth.  There is no "critical" point.

The moon has its own gravity that affects us on Earth, to a *small* extent.  The sun also creates tides, but to a lesser extent.  Tides flow to a new "sea level" when the body of water stretches far enough to experience significantly different gravity at different points.

The Great Lakes are not really wide enough for a noticeable tide, but it is still measurable, 5cm from max-min you could ever get.


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

[User] [The Day After Tomorrow] What were the social and cultural ramifications of the events of 2004?

[Assistant]
The causes associated with long term ice ages, like decreased solar output or globalized deep water cooling, don't appear to be present.  That means that the climate will likely bounce back in a number of years  or decades rather than millenia.

That won't help the human race in the short term, though.  There will be mass death and starvation, even in the unfrozen global south where food supplies will falter due to the global cooling.  Humanity may be reduced from billions of people to millions.

The global south and countries along the equator will be overburdened by refugees and their own starving populations.  Crime and insurrection will flourish.  What's left of the human race will either fall into anarchy or draconian rule as governments either fail or impose harsh measures to survive.  The anarchic territories will eventually stabilize in population via survival of the fittest.  The draconian regimes will stabilize in population via mass execution.

By the time the world's climate recovers a new set of governments will have emerged controlling a much smaller human population.  Massive land grabs will happen as the governments compete over anarchic territories and the thawing lands of the northern hemisphere.  The north will be a new lawless frontier, rife with war, imperialism, and banditry.  It will also be a place where people seeking freedom from the authoritarian south will go to establish new homelands.


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

[User]
ELI5 Why do we need Oxygen to live?

I get food and water, they are converted from one energy source to another, but what does oxygen do?

[Assistant] Oxygen is what allows you to actually get energy out of the food you eat.  Your body combines oxygen with sugars, amino acids, etc from the food you eat to produce ATP (adenosine triphosphate), which is used as an energy source by your cells.


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

[User]
[Halo] Okay, who is the idiot who designed the UNSC vehicles?

Seriously, every land vehicle is just designed wrong. The Warthog has no doors, the Scorpion can get hit by everything, and there are literally 21st century ATVs.

It doesn't matter if you spend more time in the Space area than ground, you still have to make military vehicles make sense.

[Assistant]
Most of the current run of UNSC vehicles were designed to fight the Covenant against whom armour is mostly useless. Warthogs have no doors because the extra maneuverability gained by the reduced weight is more beneficial than the marginal defense added by the doors. Same for the ATVs.

Against plasma weapons you ideally want to avoid being hit in the first place than try to absorb the damage since the plasma doesn't bounce or ricochet off. Instead it sticks to what it hits and burns constantly until it cools down enough. The only materials the UNSC has that can effectively dissipate heat of that magnitude at any rate that would be useful are super expensive. The Mjolnir armour is made with it and even that can only handle so much, and each suit costs about as much as a Frigate. Shields would work too but has the same issue.


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

[User]
Why do I cry when I yawn?

When I yawn, my eyes water. It's never as full-fledged as legitimate sobbing, but sometimes there's enough fluid to make a few tears. Why does yawning make my eyes water?

[Assistant] It's just the contraction of the muscles in your upper jaw and face putting pressure on the tear ducts. The pressure forces any fluids already in the ducts out, sometimes enough to cause tears to roll down your face.


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

[User] ELI5 what is a country's economy, and how or when does it collapse?

[Assistant]
The economy is the sum total of all goods produced, bought, and sold within a country. It is typically measured using an index called the "Gross Domestic Product," which is the total value of goods sold in that country in a given year.

An economic collapse can mean many things. It can mean a significant drop in GDP (Economists say that two consecutive quarters with a shrinking GDP constitutes an economic recession.) It can mean a spike in unemployment. It can mean a significant drop in the value of the country's currency.

As to why an economy collapses - many reasons. Droughts, wars, out of control real estate speculation, revolutions, global pandemics...


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

[User]
[Moon Knight] How did he do this? *spoilers*

Khonshu manipulated the night sky and made them resemble the sky from thousands of years ago. It seems like this would take awesome cosmic power, and considering its Marvel, can we explain it?

[Assistant]
He may have been manipulating perception of the night sky from Earth rather than actually moving cosmic bodies around in space.

It's still a tremendously powerful display, but more global illusion than cosmic-scale telekinesis.


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

[User]
CMV: You shouldnt join the military if youre gonna fly the Confederate battle flagx

Fuck the CSA. Fuck the Confederates. I dont know why anyone who claims to be an American or a patriot would ever want to proudly fly the battle flag of a racist, illegitimate, secessionist, slave-owning state who shot at and killed our troops in order to create their own country that defies the values and ideals that founded the US. Dont give me that iTZ MUH pRiDE or ItZ mUh HeRItaGe! excuse because if that were true, then Germans or those with German ancestry shouldnt have a problem with going to Israel and flying the piece of shit Nazi swastika flag while doing the Nazi salute along with shouting SEIG HEIL! or HEIL HITLER!. If we wanted to expand on this logic, then those with Japanese ancestry shouldnt be called out if they went to South Korea or China or Southeast Asia and flew the IJA flag while shouting BANZAI!!!!.

And if you want to join the military, why would you ever want to fly or hang up such a piece of shit flag that was flown in battle when traitors wounded and killed our troops as they were fighting to restore our country (and later free the slaves after the Emancipation Proclamation was issued)? That flag runs against everything that our country stands for and its a spit in the face of our nations values and ideals. The only good thing that the Confederate battle flag is good for would be if you used it as toilet paper or if you used it to keep a fire going. Other than that, no American (especially in the military) should ever be fine with or proud of flying the flag that traitors fought under as they killed our Marines, soldiers, and sailors from 1861-1865.

And because I know that this is going to be said, yeah, of course the military isnt the most PC of places. Thats to be expected. But its a little different making fun of someone because they came from somewhere or have a weird/funny accent compared to flying a Confederate battle flag.

[Assistant]
Not to invalidate the points above.

But plenty of people would feel that the American Flag is part of a government and ideology of hate, genocide, anti-LGBTQIAA, racist, Colonialist, and evil regime

One might ask after reading Zim if joining the US military or flying the US flag is anything less than hate.


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

[User] ELI5: Why do beaches have sand? Where does the sand come from and why is it all in between the ocean and the main-land?

[Assistant]
Water constantly slamming into land causes rocks to break down into tiny particles. What you get is a lot of sand. As the water continues to slam into the shore it pulls the sand out with it into the ocean slowly destroying the land around it. This is why beach front property is a risk. You might end up with a house in the water a few years down the road.

To combat this many places actually bring in tons of sand to add to the beach to replace what is taken by waves.


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

[User] ELI5: what is the difference between dishwasher soap, laundry soap and the barsoap I use in the shower?

[Assistant]
I cant speak to dishwasher soap, but hand soap/bar soap is traditionally made from a process called saponification where a strong base, oil and water are combined. This forms a compound which is hydrophobic on one side and hydrophilic on the other. This is what helps soap being able to clean, as the hydrophobic side can bond to other fatty acids and the hydrophilic side can bond to water to wash it away. As for the strong base, if NaOH (sodium hydroxide or lye) is used, the soap will be a hard bar. If KOH (potassium hydroxide) is used, the soap is softer.

You can use this soap to make laundry detergent, by grinding it up and mixing it other cleaning agents like borax and/or washing soda. This makes it less sudsy so your washing machine doesnt overflow with suds, but still able to dissolve in the water and clean your clothes effectively. And typically it will be mixed with fragrance as well, since we are used to clean things smelling clean. That would be used for powdered detergent. If you want liquid detergent, this would then be added to water, as well as some type of gelling/thickening agent to help keep it all mixed and stay in suspension instead of separating out (which it will naturally do without those agents).


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

[User]
Is atomic stability of radioactive elements affected when they form a molecule with another element?

For instance say plutonium bonds with some other element. Is it's half life reduced or is it constant regardless?

[Assistant] In general, the nucleus cares very little about its "chemical environment". The exceptions would be decay modes which directly involve the electron cloud (electron capture, internal conversion, and bound state beta decay).


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

[User] ELI5: How come "Frisbee" hasn't become a generic trademark like Band-Aid or Xerox despite the fact that everyone calls every flying disc a Frisbee?

[Assistant] Because Wham-O protects their mark by vigourously suing the pants off of any one even remotely trying to profit off the name. One of their more well known suits was against the movie "Secret of NIMH" where the main character's name had to be changed from Mrs Frisby to Mrs  Brisby.


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

[User]
If New York City and Madrid are at about the same latitude why is Madrid so much warmer than New York City?

They're both at about 40 North. Does it have to do with amount of sunlight or humidity? What accounts for the difference in temperatures?

[Assistant]
The Gulf Stream brings warmth to Europe, dragging the heat of the equator north to Western Europe.

Edit:

Should add that New York has greater extremes in temp.. the cold is colder and the hot can be hotter. This is a product of the continental landmass to the west. The prevailing winds run from west to east over the north american continent. This means that air masses are heated or cooled over the land before blowing into New York. The seasonal extremes of temperature can be much more pronounced.

Since the air over Spain spent a long time over the ocean it is a more mediated and normalized temperature. For the most part the weather in Madrid will be more mild with fewer seasonal extremes.


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

[User] ELI5:Why do down sydrome kids all lookalike in regards to their facial proportions?

[Assistant]
Because DS is caused by only one specific genetic mutation (an extra chromosome 21) it causes the same changes in the face in every affected person, to varying degrees. They have smaller mouths and bigger tongues, the bridge of the nose is flattened, the outer corner of the eyes turns up rather than down. These things together make what you are thinking of as the characteristic down syndrome face.

Nobody yet knows why the extra chromosome does these things but groups of seemingly unrelated physical characteristics (like whorls in hair or wide spaced toes) are often specific to a particular genetic syndrome and used to diagnose it.


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

[User]
ELI5 How does the Euthanasia Coaster ACTUALLY kill you?

I know that its something to do with the g forces it puts on your body, but like what does that actually even mean? Cant you just force yourself to breathe anyway?

[Assistant] The sheer scale of the coaster and the prolonged exposure to high G forces is what is supposed to do you in. A normal person can survive a couple G's for a couple seconds, but when youre facing 10 G's for multiple minutes, the blood and oxygen simply cant get to your brain and we know we have to continue to breathe to survive.


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

[User] [LOTR] Can hobbits and humans breed?

[Assistant]
Yes.

Hobbits are a race of men, therefore human.

Arguably 'Human' is a term that applies to both the Edain and the Eldar.  They are biologically the same species.

The Edain includes High Men, Middle Men and all other forms of Edain, including Hobbits.  High Men are the Dunedain/Numenoreans, Middle Men are most other men in Middle Earth, possibly including Hobbits as they share a common heritage with the Rohirrim.

The Eldar include all elves and possible the Orc/Goblin subgroups depending on the source material.  The Silmarillion explicitly says that orcs are elves, but some discount that as an error.

In theory Men, Elves, Hobbits and Orcs are all the same species and thus could interbreed.  They don't do so for various political, religious and health and safety reasons, health and safety being emphasized when referring to Orcs.

Edit:

There is also a certain amount of racism with regard to interbreeding.  Elves and the Edain are not above intermarrying (and it's implied to occur quite a bit more than written about), but this is a privilege generally reserved for the higher lineages of men, such as the lords of men.

Orcs and Goblins are discriminated against by pretty much every free race.  Though a peaceful orc is never shown, it's not outside of the realm of possibility.  Unfortunately a peaceful orc would find no quarter in any society.  Orcs would kill them for being a 'traitor' and the free people kill orcs indiscriminately.  So even if they were just mutilated elves there would never be an opportunity for an orc to have a meaningful relationship with an elf or man.  Rape can cause a child to be conceived (rape is a rare subject in Middle Earth literature), but if an orc (or anyone for that matter) were to rape an elf the elf would actually die due to the nature of their spirit.  A man would not die however in the case of rape by an orc, so they might be able have a hybrid child with an orc.  This is one of the possible sources of the Uruk-hai.

Hobbits do live by other men, especially in Bree, but intermarriage is never shown.  Hobbits tend to be a little clannish, so marrying one of the 'big folk' is probably socially unacceptable, even for the most cavalier or adventerous hobbit.


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

[User] [Watchmen] Can the infinity stones have an effect on Dr Manhattan?

[Assistant]
Yes, probably pretty significant effects if used the right way.

For example, the Soul Stone could pull his soul out.  The Mind Stone could mind control him.  The Space Stone might be able to block his ability to teleport.  The Time or Reality Stones might be able to block his ability to sense specific time periods in the future.


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

[User] ELI5: What is the scientific basis behind the observation of 'projection', i.e. that, if a person expects others to behave a certain way, it's also likely they exhibit tendency towards the same behaviour?

[Assistant]
The *psychological* notion of 'projection' has little scientific basis. It's a theory promulgated by early psychologists that relies on untestable hypotheses. Basically, the notion is that you're trying to assuage your own guilt or bad feelings by 'projecting' them onto others.

The *social* notion of 'projection' is based on the idea that our framework for understanding others is established by our understanding of ourselves. There has been research done to establish the validity of this model, so it can be regarded as scientific.


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

[User]
ELI5: How do different shapes of glasses affect the alcoholic beverage taste?

There are different types of wine glasses based on the type of wine and the same with beer. How does the shape of the glass affect the flavor and taste of the drink.

[Assistant]
Tulip
Shape:Bulb that tapers in before flaring out at the top.
Purported Benefits:concentration of aroma, support of the foamy head at the top, and comfortable drinking afforded by flared rim.

Chalice
Shape:A round bowl on a stem.
Purported Benefits:Beautiful presentation, foam support, wide mouth for easy drinkin' (in big sips.)

Pilsner
Shape:Tall, footed, slender, tapered out from the bottom.
Purported Benefits:Displays the beer's clarity, while tapered shape supports head.

Weizen
Shape:Tall, large, slender at bottom, bowled out a bit at the top.
Purported Benefits:Large size accommodates a massive, frothy head associated with highly-carbonated German wheat beers. Slender bottom shows off these beers' famous hazy color and protects its lively carbonation.

Nonick Imperial Pint
Shape:Large, slightly tapered out with bulge near top.
Purported benefits:Designed for the no-nonsense drinker. The bulge facilitates stacking and prevents rim chipping.

Shaker Pint
Shape:Slight taper outward from bottom.
Purported benefits:Cheap and easily stackable. Sturdy ones can be used for stirring and shaking cocktails.

Snifter
Shape:Stemmed, wide-bowled, tapered in at top.
Purported benefits:Designed for maximum concentration of volatile organic compoundsthat is, aroma.

Tumbler
Shape: Short and squat with thick glass and a slight outward taper.
Purported Benefits:Tradition generally drives the use of this glass, which is usually reserved for Belgian witbier and lambic.


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

[User]
[Marvel] Why did SHIELD resuscitate Steve Rogers in Times Square, New York instead of a more remote location?

To me, it seems like putting Steve Rogers where they did was just asking for something to go wrong. Why didn't SHIELD put Steve in say, a rural hospital in upstate New York that they just decorated to look like it was in the 40s? Surely that would have caused fewer problems.

[Assistant] well in the Agent Carter spinoffs we see that their preceeding organisation had NY offices back in the 40s.  maybe its a sort of "hidden in plain sight" deal. Like, would you assume that a secret SHIELD lab would be under Times Square?


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

[User]
[Futurama] How does Zapp Brannigan still maintain his job?

I mean, the guy's an unbelievably *terrible* general. In no particular order:

* He's an absolute coward.
* He's lost nearly every single battle he's ever been involved in, even to a tribe of Neanderthals.
* He stays as far away from combat as possible while his troops get slaughtered by the hundreds.
* His only real strategy for combat is to throw wave after wave of troops at the enemy, even when such a strategy fails every single time.
* His soldiers hate him.
* He's gullible enough to fall for a really obvious disguise.
* He's plain stupid.

With all this in mind, how is he still in charge of Earth's military?

[Assistant]
Because the government of the world is *also* unbelievably terrible.

It's not just brannigan- every glimpse we get at the authorities is a system that is corrupt to the point of atrocity and incompetent to the point of uselessness.

Zapp Brannigan's not fired because he's not an outlier. They're *all* like that.


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

[User]
[Astronomy] Could any of the planets in our solar system collide?

I've done a quick search looking at the orbits of the planets in our solar system and google images (great source I know) show varying paths that the planets in our solar system follow.

Some of the images though, show orbits of like (the rock/moon/dead planet/whatever we're calling it now) Pluto sharing relatively brief sections of orbit with other planets.

Would it be possible for planets to collide?  If so, have scientists estimated at how long it would going at current rates it would be until they do collide?

*Edit: In hindsight now, I hadn't considered the three dimensional fact when looking at orbits, so that even further makes this scenario less likely I would imagine.  Come to think of it, I've always sort of thought about all the planets being lined up on a horizontal plane rather flush, and that's actually probably quite incorrect, isn't it.*

[Assistant]
Pluto's orbit is tilted considerably relative to the orbits of the other planets, and its orbit does cross Neptune's (it was inside it for the last couple of decades of the last century), but they cannot collide with one another.

The orbits of the other planets have been stable for millions of years and will remain so unless some outside influence comes into play, such as a particularly large asteroid or comet entering the part of the solar system that contains the planets.


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

[User]
[40K] How can Space Marines be a significant army if they are so hopelessly outnumbered?

I can accept that individual Space Marines are nearly indestructible engines of slaughter and mayhem. But the fact remains that they are  armed with melee weapons and line-of-sight firearms while traveling at the speed of feet in quantities of 1000 or less. In the time it takes a Chapter to kill 10,000 Orks/Chaos worshippers/Necrons/etc, 100,000+ other enemies can sweep across the rest of the planet unmolested.

[Assistant] Space Marines aren't an army, just as US Marines aren't an army. They are a rapid-response initial landing force. Their job is not to scour the planet, their job is to set up a forward base of operations so that the real army - The Imperial Guard - can some in and clean the planet off.


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

[User]
I don't understand what people find wrong with bestiality. CMV.

First, some context: I was having a discussion with a friend about homosexuals, he, being a very religious guy, was adamant that though homosexuality is real, and he could be best friend's with a homosexual, at the end of the day, there's a moral code that should be followed, where it should just be a man and a woman. Myself and another friend tried to explain that condemning homosexuality only hurts people. If a man is with a man, and both love eachother, no one gets hurt. Force the homosexual man to be with a woman (due to societal/moral norms) and one if not both get hurt. My friend then counters, "So you believe bestiality is okay. I mean, no one get's hurt right?" And I was left unsure with what to say. To clarify, my friend was not equating bestiality to homosexuality. He was just using an extreme example to test my belief that if no one get's hurt, then it should be okay. Now, I am in no way condoning bestiality, I was sort of just forced to reevaluate my opinions. If it's consensual for both parties, then why exactly do we care so much? No one get's hurt, right?

EDIT: Too many grammar mistakes.

[Assistant] I think the fundamental point here is that animals can't consent. Yes, no one gets "hurt" exactly, but a man can consent to another man in homosexual relations, whereas this is not the case for bestiality.


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

[User] ELI5: Why does the visible light spectrum appear cyclic to the human eye if the spectrum is based on specific linear wavelengths of light?

[Assistant]
It doesn't appear cyclic to the human eye.  It appears cyclic to the human *brain*.

Our eyes can detect 3 "regions" of color: red, green, and blue.  If we detect some combinations of those, we typically perceive that as an "in-between" color.  For example, orange light stimulates both the red and green sensing cells in our eyes.  So stimulating the red and green cells is what we perceive as "orange".  And, interestingly, if we just use red and green light (no orange light), we can stimulate those cells exactly the same as orange light, and so we still see orange.  In fact, that's the basis for how computer and phone displays work:  They only emit red, green, and blue light, and our brains perceive combinations of those as other colors.

But here comes the strangeness!  What happens when you stimulate the red and blue cells in the eye with red and blue light?  Well, your first guess is that we should perceive the color that is "in between" red and blue on the spectrum.  But that color is green, and we're specifically *not* stimulating the green-detecting cells in our eyes.  However, your brain isn't really capable of seeing it as two different colors (red and blue) simultaneously, so it invents a new color!  Purple!

That's right, purple, the color that allows our sense of the spectrum to be cyclical, *isn't a real color*.  There is no such thing as a purple photon of light.  Purple can *only* be perceived by the human brain as a side effect of the limitations of our visual system.


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

[User] ELI5: If gas prices go up on holiday weekends due to demand, how is that not considered price gouging?

[Assistant] They go up in a reasonable amount to account for supply and demand and the natural flow of the invisible hand.  If they were to say bump prices up by $3/gallon on a weekend, then that would be price gouging.  Adjusting prices based on natural fluctuation of supply and demand is basically a core component of how to run the economics of a business, which is totally fine.


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

[User] why do prion diseases only affect the brain and not other organs?

[Assistant]
There are two aspects to this. First, prion diseases are caused (perhaps) by accumulation of misfolded protein fragments from the prion protein found chiefly in the CNS. The masses or aggregates of this material are termed amyloid due to their tinctorial properties (that is, how they stain in microscopic preparations).

But if we step back a level, amyloid diseases are more general. Look up primary or secondary amyloidosis. In these conditions, similar aggregated, misfolded proteinaceous material, resistant to degradation by the body, accumulates elsewhere causing disease. The material can accumulate in the skin, kidneys, perpheral nerves, heart, etc. This material is derived from antibodies or other proteins unrelated to the prion protein.

Another interesting disease to consider, bringing prion-unrelated amyloid back the the CNS, is senile congophilic angiopathy, a cause of strokes in the elderly.

(In regard to prion-related disease, the causal chain is not proven. The amyloid hypothesis is just that, a hypothesis. We dont know how, or if, the misfolded prion gets to the CNS from, say, food. We dont know whether different persons, similarly exposed, have different responses - that is, some get sick and others not, but that is suspected. There may also be, for example, a hereditary or acquired difference in proteosome-based degradation of amyloid material, differences in macrophage function, or other unknown factors that are related to the development of disease.)


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

[User] ELI5: Why is heroin so addictive? What does it do to the brain? Can anyone explain the feeling?

[Assistant]
The human brain has a natural set of hormones that are used to moderate pain and emotional responses called endorphins, the opium poppy based drugs imitate the actions of endorphins, that ease pain and induce and pleasurable sensations.  The most potent of the naturally occuring "opiates" is morphine.  Hold that thought.

There is a chemical and physical structure in our body called the "blood brain barrier." The brain is a seriously important organ and is isolated from much of the rest of the body's circulation for its own protection, this is good thing but can have it's drawbacks. Certain poisons don't get to the brain, good, but antibiotics may be blocked as well.  Now, back to the opiates.

Morphine crosses the blood brain barrier, if eaten, smoked, or intravenously injected it gets into the brain to work its tricks.  Heroin (diacetylmorphine) is a drug made from morphine that crosses the blood brain barrier *much more effectively*, it is quicker to get into the brain and do what morphine does.  It's heroin in the little baggie from the dealer, it's heroin in the syringe and in the vein but it is morphine in the brain.

If you were perfectly healthy and wealthy and just as lazy as hell you might be able to just hire someone to carry you around to every anywhere you wanted to go, do anything that needed to be done, lift anything that needed to be lifted.  This would have serious effects on your body, you'd lose muscle mass and become weaker and weaker over time to the point where you'd not just *want* your helper to carry, do, and lift everything, you would *need* that help.  If your helper left you'd either hire a new one or struggle to get up off your ass and *recover* from the mess you'd made of yourself.  That's addiction for you.

Heroin (morphine) takes over for your natural endorphin system that is there for the internal control of pain and does all the work to the point where your body *needs* it to avoid pain.  When heroin is *withdrawn* your body goes into *withdrawal* and **it hurts like hell.**

Feels real good when you start, up to the point of addiction, and is quite painful to quit after that.

Edit: minor spelling.


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

[User] Why is music in movies/tv often disproportionately louder than the dialouge?

[Assistant]
Nobody has answered this correctly yet. It is by design- movies generally have very high dynamic range (loud things are very loud, quiet things are very quiet). In a movie theater or a great home setup with the volume cranked up- this works great! You WANT explosions to be super loud and the music scenes to be very loud in comparison to dialog. However, when you're watching a movie late night, quietly in your living room- this can be very annoying- you'll find yourself turning the volume up for dialog and down when music or explosions happen. This is why many audio receivers have a 'night mode' setting which basically compresses the dynamic range- making the dialog and music/explosions more close in volume.

In short, high dynamic range makes audio exciting! It's by design! Great for a loud movie theater, but bad for a quiet living room.


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

[User]
Do our ears adjust when listening to very quiet sounds?

More specifically, is there a change that happens to our ears akin to pupils dilating in low light in order for quieter sounds (or sounds of different frequencies) to be picked up?

[Assistant] Yes. The series of small bones and muscle situated behind your ear drum protect your audition by tensing up when exposed to loud sounds, and relax when they are not. Furthermore, the way sound is perceived happens mostly in the brain, which has a very complex way of handling sound that is dependent on a lot of factors (psychoacoustics) so yes your perception changes a lot if you're concentrated, rested, in a quiet environment, what kind of sound... There are different well known effects such as frequency masking (loud low frequency sound "muddle up" your perception of higher frequency content) and plenty others. It's quite complex.


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

[User]
[King of the Hill] Why werent Hank and Arlen Video both arrested for possession of child pornography?

In a Season 2 episode called *Hanks Dirty Laundry*, he proved that one of the movies rented from Arlen Video starred a 17 year-old porn actress. He openly admitted to having watched it. So...is everyone just okay with that?

[Assistant]
It's a reference to an actual event in porn history.  Can't remember the actress' name atm but after it became public knowledge that she performed in numerous videos at the ages of 16 and 17 all copies were ordered destroyed and any that existed after a grace period would be considered child porn.  Tapes do still exist today but have been edited to cut out any sexual scenes with the actress so it is possible that hank saw one of the edited versions.

Edit: Tracy Lords for anyone interested.


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

[User]
ELI5: On Windows 64-bit, why do I see Program Files and Program Files (x86), and what is the difference?

I'm also a bit confused about when I download certain programs if I should get the 64 or 86 version, wouldn't 86 be more "power", or are these 2 completely different things?

EDIT: Woo, front page! Thanks for the knowledge!

[Assistant]
Using "x86" to denote 32-bit programs is an old homage to the Intel 8086 processor, but it is a bit of a confusing name to non-savvy users.

Processors can execute programs by either processing 32 bits at a time, or 64 bits at a time. If you have 64bit Windows, your computer can process both 32 and 64 bits at a time, so when you have a choice you could download either the 64 or 32, but 64 would be recommended.

x86 isn't more powerful than x64 because an x86 processor can only handle 32bits of information at a time (the number is confusing).

Now in general, a 64bit computer can be more powerful than a 32bit computer, this is due to the amount of RAM a 64bit computer can support (random access memory, its where your computer puts stuff while it's working on it, sorta like how you pull files out of your filing cabinet and work on them on your desk).

Program Files (x86) is where Windows stores all the information for the 32bit programs it has installed, to answer your title question.


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

[User]
[Matrix] How could Neo fly?

Not just fly, but all the things that the others couldnt do. Is it because he was programmed to be overpowered because he is the One, and thus, being able to end the Matrix?

I would ask aswell how could people from Zion get stuff like clothes and all that fancy stuff if they are that deep in the fcking ground, but i guess its better than having them going around naked.

[Assistant]
Neo is the sum total of all of the little things wrong with the Matrix. The fact that deja vus occur, the fact that some people can bend the rules and break the physics engine, and most importantly, the fact that some people have this tickle in the back of their mind that tells them something just isn't right.

The machines never figured out how to stop that from occurring, so instead they created the One as a way to deal with it. The One "collects" all of the little errors that pile up, and leads the dissatisfied people to Zion. Then, the machines burn Zion down and the One merges with the Source, which sets the error state back to zero.

It's imperfect, but it more or less works.

Part of that imperfection is that, as the One, he is much better at breaking the physics engine than anyone else, even the Agents. The Matrix works by reading the signals sent by a human mind through the port in the back of their skulls, and translates those thoughts into instructions.

Usually, when a human tries to do something like flying, the rules of the physics engine just say "no." But Neo has learned to send different signals, signals which trick the algorithms into doing what he wants. This is roughly equivalent to how computer hackers send specially crafted input to gain control of a computer system; it's just that with Neo, who can "see" the source of the Matrix, it's more instinctive.


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

[User] When someone suffers from Acute Radiation Sickness they go through a "latent" stage where they feel well and healthy, despite potentiay lethal physiological damage. How is this?

[Assistant]
If you get a sufficiently high exposure, it kills pretty much all of the bacterial fauna in your stomach and intestines, as well as your intestinal lining. Your digestive system just stops working. That manifests itself as rapid onset nausea, vomiting, and diarrhea. Once you're ah, empty, you feel better. No more barfing all over the place.

Unfortunately those cells aren't coming back anytime soon, and in the meantime much of your bone marrow might be dead, most of your white blood cells are dead, you might have severe organ damage. It's pretty much a matter of time. The train's already left the station, so to speak, and now you're just waiting for it to arrive.


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

[User]
Are there any animals that migrate south for the summer and north for the winter?

I mean northern hemisphere animals - do any seek out extremes of temperature like this?

[Assistant] There is one in the Southern Hemisphere. Emperor Penguins migrate further inland in early autumn (March) for breeding. After the females lay the eggs, the males stay there during the winter while the females go back to sea to feed. In spring, the females return to feed the chicks, while the males go to shore to feed themselves.


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

[User]
Does x(Px & Qx & Rx) entail x(Px & Qx)? And if yes, is everything that is entitled by x(Px & Qx) also entailed by x(Px & Qx & Rx)?

I swear this isn't a homework question, I'm just thinking through something and my logic is rusty. I'm pretty sure the answer the here is Yes, but am unsure because all of the terms of x(Px & Qx & Rx) are bracketed together.
Thanks for any help.

[Assistant] The first answer is yes the second answer is yes. If there exists something with the properties P, Q and R then there exists something that has the Properties P and Q. And since you can derive the existence of something with the properties P and Q from the existence of something with the properties P, Q and R anything that can de derived from the existence of something with the properties P and Q can be derived from the existence of something with the properties P, Q and R. In other words anything entailed by the former is entailed by the latter.


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

[User]
[Tolkien] What did movie Smaug eat?

In the book he hunted in the lands around Lonely Mountain. In the movie, it has been specifically said that he hasn't been seen in years. It'd be a bit hard to miss a dragon flying around a famous landmark.

So what did he eat? Was he just fasting all that time? Does he eat gold?

[Assistant]
Could be like a super-hibernation perhaps?

It's worth noting that in Middle Earth (and Arda as a whole) you have things like the Numenoreans who live a lot longer than regular people, a balrog that happened to be fine and dandy living in a hole in Moria for goodness knows how long and other fantastic critters. It's entirely plausible that in this age of declining magic Smaug simply *is*. Perhaps his slumber is related to the decline in magic and the fantastic throughout the ages as the song of the Valar goes on.


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

[User] ELI5: What benefits do fossil fuels have in the environment or are they only useful to humans?

[Assistant] Fossil fuels have no benefit to the environment. They are somewhat useful to humans because they are used as energy. But their use has negative effects on the environment, like creating greenhouse gases and accelerating climate change.


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

[User]
I have heard/read from a few sources that viral load is one of the factors influencing severity of the infection in Covid-19. How far is this true?

For example, if person A gets a higher viral dose than person B, is his/her infection more likely to be more severe and has there been any research/studies conducted on this? Also, I'd like to know if there's a minimum viral dose that is needed for symptomatic infection, and if this dose varies from individual to individual. The new (mutated) strains of Covid-19 are said to be more infectious- does this imply that a smaller viral dose is required to cause symptomatic infection?

[Assistant] In general, there is a positive correlation between initial inoculate and disease severity that has been shown for several viruses including this one. This at the population level, at the individual level it can be that 2 get infected by a similar inoculate but one does worse than the other etc.


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

[User]
Can many small, quieter speakers produce sound equivalent to a single larger, louder speaker?

Say I have 200 phones playing a song, does the volume increase when coming from many sources?

[Assistant]
Yes, due to a principle called constructive interference, the sound waves with matching and in phase frequencies will build on eachother, making the amplitude higher and the volume louder.
Think of a crowd cheering in a stadium for a simple example.

However, from an engineering point of view the sound would probably sound distorted unless you were listening in an open field, or the small speakers were very close together. This is because the holes you see in speakers are designed to 'spread' the sound out, and with multiple different speakers the waves could reach you at different times causing a very slightly dodgy sound (this may well be an insignificantly small error however)


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

[User] If atoms are mostly empty space and photons are so small, why don't they just pass through atoms?

[Assistant]
Photons don't have a size, they're not structured objects or anything. They don't even have that much of a position.

They typically have a wavelength that is much larger than the atom.

Photons interact with atoms because the probability of interaction is not computed by imagining they actually are little billiard balls. However, confusingly, the result is given *as if* they were (cross section). The cross-section must be computed in quantum electrodynamics (or some of its classical/semiclassical limits depending on the situation) and it's pretty large.


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

[User] ELI5: What does Bernie Sanders' "Too big to fail" bill mean when it says it is going to 'break up' big banks?

[Assistant]
A lot of the biggest banks in the US (i.e. JP Morgan / Citigroup are probably the classic cases) are financial conglomerates that house many different kinds of businesses that touch many different (and arguably unrelated) areas of finance. They might have a division that does personal banking (bank accounts for people + credit cards), a division that does commercial/corporate banking (lending to businesses and corporations), and a division that does investment banking (trading and advisory work).

The idea of "too big to fail" is that these conglomerates touch so much of the economy, that if one division has a problem that might make the bank go insolvent (i.e. huge trading losses), the government basically *has* to bail them out, since the repercussions of failure are so big.

What Sanders and others who want to "break up" these big banks want to do is basically split them into smaller entities that don't touch so many sectors of finance at once. The most commonly talked about split is to separate the investment bank (trading and advisory) from the personal banking and commercial/corporate banking divisions.


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

[User]
[Harry Potter] Wand lore and Magical Conduits?

Would it be possible for a witch or wizard to channel their magic through more than one magical conduit, like a wand, staff or orb, at a time? Harry Potter stated his writing arm to be his wand arm, so would it follow that an ambidextrous witch or wizard could use either?

[Assistant]
Wands work for wizards/witches the same way as pencils work for muggles. Most muggles use pencils in their right hand, but some use them in their left. Ambidexterity is uncommon, but not unheard of. It's 'possible' but unlikely that someone could write using two pencils at the same time.

The same is so with wands. A wizard/witch 'could' use two wands, but would have a very difficult time trying to focus on casting two spells at the same time.


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

[User]
Are there any arguments against evolution that don't involve a religion?

Today at my workplace, a coworker brought up her religious beliefs against evolution.  I am very science-y (engineering student) so I gave my opinion, which contradicted hers.

But I was thinking later, are there any feasible arguments against evolution that don't involve a religion?  I can't think of any myself.

Any input would help.  Thanks!

[Assistant]
No, just like there are no feasible arguments against gravity.

Sure, we argue over the details (just as the physicists argue over the integration of general relativity i.e. gravity, and the quantum world), but there are no feasible arguments against either.


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

[User]
[Osmosis Jones] What does surgery look like in this world?

Do surgeons open up their patients and see cityscapes, hearing teeny tiny little "honk honks" from the cars?

And what about the inhabitants of the body? Do they shit themselves when they look up and see planet-sized giants parting the skies and reaching down onto the countryside with big metal tools?

[Assistant]
The doctors are none the wiser.

Meanwhile, the city and all roads are locked down; the military is called on the spot to deal with intrusive bacteria and viruses. While this isn't normal, it isn't something to fear; the military will be taking potshots at anything that tries to get through.

The mayor will have to issue a statement regarding the sudden parting of the skies and widespread destruction of highways and the loss of a huge number of important works. The city can endure some shortage of vital supplies, but that might be offset by the IV fluid being pumped into the city. Some districts may be destroyed completely, but they're usually the ones that warrant the surgery anyway. The mayor issues more statements and tells the city to not worry.

Interestingly enough, crime rates drop throughout the city for some time before rising to their previous levels.


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

[User]
[Spider-Man Raimi trilogy] "Jesus, Parker, you are a freak." I'm sorry, what? Why weren't a lot more people AMAZED by the fact that Peter kicked Flash's ass?

Peter wasn't the most popular person, but Flash is an asshole. Hell, it seems as though very few people actually like the meat-head. And yet, when Peter kicked his ass, most -- if not everyone, besides Harry -- don't show amazement.

Why not? If it were me, I'd say that it was about a time someone showed him \[Flash\] up.

[Assistant]
You think anyone there is going to admit that?

Flash may be an asshole but he's the most popular asshole in school whereas Peter was just another weird quiet kid with a camera fixation.

Then one day that quiet kid is suddenly super strong and fast and lays out the star football player like it was nothing. Sure, Flash definitely had it coming but highschool hierarchy doesn't change in an instant.


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

[User]
Suppose there is an upright cylinder completely submerged in water. Since the top of the cylinder is higher then the bottom, shouldn't there be more pressure on the bottom and thus an upwards force on the cylinder?

I've been wondering about this for a long time. Why wouldn't the cylinder be pushed upwards? Suppose it has a total density that of water.

[Assistant]
Yes. This is what causes the buoyancy of the object.

The vertical forces on the cylinder are gravity and the pressure forces on the top and bottom. The net pressure force is *_0_*ghA, where *_0_* is the density of water, h is its height, and A is the area of the circles that form its top and bottom. And the gravitational force is mg = gAh, where  is the density of the cylinder. Ah is just the volume of the cylinder (which also equals the volume of displaced water).

So the condition for equilibrium between these forces is:

*_0_*gV = gV, or  = *_0_*.

To be neutrally buoyant in water, you need to have the same density as water. Objects with higher density will sink, and objects with lower density will float. And we call the vertical pressure difference force on a submerged object the buoyancy force, and its equal to the weight of the liquid displaced by the solid object. This is Archimedes law.


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

[User] ELI5: What a conductor does in front of an orchestra. How does it work?

[Assistant]
**without the conductor**

string "fuck percussion instruments people"

brass "fuck woodwind people"

woodwind "fuck brass people"

percussion instruments "fuck string people"

**with the conductor**

string "fuck conductor"

brass "fuck conductor"

woodwind "fuck conductor"

percussion instruments "fuck conductor"


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

[User] [Warcraft] Is there a hell? Where do people go when they die?

[Assistant]
Yes. People go to the Shadowlands when they die, and there's a place called Torghast which serves as a prison for evil beings.

We'll be invading the afterlife and likely pillaging it to the ground in the coming years.


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

[User] [Harry Potter and the Goblet of Fire] Why must Harry compete in the Triwizard tournament at all? Even though his name came out of the Goblet, no one is putting a gun to his head forcing him to do these challenges. Why go through with the events at all?

[Assistant] Actually they did have a sort of magical gun to his head. In the books, its stated that the students whose names come out of the Goblet are magically bound to compete. Thats why it was a big responsibility to enter. If you were chosen, you were bound to see it through. That was how (fake) Moody ensures that he would be in the competition, because he was the only one submitted for a fourth school, and everyone whose name was selected would be bound to compete.


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

[User] ELI5:I've seen crabs living under water and also living out of water in the sand on the beach .How can they breath in both environments?

[Assistant] "Crabs" is a huge category with many species.  Aquatic crabs live permanently in water and have gills like fish.  They can go out of water but only for short periods, but then again so can some fish.  There are also terrestrial crabs that have lungs and live on land.  These guys can swim around and actually hold a bubble of air in front of their face, but again they can only go under for a short time.  Intertidal crabs have gills, and then also have cuticles on their legs that help them breathe on land.  They have to stay moist though and can't live away from water, but they can breathe in air or water fairly well.


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

[User] [Doctor Who] "If something can be remembered it can be brought back" Why doesn't The Doctor just ask Amy think really hard about dead friends of his like Romana or Face of Boe?

[Assistant]
Because *Amy* can't remember them, having never met them. "Being told about them" doesn't count as "remembering."

And as for why it has to be Amy, not the Doctor, doing the remembering, which of them slept next to a crack in the universe for their entire childhood?


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

[User]
The United States would have been better off if the Civil War resulted in two different countries in the North and South. CMV.

As we have seen today, there are competing ideologies in the United States which has resulted in a federal government which can't seem to get anything done as a result of the conservative and liberal ideologies clashing with each other (I understand it is much more complicated than this, but I am speaking in general terms for the sake of argument). If the Civil War had resulted in two separate countries being created, it would have resulted in a more liberal country and a more conservative country, each being able to accomplish more with there being less disagreements within Congress. With the United States having grown to the size that it is today, having it be split into two different countries at the time of the Civil War would prevent the types of gridlock we see within our federal government today based on the competing ideologies that are seen in the north and the south. Please reddit, CMV.

[Assistant]
First off, this sort of gridlock is relatively new. Sure, the historic "South" tends to disagree with more liberal areas but the gridlock we see today is less than 8 years old. From a historic perspective, the liberals and conservatives are usually able to work things out.

Even if they weren't, though, just having two countries wouldn't fix that. You would just have two countries in which the liberals and conservatives disagreed. Maybe one country would lean more liberal in general, but the extreme liberals would still fight with the leaning conservatives. Hippies and rednecks are not strictly divided by the Mason Dixon Line.

Finally, if the US had become two separate countries in the 1800s, both would have had terrible economies. Two countries that just finished an exceedingly bloody war wouldn't want to trade with each other. This would leave the north without cotton and many other agricultural products. It would leave the south without machinery and therefore in even greater need of slave labor. Both countries would flounder and likely wouldn't reach the point we are at today in terms of economic and technological progress.


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

[User]
ELI5: Why do places like Costco and Walmart mark your receipt at the door before to leave?

Always confused me, and I don't see a logical purpose behind it.

[Assistant] Guessing, but it's to make sure you can't come back in, collect the same goods as are on your receipt and leave with them a second time. If you try to leave with goods and a marked receipt, they know you're trying to steal them.


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

[User]
ELI5: why do things like metal and water feel
cooler than the room temperature when all
other things are at same temperature as well?

[Assistant] What you feel isn't temperature, but *heat transfer*. Metal and water transfer heat better than, say, wood, so they feel colder at the same temperature. (Below your body temperature, at least; above, metal and water feel *hotter* than wood at the same temperature.)


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

[User]
Why is yellow the lightest color? Is there something physically light about it, or does it just stem from our definition of "yellow"?

I think you know what I mean. If you write in yellow marker, it's impossible to read, and if you color over it with another color, it gets bulldozed.

Does this have to do with the way light works at that frequency or something? Or is it just that when yellow is as dark as the other colors, we start calling it brown?

[Assistant] I think part of it is going to have to do with just what the word "yellow" means -- in common parlance, it doesn't mean merely a slice of the spectrum. Consider how if you take yellow, and make it darker, people wouldn't consider it yellow any more, they'd want to call it something else, gold, brown, whatever. Part of the definition of the word seems to include having a high "brightness", as you put it.


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

[User]
[Terminator] why doesn't skynet use bio weapons?

In all the scenes I've seen from the movies (I've just re watched the first two) the robots are using pretty traditional guns, rocketry, and some flame throwers. Why doesn't skynet try to cook up some mega flu or just release smallpox into resistance strongholds? And since dogs seem able to detect terminators why doesn't skynet at least make a dog flu to get rid of that threat?

[Assistant]
tl;dr: Skynet never had access to bioweapons.

Before Judgement Day, Skynet wasn't given control over any bioweapons, because they're useless in the fast-paced intercontinental war Skynet is designed for.

After Judgement Day, all the labs that had samples of small pox/super ebola/etc would've self-destructed (Source: The Walking Dead).


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

[User]
Do astronauts have difficulties with swallowing and digestion?

Would weightlessness mean that food and water floats around inside your body, making digestion hard? If so, how is it dealt with?

[Assistant]
The oesophagus has sphincters to help push the food you swallow into your stomach, by contracting the oesophagus at the "end" side of the chunk of food and dilating it in the front while the food progresses in the direction of the stomach. Gravity helps getting the food down but isn't necessary for the swallowing part, as you already have a biological mechanism for it.

I can't say for digestion though.


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

[User] ELI5 How can hackers crack a password through brute force if there's a limit of attempts?

[Assistant] In some cases, a hacker might gain control of the server and be able to execute their own commands directly to the software on the server or obtain a copy of the database storing the hashed passwords.  In either case, the webpage's limitations on password attempts doesn't matter because the hacker may not be using the webpage to check password attempts.