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

[User]
What is the role of men in feminism, white people in anti-racism and cishets in pro-LGBTQ movements? More generally, what is the place of someone who finds themselves outside a movement and privileged by what it fights?

Where is the line between being an ally and taking over as the voice of a movement when you yourself are someone whose voice is normally heard? It makes no sense for it to say "men should take center stage in feminism because their voices are heard" since this merely reinforces the inequality which is sought to be dissolved. Still, men can't exactly be excluded from feminism in the sense that the movement must converse and dialogue with them, precisely in order for them to change. So what exactly should be the relationship between a resisting minority and their oppressors?

[Assistant]
Check out Alice Jardine and Paul Smith's anthology Men in Feminism; Frank Wilderson III also talks about this issue in Afropessimism (surprisingly, he is not very optimistic about white anti-racism)

On a more practical note, these movements are very broad, and each group or even individual will have a different opinion. If you are thinking about getting involved in a movement, just contact an organizer and ask how you can help. They might say there is no way; they might ask you to take a back seat role, they might ask for financial support. There are a million ways to help; just follow the lead of the people who are affected.


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

[User]
Is the phrase, a star that shines twice as bright but half as long a true statement?

What controls the brightness of a star?

[Assistant]
It turns out to be *almost* true!

For stars in the main sequence, the bigger you are, the brighter you are. The brightness all comes from nuclear reactions, and how the reaction rate for nuclear fusion goes up really strongly as you increase the temperature and pressure. A more massive star has a much hotter and high-pressure core, so it burns a lot brighter.

This is actually part of why hydrogen bombs are so destructive. A hydrogen bomb is actually a double nuclear bomb. It contains a fission bomb and a fusion bomb. The fission bomb is used to reach the temperatures required for nuclear fusion, but it also helps to keep the fusion explosion contained briefly, and this little extra moment of high-pressure reactions ends up adding a huge amount to the energy output of the bomb.

It's a strong enough effect that even though a more massive star has more "fuel" to burn up, it's burning up its fuel at a much faster rate, and ends up using up its fuel source much more quickly, so it runs out of fuel and goes into its final stages of life much earlier.

So more massive stars are brighter, and don't live as long. But does it work out exactly that a star that's twice as bright lives half as long? It turns out this is not quite the case, though it's not far off. Going through the maths, a star that's twice as bright might live about 60% as long.

What happens here is that a star that's twice as bright is using its fuel at about twice the speed. But to be twice as bright, it also needs to be more massive to produce more energy. This means that it lives longer than half as long, because it has some extra fuel to burn. However, the brightness depends very steeply on the mass, so it only needs to be a little bit more massive to produce that much brightness. So it comes out that a star that's twice as bright will burn for only a little bit more than half as long.


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

[User] Do we know what early homo sapiens and neanderthals did with people who broke bones? What would happen if a person broke their leg? Would they die? Would someone kill them? Would they be abandoned?

[Assistant]
I watched a documentary once on an excavation of a Neanderthal cave, and one of the skeletons was of an older individual with a crippled arm. It wasn't totally useless, he'd still have been able to carry things. But he wouldn't have been much of a hunter.

It was an old injury, probably one he'd had for decades, but he survived and the scientists studying it attributed it to the group supporting him.


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

[User]
With nothing but hydrogen and oxygen, how come water isn't flammable?

It sounds like the ingredients of a bomb!

[Assistant]
For the same reason CO2 isn't, and the same reason an anvil on the ground can't fall on your head.  Water is what you get when hydrogen is burnt.  It's already ashes.  You can't burn ashes.

Scientifically: Water is at a very low energy state.  For a chemical reaction to release energy, it has to move from a high energy to a low energy state.  Many explosive compounds have lots of nitrogens hanging off at unhappy angles.  Nitrogen likes to form a sturdy triple bond with itself, so when its hanging off a chemical its like stretching a rubber band- a lot of energy is stored.  When the nitrogen is liberated, it snaps together with another nitrogen atom and all the energy gets turned into velocity and jiggling, aka pressure and heat.


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

[User] Why does heat cause visible waves through the air?

[Assistant] Warm air is less dense than cold air.  And different temperature masses of air have different indices (the plural of index) of refraction--they bend light by different amounts. So the air above a hot object is less dense, is rising because it is more buoyant, and bends light differently.  Naturally, light that must pass through that air to reach your eye will be distorted.


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

[User]
ELI5:Many sharks and other large fish have been kept in captivity for long periods of time but why has this not succeeded with Great White Sharks?

*thanks for all the responses! I believe I can wrap my brain around it better now.

[Assistant] Coming from an aquarist who works with sharks- Great White Sharks are what are called ram ventilators. This means they constantly have to keep swimming to keep water passing over their gills. Sharks have what is called a glide pattern- they have a burst of swimming, then having a gliding portion. When kept in human care, sharks need many things, including a certain shaped tank to allow for this glide pattern. If they do not have enough space or the habitat is the wrong shape, they cannot fully use their glide pattern to the greatest efficiency. If they have to cut their glide short, they use more calories swimming, and this imbalance makes them very hard to keep. Great whites have a huge special need for their glide pattern, so they are very hard to keep in human care. No one has ever kept an adult great white, but Monterey bay aquarium will collect and hold juvenile great white sharks for a few months before releasing them back. They never keep them longer than 6 months and there are a lot of rules about when  they can have them.


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

[User]
ELI5: Why don't soda crackers absorb mineral oil and why should I care?

My mom hosted a skin care and make up party last weekend. I came by after the party and saw a couple of Saltines (soda crackers) floating in liquid. I asked her about them and she said it was demonstration that the product rep had done.

Apparently, if you put a Saltine in a bowl of water it become soggy very quickly. If you put a saltine in baby oil (mineral oil) even after a few hours (she claimed forever) the Saltine does not get soggy. I thought that was pretty interesting and I was wondering why that it.

But it also brings up the second part of the question. The point of the demo was that this company didn't use mineral oil in their products. Because if it doesn't make a Saltine craker soggy, it's not good for you skin? I wasn't there to ask the rep why that made mineral oil bad but I was wondering if someone could fill me in on that. Thanks.

[Assistant] first of all, that demonstration sounds like its designed to deceive people into somehow thinking that what a cracker absorbs or does not absorb has any bearing on how healthy it is for human skin. Second, oils are non-polar molecules, water is a polar molecule, and food is organic (life loves water) The cracker absorbs water because of chemistry, nothing else. The cracker absorbs water because organic material and water have a lot of chemicals that play nice together, organic material does not contain a lot of non-polar molecules and reacts with oils to a much lesser extent.


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

[User]
The disproportionate success of Asians proves that racism is not what is keeping Hispanics and African-Americans back. CMV.

I work in finance and meet some very successful and well-paid people in  many fields. They are mostly white and Asian. The success of Asians in America, whether Asian-American or Asian immigrant, is a statistical fact. This suggests that the reason for persistent poverty in other minority cultures is not a result of white racism against minorities.

On top of working in finance, I live in a ghetto part of NYC (this is not unusual--gentrification and high population density mean multi-million dollar condos are across the street from the projects). I see a distorted value system amongst my neighbors: expensive sneakers, a lot of hanging out, talk about drugs. Little talk about SATs or getting A's. Again, this does not seem a direct result of white racism or oppression, and the more I am exposed to this ghetto culture the less sympathy I have towards both the poor and minorities claiming they are being held back by oppression.

So, yeah. CMV?

[Assistant]
The stereotypes of asians and those of blacks and hispanics are very different in the US.

Black people are stereotyped as lazy, athletic and stupid. As rappers, sports stars and gangsters.

Hispanics are stereotyped as unreliable, dishonest and cheap. As fast-food workers and illegal immigrants.

Asians are stereotyped as hardworking, nerdy and weak. As doctors, scientists and mathematicians.

The fact that asians achieve success doesn't show that racism isn't having an impact. The impact on asians is going to be very different from the impact on blacks and hispanics, due to the very different form of racism involved.


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

[User] [General] If someone with lycanthropy was in a coma, would they still turn into a werewolf at full moon?

[Assistant]
It's typically an involuntary reaction, so yes.

An exception might include those situations when the person transforms only when they happen to notice that the moon has come out from behind some clouds.  Those situations seem to require not only direct moonlight but also, possibly, the person actually seeing the moon.


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

[User] ELI5: Why does the wind whistle and howl when it's cold, but not when it's warm?

[Assistant]
Two part answer:

1.  The wind does whistle and howl when it's warm also.  Go to a sailing club on a windy enough day, warm or cold, and you'll hear the whistling and howling in the masts and wire rigging.

2. Cold air is more dense (heavy), so you get the whistling effect at a lower speed.  You might not hear the whistle until it's blowing 30 MPH if it's warm, while you may get it at only 20 MPH when it's cold.  Those aren't exact speeds, but reasonable examples.

As a sailor, the same temperature effect also applies.  A 20 MPH wind in the summertime is much easier to handle than a 20 MPH wind in the wintertime.  The same wind speed is hitting the sails, but the lower temperature literally makes the wind "heavy" and more powerful. There are more gas molecules per square inch per second.


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

[User] [Superman] Can Superman get cavities while on Earth?

[Assistant] Probably not.  1) if bullets don't hurt him, sugar and bacteria probably won't.  2) bacteria that cause tooth decay might not recognize Kryptonian anatomy.  3) Superman eats an extremely healthy diet (I'd imagine).


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

[User] [SuperPowers] How do people with Matter Manipulation are not considered op and don't just win every fight ?

[Assistant]
Take Wanda Maximoff as an example. She's incredibly powerful and in a straight 1v1 she's pretty much unbeatable. She would have killed Thanos in Endgame with no effort if he hadn't ordered his ship to open fire, and in Civil War, when she was holding up that falling building, Rhodey broke her concentration with a sonic blast.

So people with those kinds of powers are indeed very powerful but a lot of times they're glass cannons. Catch them by surprise and it doesn't take a whole lot to incapacitate them. You can also break their concentration and it'll temporarily stop whatever they're doing.


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

[User] ELI5: Why dont orcas (killer whales) see humans as food and attack swimmers/paddleboarders/ kayaks etc? Humans are the same size as most of their prey but them seem to mostly ignore us?

[Assistant] From what i understand about killer whales is that individual pods tend to have specific diets and hunting tactics passed down through the generations. Since humans are not consistently in killer whales hunting areas they wouldnt have developed a "taste" for humans or the tactics to hunt them. Thats obviously not to say they couldnt, they just have no reason to.


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

[User] ELI5: How come minors have to pay taxes in the US? Since they can't vote, shouldn't they be tax exempt regardless of their income?

[Assistant] If minors were exempted from paying taxes, this would create a huge loophole in the tax code. Parents would put all of their securities in their children's names, so that they never had to pay taxes on the interest and dividends. Note that to a small extent, people actually do do this, but the tax code addresses it and has removed some of the tax advantages. Regardless of this loophole, people who are prohibited from voting still have to pay taxes--"no taxation without representation" is more of an ideological or cultural belief and is irrelevant for legal purposes.


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

[User] ELI5: How do the federal banks of a country determine whether to increase or decrease interest rates? Like whats the relationship between interest rates and a country's economy?

[Assistant]
Low interest rates make loans easier and stimulate investment.

High interest rates make loans more difficult and discourage investment.

Central banks use interest rates as a tool to try to increase economic growth or decrease it.  Usually what they do is they watch the economy and they lower interest rates when unemployment is the most serious concern.  When inflation is the largest concern, they will raise interest rates to try to keep prices in check.  They try to make all changes slowly and they try to telegraph every move so that nobody is surprised or shocked.


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

[User]
Which thinker speaks about the fact that humans have to decipher themselves instead of merely know themselves?

Psychoanalysis has taught us that we have deeper levels of character that unconsciously motivate us to act. We have repressed traumas that shape the way we behave. We have instincts that spark without the knowledge, will or consent of the self.  We need to go on self-exploration in order to understand the way that our feelings, behaviour and thoughts systems work. The knowledge is not just there in our mind, accessible for us to touch.

It seems that we cannot access the knowledge of ourselves with certainty. We are guessing and second guessing the sources of our feelings and motivations, and constantly building a self-knowledge hub with probable explanations of our behaviours and feelings, a hub that helps us to understand why we feel the way we feel.

Which thinker speaks about that? In the sense that the self (as in the cogito) is detached not just from the Cartesian body, but also from its instincts, unconscious parts and any type of motivation or behaviour which are not clearly chosen and understandable by the cogito itself, where this whole mental structure is alien to us as the outer world itself?

[Assistant] I think Nietzsche was one of, if not the first to recognize this in opposition to the Catesian view. He says it explicitly in the "Genealogy of Morals" in which he says "we are unknown to ourselves, we knowers" as the first line of the book.


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

[User]
[Harry Potter (Books)] Why does Harry et al believe that the Elder Wand's power will be broken?

A good chunk of *Deathly Hallows* is spent establishing the fact that the Elder Wand's loyalty doesn't require the death of the previous owner, but rather only that the previous owner is beaten (presumably through magical means, though there's indications that non-magical means works too). We see this in action when the Wand changes allegiance from Draco to Harry after Harry disarms Draco at Malfoy Manor.

At the end of the book Harry announces that he does not want the Elder Wand. He uses it to repair his original Holly Wand, then has this to say to Dumbledore's portrait:

>"I'm putting the Elder Wand back where it came from. It can stay there. If I die a natural death like Ignotus, its power will be broken, won't it? The previous master will never have been defeated. That'll be the end of it."

Why would Harry think this, and why wouldn't anyone else  human or portrait  speak up?

Harry would have been 17 years old during the Battle of Hogwarts so by normal estimations he's probably got another 60-70 years of life ahead of him. Virtually since birth he's been fighting enemies, magical and muggle alike, and he hasn't always won those battles. He's also firmly dedicated to being an Auror and knows what the threats and mortality rate is there. But he also knows that he only needs to be defeated *once*, and not even fatally, for the Elder Wand to change its allegiance. Does Harry, Ron, Hermione, and Dumbledore all so firmly believe that over the next 60-70 years not a single opponent of Harry's will manage to disarm him even once?

The best argument that I've heard for this is, "Well, whoever disarms Harry won't know that the Elder Wand's allegiance will have changed to him, so that person would never benefit from the Elder Wand anyway." Which IMO is crap.

First, the question isn't whether or not someone takes possession of the wand. The question is whether or not the wand's power would be broken by Harry's natural death. As far as I can tell, it won't. Harry could be disarmed next week, then the person who disarmed him could in turn be disarmed a month later, and so forth and so on. Even if there were 100 disarmings, the wand's power is still there waiting for the new owner to take possession. Its power is NOT broken, even if Harry dies a natural death somewhere in there.

Second, more importantly, the odds of someone NOT knowing about Harry's possession of the Elder Wand is nearly nil. During the final battle with Voldemort the Great Hall was filled with people, all of whom heard Harry's explanation as to how the Elder Wand's allegiance was Harry's, and all of whom saw Harry take physical possession of the wand afterwards. We're talking *hundreds* of people here, and *none* of them are going to say a single word to anyone about Harry and the Elder Wand? Impossible. It'll be the biggest magical news story ever, and people who want the wand will be coming after Harry in spades. Sure, many of them will be intimidated by Harry's perceived power, but some won't. And inevitably over the years the story will be told and more people will be made aware of it, and more people will try to defeat Harry. Is Harry going to defeat them *all* for the rest of his life?

And third, another argument I've heard is that Harry won't be carry around the Elder Wand so even if he's defeated the person won't know where the wand is. That assumes everyone in the Potterverse has the IQ of baking soda. The wizarding world has always known the tight connection between Harry and Dumbledore. Following the Battle of Hogwarts, the wizarding world will also *know* that Dumbledore had it, will *know* that Voldemort was using it, will *know* that Harry had the wand in his hand once Voldemort was killed, and will almost certainly *know* that Harry never left Hogwarts with the Elder Wand. I guess the typical wizard reaction would be something like, "Hmmm, Harry took the wand from Voldemort, who had in turn taken the wand from Dumbledore's grave. Harry never took the wand out of Hogwarts. Dumbledore is buried in Hogwarts. Harry really loved Dumbledore and vice-versa. Well, I guess it's impossible to figure out what Harry did with the Elder Wand!"

So, there it is: Why does Harry and the rest of them believe that the Elder Wand's power will be broken if Harry dies a natural death?

[Assistant]
The Elder Wand is to wizards what Excalibur is to muggles. If you're hearing secondhand that You Know Who had the special super wand, you're probably not going to believe it.

Add to that the fact that the wand isn't in Harry's possession. It'll get really confusing really fast who the true master of it is.

Harry goes on to be an auror. If he's disarmed by a criminal type who gets away in like his first week, then that guy is caught by a different auror sometime down the road...Well, by the time Harry is old enough to die of old age, the nature of who the wand's master is all be nearly impossible to figure out without breaking open Dumbledore's tomb.


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

[User]
When you break a bone, which part hurts?

Is it the actual bone that hurts? Or is the bone poking into nerves? Or something else?

[Assistant] The periosteum (very thin layer that sits on top of the bone) is rich in nerve fibers that sense pain. When you fracture a bone, it's these fibers that get activated and give you the sensation of pain.


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

[User]
[Dragonball Z] What is the difference between any beam-type energy attack?

Besides aesthetics, what is the difference between attacks like Kamehameha, Galick Gun, Final Flash, Masenko, generic 1-handed beam attack, or really any other beam attack ever. From the looks of it, the power of these attacks depend entirely on the user's power, and aside from that there is no other noticeable differences between them. If Vegeta were to learn the Kamehameha how would he use this in a fight any differently than his Galick Gun or Final Flash?

[Assistant]
Ki attacks often represent the talents and goals of their creators, as they found a way to bend the energy so that it suited their talents best.

Your basic ki attack is nothing more than concentrating enough to turn your energy into an actual physical effect that can be thrown or channeled (a small beam).  Any channeled beam has the benefit of being able to continuously pump energy into it, to overcome anything the wave hits.  At low power levels, its a significant task to do this, which makes the rapid energy assaults of Nappa and such impressive (at that point).  Once you learn to control a significant amount of ki, transforming some into a sphere of energy to blast becomes a trivial effort.

The Kamehameha, Master Roshi's ultimate technique, shows his favor towards both patience and hiding his true power, by starting with a fairly low energy signature that rapidly grows as you concentrate on the  opening sphere (what forms between the user's hands) before you create a wave out of it.  As demonstrated by the exploits of Goku, Gohan, et al later on, the user's power acts as a direct multiplier of how fast energy can be gathered into it.  It also allows the user to hold back when necessary, showing the restraint necessary to use your power for good - or not hold back, such as when Cell attempted to destroy the earth with a Kamehameha wave.

Techniques such as the Galick Gun and Final Flash open with a strong burst of power that requires minimal concentration time, Vegeta's specialty.  The channeling lets him continue to add power as described above, making the move incredibly potent.

Masenko seems to be a special case.  Piccolo invented it, most likely as a way to challenge the Kamehameha in power without the focus time required.  However, it seems to lack the raw potency of its competitor, something Piccolo obviously learned as he would develop the Special Beam Cannon, which required more concentration time then any other beam attack in Dragonball, but gave it power and speed to make up for it.

Gohan used the Masenko after his training with Piccolo, most likely because its near instant prep time would be valuable to an inexperienced fighter (and Piccolo probably considered this when teaching Gohan techniques).  He rarely used it later, as he gained more fighting experience as well as mastered the Kamehameha, an overall superior technique.

Other beams vary in size and shape because of their purpose.  Freeza's "Finger beams", which seem to pierce even the most talented warriors (until Goku shows up), seem to be a more focused version of the Special Beam Cannon, with their incredibly fast travel speed and piercing power.


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

[User]
If printing money is bad shouldn't leaving it deep in a multibillionaire's bank account where it will never be used be just as good as unprinting it?

Could making the rich richer reduce inflation?

[Assistant]
Kinda sorta if you squint a lot.

In reality, your money is still an asset to the bank they can use. The money is never really "out of the system" entirely unless you take actual bank notes and stash them away.

Also, it's just kind of nonsensical policy. You hand people money on the pinky promise they won't use it while also making them richer but "not really" because they can't use it? What's the point of such an exercise?


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

[User]
CMV: If your child injures my child due to reckless behavior that went uncorrected because you, the parent or guardian, were sitting far away and not paying attention, you are responsible for any damage done, especially any serious injuries.

I've got a 2 year old daughter and we've been to all sorts of parks. I also have a 6 month old, so sometimes I can't be directly next to her on the equipment, but I'm always near. I've seen many many unattended children and the bigger the child the easier to accidentally or purposefully move smaller children. We haven't had any serious injuries or falls, our worst fall was caused by herself anyway, but if a child whose gaurdian wasn't paying attention caused her to fall and break her arm or something, I feel that the adult would be wholly responsible. Children don't have fully formed brains or impulse control, that's why they need us there to tell them safety rules. If on the other hand the other gaurdian was actively there and trying to curb dangerous behaviour and an accident occured, I wouldn't blame anyone.

[Assistant]
This can just be extended back at you. If you were near your child, you should be able to stop anything before it blows up or at least mitigate any damage.

If you couldn't stop it, than there is no reason to believe if the instigator's parent would have either.

If you are always able to stop it, then clearly injury would only happen when there are 2 absent parents.

There is of course the question of *when* a child stops needing a parent guardian. Should one not give a 10 year old some room, as they need to develop independence? Should the parent still be liable?


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

[User]
ELI5: How ancient sailors could navigate to a specific port?

How sailor going from Venice to Athens in the ancient time knew to navigate EXCTALY to the port location?

I can understand general direction by stars or even a compass but to navigate to a very specific location is other problem as I see it.

I did some foot navigation and to get to a specific point of very different then a general direction and you can't use just general direction. If you miss your journey even in 0.5 degree you will get in totally other coast and not to the port you aimed for.

It will be even a bigger problem on the ocean travels. The Portuguese ships going to South America. How the know to land exactly at the port of Mexico or other places.

[Assistant]
Venice to Athens is pretty easy since they would've had the shore in view all the time. They had maps and many landmarks to figure out their position.

For ocean travels, you only need to be accurate enough to hit the correct continent and then continue along the shore to your destination.


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

[User] ELI5: how do they know there are no matching finger prints?

[Assistant]
They arent completely unique, mathematically speaking. Testing for prints is based on probability.

The odds of someone having the same fingerprints as you that lives in the same area as you is incredibly, *incredibly* small.

Fingerprint matching is used to reduce the likelihood of the prints belonging to someone other than the suspect.

It works similarly to testing blood at a crime scene. It isn't to prove with  100% certainty that it's the suspect's blood. It's used to rule out the 99% of every other possible suspect.


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

[User]
[Animorphs] How do you develop computers BEFORE you develop books?

This is one thing that I don't understand about Andalites. How on earth can they have made a computer before they invented simple books? How can they view a book as less advanced than a computer?

[Assistant] It comes up reasonably often in the books that Ax is actually kind of stupid in comparison to most Andalites.  The things he says, particularly about history, should be taken with a grain of salt.  That said, here is a plausible explanation: Trees, while not exactly sacred, are treated with a great deal more respect on the Andalite home world.  Likewise, thought-speech is really good at conveying information and Andalites have good memories.  It's entirely plausible that ancient Andalites revered trees enough to skip from parchment (from animal hide) scrolls to computers skipping over paper books, and not developing them until after spaceflight gave them access to non special trees.


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

[User]
ELI5:  Why are fundamental Christians, who are otherwise so opposed to other religions/beliefs, generally so pro-Israel?

They do know that Jews aren't Christian, right?

[Assistant] One of the prophecies mentioned in the bible is the coming of the messiah.  The basic concept of a messiah is someone who will come along and make the world perfect, ending things like war, poverty, hunger, etc.  Christians believe that this messiah will occur as the return of Jesus, although Jews do not believe that Jesus counts as the messiah.  Regardless, if this prophecy is correct, then the coming of the messiah would be a really good thing, so Christians want it to occur as soon as possible.  One of the biblical descriptions of the coming of the messiah is that the Jews will be returned to their holy land.  Therefore, a fundamentalist Christian would reason that in order for the messiah to come back, the Jews must live in modern-day Israel.


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

[User] ELI5: Why do the air from air conditioners smell different when you turn it to fan mode?

[Assistant]
Humidity.

Ever wonder why farts stink so bad in the shower? Humidity.

Air conditioners take humidity out of the air, so you can't smell the scents in the air as well. When you switch to fan mode, no humidity is lost, so you can smell all of those scents.


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

[User] Why can insects survive so long after receiving wounds that would instantly kill a human or other animal?

[Assistant]
You're talking about cases when an insect loses its head and such, aren't you?

Their nervous system isn't like ours, to begin with.

The human nervous system consists of two main parts, thecentral nervous system (CNS) and theperipheral nervous system (PNS). The CNS contains thebrainandspinal cord. The PNS consists mainly ofnerves, which are long fibers that connect the CNS to every other part of the body.

That said, our nervous system is very concentrated in one place. Any damage to it can be pretty much fatal or develop some bloody sequels, to say the least.

That doesn't quite happen to insects. Their nervous system is simple, but much more sectioned. That means it doesn't lose too much when a limb or any other part goes off.

The basic insect nervous system bauplan consists of a series of body segments, each equipped with a pair of connected
ganglia, with a paired nerve cord connecting adjacent ganglia in each segment. The ganglia are bulbous structures
consisting of neuron cell-bodies and supporting or glial cells and acts as a local processor or computer. The ganglia are
interconnected by neurons, constituing a 'computer network'.

That can be cool and all (or creepy), but remember that, even if it survives the loss of it's head, per example, it still needs energy and water. Those are those are satiated from feeding; but if the insect doesn't have it's feeding apparatus anymore, it will eventually die by hunger and complete dehydration.


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

[User] [DC] Bruce Wayne is an identical twin, both surviving witnessing the death of their parents. How does growing up with an identical sibling who shared the same experience and trauma impact the timeline?

[Assistant]
The way the DC universe operates?

Bruce still has all the baggage and trauma from that night, and in any ordinary circumstance having a sibling at all might help them work through the trauma together.  But his twin, Bryce?  He reacts entirely differently.  Bryce wants to help, but Bruce is entirely withdrawn, responding to nothing but his rage.  Bryce does everything he can to cheer up his brother to no avail, pulling out all the stops.  Harmless pranks.  Funny faces.  Jokes.

One otherwise ordinary day, after years of trying to reach out to Bruce - and in turn, calling out for his own help and support - Bryce starts laughing.

He doesnt stop.


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

[User]
[Doctor Who] What is it with the Doctor's obsession with humanity?

Why does the Doctor's adventures/travels revolve around humans and Earth so much? What makes humankind so special?

[Assistant]
The Doctor waxes poetic about humanity quite a bit, so he definitely personally considers them at least one of the most interesting species and actively wants to be around them. Two things also stand out about them:

1. Humans have more capacity for compassion, creativity, bravery, etc. than almost any other alien race shown, all qualities The Doctor frequently praises them for and often refers to as distinctly human. Even the 'good' aliens tend to be very one-note or severely lacking in some capacity.

2. Humans are the ultimate survivors. At the end of the universe, the populace will be almost entirely humans and mutant offspring. The Doctor will always be able to live among humans and seek their companionship at all but the most distant points in time.


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

[User]
Is there a limit to how small a nuclear explosion can be?

After doing some research, I found out that the "Tzar" bomb is the most powerful thermonuclear weapon with a yield of 50 megatons of TNT. Anything within 20-30 km from the epicenter of where the bomb is dropped will be destroyed. Would it be possible to make a nuclear weapon that would only explode to become the size of a football field or smaller?

[Assistant]
Hi, nuclear engineer here.  In answer to your question, no there is no limit to how small a nuclear weapon can be.

It is true that you need a critical mass to START a reaction, but nothing dictates how long that reaction must go on.  Remove the tampers that hold the thing together so it blows apart faster (and cuts off the reaction sooner), change the geometry of the critical mass so that it falls out of a critical configuration sooner, etc etc etc.

A downside, of course, to reducing the yield is that reliability might decrease as well, and at the very extreme, your bomb might become very unpredictable.  Maybe at the football field buster size, your bomb might suffer from the problem that maybe it destroys half a football field, maybe it destroys two.  But there are few limits to reducing the average yield of the bomb.


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

[User] Eli5: There are several non filtered tobacco smoking options such as cigars, pipies, etc. Why do cigarettes have filters when they don't actually "filter" anything?

[Assistant] Filters do filter out a part of the smoke compounds. A lot of bad compounds pass through though. So smoking with a filter is still bad. The main reason for the filter is that smoking with a filter feels milder on the throat. Moreover, it is less messy, as they prevent pieces of tobacco from entering the mouth. Yuck.


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

[User]
[DC] So, Superman is apparently super duper smart. Is that because of the sun, or are Kryptonians just naturally smart?

So, I've heard that Superman has superhuman intelligence as well as super strength and speed. I've heard someone call that dumb that he'd have super intelligence because he lives by a yellow sun, but since he's an alien, I'd just assume that he's smart because he's a Kryptonian. Like, Kryptonians just have a powerful mind regardless of what sun they're under, or does the yellow sun make him smarter, like how it makes him stronger, faster, and makes him fly?

[Assistant] A little bit of both. He has sun crystals in his Fortress that can act as artificial intelligence tutors. His dad was a world-renowned scientist, so the intelligence could be genetic. The yellow sun boosts his perception and his mental capacity, allowing him to read, react, and think faster.


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

[User]
ELI5: If the Boiling point of Water is 100 degrees Why does a Kettle boil at 60 degrees?

**I did Google This don't worry, I just could not find an Answer**

I cant for the Life of me work this out. and my Facebook friends are all like;
"How do you know it's boiling at 60c"

Well Our Kettle has Settings from 60-100 Degrees Celsius (Australian)
The water is all bubbling like It's boiling at 60c then Shuts off.

At 100c It's steaming.

So does the Boiling Point of Water Means Steam is Produced?
Why does the kettle bubble the water at 60c?

Can someone Please Explain this Like I'm Five :)

**EDIT: Okay Thank you everyone for your Feedback As i can tell so far I'm Australian Not German So thank you for that.

***EDIT: AS i have gathered from your Knowledge and that of Google (now i know what to Google) That Bubbling is From the Element's Temperature Boiling the water that is touching it and Causing it to rise to the Top giving it the Appearance of Boiling. In which that bit of Water has, But the Overall Content of the Kettle is not Actually Boiling until the Total amount has Reached 100c.

This has Been Absolutely Fascinating. *YAY FOR EDUCATION*

[Assistant] Are you talking about an electric kettle? Water boils at 100C at standard pressure, *no exceptions*! However, the water temperature in the kettle is not even. Around the heating elements, the water rapidly reaches 100C, even if the water in the rest of the kettle is cooler.


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

[User]
[Marvel] Would a thread of Adamantium have the exact same effectiveness at holding up, say, a one tonne block as an Adamantium cable does?

I only ask this because Adamantium is pretty much indestructible barring reality warping and other higher powers.

Edit: I think I wasn't clear enough: The block is being hung from a crane by the thread/cable.

[Assistant]
Follow up questions:

Can adamantium break? If not, how can a thread be weaker than a pillar?

Can adamantium bend, but still return to its original state (like a spring)

Can adamantium deform (be dented like play dough)?

How thin can adamantium be?


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

[User]
[Alien Universe] How many species has humanity found in the universe?

Was the discovery of the xenomorph/space jockey our first contact? How many species are there in the Galaxy?

[Assistant]
Arcturians are apparently a humanoid and sentient species, and apparently they were our first contact according to some extended universe stuff.   The marines refer to a "bug hunt" as well, so presumably we've encountered several non-sentient aliens as well.

No telling how many other races though.  Just that Space Jockeys and Xenos aren't the first.


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

[User] ELI5: How does my body know if I'm 'being watched'

[Assistant]
It doesn't.

There have been lots of studies on this, and - in all of them - the results show that people actually *don't* know they're being watched at all. They only get it right about 50% of the time: exactly what random chance predicts.

The "feeling" you get, though, can partially be explained in an evolutionary sense. We humans only have eyes on the *front* of our head, which means we always have a 'weak spot' behind us. It makes sense for us to be nervous about that area, since predators could be lurking there. Even if it turns out to be a false-alarm, it's still an evolutionary advantage to double-check, so it would be considered beneficial.

Interestingly, the act of 'checking behind you', often *makes* people look at you (because they've detected an odd head/body movement). When you make eye-contact, you then interpret this as meaning "Aha! You *were* watching me!" and it becomes a form of confirmation bias.


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

[User]
[Star Wars] Why did Luke use a green lightsaber rather than a blue one?

From what I understand, a blue lightsaber means that you view the force as a tool to accomplish tasksthat you prefer to use the force on a physical level. A green lightsaber, however, means that you view the force itself as an end goalthat you use it on the spiritual level, and wish to study it purely for the sake of knowledge.

Luke seems more like a blue wielder than green. Hes always been pushy and anxious to use the force to do things, rather than just to study the force. Qui-Gon and Yoda are definitely green wielders, because they are very spiritual with their studies, but Luke only ever learns what he needs to know in order to succeed; he never had much of a thirst for knowledge.

So why did he choose green and not blue?

[Assistant]
Luke didn't know any of that stuff, he was just building a new lightsaber.  The meanings to colors were lost with the Old Republic. Whatever crystal he found to use was apparently green.  He didn't have any higher meaning to it.

He might have chosen green because of traumatic reactions to blue.  He did have quite a time at Cloud City with a blue lightsaber, he found out his father was alive but evil and had his hand cut off.


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

[User]
Moving to another language (from Python/Javascript)

Hi guys,

I am fullstack Engineer (self-taught). I have been working for more than 14 years  in the industry but almost always using Python or Javascript.

I would like to get a job in another language Golang, Java, Clojure or Rust. Lately with Python is really easy to find new jobs but I am kind of tired of doing the same.

Do you think company could value my experience with Python/Javascript and hire me to migrate to one of this other languages?

If you think so, which one you think I should focus more.

I am asking not based on what is going to be easy to learn. I am asking more what Recruiters and Managers could value my experience in Python/Javascript .

[Assistant]
Im baffled by the responses that suggest that kind of transition is unlikely. Languages arent difficult - problem solving is. And after 14 years youve done a lot of that. More difficult is moving domains - from a front end engineer to a distributed systems engineer for example. But even thats not unheard of.

You need to be prepared to work to pickup new tech and if you know what kind of stack you want to move into it would do you good to build some things on the side so you can talk about that space with fluency. But Im a X programmer where X is a stack and not a domain is for consultants and specialists.

Edit: Also worth noting Ive been a hiring manager and wouldnt blink at signing an experienced engineer with 14 years of experience in unrelated languages.


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

[User]
[WH 40K] What are some of the best theories behind the two missing Primarchs?

Bonus, and the other(s) not accounted for?

[Assistant] Some Imperial scholars theorise that one of the Primarchs fell like a twin-tailed comet unto a world hosting a relatively undeveloped barbarian society alongside a sizeable native Ork infestation, a not-insignificant Eldar presence, Chaos taint, some elements of abhuman ratmen and "beast" men, and some kind of bio-organic Necron presence. According to what data we've gleaned, the Primarch was raised by a tribe of barbarians before rising to its chiefdom and further uniting an entire region of tribes. He drove out the regional Ork warboss and Chaos raiders. He left for parts unknown sometime into his reign, and we have yet to rediscover his presence, or whether he was a Primarch at all.


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

[User]
CMV: Repeat customers should be the ones getting discounts, not first time customers.

I know it varies in different industries.  However, I see it more often where first time customers are getting discounts rather than the loyals.  I say, if you have spent a decent amount of money somewhere you should be the one getting a discount, rather than the person who may just be deal shopping and you're risking an opportunity to make more money.
Not only the money making aspect for shop owner, but what about customer service?  Shouldn't the loyal customers get the praise?  We're coming back and giving you MORE money.  Can you kiss the ground I walk on please ?

[Assistant] Those first time customer discounts are often loss leaders. They are a net loss in hopes that the customer will go on to become a profitable one. It is about increasing business, not "rewarding people." Not only that, but there *are* plenty of companies with loyalty programs.


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

[User]
[Star Wars] Could someone with a very low midi-chlorian count become a powerful Jedi Master through training?

Yoda teaches Luke about the force, and it feel like a lot of it has to do with believing and understanding how the force works and less to do with how many midi-chlorians can be found in his blood...

Lets say I have my blood tested and I barely register being force sensitive, but at the same time; from the beginning I fully accepted and devoted myself to the Jedi/Sith teachings.  I believe that I can lift an X-Wing because I am one with the force...

At what point does my midi-chlorian level determine how far I can go with the force?

[Assistant] Most of us believe that the midi-chlorian count is correlation not causation. That the stronger you are in the force, the more midi-chlorians are drawn to you. So while some people are better than others at using the force, and traditionally the Jedi have focused on those people with in-born skills rather than trying to teach people without force sensitivity, it is theoretically possible to train anyone. Just... it'd be incredibly difficult.


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

[User]
ELI5: How is the lethality of a substance determined in an ethical way?

I recently saw a documentary and learned that the most venomous snake on earth (the Inland Taipan) can kill over 100 grown humans with its venom.

How is that figure determined? I know that it is not likely that some scientist tried to try and kill as many people as possible. So how is it done? How do we tell if something is lethal? And how do we tell how many people it can kill?

What about a completely foreign substance? The effects of which on humans is relatively undocumented?

[Assistant]
> How is that figure determined?

Apply carefully measured doses to a series of rats until half of your sample dies. Consult prior research where lethality in rats was compared to more analogous animals such as pigs. From this you determine the LD50, the lethal dose for half of a given population. Then it is just a matter of comparing how much venom the animal typically injects vs the LD50 amount.


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

[User]
CMV: Stablecoins are not a new innovation. They are just banks. Unregulated and unsecured banks.

If I have 10 dollars in a bank account, I do not in fact own 10 dollars. I own 10 IOUs from my bank. I can redeem these IOUs for cash at my local bank, or I can use them for payment directly in a bank transfer and let someone else redeem them.

If the bank goes under, I can rest assured that my deposits are insured by the government up to 250k. I can rest assured that my bank has to comply with extensive legislation (maybe not enough though) and audits.

---

If I have 10 dollars in a stablecoin, I do not in fact own 10 dollars. I own 10 IOUs from the stablecoin issuer. I can *probably* redeem these IOUs for cash through the process set up by the issuer, though they can make it diffcult and slow. I cannot use them in regular bank transfers, though I can use them to pay on blockchains.

If the stablecoin issuer goes under, my deposits are not insured and will be lost. Stablecoin issuers do not undergo proper audits, nor do they comply with banking regulations because they do not consider themselves banks.

---

This is a short comparison of stablecoins to banks, but it gets the point across. The mechanics behind stablecoins are **identical** to the mechanics behind a bank. Crypto enthusiasts and techbros love to tout stablecoins as this new invention, but they aren't a new concept at all. Every single bank is its own stablecoin, just not a blockchain one.

The only innovation here is making a blockchain bank while pretending it isn't a bank to avoid legislation.

[Assistant]
I think that by current internet business definition this is innovation. A lot of current internet innovative and "disruptive" business models are essentially ways to do old things while avoiding regulation.

Uber is essentially just taxi-cabs without the regulation. Taxi firms have apps, where they struggle to compete is in the fact that Uber is good at avoiding being regulated as they are in many countries.

Similarly much of the business on  AirBNB is little more than a letting service that avoids being regulated as a letting service.

This is what internet entrepreneurs often mean by innovative. So in that sense they are just a reinvention of Wildcat banking while also being innovative.


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

[User] ELI5: What's the situation in Libya today after Gaddafi lost his power?

[Assistant]
There are 2 self-proclaimed governments, one in Tripoli (historical capital of Libya, west) and the other in Benghazi (center of the uprising, east). Plus more or less autonomous militias. Plus djihadists. Plus ISIS in Sirte.

It's a complete civil war. But actually Libya can still exports its oil at low price (because each side really need money to wage war), so no one cares.


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

[User] ELI5: How do bouncy balls bounce so high?

[Assistant]
Let us imagine the perfect bouncy ball. A feature of it will be that if you drop it at any height, it will bounce up to about the height your dropped it. It will not bounce any higher than the initial drop unless you put in extra energy somewhere as energy cannot be created or destroyed, it can only be transformed into different types.

Now imagine you take a hackey sack and drop it from the same height. It doesn't bounce up at all.

Now imagine a steel ball and doing the same thing. It bounces up, but not very high.

What is the differences between all these cases? Well, it is energy transfer. When you drop a bouncy ball, it gains kinetic energy during the fall, and when it hits the ground and reverses direction, very little of the kinetic energy is lost. On the other hand with the steel ball, we know that since it is not reaching the same drop height that some of the energy is going somewhere. It usually converts into heat, but there could be something else at play.

Bouncy balls bounce so high because the material they are composed of doesn't easily convert kinetic energy into other types upon bouncing. Other materials don't bounce so high or not at all because they convert a lot of kinetic energy into other types of energy.


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

[User] Eli5. How its possible for the light to travel constantly with out stop slowing down from the most old galaxies?

[Assistant]
Light is special because it has no mass and always travels at, well, the speed of light. This is one of its fundamental properties due to the laws of physics. You cant really compare light to say, a spaceship, because its just not the same thing.

But almost anything can move long distances in space without slowing down. By default, things continue moving at the same speed theyre already moving unless something acts to slow them. On Earth, everything needs to fight air resistance or water resistance or friction with the ground to keep moving. But in space theres nothing to bump into (at least its very rare to hit something) so if you do nothing, you keep moving.


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

[User]
ELI5 Why do batteries work again after heating them up?

Sometimes if a remote or some other small electronic stops working because the battery is dead, I take the battery out and heat it up by putting it in my arm pit. The warmth heats up the battery and give it a little more juice allowing me to use it again for a minute. I also remember doing this with old mobile phones in the early 00s and it would let you turn on a dead phone and use it for a few minutes.

I have no idea how this works and dont remember where I learnt how to do this.

[Assistant]
Youre not necessarily recharging the batteries. But heat makes batteries more efficient/effective. Batteries have a chemical solution inside them that stores electrons. When the temperature of the battery is low, the chemical processes inside the battery is slower meaning the movement of those electrons is also slower. When you warm up a battery, youre able to speed all of that up. When you put the batteries back in the device, that manifests as a minute or two of extra charge. But you havent actually added any more electrons (or at least not enough to be meaningful) to the battery, the electrons just move more efficiently & electricity is just electrons in motion.

Edit: rewrote the last phrase to make it make sense. Sorry for the autocorrect confusion.


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

[User] Is it true that there are as many numbers between zero and one as there are between zero and infinity? A math teacher made this claim and I'm wondering how it could be proven.

[Assistant]
You do this by showing there is a one-to-one mapping between these two sets.

First, we pair every number x between 0 and 1 with 1/x. These 1/x will be between 1 and infinity. So this shows there as many numbers between 0 and 1 as between 1 and infinity.

To get the pairing needed to show what the math teacher said, we instead pair every number x between 0 and 1 with (1/x)-1. So each number between 0 and 1 is paired with a unique number between 0 and infinity, and vice-versa. Thus, there are as many numbers between 0 and 1 as between 0 and infinity.


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

[User]
ELI5: The process and significance of "making partner" in a law firm

How does one become a partner? What changes? What are the advantages/disadvantages, if there are any?

[Assistant]
It takes anywhere from 2 to 10 years to make partner at an average law firm (sometimes longer). In order to be considered for a partner position (while working as an associate), you usually need to work very hard and contribute a lot to your firm's business. It helps if you can pull a lot of all-nighters, find new clients through connections, publish articles in law journals to gain prestige for your firm, or show great talent in a particular field of law that your firm works in.

In some firms, once you've gained enough experience, you're given a big, important client or assignment. If you succeed, you are promoted to partnership. A partner usually owns a share in the company, which means that they automatically make money every year by receiving a portion of the company's profits. There is also less pressure on a partner to work hard, because they've already "made it". So as a partner, you can take it easy unless you're really into your work or want to make even more money. An associate at a big law firm makes around $100,000 per year. A partner at the same law firm will make anywhere from $300,00 to over a million. In small firms that only have a couple of partners, your last name will also be added to the firm's name. So if your name is Johnson and you work at Anderson and Smith, your firm may be renamed to Anderson, Smith and Johnson once you make partner.


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

[User] ELI5: What does it mean to argue in bad faith?

[Assistant]
It means that you're not arguing to come to a mutual understanding. In a true debate/argument, both sides must be willing to acknowledge if the other side has good points and be open to changing their minds. If you tell someone you want a "debate" but you really just want to antagonize them or preach to them, you are lying when you say you want to "argue".

Bad faith generally is an intent to deceive.


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

[User]
[Spongebob] How is the Flying Dutchman so powerful?

I know the powers of ghosts varies from franchise to franchise, but one thing that has always made me wonder is how is the Flying Dutchman so powerful, like he is nigh-omnipotent (He can grant his own wishes), how is he so powerful when he is just the ghost of a deceased person? Also when Spongebob and Patrick became ghosts they had none of those powers, which raises further questions.

[Assistant]
The Flying Dutchman is more than a ghost.

He might've been a man before his death, but now he collects the souls of the bikini bottomers, even officially since nobody questioned him showing up at the hospital to take Krabs soul.

So while he enjoys scaring the underwater residents and haunting the seas, his more like their version of the grim reaper and that job comes with a lot of extra powers.


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

[User]
How do mosquitoes find water to reproduce?

I live near the Mediterranean, in a region where it doesn't rain 4 months a year, and we still get plenty of mosquitoes every summer. There is practically zero fresh water in the area, still or running. This leads me to think that mosquitoes aren't just flying around looking for water to lay their eggs through sheer luck. They must have a way of detecting those places where water is present.

[Assistant]
Mosquitoes like many insects have incredibly sensitive sense organs in the form of antennae. These are able to detect a whole range of molecules including water. It's similar to us being able to smell but way way more sensitive.

Many mosquito species (such as aedes aegypti) will lay eggs in containers just above the water line, so when it rains these eggs get wet and hatch. Other species will lay eggs in mud and only after a number of rewettings will they hatch.  This is why you get a massive increase in the population very quickly.


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

[User]
If I'm playing my music at a volume of 8/10, would that use up my battery faster than if I played the music at 3/10?

Does playing something louder use more battery life?

[Assistant]
It depends largely on the impedance of the headphones. Most headphones designed for portable listening are going to be less than 25 ohms. Headphones with larger drive coils tend to have higher impedance, and will take more power.

But for things like earbuds, the difference between 3/10 and 8/10 will be negligible. The phone is using more power keeping the CPU active while decoding the music than the headphones will ever use.


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

[User]
ELI5: Why is it that when people read orders from others such as "you're now breathing in manual mode", they become aware of breathing and find it laborious?

I just read several comments telling people that they're now aware of their breathing, or that they've now got an itch somewhere on their body that they just *have to* scratch, or manually blink, and others below are cursing the guy out for making them feel uncomfortable.

Why do people become "aware" of these facts, why does it make them uncomfortable, and why can't they just ignore such comment?

Or am I weird for not being affected by such suggestions?

[Assistant]
All of the functions you describe are semi-autonomous. Normally, your body just kind of takes care of blinking and breathing by itself, like it does with your heart and digestive system.

The ability to actively control blinking and breathing has its obvious advantages, but the mere ability to consciously control them means that we tend to take "manual control" whenever we specifically think about the action.

Itching is a bit different, that's mostly a psychological trick.


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

[User]
ELI5: What's the purpose of the cartilaginous tab over the ear hole?

Most people's ears have a cartilaginous tab that fits right over the ear hole (to block it), if you presse with the finger.  Safe to say that's the purpose it serves?

[Assistant]
Update: ok, after learning from a video that the floppy part of the ear is called the "pinna" it made me want to dig around to find what the name of that "tab" is, and turns out it's called the "tragus".  Now armed with a googleable name, the search was on, and it appears that the tragus does aid in collecting sounds from behind (and interestingly in bats it's even more evolved to function even better in that way).

Still, for me it will always be an earhole sealer, when needed:)


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

[User]
[Futurama] What does Bender do with all the cash and swag he steals?

Bender loves stealing and taking things.  Plus he's got a minimum wage job as a ship's cook.  We've seen him steal millions in cigars, jewels, swords, cash, various swag etc.  So what does he do with it all?

Is he paying down a pay day loan from when he was younger?  Child support?  Legal fees?  Save it for a rainy day?  Hoard it like a dragon?

[Assistant]
On a day to day basis when he has small scores he spends it on booze, cigars and prostitutes.

When he has a big score and has a lot of money, he spends it on really fancy and expensive booze, cigars and prostitutes.

Anything left goes to ass shining sessions and occasional purchases of robot pornography.

It's also worth noting that he likes stealing almost more than he likes having stuff, so he is fairly careless with what he does with stuff once it's stolen. A lot probably just gets lost, thrown away or pawned for way less than it is worth.


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

[User] ELI5: If symptoms of being sick (mucous, sore throat, fatigue) are immune system responses, what does the cold virus actually do?

[Assistant] While your immune system is fighting them, pretty much nothing. However, if they were allowed to keep reproducing without a fight, then they would just keep killing off cells at faster and faster rates, eventually preventing vital functions from working and killing you.


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

[User] [The Purge] Why haven't other countries tried to imvade the US during the Purge? Would their invasion and take over technically be legal and accepted by other nations?

[Assistant]
We know that important infrastructures like hospitals or police stations are still protected during the Purge so Military infrastructure is probably also protected an ready to go.

Also the Purge is just a way to get poor people to kill eachother, it doesn't have to be consistent in it's rules.


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

[User]
[Fallout] Are the Mr. Handy robots sentient /self aware?

When you meet codsworth after your 2 century disappearance in fallout 4, you can ask him why he is acting strange, and then starts telling you about how lonely he is and almost starts to have a mental breakdown.

This, along with some of his actions and comments about things, makes me wonder if they are somehow alive, or just the products of some very sophisticated programming.

[Assistant] Past experiences with robots says yes. Yes they are. They aren't typically recognised as such, but certain ones do exhibit characteristics which would mark them as both sentient and self aware. EDE, for instance.


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

[User]
I think that standardized tests are a waste of time and resources. CMV.

Please note that I am not referring to the SATs or other tests of that nature because I can understand why they exist for the purpose of college. I am also American so I am mainly referring to american tests as I don't know much about standardized tesing in other countries. I am mainly referring to  the tests issued by each state (soon to be the country) to public schools across the USA.

Curriculum in American schools is heavily based on these tests. So much time is spent in classroom preparing for these tests and teaching kids things that they have already learned, are not ready to learn, or are learning at a good time for themselves. I just think it distracts from learning and more time should be spent in  making sure each student learns at their own pace.

Maybe if standardized testing was based on the learning capabilities of each student and not their age, then I would be more open to it.

[Assistant] Standardized tests allow for easier comparisons between schools, meaning that if schools perform poorly then it shows them what subjects they aren't teaching well. Without tests that need to be administered by every school, it would be very difficult to determine how well schools are teaching their students.


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

[User]
Thoughts/questions about quitting PhD

My apologies in advance for somewhat of a rambling post - I'm a 31/m, have a wife and 2-year old with plans for a second child currently on hold because of financial constraints. I'm currently in the 5th year of a upper mid-tier history PhD program and am juggling quitting. I've lost most all passion and drive for academic research and writing, and the thought of having to finish writing my PhD looms over me and infects every part of my life. It makes me sad, because I have an exciting topic in contemporary European history and have essentially gathered enough sources and interviews (with some unique finds) to complete writing. It's modern and "sexy" enough that I would very likely be able to find a publisher for the manuscript afterwards. But I am miserable.

Once upon a time I was a very social person, always positive and optimistic, likeable and outgoing, but the isolation of writing has turned me into a cranky recluse with zero interest in keeping up with friends and family. I used to spend free time with hobbies like music writing, biking, auto restoration, but now I spend my free time finding ways to shut my brain off, which usually means having a few drinks and sitting in front of the tv pretending to watch something while my mind wanders. I view hanging out with friends and family now first and foremost as a good excuse not to be working, instead of genuinely enjoying their company. I still have that intellectual curiosity and genuine interest in knowledge that started me on this track, but I can't bring myself to pick up any new interesting book, because I instantly feel guilty for investing mental energy into something that is not my dissertation.

Doing a PhD seems to have brought out the worst in my personality in terms of not handling the stress of a large, looming project and letting it overtake my life, poor time management, constant confusion and disorganization and inability to ever be fully "present" when spending time with others etc. I was never one to shirk from work before and always considered myself to be a hard worker and someone happy to put in the extra time and effort to ensure something was done right the first time. I used to be sharp, on the ball and reliable, now I come across as not very bright, disorganized and overall not someone you would want working for you in any job capacity.

I confidently feel that deciding to do a PhD was the single worst decision of my life. I no longer like who I am, and I feel like the strengths I used to have (confidence, social skills, empathy, ability to read people extremely well) have been eroded to the point where I wouldn't even know where to start looking for an alternative job, especially with half a PhD and zero work experience outside academia or teaching for the past 8 years.

At this point, I am only holding on with the hopes of landing a teaching gig at a lib arts college or something similar, as teaching is the only aspect of my professional life right now I still feel rewarded by. Teaching is really something I get passionate about, but I realized early on I didn't want to teach in high school for a variety of reasons. I was very close to quitting my PhD during and right after comps, but I landed a year-long research fellowship and took that as a sign I should stick with it. Now I am still hanging on with the hopes that my persistence will be rewarded with a college teaching gig. Or that my PhD will perhaps help me in landing a decent government job (the US gov. recognizes grad education as a substitute for experience for many positions). I would jump all over virtually any alternative job opportunity that presented itself to me right now, but of course nothing is going to just fall in my lap if I'm not actively making it happen.

I guess I'd like to know how common it is to feel this defeated during a PhD. How bad was it for those who made it through? Would it be dumb to make it this far and stop, or dumb to waste another day of my life being this unhappy? When I signed up for grad school I made the decision to forgo immediate fun (I was teaching abroad and traveling a lot) in order to secure a career and future, and that has been my motivation throughout this, especially the "light" at the end of the tunnel of teaching 15-20 hours a week and having significant schedule flexibility to be a better family man. But are the prospects of a career in the field so slim that I would be crazy to continue doing this to myself for the off chance I land a fleeting academic job?

I'd really appreciate any advice, suggestions or observations. I've been running around in circles between quitting and sticking it out for months now and I'm reaching my wit's end.

edit* In case any one was wondering, I've brought it up with my wife before, though not recently, and she's always been supportive. I'm 100% sure she would back me up in whatever I decide.

[Assistant]
1. If you put your nose to the grindstone, how quickly do you think you could finish your degree?

2. If you dropped out tomorrow, what would you be doing instead?

3. If you dropped out 6 months from now, what do you think you could be doing and how likely is it that would occur?


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

[User]
Can a planet have a moon the same size orbiting it?

What would be the consequences both on the inhabitants and the two bodies?

If it isn't possible, why not?

[Assistant]
Neither would be a moon. They would be orbiting a point between them. (Like how pluto and charon orbit a point in space between them, but much closer to Pluto).

They would probably be tidally locked (same face facing each other, like the moon is tidally locked with Earth).


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

[User]
Is there a reason the angular size of our moon is almost identical to the angular size of the sun? Or is it coincidence?

Assuming there is intelligent life on other planets, and that we do communicate with them at some point, will we be able to brag that we're the only folks who can see both a complete solar eclipse and complete lunar eclipse?

[Assistant]
It is a coincidence. They both get bigger and smaller from our perspective throughout the month/year, so there is some overlap in their range of sizes, rather than both being the *exact* same angular size all the time.

In many billion years the sun will be bigger and the moon will be farther away, so this won't be the case any more.


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

[User] [Dragon Ball/Z/Super] What determines the color of a specific energy attack? Is it something the user can choose at will?

[Assistant]
It seems tied to specific techniques.

Generally people seem have their own Ki energy, but people with similar styles/training share the color.

Turtle School / Kamahameha : Blue Energy
Kaio-Ken : Red
SSJ Ki: Yellow

Since Ki is just a manifestation of the users energy in DB, it's most likely just focused in a different way or perhaps amount resulting in a different appearance.


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

[User] If you were to scream in the vacuum of space, would you be able to hear your own voice through the vibrations in your head? Or would you just hear silence?

[Assistant] Barring the other physical consequences of being exposed to space vacuum unprotected....if you had air in your lungs to exhale and 'scream' with, the vibrations from your vocal chords would propagate through your bodily tissue/matter and you'd 'hear' it--just like you already do in an atmosphere (except you probably 'hear' more of your voice projection/reflection vs. internal conduction).  Of course, if you didn't have a nice lungful of air to exhale in the first place, there would be no vibrating of your vocal chords because they require the pressure from the air in your lungs to vibrate.


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

[User]
[Jurassic Park] Why did the Velociraptors have so much trouble searching for Lexi and Tim in the kitchen?

Lexi and Tim were making a total racket; scuffing their hands and feet on the floor, bumping into metal cupboards and worktops, spilling cutlery, shrieking and breathing loudly etc. How in the hell did the Velociraptors take such a long time to spot them? Couldn't they be heard in what was an otherwise eerily silent building? What about their sense of smell too? That one Velociraptor could smell enough food residue on that chef's spoon to lick it off but she couldn't smell Tim literally right in front of her?

[Assistant] They had to cope with all the unfamiliar stimuli of an artificial environment. Their ears weren't used to all the echoing of hard smooth surfaces, and their noses were still coping with all the new scents, including the lingering scent of hundreds of previous humans permeating everything.


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

[User]
ELI5: How can we estimate the age of a star based on its size?

I have a homework problem that boils down to this: globular clusters have stars of a certain size in them, and when you plug that size into a formula, it says they are about 30 billion years old. (The universe is only 14 bil) I just don't understand the entire concept of getting a star's age from its size... why couldn't the stars be made yesterday just because they are a certain size?

I get that a big star dies younger and therefore couldn't be more than x years old etc, but how on earth could we know when a star was "born" just based on how big it is, outside of setting a limit on how long the star could have lasted?

[Assistant]
Well you can't estimate the age of a star by its mass alone and if you are getting a value greater than the age of the universe you obviously went wrong somewhere.

You can use the size in combination with its luminosity to estimate its age, because stars get brighter as they age. Obviously bigger stars give of more light than smaller ones so we have to account for that too. We can say things like: a star of this size should be this bright when it is young and that bright when it is much older.

This does not work for all star though. There are different types of stars that age in different ways.


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

[User] ELI5: If someone we're to step onto a gas giant planet would they just sink to the core of the planet? What would happen?

[Assistant]
Assuming you somehow lived through all the fun things that would happen to you while falling?

Eventually you'd hit a layer that had been compressed enough to be denser than you are, and you'd stop there.

Realistically, other things would kill you before you got that deep.

You run into a 1000kmh cross winds, pressure will crush you, it'll get hotter the lower you get, and its radioactive.


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

[User]
How does RSA generate the two prime numbers used for encryption so quickly when its security is based on the difficulty of finding primes?

When I generate an RSA key, it takes a very short amount of time to produce the key, and thus to produce the two primes. How does is RSA secure when these primes are found so quickly? I guess there are two fundamentally-linked questions here.

(1) How does RSA produce two primes so quickly when cracking the primes would take a petaFLOPS computer 10^1210 years to crack it (RSA-4096)?

(2) How is RSA secure if primes can be produced so quickly?

[Assistant]
It is an asymmetric problem.  It is computationally easy to test whether a number is prime and easy to multiply two numbers together.  However it is computationally hard to factor a given number.

So, you pick two large prime numbers (easy), multiply them together (easy) and tell people their result.  If they want to break the code, they need to factor the result (hard).


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

[User]
Are left-handed people more common in countries that write from right to left?

Seems quite obvious, but: if that would be the case, do right-handed people suffer from the same problems as left-handed people in languages that write from left to right?

I don't know if this is a part biology, human body or linguistics....

[Assistant] Everything I've ever read indicates left-handedness is a stable 10-12% of the population around the world, despite the various social pressures put upon us.  I've wondered about righties in right-left writing systems having the same smudging problem as I've always lived with, but perhaps the writing positions in those languages are different and minimize smudging.


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

[User]
[MCU][Endgame Spoilers] What's so special about the Soul Stone?

So, who knows where these things were originally, but the earliest appearance of the Space Stone is in some viking temple in Norway, not some weird non-Euclidean spatial configuration.

The Reality Stone is just a weird pool of goo and all you have to do to get it is touch it, apparently. You don't have to pierce the veil and see through an impenetrable illusion or something.

We don't know where Thanos originally got the Mind Stone, but there's no indication he had to solve an impossible riddle, and if he did, no one else had to after that.

I could go on, but there's no indication that any of the other Infinity Gems have *one weird trick* that you have to use to get them, but the Soul Stone can apparently only be obtained by sacrificing the thing you love most, and it apparently even has the power to enslave a former wielder of the Space Stone as a tour guide. So what makes the Soul Stone so special that it gets its owner creepy guardian and fancy rules about how to get it?

[Assistant]
No one had to go through a non-euclidean test of sacrifice and death in order to get the Soul Stone *after* it was removed from Vormir, either. Just grabbing it worked just the same as with every other stone, once it was "out of the box".

Vormir and the "Drop One Loved One For Access" puzzle was just where the thing had been hidden for so long that no one remembered where it had been put. Similar to how the Reality Stone was in a gap between space and time for a very, very, very long time, and the Space Stone was buried in the Arctic ice pack for a few years there.


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

[User]
What is the maximum theoretical efficiency of an air turbine and how close can we get to it with current technology?

The maximum theoretical efficiency of an open air wind turbine is defined by Betz's law to be 59.3%. But if instead the turbine was inside a circular tube of constant diameter, and had a pressure drop of so many pascals across it, how would an ideal turbine behave? As in what would the air flow rate through it be, and how much energy would it extract from this flow? (Given a certian air density) How close can current technology get to that figure?

edit:

This is in the context of a solar updraught tower. There is negative pressure at the bottom of the tower due to the buoyancy of hot air in the tower (stack effect) compared to outside. If there were a turbine in the tower, how much energy could it generate?

My situation is as follows: the tower is 20m diamater. The negative pressure generated by the stack effect is 630Pa. If there were no obstructions in the tower, roughly 7500 cubic metres of air per second will flow up the tower. Since the air density is 0.938 kg/m3 and the air is rising at 24 ms^-1 , one cubic metre of air will have the kinetic energy of 270J. There are 7500 of these per second, so the total kinetic power is about 2*10^6 watts.

That is for an open tube with no restrictions. A turbine will act as a restriction for the air (like a resistor in an electrical circuit), so the flow rate will be lower. I was just wondering if there was a rule-of-thumb equation or number concerning the flow rate through an ideal turbine given a pressure difference (or how much it will impede the air flow stated above), and how much energy will be captured by it.

By "efficiency" I mean the proportion of the kinetic energy in the rising air captured by the turbine.

[Assistant] Modern multiple stage bladed turbines typically reach 6070% efficiency, while large steam turbines often show turbine efficiency of over 90% in practice. Volute rotor matched Tesla-type machines of reasonable size with common fluids (steam, gas, and water) would also be expected to show efficiencies in the vicinity of 6070% and possibly higher.


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

[User] ELI5 - How can oases exist in deserts? Where does the water come from? How come they don't just vaporize? And where do trees and plants there grow from?

[Assistant] Oases exist where groundwater comes to or near to the surface. This usually happens in low places, where all the underground water flows end up. The water itself comes ultimately from rains, which, however rare, occur in every desert. The water then seeps down through the ground until it reaches a barrier made of impermeable rock, and then flows down along that barrier towards an oasis, where it accumulates. This way the infrequent rainfall over many thousands of square kilometers of desert can support a single small oasis in the low place of the area.


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

[User] ELI5 What's happening in my head when sound gets drowned out while falling asleep and then a minor disturbance "opens" up my ears?

[Assistant] Your brain differentiates between expected and unexpected noises. So the hum from the fridge or the music you left on is expected, but broken glass or some other noise is unexpected and your brain wakes you up.


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

[User] ELI5: ELI5: how does odor transfer through plastic? And does it mean the object giving off the odor is technically penetrating the plastic?

[Assistant]
Yes, any time you smell something *actual pieces of that substance are going into your nose*. Smell is physical contact between molecules and sensory cells in your nose.

If you smell something through a wrapper or bag, yes, the odoriferous molecules are penetrating through the plastic. The molecules we smell tend to be pretty small and light (hence they are able to come off the substance and float in the air) and plastics are quite permeable compared to say, glass.


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

[User]
Why don't dinosaur exhibits in museums have sternums?

With he exception of pterodactyls, which have an armor-like bone in the ribs.

[Assistant]
First of all: pterosaurs aren't dinosaurs.

Second of all, laziness probably. The sternal elements in most dinosaurs except ankylosaurs, *Limusaurus*, dromaeosaurs, troodontids, jeholornithiforms, and pygostylians are unfused, which makes them more difficult to mount. This is also why the gastralia are often missing.


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

[User]
[Star Wars] why doesn't R2-D2 have speech capabilities?

you would think it would be pretty simple to do given that he already seems capable of thought and has a personality etc.

[Assistant] Same reason all cars don't have bluetooth capabilities. It's not their primary function and it costs the manufacturer money. R2-D2's main function is to communicate with computer systems, such as those among ships, and to maintain and repair them. Speech is not necessary. Would it be helpful? Sure. But not necessary.


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

[User] [Werewolves] So in fiction when people turn into Werewolves, does the Inner Beast have a mind of its own? Is it sentient? Is it intelligent and capable of rational thought? Is it kinda like a demonic possession?

[Assistant]
Generally speaking its mindless hunger and animal ferocity. It's smarter than an average animal but still driven by instinct. Some imprint of the human psyche remains leading to targeted attacks against rivals from the human side or ignoring love interests.

And in others it's just a normal human intelligence within a beasts body. Hunger and rage seem to be heightened to extremes but they still reason and think like a person.


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

[User]
CMV: A total ban on guns won't work in the United States.

Criminals won't abide by the law, and making more won't stop them.
The only reason we have mass shootings is because of people being screwed up in the head ie: parkland girl admitting to bullying the autistic foster kid, saying he deserved it and it's the guns fault that the school got shot up.
The state of mind in the United States means we will never have a ban on guns, or we will have an American Viet Cong on our hands.
I'm all for having "mental health checks" on current gun owners, however if we are to do what the high school kiddos are suggesting and confiscate all "fully semi-semiautomatic high capacity 30 round clipazine assault rifle 15's" then things wouldn't be pretty.

[Assistant]
You're kind of all over the place here.

A total ban cannot happen because of the second amendment.

What can happen, and did in the 1990s, is a limit on the more military-style weapons.

As for your criminals argument - the state has a monopoly on force and could allow cops to have any guns they need.


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

[User]
Why does it feel warmer when it's snowing?

Is it actually warmer?  Or am I just imagining the difference in temperature?

[Assistant] It can only snow within a certain temperature range, if it's too cold there won't be any moisture in the air.  A warm front bringing moisture in will warm the air up some and lend enough moisture for snow to form.


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

[User] ELI5: Why does it take so long to close a frozen program with "End Task" in task manager, yet killing a process is instantaneous?

[Assistant]
End Task relies on sending a signal to the program telling it to die. That requires the program to respond and terminate, which it wont if it's really stuck. After some time the option to try and force close is made available.

Killing a process just outright stops giving it resources so it instantly is removed from the process tree, stops calculating, etc.

It's preferable to have the program kill itself where possible so it can perform any needed cleanup, but sometimes a program is so stuck it can't.


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

[User]
[Star Wars] how is no one ever burnt by climbing through fresh glowing hot holes in the floors/ceilings cut by lightsabers?

Sometimes they even directly touch the glowy orange melted metal and don't get burned. How?

[Assistant]
Metal in ships and floors of the universe aren't like earth metals. Under extreme heat or pressure they'll emit an orangish red light but not heat itself. They rather marvelously dissipate heat as well throughout the whole of itself. This leads to stronger building materials that are heat resistant but also indicate where too much stress can be causing issues on the structure while building.

Not based on anything just trying to make sense of something that's nonsense.


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

[User]
Can you delete specific memories by removing specific brain cells?

If a surgeon, say, uses a scalpel to scrape some cells out of the temporal lobe, would the patient wake up missing certain memories?

[Assistant]
It's not that easy.

Memories are stored distributed around the brain and can't be said to be stored in any specific cell or set of cells. Such a "scraping" procedure -- if it affected memory at all, instead of some other function -- might disrupt certain memory connections but it's hard to defend the idea that the memories would be completely removed from a small-scale injury.

If you want to get down to sci-fi, theoretically speaking, since there are a finite number of synapses in the brain, there must be a finite number of cuts necessary to remove all connections involved in a certain memory. That says nothing to whether it would be possible to surgically remove SPECIFIC memories without otherwise disrupting normal functioning, nor does it imply there is a way to determine which neurons and synapses are particular to a specific memory.


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

[User] [The Matrix] Would the Matrix have kept its deal with Cypher, or just kill him?

[Assistant]
I would imagine not. Cypher wants to go back to how it was before, and before, he *chose* to leave the Matrix. He can  be rich, famous, everything he asks for, but he'll have that nagging question returned to the back of his mind.

And from Cypher's point of view, there isn't much material difference to him being mindwiped and put back in, and just being bumped off. Either way things go dark and some other guy comes out the other side, alive or dead.


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

[User]
ELI5: What is energy?

What technically is energy, not how it is measured, used, or converted into different forms.  I am looking for what energy actually is.

[Assistant] Energy is the capacity to do work. Many forms of energy can't be used to do work we would think of as practical (like low temperature differences and low heat), but energy is just that element of physical reality that is the capacity to do work.


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

[User]
Eli5: why isn't the british army called the "royal army"

Royal Navy, Royal Airforce, even Royal Mail.

Why doesn't the army get to be royal?

[Assistant]
Historical reasons. The army is allowed to exist by order of the parliament, whereas the navy was personally controlled and raised by the monarch.  The army exists, legally, because parliament allows it to.

The distinction is less relevant today than once it was, obviously.


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

[User] ELI5: Why is the glass on our phone screens more slippery than the glass in windows?

[Assistant]
The glass in your phone has special coatings to make it slippery.  You drag your finger across it constantly so it needs to be slippery.

Window glass need to be glass.  Thats it.  Were you to make windows out of iPhone glass they would be prohibitively expensive.


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

[User]
[Star Wars] Why did Leia think it remotely plausible to claim they were on a diplomatic mission?

She tells Vader they were on a diplomatic mission. He doesn't believe her. Then in Rogue One we find out why. Because he literally followed her from a battlefield.

How did she think this defense would be even remotely plausible?

[Assistant]
They aren't the only Corellian Corvette in existence and it's not like they have license plates. She was basically denying that they were the one on that battlefield.

Yeah it was a weak excuse but a weak excuse is better than none and she wasn't even trying to convince Vader but rather was threatening to cause trouble for him with the Senate.


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

[User]
If I am trying to model one single electron (or one hole) delocalized among a small number of molecules, is it appropriate to use a Fermi-Dirac distribution or a Boltzmann distribution for temperature dependence, and why?

Please let me know if any clarification is needed to answer my question.

[Assistant]
Recall that the Fermi-Dirac distribution is the grand canonical ensemble, and the Boltzmann distribution is the canonical ensemble (your terminology is correct, the other answers are confusing "Boltzmann distribution" with "Maxwell-Boltzmann distribution"). So, if your system cannot exchange electrons from elsewhere (either your heat bath or the molecules), and your delocalized energy levels are all unoccupied (and therefore accessible to the electron), then you should use the density matrix diag(e^(-E_n/kT)/Z) in the energy basis. However, if you're trying to look at one electron in the system which also happens to contain many other electrons, you need to take statistics into account with the degeneracy of each level, and it's far easier in Fermi-Dirac (number fluctuations *should* be small for enough particles).

For the other answerers: the assumption that the system is exchanging heat with the environment means that this **is** a system + heat bath of a large number of particles. OP is just focusing on the subsystem (i.e. we are not in the microcanonical ensemble). This is totally standard when modeling a non-interacting state - the multi-particle partition function simply decomposes into its one-particle partition functions.


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

[User] ELI5: How do companies such as Arm & Hammer make a profit off of baking soda when sodium bicarbonate is the only ingredient in a non-proprietary formula with off-brands offering the same product, cheaper?

[Assistant] I worked at an Arm & Hammer factory where they bottled laundry detergent.  They would run a batch of the name brand stuff and then a batch of the cheap stuff.  Same machine,  same ingredients.  Different bottle, different price.  They have both markets cornered because they are their own competition.


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

[User] Is it possible to transform martian soil into fertile soil through bacteria and fungi?

[Assistant] Youd have to find a way to thicken the atmosphere first. If we had bacteria or fungi that could function in a near vacuum. Add to that the problem that water boils at about 10c on Mars, and youve got a bit of a problem.