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

[User]
[Frozen] Did Anna also have magical powers, like Elsa?

It's never really explained where Elsa's magical abilities come from. When the King took his daughters to the Grand Pabbie (troll), he says that Elsa was born with "the powers", so I suppose they must be heritable in some way. Could Anna have inherited them too? And when the Grand Pabbie turns his attention to Anna, he says "I recommend we remove all magic, even memories of magic to be safe." Remove all magic? He could just mean the effects of Elsa's magic on Anna, but it sounds like something more.

Could Anna have been born with magical abilities of her own that she simply hadn't yet grown into exploring? Perhaps fire magic of some kind? Did magic run in the family? It couldn't have been too common, or Elsa's powers wouldn't have struck such fear into everyone. What's the story here?

[Assistant]
There never seemed to be any sort of visible manifestation of powers within the younger sister. Anna's lack of powers could be explained as simple luck of the draw. Maybe a witch cursed Elsa. Maybe Elsa just inherited some recessive traits, while Anna didn't. No real way of knowing.

Since it's Disney, I'd say curse. Maybe their parents pissed off a local witch, and they just sort of... forgot about her threat to freeze the hearts of their child.

Probably a witch.


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

[User]
ELI5 how muscles get stronger.

Like the tittle says. I'm not really sure how 'hurting' them or using them alot helps :)

EDIT:Thanks everyone for answering!

[Assistant]
Imagine a village that has a very valuable treasure in it and the villagers build a big wall around it to protect the treasure!  Well lets say someone comes along and tears down the wall to get to the treasure.  The villagers are really upset by this and after the wall is torn down they decide to build it back up even bigger than before to keep people out and away from their treasure!  After all, the wall didn't do a good enough job the first time so they need a bigger, better wall to hopefully make it work the next time!  Of course, the villagers need really great materials to make a really great wall but as long as they have those great materials they'll keep building the wall back a little bit bigger and better each time it gets torn down.  After all, they have to protect that treasure!

Now think of muscle growth that way except that the wall is your muscle, the tearing down is your weight training, the materials for the wall are your diet, and the villagers are your body.


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

[User]
Why are microwaves used for Microwave Ovens instead of visible or infrared light?

If there is more energy in visible light and infrared, why do we use microwave light for Microwave ovens?

Wouldn't a Visible Light appliance with the same concept of a Microwave be even more efficient at beating our food? The same could be said for Infrared Light?

[Assistant]
No, a 600 watt incandescent light bulb would not last as long as a magnetron. The heat would be dissipated mostly in the oven walls. It would not penetrate the surface of the food. It would be a conventional oven. Microwaves penetrate around 10mm and they don't heat the walls.

The GE trivection oven uses convection, infrared, and microwaves. It was invented by Jack Donaghy.


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

[User] [Batman] does Batmans no kill rule only apply for humans?

[Assistant]
Batman has no problem killing the undead (such as Dracula and Solomon Grundy) and mindless living beings (such as the rampaging Doomsday clones from "The Supergirl from Krypton" arc of *Superman/Batman*).  Aliens are generally on a case-by-case basis.

He also fatally shot Darkseid with a gun and a New God-killing bullet, but that was explicitly a once-in-a-lifetime exception for him.  Batman's *only* options then were to kill Darkseid and save all of reality, or allow Darkseid to live and ensure that he *destroys* all of reality simply by *existing*.


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

[User] [biology] why do most other mammals, and animals in general, have a litter of offspring, whereas humans only have 1 child?

[Assistant] Human newborns are very vulnerable and remain this way for an extended period of time. We're not able to walk, communicate very well or defend ourselves at all.  Only having one child at a time allows for a greater chance of successful development since the parent can focus solely on the newborn's extensive needs and complex upbringing.


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

[User]
[MCU] Why was Howard Stark so harsh on Tony?

I never really understood why Howard Stark always acts so harsh to Tony if he supposedly cared about him. What was the logic behind it? All it accomplished was giving Tony issues later in life.

[Assistant]
Remarkably talented and successful inventors and businessmen don't often turn out to be the best fathers.
Howard thought he was crafting Tony into a better person, as any father wants to do, he was just wrong about what the consequences of his actions would be.


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

[User] ELI5: For movies, how is 24 frames per second more "cinematic" than 30 frames per second?

[Assistant]
Only because you're used to it. Movies "look like movies" in 24 fps because movies are all shot at 24 fps. that's literally the only reason.

30fps is what they use for TV, so your brain associates the look of 30fps with things that are on TV.


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

[User]
[General Fantasy] Why do you think the atlatl is generally unheard of in epic fantasy?

Generally speaking, as non-gunpowder weapons go, it's extraordinarily effective. Plus it's cool. I'm curious if anyone can offer up a reason why we just don't see it brought into epic fantasy tales.
I've no doubt that some of you can come up with examples where it has been used, but everyone ought to agree that it's vanishingly rare.

[Assistant] Because bows offer a number of mechanical advantages over atlatls, not least of which is that they are much easier to use. In our own history, to use one world's comparative example, very few societies stuck with the atlatl, especially once they discovered the bow.


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

[User]
What is it that determines the heat capacity of a substance?

Apart from the amount of substance, what are the things that affect how easy or difficult it is the change the temperature of a substance?

[Assistant]
A substance can "store" energy in a number of different ways, such as translation, rotation and vibration. Not all of these modes are available to all substances - a monatomic gas (such as argon) cannot store energy in vibration because there are no bonds to vibrate.

As for the numerical value of a substance's heat capacity, this is in turn determined by the number of degrees of freedom that the molecule has. The most significant contributor to this number is vibration - all molecules have three translational degrees of freedom (x, y, z) and either two or three degrees of rotational freedom, but may have dozens of available vibrational modes. A relatively large molecule like ethanol has many bonds, each of which is capable of storing energy in vibration, so a certain number of molecules of ethanol will have a higher heat capacity than the same number of molecules of, say, dioxygen which only has one bond that can vibrate.

Peculiar cases like water exist - as a small molecule with only two bonds it might be expected to have a relatively low heat capacity. However, water molecules form extensive networks of hydrogen bonds in the liquid phase, each of which is capable of storing energy.


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

[User] ELI5: How does P2P encryption work?

[Assistant] Whenever you send a message, the message is locked (encrypted) using a key . The key is unique in the sense that you and only the intended recipient has the key to that lock. Thus, only the recipient can unlock (decrypt) the message.


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

[User] I saw in a video that chimpanzees and gorillas do not knuckle-walk in the same way, but they didn't explain what the difference is. Could someone elaborate on the physiological/anatomical differences?

[Assistant]
Gorillas use columnar knucke-walking, where the wrist and hand joints are aligned in a relatively neutral, straight position, which helps with weight bearing. Gorillas are not as arboreal (tree-dwelling) as chimpanzees, so their form of knuckle-walking evolved to maximize terrestrial movement, as well as the aformentioned weight-bearing.

Chimpanzees knuckle-walk with extended wrists, which is due to the fact that they, like most primates, extend their wrists to preserve their balance while engaging in arboreal activities. Due to this need to extend their wrists to preserve balance and protect themselves in an uncontrollable fall, the chimpanzee's wrist bone anatomy has evolved to differ from that of a gorilla, which results in a different form of knuckle-walking.


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

[User] How does Jupiter's storm never go away?

[Assistant] Vertical flows. They move hot and cold gases in and out of the storm, restoring much of the energy lost to turbulence. There are deep sea vortices on Earth that can last for years and exhibit the same properties.


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

[User]
[Marvel Comics mutants/DC comics metahumans] How do power Dampeners or collars work for people like Wolverine , Angel, Timber Wolf, or king share when their powers are a literal part of their working anatomy?

like what's the dampner doing that stops the muscles in Wolverine's arm from unleashing his claws or using his already unsheated  claws ?

[Assistant] Oh thats easy. Power dampeners work by (TRUCK RUMBLES BY) which allows them to (JACKHAMMER) which causes their powers to (ROOMMATE PRACTICES TRUMPET) prohibiting the use of said ability. Does that clear it up?


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

[User]
What limits the height at which something can fly?

Birds, insects, planes, etc. all seem to have a glass ceiling as to how high they can go.  Why?

[Assistant]
Air density.

The density of a ~~liquid~~ fluid relates directly to how easy it is to generate lift, so you need to fly faster. On the other hand, drag also decreases, but for propeller driven craft (such as prop planes, helicopters, and birds) you can be limited by the internal losses of the propeller system, plus you always have to fight gravity regardless of drag.

Air density also causes problems for anything that needs to breath oxygen. This obviously includes birds, but less obviously includes helicopters and planes. Both helicopters and planes work by burning fuel and oxygen. Spaceships must bring the oxygen with them, but planes and helicopters save weight by burning air scooped up from the nearby atmosphere (actually, your car does this too). When the atmosphere is less dense it is harder to pick up enough oxygen to power the engines.


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

[User] ELI5: When Toyota or Volkswagen has a massive recall on their cars, it costs those companies millions of dollars. But when the F-35 runs into problems, why do we (the taxpayers) cover the cost, not Lockheed Martin?

[Assistant]
You didn't design the car.

Plane designs incorporate feedback and testing from the customer, who is then responsible if the design is a death trap.

If you asked VW to add something non stock and they made it to your specifications, you would be responsible for that fix, too. But mainstream car companies don't do that.


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

[User]
How can Marie Curie's notebooks still be radioactive?

Hi Reddit,

So I've covered some relevant physics (alpha, beta, gamma radiation, half-lives) but from my understanding alpha & beta radiation decay relatively quickly, gamma radiation goes through pretty much anything and the radioactive substance used by the Curies have long been removed.

If my understanding is correct, why are the Curie's notebooks still radioactive?

[Assistant]
Radioactive half-lives can be short or quite long, anything from sub-nanosecond to longer than the age of the universe.  It all depends on the properties of the parent and daughter isotope.

If Curie's notes are contaminated with radium-226, that has a 1600 year half life and so very little of the contaminant has decayed yet.


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

[User] ELI5: If it takes 24-72 hours for food to digest, how come sometimes you can eat bad food and get diarrhea 5 minutes later?

[Assistant]
When the body detects something so bad that it needs to expel it ASAP, it can either go up (vomit) or down (poop).

When you get sudden onset diarrhea, it isn't necessarily the food that you just ate that is coming out your butt.  The body is trying to get rid of the bad stuff in the gut....so all the stuff already in the system is hurried along.


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

[User] If a pregnant woman has cancer, is it possible for the cancer to spread to the fetus?

[Assistant]
Its exceptionally rare.  Metastatic disease is usually caused by seeding through the blood supply, or, invasive growth into new organs.

Because mums and bubs dont actually share a blood supply (their supplies run very close together in the placenta, facilitating transfer of nutrients etc, its very hard to seed from one to the another, and invasive growth is pretty damn hard through amniotic fluid.

Theres a couple of dozen of proven cases, mostly leukaemia and melanoma (while melanoma is a solid tumour, its insanely invasive), and leukaemia is a liquid tumour which would facilitate the transfer from mum to bubs blood.


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

[User]
ELI5: The history of gaming as it refers to 8/16/32/64 bit. What exactly is "bit?" What "bit" are we now?

What exactly does "bit" refer to in gaming? Why did it progress from 8 to 16 to 32 and so on? All I know is that 64 bit was the huge revolution into 3D gaming. What "bit" do we use in this modern era of HD, near photo-realisitic game graphics?

[Assistant]
A binary digit, or *bit* for short, is a number that can only be 0 or 1. It's the way computers store information.

Old computers had enough electronics in them to routinely process 8 bits at a time. As computer chips got more transistors on them, newer ones could handle 16 bits at a time, then 32, and now 64 bits at a time is quite common.

The more bits of data you process at once, the more detail you can calculate and draw per second.

Also, the more bits you use to count the locations in your computer's memory chips, the more memory your computer can keep track of.


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

[User] Is there any reason why all the gas giants in our solar system formed in the outer solar system? Why didn't any gas giants form in the inner solar system?

[Assistant]
What's important here is a concept known as the "snow line".

Water can only exist in two states out in space - as a gas, or as ice. Since the pressure is essentially zero in space, water's phase will only depends on temperature. In our solar system, this threshold is located somewhere around 5 AU (where 1 AU = the average distance between the Sun and Earth), and is known as the snow line. For space inside of 5 AU, water is generally found as a gas, while for space outside of 5 AU, it's generally found as ice.

This threshold is very important for solar system formation. If you imagine proto-planets slowly building up from dust grain sizes up to planetary sizes, you can build a lot faster with rock and ice rather than rock alone. This is especially important if you want hydrogen gas to be a significant percentage of your planet - the general rule of thumb is that a proto-planet needs to be about 10 Earth-masses or greater before it has enough gravitational force to hold on to hydrogen.

Also remember that as the Sun ignites, it also starts blowing all that gas out of the system over relatively short timescales, so the places where the proto-planets can grow to 10 Earth-masses the quickest are the places that are eventually going to have planets with lots of gas. Again, reaching this 10 Earth-mass threshold will happen the fastest for planetary cores made of both rock and ice rather than just rock alone...but that can only happen outside the snow line.

It's no surprise, then, that Jupiter is at 5.2 AU, just outside the snow line, and the remaining giant planets are out beyond that. Inside the snow line, meanwhile, nothing got massive enough to hold on to hydrogen gas, so we just see rocky planets there.

**TL;DR**: Out past 5 AU, water in space becomes ice. This is important because the proto-planets beyond that distance could be built from both rock and ice, allowing them to more easily reach the 10 Earth-mass threshold required to hold on to hydrogen gas.


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

[User]
CMV: When large corporations have campaigns supporting LGBTQ rights or other political movements, they dont actually care, theyre just doing it to improve their image and get more customers.

Sure the people at the top may agree with the cause or may disagree, but thats irrelevant for them. What they actually care about is getting more business. Its called the shareholder principle. The theory that every business should do whatever it has to to raise its share price the most. It sounds like an immoral principle, but generally it leads industries to do more ethical things. For instance companies may try and be more environmentally friendly as customers become more environmentally conscious and take that into account when choosing a business.

My belief is the people at the top will just do whatever helps their business look best in the public eye because that is what will help them make more money long term. I think some smaller businesses definitely do care about whatever the cause may be, but large corporations do not, they are focused on the shareholder principle and sometimes it makes them look like they actually do care. I dont think there is anything wrong with that because the ends can justify the means, but I think its nonetheless the case.

[Assistant]
When a company get's large enough it's like a government with competing parties inside of it that want different things.

When a company takes a public stand it's like they passed a resolution.

Microsoft for instance took a stand for LGBT rights in 1989 adding it to their list of thing you can't discriminate against at their company for hiring. This was because of group called GLEAM or Global LGBTQI+ Employee & Allies at Microsoft, that lobbied the company.

For the record Ellen came out as a gay character in 1997 so 8 years later, so at the time for Microsoft this was not a good thing for their publicity and arguably profits.

This is arguably because Microsoft as a tech company had more LGBT+ individuals and had more accepting members and they lose staff if they didn't make this decision, which might affect profits, but in the end it was to make working there a better place.

Hobby Lobby would be an example of a company acting the same way but for opposite reasons.


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

[User]
How do black holes overcome the Pauli Exclusion Principle?

Neutron stars overcome the Pauli Exclusion Principle because the protons and electrons combine into neutrons. Does something similar occur when a black hole is formed?

[Assistant]
TL;DR: We aren't sure.

We cannot obtain sufficient information within the Schwarzschild radius to rationalize a definitive conclusion. However we can infer through our knowledge of matters behavior in the past that the region occupying the Schwarzschild radius is like a quark-gluon plasma.

[edit] "like"


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

[User]
[Doctor Who] What IS the Beast?

Like what is he anyway? All we know is that he's a being older than time itself and that he may have been the inspiration for all personifications of evil in all religious, but what kind of being is the Beast exactly?

[Assistant]
It claims to be from a previous universe, but the Doctor believes that's impossible.  It's certainly not long on honesty, so who knows?  The Great Intelligence claimed the Doctor himself would be known as The Beast, but that's also a source that is short on honesty, and was certainly trying to rattle the Doctor.

We know it's mostly psionic, and an energy being.  We know it was trapped in a corporeal form.  We know that it survived falling into a black hole, we also know it wasn't entirely sure it would survive falling into a black hole (or it would have attempted escape and triggered the trap).  That suggests the "surviving the end of a previous universe" was a lie, since certainly the end of a universe seems more intimidating than a black hole.

That implies the corporeal form anchored it somehow, and maybe enhanced its powers.  That makes it seem unlikely that it's the doctor (as none of this is things we've seen in the Doctor's repertoire, in any form).  A relic of the Time War?  Something from the Shadow Houses that didn't get erased?  A being actually older than the universe?


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

[User]
i is a very pervasive and highly used value in higher math, from my understanding. Despite this, though, its difficult to conceptualize i (for me, at least). How and why did such a strange, complex number become so important and widely used? Apologies if the flair is incorrect.

I only briefly touched on i and the complex number plane in my Algebra 2 class, so my knowledge is highly limited. From what I was taught, it is defined as -1 , which leads to the different interactions i has with different exponents. How, though, did this number become so important? What sorts of uses does it perform?

Also, Im not sorry for the joke in the title.

[Assistant]
The real numbers are a _field_, roughly meaning that they form a complete set of numbers you can do all operations on: add, subtract, multiply, and divide.

The problem with the field of real numbers is that if you create equations with real numbers, you can write equations that have no solution. For example, x^2 + 1 = 0 has no solution that is a real number.

The "solution" (punny!) to this problem is adding _i_ to the field of real numbers to create a new field, the complex number field. It turns out that the complex number field does _not_ have the equation problem that the real numbers have. Meaning, if you write an equation using complex numbers, then the solution(s) of that equation are always complex numbers. There are no equations you can write using complex numbers that have no solution.

That's why _i_ is so important: it creates the complex field, and the complex field is algebraically complete.


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

[User] ELI5 why do we have bones around almost all places but not around our tummy?

[Assistant]
Bones provide *stability*; muscles and similar tissue provide *mobility*. The belly needs more mobility, both for things like digestion, pregnancy and breathing, and for things like the range of movement our torso is capable of (bending, turning, lifting, etc). With too many bones in the torso, these essential activities would be much more difficult.

Your abdominal wall is 4 layered sets of muscles and lots of cool related tissues, giving some containment and structure as well as the capacity for all those actions. Bodies are amazing!


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

[User]
[DnD] I am in a party of adventures and this guy is using his fists. How will he honestly fair against plate armor?

Gi the Monk says he can easily fight a man in plate with his bare hands. I don't care what divinely ordained temple you're from that should shatter your fists, right?

Feasibly before any Hocus pocus what can someone trained in martial arts do against someone in plate armor? Could it make a feasible difference?

I don't want this armorless weaponless git to die in a dungeon.

[Assistant]
This isn't just someone "trained in martial arts", this is a *monk.* They're channelling ki to perform semi-mystical effects, including such things as turning invisible and speaking all languages and, yes, punching through metal.

Sure, a guy just using his fists can't punch through plate armour, just like a guy who's just smart can't summon fireballs. But a wizard is more then a smart guy with a book, and a monk is more then just a martial artist.

He'll be fine.


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

[User] What would happen to someone as they got closer and closer to a neutron star, and hypothetically, if lived, what would they see?

[Assistant]
Either a very bright light, or nothing at all due to the intense magnetic fields that would greatly alter the flow of the fluids and charged particles in your body.

Since your body communicates using mainly fluids and charged particles, it's going to kill you. Uncharged particles are also going to get charged, so it's going to kill you too.

Essentially according to your question you're just going to see a bright light.

Neutron stars look very boring in the visible light range.

If you're looking for the gravitational effects instead, the neutron star will fill up a greater field of view than expected for that distance due to gravitational lensing, and you would be able to see a non-identifiable spot somewhere on the opposite hemisphere of the star instead of being limited to only seeing one hemisphere.


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

[User]
[Warhammer 40K] How much fighting does the imperial guard do against other humans compared to the amount of fighting they do against xenos/chaos threats?

What I really want to know is how likely is a solider to see combat against what?

[Assistant]
The Imperial forces are more likely to see action against Rebels, Separatists and Heritics than any other threat. These are ongoing struggles throughout the Imperium, even though they somehow manage to keep knowledge of Chaos on the down-low.

The next most common threat are the Orks. They are everywhere, and almost impossible to exterminate. The majority of these encounters are likely dealt with by PDF formations as they are little more than feral Orks who haven't reached the population necessary for Meks to manifest.

Next come Tyranids. These are increasingly common on the Southern edge of the Galaxy, though wandering splinter fleets have been seen as far north as the Eye of Terror.

The least common of the major powers are the Eldar (both types, though Dark Eldar are more likely to attack human worlds) the Tau and the Necrons. These powers, while mighty, are either too localised or too disinterested in the Imperium and it's worlds. Conflict only comes when the Imperium is the aggressor, or under rather specific circumstances (neutralizing threats, trespassing, or even helping against common enemies).


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

[User]
[The Matrix] How can people have a residual self image if they have never seen themselves irl?

As people are grown and "harvested", how would they know what they look like in the Matrix?

Bonus question, How do pregnancies work? Do they just plug a baby into the matrix and boom someones a parent?

[Assistant]
Everything coded into the Matrix is done so as to make it as realiztic as possible, so that the host does not reject the program. At a nervous-system level, your body is going to be aware of itself. It has to be, or function like digestion aren't going to work right. So, for the purposes of this realism, the Matrix gives you the image of the host body - it's nothing to monitor the base appearance of a subject and make this their image inside the matrix.

And so, having grown up with that image programmed into you, it becomes your image even when you hack in. Your mind is just used to it.

Babies are even easier. The Matrix tracks sexual encounters, and when its determined that the counter will cause a baby to be born, it takes the egg and sperm from a couple, performs in-vitro fertilization, and implants the embryo into an artificial womb.


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

[User] ELI5: How does fire emit light (the sun, a candle, a fire, etc.)?

[Assistant]
It's a couple of different things going on, and how much each process contributes to the light produced depends on the type of fire.

The first one, which is responsible for most of the light from things like campfires and candles, is called black body radiation. This is the phenomena that all objects convert heat to light. You don't see cold objects light up, because the amount of light and the wavelength (color) of the light depends on the temperature of the object. Colder objects throw off low energy light like radio waves and infra red. Heat them up more and they start glowing red. More and you'll see more yellow, blue, or white light. Fires give off light like this because the gasses and tiny solid particles flying up from the fir are hot enough to glow.

The other process is due to the burning process giving the electrons inside of the fuel energy. Electrons in an atom are on a kind of energy ladder, where they can step up and down rungs. The burning process takes an electron and bumps it up the ladder a step (or maybe two or three), then the electron falls back down to where it was before. To do this it has to release all that energy that it just had, which it releases as light. When light is produced in this way, it's only in a very narrow wavelength, which means you see a specific, pure color of light from this process, some of which you're unlikely to see from black body radiation which sort of releases a blend of wavelengths together. This is what you see when you burn copper and the flame is green.


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

[User]
ELI5: Why can we accidentally make bacteria resistant to antibiotics but we can't make ourselves bacteria resistant through a similar but opposite approach?

Over the last century (or so) we have made bacteria stronger and stronger via antibiotics. Why isnt there a plausible way to do the opposite by any means that isnt just letting evolution take its course? This may be a confusing question but I'll rephrase. Is there a way to kill *only* the strongest strain of bacteria and let the weaker (and less deadly) bacteria live? This would reduce the need for superpowered antibiotics and possibly(?) eliminate the need for them. Could we see bacterial infections so weak that we wouldnt even notice them?

[Assistant]
The reason those bacteria became stronger is because they survived our best effort to kill them. We forced evolution's hand by eliminating the weak ones, and only the strong managed to survive. We already created superpowered antibiotics, and they resulted in super strong bacteria. The problem is that we have to make them strong enough to kill even the strongest bacteria, but not so strong that we kill the human cells at the same time.

Bacteria mutate much faster than humans can, since bacteria are ~~small and~~ relatively simple and reproduce far more rapidly than humans (i.e., mutations happen over generations, and bacterial generations are much faster than human generations). It's much easier for a simple organism to evolve than one as complex as a human. Also, consider the difficult position of defense. When you're on offense, all you have to do is find one way to beat your opponent. When you're on defense, you have to find all the ways to stop the attackers. It's much harder to build something that can defend against hundreds of different attack tactics than it is to find one really good attack strategy.

If we did manage to kill off all the strong bacteria, the weak ones would just mutate into stronger versions, and the cycle would repeat.

Edit: Added in the important stuff that Chel_of_the_sea caught me on.


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

[User]
CMV: I dont think there's anything wrong with swear words and I dont think there's anything wrong with saying them around children.

It's just words. When we get to a society where people aren't constantly doing offensive actions then maybe we can start worrying about offensive words and I wont mind, but it seriously bothers me the way we decide some words are offensive and rude.

To me it just goes to show how manipulable peoples opinions are if you feed them the opinion from birth and raise them in a society that doesnt question it.

Its far worse to raise your kids in a culture of violence eg. using guns and watching UFC on tv than it is to swear around them.

[Assistant]
>it seriously bothers me the way we decide some words are offensive and rude

I mean, that's the entire point of words. Otherwise they're meaningless grunts and utterances. They have meaning because we as a society choose to abide by that meaning, just like how paper currency has meaning because we say it does.

>Its far worse to raise your kids in a culture of violence eg. using guns and watching UFC on tv than it is to swear around them.

So? No one's presenting or forcing the option of having to choose between swearing near kids or raising them to watch UFC. Raping a child is worse than swearing too. The comparison doesn't mean anything. No one's forcing you to choose between the two.

If people don't want you swearing around their kids, for instance, if you're at their house, you ought to respect that.


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

[User]
Who would win in a war, The Borg, or The Zerg?

This was a debate between two of my friends. What do you think?

[Assistant]
I think the Borg would win.

Let's assume, for the sake of balancing equal factors, that the Borg cannot assimilate Zerg because of their peculiar biology and the Zerg cannot infest the Borg because of their particular composition and immunity/adaptation systems.

The bottom line is that the Borg are thousands of years ahead of the technology available to the humans combating the Zerg in Wings of Liberty. The humans successfully gun down Zerg even to the point of invading their home planet. But these same humans would be useless against the Borg. The Borg adaptation mechanism would render any Zerg or Human weapon useless.

So the Borg's weapons have firepower that can destroy any ship in the galaxy, even in a future beyond StarCraft (save for the transcendent species that USS Voyager encountered), and armor/shields that is immune to any known form of weaponry, would be pitted up against fleshy creatures that can be killed with mere bullets.

The only way to turn the tide of the war is for the Zerg to be able to infest Borg (without Borg adaptation) and Borg be unable to infest Zerg.

Borg use intelligent nanobots to adapt and assimilate and the Zerg use micro-organisms to infest. There is no reason to think that Zerg organisms would be able to outmatch Borg nanobots.

Maybe in some distant future, when the Zerg have progressed like the Borg have, they might be a match for each other. But the boundless galactic empire of the most fierce-some, malicious, and invincible cyborgs verses the war-torn, primitive, and petulant Zerg leaves little room for debate.


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

[User]
ELI5: Why Is It That I Can Hold My Bladder During 8 Hours Of Sleep?

I am not sure if I'm alone in this but, sometimes before falling asleep, I can feel that my bladder is full, and by full, I mean "I would piss like a race horse if I'd dare to relieve myself" full, and I'm too tired to get up to go to the bathroom, but I can spend the whole night with my barely-exploding bladder and still not wet my bed.

How is it possible that my bladder muscle (not sure if it's an actual thing), keeps all that piss in without me actively trying not to piss meself.

[Assistant]
Because when you fall asleep, you pituitary gland produces the hormone antidiuretic hormone (ADH) which instructs your kidneys to slow down the production of urine. This prevents your bladder from getting too full (the internal urinary sphincter automatically opens when your bladder is about 80% full, and you piss yourself).

In very young children with bedwetting problems, the body have trouble producing ADH, and so they do not slow down urine production during the night and they wet themselves in bed.

Also, your bladder is elastic, and can stretch to accommodate more urine when needed. When you get older, your bladder loses elasticity, and you need to get up during the night to pee.


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

[User] [Star Wars] Why is inefficient moisture farming an industry on Tatooine when, surely, any enterprising ship captain would be happy to make a profit just importing water en-masse?

[Assistant]
People in the Starwars Galaxy have learned their lesson to not rely on Trade, as its an easy way to get exploited on a planet-wide scale.

Remember, trade in the Starwars Galaxy is monopoly-ed by the Trade Federation, who used their profits (from exploiting planets) to fund a war against the Galactic government.


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

[User] ELI5: Why does your mouth water like crazy when you're nauseous?

[Assistant] Your stomach is filled with a somewhat weak acid. Throwing up acid is unpleasant, and can damage soft tissues in your mouth and throat. To combat this, your body produces extra saliva to coat your mouth and throat with a little bit of extra protection.


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

[User] A friend of mine in her late teens with no apparent defects suddenly passed away last week, during her sleep. The autopsy gave nothing as to what happened. Is this a common conclusion in autopsies ?

[Assistant]
Ditto to comments on drug overdose and rate of inconclusive autopsies.  Sometimes people, especially young ones, have heart arrythmias thst can lead to sudden death and in general that is very difficult to diagnose at autopsy.  Also in many labs two weeks is not enough to return a toxico!ogy screen.  So maybe the autopsy showed no anatomical cause of death but is still waiting on the laboratory studies.

I wish you the best in handling this sudden grief.


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

[User]
[Star Wars] Why did Qui-Gon not just take what he wanted by force?

He was willing to try to mind control Watto to had over the Hyperdrive, I don't see how pulling a light sabre on him would be any less honourable. Watto didn't seem to have any enforcers and it's likely that the only large armed presence would be under the control of the Hutts, so they could be in and out before anyone was the wiser.

Failing that he could just wander round the other stores until he found someone he could mind trick in to exchanging his Republic credits then return to buy it.

Seems easier than a convoluted pod racing gamble.

[Assistant]
While Watto may not have had muscle immediately there, Qui-Gonw as well aware that this was a Hutt world and he had no means of immediate escape. The Hutts do not take well to Jedi attacking and stealing from traders and would at the very least have taken a great interest in Qui-Gon and his ship.

Qui-Gon was trying to keep a low profile, the last thing he needed was the Hutts poking around and finding Queen Amidala and deciding to take her and then random her off to the highest bidder, or worse! Remember, it took a while to install the drive on the ship and a Jedi would have got a LOT of attention very quickly.

In regards to finding another one - the hyperdrive he needed was quit particular and he could tell that Watto was at least telling the truth when he said that no one else would have one. He was stuck trading with him.


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

[User]
How is mass converted to the energy of gravitational waves?

In the recently detected waves, three solar masses worth of black hole ... stuff ... was converted into gravitational waves. But any two masses orbiting each other produce waves, even if they're undetectable. Those waves are carrying energy, which apparently comes from a reduction of mass in the system. How does that work?

I'll pick an example: the earth-moon system is radiating gravitational waves at a frequency of about 4 x 10^-7 hertz at some teeny tiny eentsy beentsy wattage. Is the ordinary, non-black-hole-matter mass of the system shrinking by that same wattage? How?

[Assistant] Gravitational waves decrease the kinetic energy of the bodies, not by taking away mass. It's like a ping-pong ball bobbing in a pool of water. Over time, the amplitude of the bobs goes down, corresponding to a loss of energy of the ball (eventually it settles down and stops oscillating). That energy goes into the ripples in the pool.


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

[User] How do water molecules on opposite spokes of a particular flake "know" to reproduce a specific pattern?

[Assistant] It has to do with the crystalline structure. Water molecules have a specific shape, and they like to align together in specific ways. That leads to a hexagonal pattern in the crystal (and six-sided symmetry). But like tiling a floor, once you start the pattern, only certain alignments will then be allowed. And because it started symmetrical, it continues in that symmetry. So each 'arm' of the flake looks like each of the others because it started from the same pattern.


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

[User]
[Ghostbusters II] Where did Winston go?

Okay, so our establishing scene with the Ghostbusters centers around Ray and Winston getting goobered by overprivileged nine year olds. Then Dana's incident pops up and the plot gets rolling.

The Ghostbusters visit Dana's apartment, and Winston isn't there.

The Ghostbusters dig a very large hole in First Avenue, and Winston isn't there.

The Ghostbusters go to court, and Winston isn't there.

But then the Ghostbusters go back into business, and suddenly Winston is back. But he wasn't ever *not* a Ghostbuster...!

So what gives?

[Assistant] Winston was always jsut an employee of the Ghostbusters.  He wasn't a scientist and didn't reallycare what he did as long as he got a steady paycheque.  So when the ghostbusters see Dana they are visiting a personal friend, when they are digging the hole they are doing science in court they represent the company.  When they go back in business Winston is still employeed to bust ghosts.


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

[User] ELI5 Why do the Bloods and the Crips hate each other so much?

[Assistant]
It wasn't always that bad until drugs got involved. With the advent of cocaine and crack, the gangs needed to have places to sell it because it was an extremely profitable revenue stream. Eventually, those territories began to overlap and what was once minor disagreements turned into outright violence.

In short, C.R.E.A.M.


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

[User] How does a blacklight work?

[Assistant]
Black-lights shine UV light which you cannot see. There are many molecules and complexes that fluoresce under UV light.

What is happening is the UV photons are absorbed by these molecules which very briefly go into an excited state. They then lose some of the energy by non-radiative processes before emitting a photon that is slightly less energetic. If the difference is great enough the emitted light will be in the visible spectrum.

look up fluorescence on Wikipedia for more details.

If you mean "How does a black light produce UV light" that is down to the nature of the phospor material used in a fluorescent bulb.


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

[User]
ELI5:Why do powdered donuts taste "cold?"

You know what I mean? Whenever I eat powdered donuts, no matter how room temperature they are, they always taste "cold." It is the weirdest thing.

[Assistant]
The sugar, even in powdered form, retains a certain crystal structure. When in contact with water (in your mouth) it requires a certain amount of energy to "break" this structure and dissolve. It takes this energy in the form of heat from its surroundings (in this case from your tongue), making it feel cold in return.

If you want to know more about it, the energy in question is called "enthalpy of solution" and depending on the substance you're dissolving, it can either require energy to do so (making things cold) or release energy (making things hot).


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

[User]
[Harry Potter] Why wasn't Harry able to see the thestrals before Cedric's murder?

He saw his mother murdered in front of him as an infant, does the death only count if you can remember it?

[Assistant]
According to JKR, Harry didn't actually see his mother's death it because he was in his crib and it happened out of his field of view. He did't witness Quirrell's death because he passed out before it happened, and he didn't actually *see* Cedric die because he had his eyes closed when it happened.

Apparently literally witnessing a death isn't a requirement to be able to see them - rather, it seems to be that you have to have an intimate appreciation and understanding of death. Seeing someone kick the bucket in front of you just seems to be a good way to get there.


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

[User] Why does snow making a crunching noise when stepping on it?

[Assistant]
The small crystals of ice as they compress under your shoe rub against each other or may fracture and break in and of themselves. It's that friction that causes the sound, specifically the way in which it happens, because you're applying force over a large area there's many individual squeaks or creaks from ice grains breaking apart which happen to sound like a crunch or a more high pitched sound depending on some more specific factors.

You might have hear a similar sort of model of this when you bite an ice cube.


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

[User] ELI5: Why does a flock of birds fly in this "V" shaped pattern?

[Assistant]
The lead bird produces a V-shaped wake behind it like a speedboat.  The next bird will fly in this wake to gain an aerodynamic advantage and spend less energy flying.  The third bird gains an even greater advantage, and so on down the line.

Migratory birds use this strategy to cover vast distances without landing to rest, since the leader can drop to back to coast when its tired.

Typically the prime-aged birds will cycle through the lead and elderly birds and that years fledglings (who dont know the route anyway) will hang in the back the whole flight.


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

[User]
[Cars] How did the 10 or so local cars of Radiator Springs stay in business after the Interstate was constructed?

From my understanding, the Interstate bypassed the town, eventually removing it from the map and cutting the average amount of customers to almost 0. So how did Flo and Ramon and Luigi and Guido and Mater and everyone else stay alive if they barely have any income?

[Assistant]
Well, they all own their properties outright, so no rent or mortgage or anything like that.  And if they've gone so far as to take them off the map, one assumes that the tax-car isn't stopping by to collect anytime soon.  All told their expenses will be very low.  Add to this the communal nature of their town, and it doesn't take much cash flow to keep things going.

Between natural resources around, and one or two of the residents occasionally going into the bigger city to sell stuff, they get by.


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

[User]
ELI5: Why can plastic nurdles be made into other plastic forms but formed plastic can no longer be as easily recycled?

To my knowledge, nurdles are the primary pellets that are used as the source to form all plastic pieces. If they get melted down and formed into other plastic parts, what changes that makes those formed parts so much more difficult to melt down into another form?

[Assistant]
Once some types of plastic undergoes that melting process, it chemically changes and won't melt again, but burns instead. Try heating a plastic water bottle (don't).

You can re-melt other types of plastic, but with our current supply chain setup, it's cheaper to buy new pellets instead of collecting, transporting, cleaning, sorting, and recycling it. China used to buy a ton, but they've toned down recently.


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

[User] How do rockets burn fuel in space if there isnt oxygen in space?

[Assistant] They bring the oxygen with them in the rocket! There are two parts to the fuel a rocket carries: the fuel and the oxidizer. The oxidizer is not oxygen gas, it's either a solid compound that plays the same chemical role (like ammonium perchlorate) or a liquid (like liquid oxygen). In fact, rockets need to use the oxidizer while they are still in the atmosphere as well, because they need to burn so much fuel so quickly.


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

[User]
[Highlander] What makes an immortal "powerful"?

I'm thinking more about the chronicles of Duncan McCleod, not his clansman Connor (whom I'm less familiar with).

I've heard a lot about "when you take an immortal's head, you take his power". And I've also seen the videos of the "quickenings", when heads are taken, which are quite destructive (and more destructive for older/more "powerful" immortals).

I also recall seeing some documentaries where the dead immortal sort of takes over the live immortal (Duncan McCleod was once taken over by a "dark quickening", where he effectively became evil, and another where Richie Ryan took on characteristics of an immortal he killed, including falling in love with his girlfriend).

All that being said, I don't understand what they mean when they say, "when an immortal takes another's head, they take his power". It seems to me that Duncan McCleod is "powerful" because he trains like crazy and has trained with some of the greatest masters. Richie Ryan is able to kill many immortals that are much older and more supposedly "powerful" than him, likely because he trains with McCleod.

TL;DR: What does an immortal's "power" actually refer to?

[Assistant] It's the sum of an immortal's strength, knowledge, experience. Everything. Basically all the things that made them a person, their soul you might say. Since immortals, true to their name, live a very long time they tend to build a much greater reservoir of knowledge and experience than normal people, not to mention any they might have collected from killing other immortals.


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

[User]
When they measure the distance between objects like planets and suns, at what point do they start the measurement?

Do they start at the center of the planet and how do they handle elliptical orbits?

[Assistant]
It depends on the application. Typically in the solar system, we do it between the centers of mass of objects. This is good for figuring out where planets will be if you want to send a lander to them, for example, but then you really care about where the lander will actually land and so you also need a measurement of surface feature to surface feature.

For objects like stars, we don't know their distance precisely enough to care about the difference between start the measurement at the Earth or the Sun. And any ellipticity, while we can measure that because we can see the relative distances change or the position on the sky change, don't affect the overall measured distance, again because the errors on the absolute distance are so large.


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

[User]
When it is said that someone in a third world country lives on a dollar a day, what does that actually mean?

When it is said that someone in a third world country lives on a dollar a day, what does that actually mean?

What if you could buy a whole entire mud hut for just a few dollars?

How do they decide exactly what to put in the basket of goods?

Can't some places have higher cost of living, even in real terms?

[Assistant]
Usually, although these sort of reports never explicitly state that, they have already been adjusted for Purchasing Power Parity. That means that the converted value of the currency is adjusted to prices under the assumption that the same amount of real money should also anywhere on earth buy you the same representative bundle of goods (adjusted for regional idiosyncracies).
Once it is determined what a representative bundle of goods (usually consisting of food, housing, utilities, etc.) costs in both countries, the values are adjusted and the money a person in the third world survives on per day is then converted to dollars.
To summarize: real income is already adjusted due to purchasing power parity to accurately tell you: a person in the third world has to survive on that amount of money that would be equivalent to an american having to survive on one dollar per day.


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

[User] ELI5 Why do courts use not guilty instead of innocent?

[Assistant] The legal system is designed to determine whether someone is guilty, not whether they are innocent. When the prosecution fails to prove guilt, that in itself is not proof of innocence. Therefore the court states that they are not guilty instead. Innocence is presumed.


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

[User] ELI5: How do microphones work? I just do not get it.

[Assistant]
The sounds we hear are vibrations of air molecules. The pitch of those sounds relates to the frequency of those vibrations. Microphones have a lightweight sheet in them that easily starts to vibrate with the vibrations in the air. The sheet is attached to a magnet, (or a coil of wire) which also starts to vibrate.

Around this magnet, there's a really long coil of very thin wire. Whenever a magnet moves inside a coil of wire, (or a coil moves around a magnet) an electric current is induced into that wire. In a microphone, that current is very small, so the wire is connected to an amplifier which reads the current and makes it stronger while keeping its frequency untouched.

We can then take this current and feed it to a speaker or a recording device.

Fun fact, speakers are reverse microphones. Sound waves vibrate a magnet in a microphone which generates a current. A current vibrates a magnet in a speaker which generates sound waves.


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

[User]
How does the body eliminates fat tissue?

I have been changing my life style, eating habits and exercising more. And it made me wonder, how does my body eliminates the fat issue previously stored?

[Assistant]
It depends on what you mean by fat tissue.

Your fat, like the fat in your belly, is made up of huge adipocytes 100x+ more voluminous than fibroblast cells. These adipocytes are tethered together and packed densely with capillaries and larger vessels wending through. When you lose weight due to exercise or eating habits these adipocytes shrink in size (they're undergoing lypolysis). Basically, the lipid they've been storing is being burned up, so they shrink.

If you continually run a calorie deficit then eventually, and here the research is incomplete, your fat cells will decrease in number as well. The thought is that there is a certain turnover rate of fat cells, atomic labeling studies show ~10% of adipocytes turn over every year. So, unless they are replaced at the same rate, you will eventually decrease the number of adipocytes you have. Eating certain foods, and having a calorie excess, can lead to more pre-adipocyte stem cells to decide to differentiate into adipocytes. Just so, if you're running a deficit fewer pre-adipocyte stem cells will differentiate into adipocytes. So, over time, you'll lose cells naturally and they won't be replaced if you are restricting your calorie intake.

So you lose fat by the cells shrinking, and by the cells dying.


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

[User]
[Pokemon HGSS] I live in Goldenrod City and just saw a trainer walk his Wailord through the middle of the street. How!?

I don't even understand what I just saw, his Wailord was following him like it was nothing on dry land, with buildings and people everywhere! I've seen people walking their Goldeen and Remoraid on land before, but this is just crazy!

Edit: TIL Wailord is lighter than air. But what about the fish Pokmon I've seen strolling around?

[Assistant] If you examine Wailord's size and weight you'll discover that Wailords have such low density that they are able to float.  That trainer probably attached a string to the Wailord and pulled it around like an oversized balloon.


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

[User] ELI5 - Why does someone wake up feeling more tired after a lot/good night of sleep but feels more awake after a little/bad night of sleep?

[Assistant]
To get into a nice deep restful sleep your brain has to release lots of chemicals that make you sleepy.

When you wake up you are still clearing out those chemicals so you are drowsy.

If you don't get down into that deep sleep then you have less of those chemicals to clear out so you aren't as drowsy.


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

[User]
ELI5: What does the pope do?

He's just a figurehead, right?

[Assistant]
Figurehead? No sir he leads the entire Catholic church in a very real sense.

The pope is considered the one man on Earth closest to God, he has the power to set new doctrine, change church stances, call councils and much more.

To give you an idea of the power invested in the papacy there is a belief called infallibility, when the Pope speaks inf an official capacity on church dogma it is literally impossible for him to be incorrect.

And yes there was once a time where the Pope had more tangible power, actually acting as more of a king then spiritual leader, but the office remains one of the oldest of its kind in all of human history and the pope does remain very influential on many levels. His Holiness remains arguably one of the most powerful men on earth, leading a flock of over one billion faithful.


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

[User]
What is a bose-einstein condensate?

I've long since wanted to know what a bose-einstein condensate is but even after looking it up several times (I've wanted to know for a long time) I still have no clue. I just can't wrap my mind around it. I can't visualize it and even after trying google images, I just find graphs and unrelated stuff. Like plasma, and PLEASE correct me if I'm wrong, I imagine as a sort of goop or runny slime consistency but generally in a ball. Also, I know it's a superfluid, does that also make it a fluid? Is a superfluid just a sub-category of fluid? Please help.

[Assistant]
A Bose-Einstein condensate is a collection of atoms that all occupy their ground state, exhibiting quantum phenomena on a large scale. You definitely could not hold one or really even observe one with your naked eye since they tend to be very dilute, *very* cold, and need to be confined in some way. This is why you can't find pictures of one, just illustrations and density graphs from experiments.

Bose-Einstein condensation is related to superfluidity, but they are not the same thing, Bose-Einstein condensates are not necessarily superfluids.


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

[User] ELI5: Why do we say things like 'uh' and 'um'?

[Assistant] It is a filler we use. When we are speaking, often we need to gather and formulate our response before we speak. We also feel the need to respons as soon as possible when spoke to, even if we have not gathered our thoughts. These filler noises do not interfere with our thinking as speaking does, recall how hard it is to speak on one subject while actively thinking about another. These noises acknowledge that we are spoken to or that we are not done speaking while enabling us to continue to formulate our response.


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

[User]
[Back to the Future 2] So when Marty and Doc realize in bad 80s that Biff gets the Almanac magazine, why don't they just travel back and kidnap him and remove him from 50s timeline?

I mean, instead of going through all that effort to keep him in the timeline (when they know he is evil, for crying out loud, he tries to *kill* Marty in the bad 80s time line) why don't they just push him into the time machine, wow him by it's flying abilities and drop him off in the 1400s where he wont bug anyone? Or if that's too evil (basically condemning him to die with no native language skills and no supplies, they can't let him keep any lighters or anything that would maybe mess with the timeline), why not just get him drunk and while he's passed out fly him far away in their fast future flying DeLorean but stay in the same 50s timeline. Just make sure he is far away (location-wise) .... somewhere that future self can't find him. Then future is preserved and they don't have to do all the weird scrambling around that they did in the movie. What say you all?

[Assistant] Chaos effect - doing either of these things violates the established timeline they're trying to return things to.  They don't want to create further possible deviations, they're trying to steer the timeline back to its original (modified by Marty) path.


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

[User] ELI5: What do people mean that centrifugal force doesn't exist?

[Assistant]
Centrifugal 'force' is the sensation you feel when an object you're in turns, such as a car going round a corner. It feels as though you're being pushed away from the centre of the turn, onto the outer wall of whatever object you're in.

In reality, the object you're in is turning toward the centre, and it exerts a force on you toward the centre of the turn. Without this 'centripetal' force, as it turned, you would carry on in a straight line.

Essentially. The actual force being exerted is centripetal (toward the centre of the turn) but you *feel* as if you're being pushed outward (centrifugal).


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

[User]
How do out memories stay intact even when cells/neurons are completely replaced?

The human body replaces all of its cells every couple of months, right? Well, how is information like memories in neurons or scars on the skin kept through the replacement? Wouldnt the scar eventually become same old skin, or the neuron become a new cell to be engraved with information- as if it was a computer file being overwritten? Some scars do fade, i guess. But others seem to stay no matter what you do, even after decades when the cells have surely been replaced.

[Assistant] Neurons aren't replaced like other cells. There is very minimal neuronal regeneration in the brain. Further, our current understanding is that memories are stored at the circuit level, not the single cell level. So disruption to any part of the circuit could impact a memory. Unfortunately, even the process of accessing the memory allows the opportunity to corrupt it.


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

[User]
[Star Wars] Does the theory of relativity apply in the SW universe? Do some planets go through time quicker than others?

Since someone here once posted:

>"One piece of evidence for relativity in Star Wars is that Luke receives all his training from Yoda in the time it takes Han and Leia to travel to Bespin without a hyperdrive.

>That would be consistent with the idea that the Millennium Falcon is travelling at a high sub-light speed, enabling Luke's months of training to coincide with a few days on the Falcon."

[Assistant]
Relativity is bypassed by the rules of the Star Wars universe, but it does exist.

The example of Luke training while Han and Leia went to Bespin actually has a much more mundane explanation. As you remember, their hyperdrive was down. They had to travel to Bespin on their backup hyperdrive (much slower) which took them several weeks.

The reason ships traveling at superluminal speeds doesn't break relativity, and can happen at all, is because hyperspace is a separate dimension that is parallel to our own. The ships access this and use it to travel between points without breaking the laws of physics and to avoid the effects of time dilation.


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

[User]
Where did the concept of "words as violence" originate from?

I can't seem to find where this idea originated. And besides it being a discoursive way of thinking - is there any hard science that justifies equating the spoken word with (physical) violence?

[Assistant]
The notion that words--or more properly discourse--cause violence   gained steam with the post-structuralist philosophies of Foucault, Derrida, and so forth. Foucault, for instance, wanted to demonstrate the categories, classifications, and system of discipline (see both *The Order of Things* and *Discipline and Punish* in particular) had material effects on bodies. The point being that classifications and so forth aren't neutral systems but productive of the world we live in. When some bodies/subjectivities fall outside of the dominant classifications, then they become classified as delinquent, insane, or otherwise undesirable and, thus, in need of correction or punishment.

Judith Butler did a great deal of work incorporating these insights into feminist theory. Her point is that hetero-normative and gender-normative systems of discourse and classification do violence to identities that fall outside of those frameworks by both authorizing attempts to 'normalize' and to punish those that refuse to change to the established norm as well as causing mental anguish to those that fall outside the norm.

So the prevalence of discourse that constantly position, for instance, queer identities as immoral, illogical, and/or correctable does violence to the bodies of queer people because it both authorizes physical attacks on those people as well as causes mental pain and anguish.


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

[User]
ELI5: The Higgs Boson, Quarks and the Standard Model

I recently saw that the Higgs Boson has been discovered and I always thought it had something to do with string theory however Wikipedia said something about Quarks and the Standard model, could someone ELI5?

[Assistant]
The Standard Model is the theory used to explain the other things.

Quarks are fundamental particles which make up subatomic particles.

There are 6 flavours of Quarks; Up, Down, Charm, Strange, Top and Bottom.

These are divided into 3 families. The first family is Up and Down. The second family is Charm and Strange, which are heavier versions of Up and Down. The third family is Top and Bottom, which are even heavier versions of Up and Down quarks. Families 2 and 3 decay incredibly rapidly into Up and Down quarks; so everything we see around us which is made of quarks is made up of only these two quarks.

Inside an atom, the nucleus consists of protons and neutrons. A proton is made up of 2 Up quarks and 1 Down quark. A neutron is made up of 1 Up quark and 2 Down quarks.

This means that in order to make an atom, you need Up quarks, Down quarks; these are part of a group called Hadrons. You also need electrons, which are part of a group called Leptons.

Hadrons can be thought of as having volume associated with them; Hadrons cannot be smashed down and must occupy distinct spaces. Leptons, on the other hand, don't have a limit on how many can occupy any given space.

You also need Gauge Bosons, which are force-carrying particles. They mediate the fundamental forces; electromagnetic, strong nuclear, weak nuclear. Photons carry the electromagnetic force. W and Z Bosons carry the Weak Nuclear force, and Gluons carry the Strong Nuclear force.

The Higgs Boson is a different beast entirely. Normally, in empty, uncharged space, you'd expect any given field to be zero. This is how it works for most forces. The Higgs field, however, is non-zero in empty space.

This is important, because the maths for how particles interact has all the particles as massless - mass terms foul up the maths, and make it not work. However, since the Higgs field is non-zero in free space, that means that things moving through space are having to push through it, and this is what gives them mass.

Photons don't interact with the Higgs field, and remain massless, but anything which has mass interacts with the Higgs field.


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

[User]
What is the storage capacity of the human brain?

Do we have any estimate for how much a person can actually know?  And what happens when they reach that limit?  Does learning new things become impossible?  Do older memories simply get overwritten?  Or do things just start to get jumbled like a double-exposed piece of film?

[Assistant]
You seem to think that biological memory storage is in any way similar to computer memory. The two cannot be more different. You have to come up with a completely different way to measure memory capacity for your question to make sense.

In biology minor details are unimportant and easily replaceable. Generalization and reconstruction from those generalizations are the norm. Selectively forgetting is in fact one of the most important function of our brain. Its how generalization becomes possible.

If you know something about polynomial approximations, the brain is like a very high order polynomial approximating that data that you think its storing. It would gladly replace one similar situation by another and interpolate your memories to fit. Save for a few highly-trained or neuro-diverse individuals, memory is very unreliable when it comes to specific details from long ago. Only the contours remain.


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

[User]
ELI5: How is it that illiteracy still exists in the United States?

Given that school is required for kids how is it that not everyone has become literate by now in the United States?

[Assistant]
Illiteracy still exists because: Some kids actively refuse to learn to read, and they manage to fake it well enough that they fall through the cracks of the schooling system. Others are severely dyslexic and so are really only partially illiterate, or they have severe mental handicaps preventing them learning to read.

But statistically these people make such a small percentage of the population that we do have a fully literate society for all practical purposes.


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

[User]
ELI5: The myth that humans only use 10% of the brain. How is it incorrect?

With the new movie coming out and this myth being talked about a lot, can anyone explain exactly how it's wrong?

[Assistant] When you point at something, you only use 10% of your fingers.  Obviously, that doesn't mean only 1 of your fingers is functional, just that your other nine fingers aren't needed for that activity.  Also, it doesn't mean using 100% of your fingers to point at something would make you "better" at pointing, you would just look like a weirdo trying to cast some kind of wizard spell.


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

[User]
Why do cats like to knock things off of count tops and tables?

My cat has been doing this like crazy lately... There has to be done evolutionary reason, right?

[Assistant]
Cats, like many mammals, are incredibly intelligent, social creatures who engage in play behavior and are good at detecting patterns. What may have started as an innocuous play behavior (batting around an object) escalates into an attention-seeking behavior if and when the cat notices you react strongly to it.

There is no evolutionary reason in the sense that "cats who knock things off tables are more likely to breed" or anything. Rather, cats evolved to be smart, and smart enough to figure out how to play dirty mind tricks on humans.


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

[User] ELI5: Why does Benadryl make me sleepier than OTC sleeping pills.

[Assistant] Benadryl (diphenhydramine) is actually the main ingredient in almost all OTC sleeping medications. You probably think it makes you sleepier because you often take benadryl when you are trying to stay up, where you would notice it much more than if you took it when lying down (where you would just drift off)


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

[User]
ELI5: I hit the 'a' key on my keyboard, and a letter 'a' appears on my screen. What are the steps that link these two?

Let's assume I'm using a word processor like Microsoft Word. What then are the steps from 'pressing a key' to 'text appearing on screen', both in terms of the hardware and the software.

[Assistant]
**ELI5**
The controller circuit in your keyboard detects the press of the key. It sends this information to the USB controller. That controller sends this information to the USB host controller inside your computer.

The USB host controller sends that information to the processor. At this point it's a software thing.

The OS sees that a key has been pressed. It checks to see which applications are open and which one "has focus" (meaning the last program you clicked the mouse in).

In this case that program that has focus is MS-Word. The OS passes the info about the key press to MS-Word.

MS-Word checks to see what the key was and decides what to do based on that. For this example let's assume a document was open and the cursor is visable. MS-Word sees where there cursor is and adds an "a" to the document at the cursor position.

**ELI>5**

There are lots of levels of detail here. As an example, the keyboard actually sends two messages. One when the 'a' key is pressed and one when it is released.  Also the OS checks first to see if the 'a' has any system wide meaning. Since it's 'a' it doesn't, but if it was instead something like "volume up" or  CTRL-ALT-DEL then it would "trap" the signal and perform the system function instead of sending it all the way to MS-WORD.

Similarly word does the same thing. Many of the menu items in word have special keyboard shortcuts so word checks to see if the key is one of the shortcuts.


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

[User]
If your skin temperature is lower than usual and you stick your hand/foot in hot water, does it do actual damage?

I was thinking of this as I went to take a shower last night and my feet were cold. The water wasn't hotter than it normally would be but it felt like sticking my feet in boiling water. Is it just the sensation or is there actual damage being caused? Also, what exactly causes this to happen?

[Assistant]
Sensory or neural adaptation is a change in time in responsiveness to a constant stimulus, for example, what your clothes feel like on your skin.  When your feet are cold, the neurons that transmit a feeling of warmth are not firing.  When you submerge them in warm water, these warm-sensing neurons begin firing rapidly signaling heat, but you're also signaling a rapid temperature change.  Because of the rapidity with which your body was sensing the rise in temperature, nociceptors, or receptors that signal pain, became activated, warning you that something may be potentially wrong.

Unless you are actually using boiling water, there is likely no damage being caused.


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

[User]
[Marvel] What if Bruce Banner was fat?

Imagine if Bruce Banner was 400 pounds, crazy eating disorder.

Does the Hulk remain the same?

[Assistant] In one future, an aged Hulk appeared to have a gut (even before he swallowed a gray-haired Logan). However, when this Hulk reverted to being Banner, he was as scrawny as ever.  This suggests that Hulks can get fat, but also that fattening up their human form may not be the way to do it.


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

[User] ELI5:. How can I sit in a ~200 F sauna and not get burned, but water the same temperature spilled on my arm will burn and blister my skin?

[Assistant]
Both correct answers are here already but neither in the same post with one another.  First, water has high heat capacity.  That means that even a small change in temperature for water = a ton of energy.  So 200 degree water has thousands of times more heat than air for every degree of temperature change, and that's based on MASS.  The density of water is much higher than that of air so there's a lot more of it close to you when you're exposed to it.  Finally, because of the density, it transfers energy much much faster.  Heat is transferred when molecules hit one another - more density means more molecules close together, which means more collisions = faster energy transfer.

For an example of this at work try to bake a potato in a 450 deg F oven while boiling one in 212 deg F (boiling) water.  Should go alot faster in the water.

tl;dr - Water has more energy in a smaller space and transfers that energy much faster.


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

[User] [Star Trek DS9/Voyager] How might things have played out differently for both series if the Bajoran wormhole ended in the Delta Quadrant and Voyager was thrown into the Gamma Quadrant?

[Assistant]
Not complete by any means, but just a few thoughts on the matter...

From the Romulan side, the Dominion War wouldn't have happened so they (most likely) wouldn't have pressed the Remans so aggressively into service and relied so heavily on them as shock troops and weaponsmiths/shipbuilders.  This would prevent the rise of Praetor Shinzon and the annihilation of the Romulan Senate.  Instead of the Romulans becoming tenative allies with the Federation following the Nemesis Incident, they would have maintained their aggressive and meddlesome activities in the Alpha Quadrant.

The Klingon Empire really received a much needed morale boost with the dawn of the Dominion War.  They were a stagnant, listless society and a pawn being played with between the Federation and the Romulan Star Empire.  Mobilizing and uniting the entire Klingon Empire to crusade in glorious battle reignited a passion in these proud warriors.  This brought them respect and fear placing them once again as a major player in the Alpha Quadrant.

With the Borg *so* much closer to the Federation than ever before, the Federation would ramp up to a war footing that made their recovery from Wolf 359 up to the Dominion War look like a recess at elementary school.  The dogs of war were already barking loudly at Starfleet Command and with a massive and imminent Borg threat at their doorstep, the military would be given levels of power and control never before seen in the history of the Federation.  Frankly, this could even possibly lead to the rise of a prime universe Terran Empire akin to its dark mirror universe cousin.


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

[User] What exactly does it mean to "lock" your legs and why does it cause people to faint or pass out while standing?

[Assistant]
It means your knees are bent slightly backwards, so that your thigh and your shin are closer to each other in the front than in the back.

The movement of your leg muscles is part of what brings your blood back from the legs to the heart. This is called the muscle pump.

Locking your knees means you arent moving your legs, which means no muscle pump  and in absence of muscle pump, your blood pressure is lower than usual.

Low blood pressure can cause low oxygen to your brain, which results in you passing out.


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

[User]
ELI5: Why are logical fallacies so convincing?

It seems that the entirety of most debates and politics (including on this site) consist of logical fallacies. The most common examples are Ad Hominem attacks.

Why are these so convincing? I am completely ignorant of psychology or sociology, but am very schooled in logic and math. However, even I am surprised by how easily I am swayed by these fallacies.

[Assistant] Because human brains aren't built to be rational. It's possible that people can instinctively *recognize* when rational principles are true, but actually applying them is very much something you have to learn.


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

[User] [Star Wars] What kind of droid is BB-8? What is his model's original purpose? C3PO is protocol, R2D2 is an astromech, BB8 is...what? A pet?

[Assistant]
He's an astromech like R2-D2.

His unique shape is because each of those round orange circles on his body are actually tool-bay discs, each containing a different gadget. This means that when he's docked inside a ship he can move his body a full 360-degrees to fix problems. Outside of a ship it makes him totally upgradeable - if you want his to have a different capability just switch out one of his old tool bays for a new one.


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

[User]
[Marvel] Can daredevil safely drive a car at rush hour using his echolocation powers?

Even though he is blind his other four basic senses are heightened and his superhearing ability gives him sonar-like powers.

So can he drive a car in a big city at rush hour time without getting involved with an accident?

Edit: Should have capitalized Daredevil :)

[Assistant] Sonar waves hit the first solid object and return to the receiver, which is how position is determined. Daredevil would have a really clear "picture" of where the windshield was, and hear the screams of all the soft, vulnerable pedestrians as he ran them down, but that's about it.


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

[User]
ELI5: Why is Homosexuality the big issue in southern christian parts of the USA and some other nations in the world? Doesnt the Bible forbid alot more than simple homosexuals, like alot more?

Why isnt something like sodomy/anal sex (which is probably alot more widespread than being gay) the "big issue"?

[Assistant] Because a lot of religious folks like to pick and choose which parts of the bible they are against. If they think it's wrong then "it's against God's word!" But if it inconveniences them they conveniently ignore it.


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

[User]
The relationship between distance and torque seems like magic to me. What is actually happening to increase torque with a longer lever?

Why is the torque increased simply because you are farther away from your pivot point?

[Assistant] A more intuitive way to think about it is if you lengthen the arm  you are actually creating a longer distance to travel to get the same amount of work done to rotate  the same amount.  Since you are moving a longer distance it is easier for you to move the arm. You do not have to put as much peak force on it.


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

[User]
[Mass Effect] Shepard is successful and established in the military, yet knows almost nothing about basic interstellar life. How did Shepard get such a high rank while so uneducated?

Shepard's N7 armor indicates education to the highest degree possible at Interplanetary Combatives Training, known for being an intensive school - and has worked up to the rank of Commander.

Yet Shepard has to be introduced to all the other races as if it's the first time, doesn't know what the Citadel is, doesn't know how Mass Relays work - and frequently reacts with surprise when hearing basic explanations.

How can a Commander with so much education have so little knowledge, and how did it not affect such a significant military career? Why does nobody question such ignorance on basic facts?

[Assistant] They taught him all that humanity knows about the galaxy, which at the time wasn't that much. Remember humanity hasnt even been in the Galactic community not even a century. Shepard was famous because he/she made a lot of firsts for mankind. Shepard is the person who rewrote textbooks and politics of interstellar diplomacy and knowledge.


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

[User] I've heard that Einstein's equation of relativity, E=mc2, is not the full equation in some cases. Can someone explain when this is not the entire equation, along with how it is used?

[Assistant] That is the energy that something has at rest. When something is moving (relative to some other reference frame), it has kinetic energy. When this is slow, this is 1/2 mv^2 so you could write the whole thing as mc^2  + 1/2 mv^2 , but if you're dealing with relativity then things probably aren't slow, so the whole thing is E=ymc^2 where y=1/sqrt(1-v^2 /c^2 ) is the Lorentz factor. Equivalently, you can write it E^2 = (mc^2 )^2 + (pc)^2 where p is momentum.


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

[User]
[Teen Titans] After realizing that Ravens father was going to send Slade/someone to capture Raven why didn't the Teen Titans contact the Justice League?

I feel like while Slade and his army was strong, it would be hard for him to fight the Teen Titans and the Justice League at the same time (especially Superman). I mean this is the end of the world, why take chances?

[Assistant]
The same answer to every [Why didn't super hero A contact other super heroes] question.

They wouldn't be super heroes if they ran to the grownups every time something got hard.

They could either handle it or thought they could.


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

[User]
ELI5: Why did China never explore the world like Europeans?

I'm just reading about the greatness of Zhanghe's fleet in 15th century china in my history class. Seems like they had the technology but somehow where just missing that spark. Why didn't china explore the Americas, Australia, Europe, etc.?

THey had compass centuries before europeans...

[Assistant] Under the Ming dynasty, China adopted a policy of *Haijin*, meaning "sea ban". Convinced that it was already the most advanced country in the world, the Chinese Empire became isolationistic and inward-looking. By the time they realized that the Europeans had become more advanced, there wasn't much they could do about it.


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

[User] [DC Comics] So how powerful is Mr. Mxyzptlk? What are the most impressive things he can do?

[Assistant]
Anything short of unmaking his entire universe, really.

He's effectively a whisker short of true omnipotence, only limited by his status as a fictional character. (A fact he is aware of.)

He could tear every individual atom in Superman's body apart. He could pack the entire Earth, and everything on it, into a sphere less than a nanometer wide. He could bend the gods of the DC universe to his will without effort.

And despite all his power, he still holds back immensely, because he finds it fun to mess with lesser beings like Supes.


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

[User] ELI5: Why does salt and ice make it colder, but at the same time when you put salt down on snow, it melts it faster?

[Assistant]
Putting salt on ice doesn't make it colder or change the temperature of things at all. It only lowers the temperature required to make water a solid, which is why ice begins to turn back into water (it's not cold enough anymore).

If you're wondering why you mix ice and salt when using things like an ice cream churn, it's because having 32 degree Fahrenheit (or less) water helps by creating more contact area with the ice cream tub. So by having literally ice cold water, it helps freeze the ice cream faster than having ice cubes stacked around it with minimal contact.


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

[User] How detailed is our knowledge of our own solar system? Is there any possibility of there being a physical body large enough to be classified as a planet that we have not discovered yet?

[Assistant]
First let me tell you the story of how Neptune was discovered.

All planets prior to Neptune were discovered by astronomers looking at the sky.  As some scientists were looking at the data for the positions of Uranus in the sky, they noticed that Uranus was not behaving quite as predicted by Newton's gravity.  They did a few calculations and determined that another planet had to be out there, gravitationally pulling on Uranus to give it the orbit that it had.  Lo and behold, when astronomers pointed their telescopes where the scientists told them, there was a planet right where it was supposed to be.

So, long story short, it is unlikely that there is any planetary sized body in our solar system as we would have detected its effects on the orbits of the other planets.


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

[User]
ELI5: Why is the consistency of my ice cream different when it melts and I refreeze it?

My ice cream is so frosty :(

[Assistant] Ice cream isn't just frozen. It's frozen while being churned. This gives it a fluffier consistency, filed with air pockets.  You'd have to refreeze the ice cream while keeping it moving. While at rest, it freezes solid.


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

[User]
[Hulk/Bruce Banner] Why do certain Hulks appear nonhuman?

Bruce Banner has a wide range of personas *and/or* transformations, despite their main shtick revolving around getting angry.

Theres Savage Hulk (most common Hulk), Green Scar (Sakaar), Joe Fixit (a gangster/enforcer), Professor Hulk (Nikola Tesla with muscles), *Immortal Hulk (self explanatory, but weird),etc. These Hulks look more or less human and can pass as such (mostly Joe Fixit). But there are other Hulks who look *less than human.*

Theres Kluh (Hulk when he Hulks out), Guilt Hulk/The Beast (Banners remorse and regret), and Devil Hulk (trauma from Banners father). These Hulks appear almost reptilian-like. Kluh has armored skin, sharp teeth and claws. Guilt Hulk has spikes and claws all over his body, and has a muscular but elongated body. And Devil Hulk looks like Godzilla as a Hulk.

Why do most Hulks look human and others dont?

*Note: Immortal Hulk goes through unique transformations, but for the most part looks human.

[Assistant] Most people think of the Hulk and his powers in absolute terms of what a particular Hulk can do as part of the overall "Hulk Powerset" - that is strength and regeneration being common to all with distinct gamma twists for the extra abilities different incarnations can have. But taking this point of view is analogous to only considering the symptoms and not the disease. The true power here is actually Banner's - the power to manifest himself into different aspects of his own subconscious personalities. Essentially a personal form of reality warping if you will, fuelled by his personal self-sustaining infusion of gamma energy.


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

[User]
ELI5: why when you think or see very sour things, you start to salivate

I was watching a video of someone eating lots of warhead candies and I started to salivate, this has happened before, I was wondering why this happened?

[Assistant] A sour taste comes from acids in the food, so it may be a response to help protect tooth enamel from being destroyed by the acid.  This is why you salivate before vomiting, as well.  So your brain could be deciding you're about to eat something acidic, and pumps up salivary production in response?


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

[User]
[Life] How would the alien lifeform be such a dangerous threat to Earth?

They didn't show anything about it reproducing and the only real dangers seemed to be it's durability and ability to consume matter and grow in size. So would it become some Godzilla sized lifeform and grow indefinitely?

I was also wondering why dangerous alien lifeforms always seem to incorporate tentacles as their primary weapons, why is that? Think of Sentinels in The Matrix (not alien but still), Aliens and their tails, etc. Is it because multiple appendages are superior to less?

[Assistant]
>I was also wondering why dangerous alien lifeforms always seem to incorporate tentacles as their primary weapons, why is that? Think of Sentinels in The Matrix (not alien but still), Aliens and their tails, etc. Is it because multiple appendages are superior to less?

Tentacles are simpler than limbs of endoskeletal or exoskeletal creatures. They are a relatively simple design, just a limb of muscle with no distinct joints.

Tails are a different matter. Because they are attached to a spine, they can be made to pack considerable velocity, while not being occupied with bearing the load of the creature - although kangaroos do stand on their tail while delivering a double kick.


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

[User]
[Mad Max] What was in the War Rig's tank?

Was it just completely full of milk except for the smuggler's compartment? Why?

[Assistant]
The extra tank on the back had Guzzoline. The big tank seemed to have a few things in it. From shots we get to see from the inside of the smuggling compartiment, they seem to be hauling vegetables and milk.

The Warboys announce what they're carrying when they leave Joe's fortress. They're haulin Aqua Cola (water), Produce (vegetables) and Mother's Milk (mother's milk). They're probably using that to trade with Gas Town for Guzzoline and to trade with the Bullet Farm for, well, bullets.


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

[User]
Whats going on in your body when you get the irrational "I feel like something is behind me" feeling?

I'm sure everyone has gotten this at some point. Its the uncomfortable feeling you get maybe if its late at night, where it feels like someone is behind you. Its an urge that can only be satisfied by turning around and checking. What is going on internally when this happens and what causes it?

[Assistant] Humans evolved in the wild. We were not always so completely safe from other predators. People who developed a good response to the possible threat of a predator typically survived long enough to reproduce and pass on those traits. What you consider as irrational now may have been a perfectly justified response when our ancestors roamed and foraged. Having an instinctual response to a possible risk of predation is commonly seen in other animals ranging from fairly basic animals right up to primates. It's a fairly basic response, except in humans it has developed as a complex state of alarm and corresponding changes to things like adrenaline release, feelings of anxiety and paranoia, goosebumps which (were we to have hair like apes) would make us look bigger and more threatening, also blood in your body is redirected from your gut and viscera to your limbs and brain to allow fight or flight. This is your sympathetic nervous system engaging.


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

[User]
Can logarithms have imaginary bases? And is log(i) defined?

I understand that e^(ix) = **i** sin(x) + cos(x). But can we go the other way and take the logarithm of imaginary numbers?

EDIT: Thanks for the responses! (And I switched the "i" from "cos(x)" to "sin(x)"

[Assistant]
Start with that identity, but remember the i goes on the sinx, not cosx. Let x=/2 . Then e^(i/2) = i. Then log both sides: (i/2)log(e) = log(i). Then all normal log laws apply.

As for imaginary bases, remember that if a^x = b, log^a (b) = x. So if you have log^i (p) = q, that means i^q = p. Then i^q = e^qlni = e^qi/2 = cos(q/2) + isin(q/2) = p.