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

[User]
When a magnet attracts a piece of metal upwards, where does the energy come from?

Let's say I have a piece of metal on a table and I hold a magnet over it so that the piece of metal is attracted upwards. It has increased its potential energy, but where did that energy come from?

[Assistant] The best way to understand this is to reverse the process.  Say you have a magnet holding an iron bar over a table.  With your hand you pull the bar off the magnet and put it down on the table.  Where did the energy to do that come from?  From you.  You stored energy in the system by separating the metal from the magnet, putting the combined magnet+bar at a higher potential (with respect to the magnetic field) than it was before.  If you let the magnet get close enough to the metal to pick it up again, you're just releasing that energy that was stored there, and putting the system back at a lower potential (wrt to the magnetic field.)  Or alternatively, you're trading energy between being stored as gravitational potential and magnetic potential.


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

[User]
ELI5: How many languages can a baby learn naturally during the language developmental stage?

Most kids learn one, maybe two languages during this stage, but what's to stop someone from learning, say, five or ten languages? How many is too many for them to process? Am genuinely curious about this.

[Assistant]
Unfortunately there isn't going to be a concrete answer.  Theoretically any child could learn an infinite number of languages, but in order to learn any number of languages, whether 1 or 1,000, it takes immersion in the language.  Computers and flash cards can't provide this immersion; it takes human interaction with fluent speakers.  It would be difficult to provide this type of environment to say the least.   Just imagine the scenarios that would have to take place for a child to be immersed in 5-6 languages.  Possible?  Oh yes.  But, also a very atypical upbringing.

Children learning multiple languages have been studied and their ability to avoid confusion is something that has fascinated researchers.


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

[User]
[General Horror] What's the police report on horror movies?

Your average horror movie ends with a fuckton of murder victims, killed in a variety of weird and sometimes literally impossible ways. There have been no sightings of any suspects, no clear motives, often no clear *opportunity*,  and the survivors are all giving insane but extremely consistent stories that the killer was a skin-wearing jazz monster or something.

So, what the fuck is going on?

In most horror movies, it seems like people don't know the supernatural exists. So what does the police report on this look like? Do they arrest the victims who are the last witnesses? Do they just leave it unsolved? Or do they just shrug and put out an APB saying the suspect is African-American, 6,5, made of angry bees and last seen inside a bathroom mirror?

[Assistant] Basically the end of an horror movie is the premise of another horror movie. There is some short lived fuzz from the media, police conduct some investigations but then they found a scapegoat (usually a dead victim) or put all under the rug because admitting a supernatural explanation would shatter their vision of everyday life. Witnesses are eventually outcasted or they convince themselves that was all a trick. Until the next protagonists the horror movie reach them to investigate on the old case that now is haunting then. A vicious circle.


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

[User]
[Ghosts/General] Do ghosts continue with their paranormal activity even if no one is around to witness it?

If a house was completely abandoned with no cameras or witnesses or anything like that, would the ghost that is haunting it continue to throw things around or turn lights on and off?

I know ghosts don't always know they're dead but that can't always be the case, some are intentionally trying to creep the inhabitants (or any visitors) out but what are they doing if there are none?

[Assistant]
It depends on the type of ghost. Some things we call "ghosts" are mere manifestations of an emotion. If there's anything around that they can draw energy from, people or higher order animals generally, then they will convert it into that emotion and lash out with it. When there's no one around, they go dormant.

Other ghosts, with more of a sense of self, try to scare people away so they can have the place to themselves. Then they go back to whatever their routine was. Some may not be capable of thinking beyond whatever moment they're re-experiencing. Some may be free to do more stuff.


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

[User] [Batman] Would Batman allow any of the Robins to continue fighting crime if they became fathers?

[Assistant]
I mean define "allow", because in that context each of the Robins would be full adults, not children. They can do whatever they want. Batman's not their god, even right now his own son has run away from home to go fight in a shonen tournament.

But would Bruce have a problem with the Robins fighting crime as parents? No, not really. He's a parent, he fights crime, he lets his own biological and adopted children fight crime. He fought crime after his adopted son died, he fought crime after *he* died, and he fought crime after Damian died. Depending on the timeline/continuity, one of his children (either Dick, Tim, Damian or Helena) goes on to become the next Batman, so barring some major character shift, it's doubtful he'd have a problem with it.

Bruce actually tries not to press too much of his own issues on the Robins. Yeah he's moping and broody, but he still wants each of his children to be happy, or to at least live independent lives. That's why if a Robin chooses to leave, Bruce doesn't make them stay. If they would choose to have a kid, then Bruce would probably just be a proud grandparent.


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

[User] Since H2O is a polar molecule, can you magnetize water?

[Assistant]
The polarity of water is its electric dipole not its magnetic dipole.  You normally see magnets where atomic spins (magnetic dipoles) line up rather than molecular electric dipoles.

But could you align all the charges?  Yes.  If you put water inside a really strong field it would indeed macroscopicly orient to align with that field.  The caveat being it would have to be an extremely strong field to overcome the inter molecular forces at work.  If the system was then cooled (think sub 10K) it could stay in that orientation without the field until each molecule got enough energy to rearrange.


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

[User]
[Star Wars] How did palpatine get rid of the republics debit?

So from my memory of the clone wars show theres a couple episodes about banking and the republics debit which make it clear there in extreme debit, and were planning on going into even more debit had padme not stopped them. However considering the empire is building a moon sized battle station in the original trilogy it doesnt seem like there in any debit. So how did palpatine get rid of the existing debit and how did he ever plan to recover from the insane amount hed get if not for padme stopping the senate?

[Assistant]
Palpatine controlled the IGBC (Inter Galactic Banking Clan) as well.

It's exactly how he managed to control the funding of both sides of the war, by restricting funds where and when he needed it.

Once you become Emperor and the Republic is dissolved, you can do what you want with that money.


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

[User] ELI5: How exactly were cave paintings made and how have they stayed in relatively good condition for tens of thousands of years until our time?

[Assistant]
For starters, we wouldn't know of cave paintings that *didn't* make it to modern times. If a cave sweats enough to wash away the paint or some other phenomenon happens that erases the paintings we would never know a specific cave ever had any cave paintings.

For the paintings that *did* last to modern day, caves are surprisingly well protected from weather patterns. Unless a painting was close to an opening, there's next to no moving water to wash it away, there's very few plants, if any, that can grow (to break apart the pigments), short of a cave collapsing on itself or animals rubbing against it, there isn't that much that will get rid of the paint...so it tends to stick around for a long time.


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

[User]
ELI5: How do dollar stores manage to sell brand named products for such a low price?

2 liter bottle of Coke for a $1 vs. the same drink for $2.50 a grocery store.

[Assistant]
Dollar stores generally operate on a high volume, low margin basis. What this means is the store attempts to sell many more items per day than a large grocery store but receive less profit per item. They rely heavily on buying from wholesalers at low cost and having very little operating costs.

You may also notice that many dollar stores carry very few or no perishable goods. A large grocery store may require extra profits on items like Coke because they may have to discard the $200 of turkey meat that is now expired and no longer salable.

There are many other factors that can contribute to the sales price, however. Some Dollar stores are large chain franchises that heavily utilize economies of scale to obtain large price cuts from wholesales. Small Dollar stores generally rely on low financing costs.


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

[User] [Phineas and Ferb] Dr Doofenshmirtz is able to create machines that can warp reality and built a super advanced AI. Why does the government do anything about him and why is he always foiled by a platypus of all animals?

[Assistant] Do you mean to ask why doesn't the government do anything about him? That makes more sense syntactically, but the government does do something about him. They send Agent P. They can't arrest him before he does anything because that would be constitutional. As to the second part of the question, are you saying Agent P isn't a good agent because he's a platypus? That's racist.


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

[User]
[The Flash TV] How can Dr. Wells afford to keep the Star Labs property and equipment, employ two of the best scientists in the world, and to have such a nice home after the accident?

Does he steal money as Zoom, or did it come from somewhere else?

[Assistant] The guy's from the future and has an AI with a record of all the things he can't remember, as well as the ability to track changes in the time stream.  Dude plays the stock market and makes a killing.


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

[User]
ELI5: Why isn't there a webcam on the moon to watch the earthrise every day ?

I just saw the picture of the earthrise again and think to myself, taht it would be awsome to see the earthrise every day live from the moon. the picture captured isnt even a fullearth ;). I would sit there all day to see the moon in the universe :)
We could run the webcam with solarpanels and there is even Internet on the moon :D.

[Assistant]
One thing to note, you wouldn't have a normal Earthrise like you have a moonrise on the Earth. The Moon is tidally locked with the Earth, the same face of the Moon always faces the Earth. This means that there are places where the Earth is always in the sky, and places where it is never in the sky.

The moon does experience something called libration, an oscillation, meaning that there are locations near the terminator where you could see the Earth rise and then set at the same horizon. However, the process is very slow, just to see the diameter of the Earth clear the horizon would take roughly 2 days, and the full cycle would take about a month, certainly not daily.


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

[User] Why is sound-insulating material typically textured with pyramid-shaped protrusions, why wouldn't you just use a uniformly thick material instead?

[Assistant] When a sound wave of energy S hits a surface (usually a foam in this case) some fraction x is absorbed and the remainder S\*(1-x) is reflected. If you could get the sound to bounce off the wall twice, you'd get sound energy reduced by S\*(1-x)^2. If you could get it to bounce off n times, you'd get S\*(1-x)^n, which gets vanishingly small as n grows. So instead of a flat wall, if you make wedge shaped holes, the waves entering that hole skip off one wall (losing energy when they do), then skip off the opposite wall, bouncing back and forth until they reach the back of the wedge-shaped hole at very low energy, so there's not much left to reflect back. So the points aren't the real trick - the points arise from the fact that you are making wedge-shaped holes in the wall.


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

[User]
[Stranger Things] What kind of doctor is Dr. Owens?

He seems (at the very least) equal parts pediatrician, biologist, psychologist, virologist and physicist (given that he works for the Department of Energy). So what kind of training/background enables him to run Hawkins Lab  including singlehandedly overseeing the management of an extradimensional force trying to encroach into our world  while supervising Will's medical care?

[Assistant]
>physicist (given that he works for the Department of Energy)

Just because you work for the DOE doesn't mean you're a physicist.

He seems to be mostly a biologist picked for his pediatric skills and ethical behavior, the virology, psychology, and other stuff he seems to get from consulting his staff.


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

[User]
Why can't metal be translucent?

When I was really young I used to wonder why, when glass was so fragile, we didn't use see-through metal for windows and windshields. Is such a thing possible, or will it ever be?

[Assistant] A metal has a partially full conduction band (typically described as a sea of free moving electrons) and there are many energy states for these electrons to jump into if they are excited.  The electrons in this conduction band are typically able absorb energy from all photons of the visible spectrum, so they don't pass through the metal.  Glass and certain ceramics have a band gap that prevents electrons from absorbing photons of specific frequencies, these photons don't have enough energy to allow electrons to overcome the band gap.  If this band gap's size is larger than the energy of a photon in the visible spectrum the photon will pass through the material and not be absorbed.


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

[User]
ELI5: Where did all the soil come from?

When the Earth was being formed it was essentially a ball of rock. How did soil come to be if there was nothing but lava and rock?
Or am I just missing something here?

Edit: Wow guys, thanks for the replies.

[Assistant]
TL;WR :: Erosion, Dissolution, and Poop

1. Gross mechanical processes turn large chunks into small chunks.
2. Chemical processes dissolve things, particularly water and such.
3. Biology is chock full of gross mechanical and chemical processes.

So there's a difference between "dirt" and "soil".

Dirt (and silt, and clay, and sand) is the mechanical, un-living accumulation of fine particles of minerals and metals and ash and whatever.

Soil is what happens when dirt is full of living material and organic byproducts (recently living but now shredded or dead stuff).

So dirt is formed by grinding up and dissolving rocks and such.

When a little dirt shows up somewhere then hardy organisms tend to show up just a little later - or in the case of lichen and moss, sometimes really super hardy organisms show up first.

Windblown dirt-and-dust collects in the crevices and then organisms (bacteria, fungus, algae, whatever) take shelter in the dirt-and-dust and use the mineral wealth of the dirt to thrive. As they grow and die there's now more mineral wealth along with some fixed carbon and nitrogen in the little microscopic corpses and poop stuck to the dust and dirt, and larger organisms can show up.

With more sticky and more crevices comes more dirt and dust, with more dirt and dust comes more places to get sticky and so on.

So if you grab a selection of moss you'll find that dirt is collecting between the fibers and becoming soil.

If you look at a decaying woodpile, you'll find the same thing.

So all these small cycles add up over thousands of square miles of dirt and dust, over millions of years.

Eventually you've got herds of bison and cows and deer and raccoons and prairie dogs and spiders and bugs and whatever constantly living and pooping and dying. Turning more and more dirt into thicker and better soil that's full of more and more diverse things like bacteria and fungus and bugs and worms and microscopic plants and animals and so on.

We'd be neck-deep in soil... but soil has enemies too.

Soil can get washed away, which at natural levels is good for the water right there and down-stream. Soil can be crushed until it suffocates and becomes packed dirt again. Soil can be buried under dirt or ash and so sufficate. Soil can be dried out until it's just dust.

Soil can also be killed by too much acid or too much alkali or to much salt (salt being what you get when you mix acid and alkali).

And some biological systems "don't like" soil.

For instance "rainforests" tend to have very little soil. The rainforests are deeply invested in the nitrogen and nitric acid cycles. So all their biological value is in the living plants. The ground beneath the plants is very acidic and so there's lots of dirt but only a tiny layer of soil. This is a _necessary_ configuration, but when someone decides to burn down some rainforest to create a cow pasture or farm, they'll use up the tiny, crappy layer of soil in just a year or two.

It's easy for something disruptive, like a farm, to "use up" the soil and then there's nothing left but dirt. Especially if the local soil is the result of buffalo and grass and wolves and prairie dogs, but the farmer drives off all of that and just plants corn or wheat. The soil was used to a diet of all that other stuff and now it starves... like trying to make your dog a vegan, it's just not the right food for the organism at hand.


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

[User] Why do our breath stink when we are hungry?

[Assistant]
Hunger triggers a primal instinct to act & search/hunt for food. It does this by stimulating your stress hormones, cortisol and adrenaline. When you have an adrenaline rush (like when you're scared or nervous), your mouth dries up. This is because adrenaline inhibits saliva production. Salivating is not much use when running from a predator!

Saliva is a natural cleanser for the mouth. A dry mouth will soon start to smell bad as bacteria grow and secrete waste.

This phenomenon also happens when you sleep. Saliva production mostly slows down when you're asleep, which is a large part of why you wake up with bad breath.


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

[User] What makes some kinds of leafy greens edible, and others not?

[Assistant] Oxalates and tannins often make leaves inedible.  Both are antinutrients, which hinder the uptake of nutrients by the body and interfere with digestive processes.  There's a wide variety of other compounds that can be found in plants, ranging from mere indigestible fiber all the way up to potent toxins.  Plant leaves really don't want to get eaten and have all sorts of nasty biochemical tricks to deter herbivores.  This is one of the reasons the world is green: the reason there's a lot of plant biomass hanging around not being eaten by herbivores.


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

[User] ELI5: How do our brains know when to wake up? What keeps us from just staying asleep forever until something disturbs us?

[Assistant] Histamine and melatonin are the two cycles. Histamine builds while you sleep, melatonin while you are awake. Thus if you take benadryll (histamine blocker) you get tired, or take melatonin to help you sleep. These are controlled by the thalamus on the dopamanergic pathway, hence stimulants wake you up.


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

[User]
[Mythology] Athena invented the chariot, Hermes invented the Lyre-- Which gods created modern day inventions, like computers or cars?

(This isn't limited to Greek Mythology, those are just the first two examples that came to my head)

[Assistant] Presuming they hadn't been usurped, it would still be the Olympians and/or their descendants getting up to that sort of business. A lot of heavy industry would track back to Hephaestus, and the Internet would likely show a lot of the hand of Athena (particularly the parts that descend from DARPANet), Hermes (especially the corporate-built parts), and partially Apollo (the fiber-optic bits). In fact, barring a major shake-up, Athena would be metaphorically balls deep in the 20th and 21st century; a lot of modern tech is derived from either military projects or large scale civil engineering, both of which would fall into her wheelhouse. In such a world, much of America's success would probably be attributed to her favor.


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

[User]
CMV: If you can anaesthesize a human for surgery, all executions can be humane and painless

I do not understand whyif they can put a human being to sleep to the point that it does not notice being cut open and having its heart replacedthere is any difficulty in "humane executions" for states. Why would electric chairs, firing squads, hanging, lethal injections and anything else even be needed?

Put the convinct under general anaesthesia and then chop off its headas humane as capital punishment can get.

In fact, the government where I live offers government assisted suicide for those that no longer wish to live. One takes a pill, goes to sleep, and never wakes up again.

If they really want humane executions, why not use something like that?

[Assistant]
Probably a few reasons -

1. Need an anesthesiologist to do it correctly - and they take the Hippocratic oath so they would not be able to take part in an execution.
2. The companies that make the drugs for anesthesia do not want those drugs to be used during executions.


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

[User]
ELI5 How a doctor knows when somebody 'died on impact'.

Aside from the obvious like decapitation or something like that.

[Assistant]
Technically... they don't. But, it seems plausible and sounds much nicer than,

"due to the injuries it's possible he died immediately, however it is also possible he spent a few minutes trying to move around slicing his muscles apart on broken bone fragments until he choked to death on his own blood. Goodnight, Timmy."


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

[User]
ELI5: How does a Christian rationalize condemning an Old Testament sin such as homosexuality, but ignore other Old Testament sins like not wearing wool and linens?

It just seems like if you are gonna follow a particular scripture, you can't pick and choose which parts aren't logical and ones that are.

[Assistant]
Paul.

In the Gospels Jesus is fairly clear that the old law has been abolished (see Mathew 15:11 as the standard proof text for this)- that is that those Old Testament sins are no longer sins.  But, the Gospels are not the end of the New Testament.  In the Epistles the Bible condemns homosexuality (and other Old Testament sins).  To the mind of many that makes it clear that while many of the Old Testament laws have been abolished not all of them have been.  (Roughly those break down into laws about purity which are abolished and laws about social and sexual behavior which are not).

Obviously, this explanation is less that convincing to many, but it is one of the standard explications given when this question arises.


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

[User] ELI5: Why do people blackout/see red when they go into a rage, and sometimes not remember much/ or any of it?

[Assistant] Its not just confined to rage. Any emotion that causes vaso-dilation (expanding of the blood vessels) can cause this. Seeing red is caused by the blood vessels in the eye becoming so expanded the brain no longer ignores them. As for not remembering much. The brain sometimes switches off unnecessary parts of the brain, including in some cases short term memory, in times of heightened stress or adrenaline levels.


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

[User]
[Dune] How exactly was Baron Harkonnen able to break Yueh's imperial conditioning?

Dr. Yueh's conditioning was a big deal in the book and many are shocked that it was able to be broken.  If its such a strong guarantee of loyalty, how was the simple act of kidnapping his wife able to break it?  I've read the book multiple times and this was never clear to me.

[Assistant] It's not detailed in Dune, but later novels expand on it.  Dr Yueh was  married to a Bene Gesrerit sister, who was abducted by the Harkonnens.  As the Harkonenes are famous for their torture of their hostages, making this is particularly horrifying prospect.  The sisterhood have also mastered sexual conditioning, which appears to have been stronger than the imperial conditioning in this case.  Apparently the Harkonenen mentat used this cleverly to leverage to blackmail Yueh into his betrayal.


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

[User]
eli5: Why does diffusion happen?

Why do molecules have to spread out evenly? What is making that happen...

[Assistant]
Take a bunch of blindfolded people and stick them in one corner of a fenced in backyard. Now tell them to wander around aimlessly. They're going to slowly spread out throughout the yard, occasionally bumping into each other and the fence, but eventually kinda spreading out evenly-ish.

Molecules are also just kinda moving around randomly bumping into each other, so eventually they'll start spreading out by random chance.


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

[User] Eli5, Does teeth whitening toothpaste damage teeth enamel?

[Assistant] Whitening toothpastes typically use a mild grit to scrub plaque away. There's some potential to also scrub away enamel over time. Most dentists recommend soft bristles, a light tough, and no whitening toothpastes.


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

[User] [MCU] We saw how the Ancient One was able to subdue Banner by literally pushing his astral form out of his body. Couldn't Strange have used this method against Thanos to do the same thing?

[Assistant] By that point Thanos had the Soul Stone, he seemed to be able to counter Strange's other spells with a combination of stones. Soul Stone might have been a counter to that method. Additionally, Strange had already seen the future and it was going according to his plan.


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

[User] ELI5: Why do sugar granules dissolve faster in liquids when you stir them with a spoon, than just leaving it to sit?

[Assistant]
When something starts dissolving in water, it increases the amount of stuff dissolved in that particular part of water. The more stuff is already dissolved, the less likely it is that more dissolves into it.

If you just leave it sit, diffusion is the only process that carries the dissolved molecules away so fresh water without anything dissolved can come by to pick up more molecules. If you stir, you artificially accelerate the carrying-away of dissolved molecules, making more space for new ones to dissolve faster.


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

[User]
What happens when you "zone out" and why do we do it?

Why do we zone out? An example of this is when I'll be doing homework or be reading something and I'll just get blurry vision and just sit there.

[Assistant]
"Zoning out" is a common form of microsleep, which the brain begins to experience after a combination of lack of sleep and a high amount of use (such as a lot of thinking during work, school, or other activities). This is especially so if you're repeating the same task over and over, as the brain goes into "auto" mode, which is also why it is often linked to boredom.

Microsleep is named so because it only lasts about two seconds to less than a minute.

Additionally, if the person is under emotional distress, or has something "on their mind" that is pertinent to their well-being (or they think it is), they are more prone to experience "zoning out," as their mind is more likely to enter into a state of deep thought, connecting their conscious mind to their subconscious, much like just before or during sleep. This is also why people seem to "come to a conclusion" just as they're drifting off into sleep.

Hope that helps answer your question!


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

[User]
ELI5: How do we know for sure that cancer and other deceases aren't caused by being constantly exposed to small radiations from electronic devices and 3G, 4G, WiFi, LTE, Bluetooth-signals?

I am in no way trying to be ignorant. I am certain that scientific studies has drawn some kind of conclusion, but how do we know *for sure*?

If you think about it, there are rarely times where you can enter a room and not being in the way of some kind of signal. It just crossed my mind, how heavily has this area been studied?
    How do we know that testicular cancer is not a consequence of an electronic device constantly receiving signals from various sources?

Best regards, and merry christmas!

[Assistant]
Simple, cell phones/wifi/etc all emit either radio- or microwave radiation. These two types of radiation fall under the umbrella of non-ionizing radiation. Other types of radiation in this category are infrared and visible light. Ionizing radiation includes UV, x-rays and gamma rays as well as radiation from nuclear reactions.

Now, what separates non-ionzing from ionizing? Well the former can't knock electrons from atoms and thus can't make ions. Now to cancer, cancer is a genetic mutation where the DNA that controls cell reproduction is damaged and runs uncontrollably. In order to have this happen, you have to mess up the bonds in the DNA, which means you need enough energy to strip away electrons. So its physically impossible for non-ionizing radiation to cause cancer. The worst thing that going to happen from cell phones use, etc.. is your face is going to get a little warm.


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

[User]
[The Owl House] What Exactly Makes a Glyph Work?

Okay, so the main magic system in the Owl House essentially works by someone drawing a circle in the air, with either their own fingers or other objects, and then, they use the magical energy inside them, stored in an organ called a bile sac, to cast a spell.

However, the MC of the show, Luz, discovered a different way to use magic. Essentially, in either nature or even in spells themselves, there are hidden glyphs inside them, and by drawing those glyphs, you can recreate the spells or do something similar. You can even combine glyphs to make new spells, with there seemingly being no limit.

The thing is...what exactly makes a glyph "turn on"?

So, there are several times when Luz draws a glyph, it does nothing, and only activates on touch, seeming to imply someone has to channel magic into them. But Luz doesn't have a bile sac, so she can't channel magic into it. There are even moments when Luz doesn't have to touch the glyphs to activate them, like once she used another person's staff and activated them from a distance to make a bunch of explosions.

I don't think it's just drawing ambient magic from the air to "turn it on", because then every time someone draws the glyph it would atomically activate. And the doesn't explain how a character who can't actually channel magic turns them on by touching them, or how she can apparently use them from a distance.  So, how does a glyph actually work?

[Assistant]
Basically, it seems Luz (and anyone) can *technically* channel magic. It's just that she just doesn't have any magic *to* channel. A witch has an internal source of magic to channel, and they assumed that was the only one.

Luz, meanwhile, learnt to channel an external source of magic- the Boiling Isles. She's doing the same thing witches do- channelling magic into a thing that causes that magic to influence the world. It's ambient magic and paper rather then innate magic and phlegm, but it's the same principle. She's not the only one- Belos has apparently created a way to channel magic using technology.

The fact that magic can be channelled in ways other then the witches bile sacs seems to be becoming plot relevant. Basically, the original story was at best a half truth.


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

[User]
[Warcraft] Why are Warlocks more or less accepted in society?

If the vast majority of Azeroth is aligned against the Burning Legion and other demons and Warlocks associated with the Burning Legion, why are warlocks more or less accepted in the Alliance and Horde societies? Furthermore, seeing that Warlocks are given free reign, why are Demon Hunters maligned, shunned, or even themselves hunted?

[Assistant]
Free reign? They have to set up their guildhalls in secret, and nobody trusts them.

They're really useful in an adventuring party as long as they're ripping your enemies apart, so that's the reason most adventurers won't kill warlocks on sight. And what is the town watch gonna do about a Warlock adventurer strutting around town on his hellbeast mount? Oh, yes, I'll just walk up to him and politely ask that he kindly stop summoning demons in the city limits and ohpleasedon'tburnmeIhavethreechildren! It's fine anyways, most warlocks don't stay in the same town for too long, just like any other adventurer.


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

[User] Suppose instead of a giant pool, the Olympic swimmers had their individual lanes of water seperated from each other. Would this affect their swimming, and if so by how much?

[Assistant]
One of the issues in a giant pool is that backwash off of the side creates more turbulent water for the swimmers on the sides of the pool as opposed to the swimmers in the middle (this is why swimmers with the fastest heat times are placed in the middle; kind of a "seeding" of sorts). This does slow the outside swimmers a bit. However, this issue has been remedied to a great degree by deeper pools, flow gutters and more separation between the outside lanes and thew all. From a physics standpoint, the times probably wouldn't change much, if at all.

However, a non-scientific reason separating the swimmers might change their times is that they wouldn't be able to see the other swimmers as easily. This might actually have the effect of *slowing* down times, as the adrenaline burst obtained from having to chase someone would be largely taken out of the equation.


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

[User] ELI5: Just saw something that said if you can produce a sound louder than 1100db you can create a black hole that could destroy the galaxy (or something like that), is this true and how does it work?

[Assistant] That's because the decibel scale is a logarithmic scale and not a linear one.  A 100 decibel force is 10 times as strong as a 90 decibel force and 100 times as strong as an 80 decibel force.  So if you go from 100 to 200 decibels you haven't doubled the strength of the force, you've increased it by a factor of *ten billion*.  A 1100db sound would be 10^100 more intense than a 100db one.  Simply put, the energy required to even generate a sound of such intensity is greater than the entire mass-energy estimate of the whole universe.


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

[User] ELI5: How come fruit like pears/plums/peaches etc go from hard to juicy. Where was the juice all that time?

[Assistant]
The juice is always there, however the cells that make up the fruit are turgid which means they have the liquid absorbed inside them and become like a balloon filled up with air(makes fruit hard).
 As more of the cells die(when the fruit gets older and left out)  they cannot hold the liquid as well so it leaks and the fruit becomes juicy with cells becoming softer (like a ballon with less air in it) as the juice moves in between cells and does not stay inside the cells.
Basically the reason is that there is always water in between the cells, which evaporates, cells die, and as the juice wants to equal out between the cells and outside the cells(but still in the fruit), fruit gets more juicy. This is why when you bite into a hard fruit, the juice releases, but a soft fruit already has most of the juice in between the cells.
 Edit added ballon analogy.


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

[User] ELI5: Why does it take years to make a single 1.5 hr film but HBO can create hour long episodes that air week after week?

[Assistant]
A movie typically shoots for 30 days. The 6-18 month period prior to this is called the 'pre-production' phase and involves not just writing but casting, booking directors, booking editors, booking DOPs, rehearsals, location scouting, costume design, set dressing and construction, etc. Then there's the short production phase, and then you enter post-production where you do the offline edit, online, VFX, and ultimately lock for release. This period can last 6 months itself.

All of these phases are drastically shortened on a TV show.

On a TV show, you still have to cast, book directors, editors, DOPs, build the sets, etc. But you only have to do those things *once*. You keep those people on staff, you keep the sets you built, you keep the cast. 90% of pre-production work is eliminated for every episode beyond the first.

Rehearsals are shortened, too. The actors learn their characters, their mannerisms, accents, attitudes, they start to get the comedic timing of the show and their co-stars. Of course, they still have to rehearse scenes and learn their lines -- but TV rehearsals quickly become far more streamlined, quick, and low-stress compared to movie rehearsals where the director is carefully watching everything and making adjustments so the actors "get" the movie and their character.

This is true for other staff, too. Writers, editors, and DOPs all get into the swing of things after a few episodes, they learn the show's style and format, and they can work faster with less supervision.

On top of all this, TV shows aren't actually producing episodes week to week. Shows typically run year-round, and actors will be shooting scenes months before they air on TV. A show might run 16 episodes but be in production 50 weeks of the year.

And then add one more factor: multiple teams working side-by-side. American TV shows don't just have one writer and one director, they have many. Breaking Bad was written by 10 people and directed by 25. Each writer can work on scripts separately and simultaneously, and 2 or 3 directors can be making episodes at the same time. Obviously this doesn't happen for movies. (Movies do often have a 'second unit' with its own director shooting scenes separate from the main director, but this is almost always just minor stuff like exterior/establishing shots, plates, and special stuff like the news-show segments from House of Cards.)


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

[User]
[Star Trek] Could You Hypothetically Make a Vulcan Laugh?

Let's say I tell a Vulcan a mind-bendingly unexpected, incredible joke the likes of which the quadrant has never experienced before.

Is it hypothetically possible that I could - for a split second, get an adult Vulcan to crack a genuine smile or even laugh despite their most potent efforts to suppress the emotion.

[Assistant] Vulcans have emotions (in fact, they have quite strong emotions) but are taught how to suppress their emotions and instead rely on logic to make their decisions and how they display themselves.  However, different Vulcans are better or worse than other Vulcans at doing so and in private with family and very close friends may choose to lessen how much their suppress their emotions at that time.


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

[User]
Why is Ethical Egoism so out of favour?

What makes something like Utilitarianism so much more popular among philosophers than Ethical Egoism? I have read the SEP article on Egoism and it has not brought me any closer to understanding why it is supposedly so inferior to other moral philosophies. It mentions a lot of different arguments that have been levied against Egoism but also provides seemingly sound counterarguments. All while ignoring the similar arguments that can be brought against Utilitarianism. Understandably that isn't really in the scope of the article but it doesn't help me with my question.

Ethical egoism certainly seems internally consistent to me so am I missing something? Or is it simply the case that Ethical Egoism does not fit the bounds for what a moral theory must be? If that's the case then where does it fail?

[Assistant] Because the idea that it is moral to only help yourself is arbitrary and totally random. It doesn't really make very much sense to begin with. It conflates personal benefit with the idea of an objective good to do. Even though those don't have much reason to be conflated, and are often seen as opposed.


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

[User]
[scrubs] Is Sacred Heart a good hospital?

It's kind of all over the place. On the one hand, you have doctors who would never get a job at a decent hospital due to their neuroses (or just plain assholery), and chronic lack of funding, but on the other hand, you have some very expensive suites used by rich people, some very wealthy board members, and some landmark surgeries done there.

So is Sacred Heart a high end or low end hospital?

[Assistant] It seems to do ok provided you have insurance, the Doctors are quite personable and genuinely seem to try their hardest, the Surgeons do their best even if it's just so they can have bragging rights later. Their Chief of Medicine is a hardass but he damn well makes sure the Hospital is running as efficiently (and cheaply) as possible. Having said that don't seek medical legal aid there, avoid the nervous doctor with the fanny pack and DEFINITELY do not cross paths with the strange but menacing janitorial staff.


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

[User]
[Star Wars] How did Republican Officers react to Order 66?

Because they had no chip inside of them when the order was sent out, did they just support their clone troopers below them when they decided to execute their Jedi Generals, who were considered the Republican Officers' friends of nearly the same rank?  Wouldn't this have confused the Rep Officers?

Or, did high ranking Officers with a security clearance know of Order 66?

[Assistant]
Considering there ended up being a substantial presence of former Republic Military within the Rebel Alliance, i would hazard a guess that many of them didn't take too well to the order.

Ultimately, it's probably going to run a wide spectrum of reactions. Some may oppose the decision, but considering how deeply entrenched Palpatine was by that point, they would be quelled pretty quickly. Others would fear for their own safety and, while they would object, they'd keep quiet. Others wouldn't care. And some may even see it as room for personal advancement.


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

[User]
Question about the M82 star that just went supernova

Okay, so I have a question about the star that "just" exploded in the M82 galaxy. The article that I read states that the star is 12 million light years away. I was wondering, does that mean the star actually exploded 12 million years ago, and we're just seeing it now?

[Assistant] Yes, exactly. So to speak, when you look into the stars, you look into the past. Kinda. Even weirder, the stars you see to next to each other may be millions of years apart in time. Some of them probably don't exist any longer.


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

[User]
[Marvel] Could there be a way to make a mask for Black Bolt to speak through that doesn't destroy everything around him?

Could Black Bolt have a special mask for him kinda like Cyclops' visor? Like a vibranium adamantium alloy that could absorb the energy of his voice while still being strong enough to not explode?

(Is this the right subreddit to ask this kinda thing?)

[Assistant]
It's nigh-impossible, or at best woefully impractical. Not many things can take the energy released when he speaks, and those that do are hard to speak through.

Black Bolt has special chambers prepared that suppress his powers when he really needs to speak to someone, but usually he relies on sign language and his wife. Or, now ex.


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

[User]
ELI5: Why does salt make such a big difference in recipes or adding it to food? Adding a little makes such a big difference. Why?

Edit: Thank you everyone for your responses! Ive learned so much reading through them and Im happy to have sparked an engaging discussion!

[Assistant]
Salt is its own flavor, but it also acts to enhance other flavors by increasing the polling rate of the cells in our tongue which detect flavors. By the same token a lack of salt will make most foods taste bland or one-dimensional.

Presumably this is an evolved response to encourage animals to seek out and consume salt, given how critical it is for us.


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

[User] Why is hydraulic fluid so toxic to humans ? (questions stems from recent pics of a NSFW hand that was operated on to remove high pressure fluid from a leak)

[Assistant]
Aircraft hydraulic fluid is phosphate-ester based. Phosphates dissolve oils very well; they were a standard component of electric dishwasher detergent until recently, when they were removed over groundwater pollution concerns. It's chosen because it's incompressible, less dense than oil (lighter), and is very temperature-stable.

Automotive brake fluid, on the other hand, is based on glycol ethers. In this case, the composition is chosen for its very high boiling point and thermal conductivity. In a passenger car the brake fluid might see a temperature of 400F; in a race car 500F+. Glycol ethers are a common solvent used in paint, and they are very hygroscopic (absorb water) which makes them a skin irritant, but their toxicity is considered low.


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

[User]
ELI5: How does reattaching limbs/body parts work?

When a limb or other body part gets severed, how does reattaching it work? Do doctors/surgeons/etc have to reconnect every single nerve ending, blood vessel/blood arteries, strands of muscle and cartilage, etc somehow?

If they reconnect blood vessels/arteries, how does the reconnection process work since blood vessels are basically hollow cylinders (do they reconnect it in a way that somehow allows blood to flow again)?

[Assistant]
They do sew together muscles and nerves and veins the best they can, but the general goal is not to make it perfect or even good, the goal is to turn it from totally disconnected arm that is across the room to a really bad injury the body can heal.

Like you don't sew the bone together so it's perfect, you get it good enough it's just a broken bone that could heal, and like you don't sew the muscles to the point it's a perfectly working muscle, you just sew it till it's a big injury that could heal. etc. You don't sew every single tiny vein, you sew enough of them just good enough the arm won't die then it will heal that over time itself.


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

[User]
Why is recursion so praised despite it typically using more memory and not being any faster than iteration?

For example, a naive approach to calculating Fibonacci numbers recursively would yield a time complexity of O(2\^n) and use up way more memory due to adding calls on the stack vs an iterative approach where the time complexity would be O(n). Even if you use dynamic programming for a recursive solution, you'd get the same time complexity as the iterative solution while using up much more memory. Especially if your iterative solution just uses an array of two elements to calculate the numbers in the sequence.

[Assistant]
Because there are times when it's clearer to define an algorithm recursively than iteratively, and it can be cleaner in the theoretical sense (less explicit tracking of state, for example).

Consider looping through the nodes of a tree. In a recursive algorithm, the state of your search is stored in the call stack. With an iterative approach, you may have to use a structure like a stack to store which nodes to visit next. It's doable, but not as pretty.


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

[User]
ELI5: If carbonated drinks are stored similarly in canisters for fountains and aluminum cans, why does the fizz lost much quicker when transferred?

Fountain drinks stay fizzy longer. Canned drinks poured into glasses/solo cup lose fizz rapidly. Why?

[Assistant]
Carbonated water loses the mixed CO2 in direct relationship with the amount of surface area the liquid has at any given point in time. Fountain drinks have the benefit of having been immediately carbonated by the fountain (since that's what a fountain does - carbonates water and mixes with syrup to produce a drink), and at most fountains the amount of injected CO2 is pretty high to make up for the fact that a ton of it is lost on impact (i.e. the drink from the fountain hitting the bottom of the cup).

Most canned/bottled drinks aren't carbonated as much because carbonation increases the pressure inside the container, and if you add too much carbonation the can or bottle will explode when you shake it (worse than it does normally).


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

[User]
ELI5: Stocks and Bank Transactions.

So I sold stock last Thursday. Why does it take 2 business days for a stock to be sold? Where Crypto and E-payments nowadays take real time. Also I need the money to be wire transfer to international bank. Why does this is not also real-time it will take like 4-7 business days before it will be on my bank account. Why does the transfer not working on weekends? So basically why everything is still slow and why everything can't be done on weekends?

[Assistant]
Just to clarify, the sale happened straight away. What takes two days is the clearance: the actual money moving from the buyer to the seller. The buyer may not even have the money yet and has two days to pony it up.

International transfers are kinda similar: the person does the transfer and the bank could add it to your account straight away. But then you could spend it straight away and then the bank is temporarily out of money because it's still waiting for the money to arrive from the other side of the world.

Note: that can be solved. For example, within the SEPA area transfers are expected to be basically instant (benchmark is <10 seconds IIRC). So a person in Portugal can transfer money to a German account basically instantly. It helps that there is no currency conversion happening, that adds a whole other layer of complexity.

When you pay by credit card, the money is immediately deducted form your card, but it can take days before the merchant gets it.


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

[User]
ELI5: Why do some large military planes use propellers instead of jet engines?

I though that jet engines are more powerful and more fuel efficient? How come we don't see any smaller military applications using props?

[Assistant]
Jet engines are more fuel efficient at high altitudes and speeds.  Propellers are more fuel efficient at lower altitudes and speeds.  Giant transport aircraft aren't generally going to be flying at high altitude, nor are they designed for supersonic flight.

The high power-to-weight ratio of turboprop engines at low speed allows these planes to take off from land on runways that are much shorter than if they used turbojets, as when you're bring supplies or troops to the front line you probably won't have a long paved runway.


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

[User]
ELI5: Why is water incompressible ?

While we're at it, why does google chrome think incompressible isn't a word?

[Assistant]
Actually, water is just really, really difficult to compress.  The molecules are already so close together, it's hard to squeeze them any tighter without them being in constant "contact".

(Contact is technically incorrect, but it's close enough for this discussion.)

This is different from a gas, where there is plenty of empty space in which to wiggle around.


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

[User] Does there exist a dielectric that would lower the capacitance between two plates instead of raise it?

[Assistant] No. The effect of a dielectric will always be to increase the capacitance. The weakest dielectric is a vacuum, which has a relative permittivity of unity. All materials have permittivities greater than 1 and consequently increase the capacitance.


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

[User]
[Star Wars] Is the Death Star big enough to generate its own gravity?

The original death Star is 160 km in diameter. Approximately the size of a "small moon" are moon has enough mass to generate a little bit of gravity. I'm thinking that the death Star is large enough to generate some of it's own gravity but skeptical about whether or not it's large enough to have the gravity that is depicted in the films. If it's large enough to generate some gravity how do they supplement it?

[Assistant]
Everything that has mass has gravity, so yes the Death Star is big enough to have it.  It's not as dense as a moon meaning its natural gravity would be weaker than a moon of equivalent size.

It's pretty evident that they've figured out how to simulate gravity on space borne craft however. It's likely the same technology that allows people to mill about the Falcon without floating works on the people who live and work on the Death Star.


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

[User] [Marvel] Since Luke Cage's skin is denser than average, is he more resistant to stuff like radiation? Could he be picked up with thermal imaging?

[Assistant]
Does he ever get an x-ray? If his skin doesn't block that then he would be susceptible to gamma radiation as well. The danger from radioactive fallout/particles is the ingestion of the material where it lingers in the body, so  you could poison LC with polonium in his corn flakes.

And density of skin wouldn't affect a thermal scan, his body produces heat that has to go somewhere so he doesn't cook like a potato in foil.


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

[User]
[Lord of the Rings] How do the Nazgul/Ringwraiths work?

I know they're undead, but past that, I don't know what's going on there. Their bodies are gone, but they're corporeal somehow or something? Can someone explain that one to me.

[Assistant]
There is the world, and the unseen world. The Maiar seem to be native to the Unseen World, but can fashion bodies to appear in the regular world. Sauron is cursed to always seem evil to men in corporeal form.

Presence in Unseen World can be equated to magical power. Looking upon the Two Trees gave the Eldar a presence in the Unseen World, and this is the source of their "glow." Men don't have have any native presence in the Unseen World.

The Rings of Power have the effect of bringing the wearer into the Unseen World. This makes them invisible to persons in the regular world and allows them powers they don't normally have. They see and can be seen by other beings in the Unseen World. Glorfindel could not join the Fellowship of the Ring because he had an exceptionally strong presence in the Unseen World and would be trivially easy for the Ringwraiths to detect.

The Ringwraiths were kings of Men who wore rings subject to the One Ring. They gained a presence in the Unseen World, and thereby power. They also became subject to Sauron's will, as Sauron provided the rings.


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

[User] At any given time, could a line go from the center of the earth to the edge of the observable universe and not get intersected by any matter.

[Assistant] Sure. In fact there are many more such rays a line that starts at some point and extends without limit is called a ray; there's your trivia for the day than there are rays that end at some particle. Our view of the cosmic microwave background the surface of the sphere that contains the observable universe is for all intents and purposes unobstructed.


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

[User]
[X-Men] If everyone knows that bullets are useless against Wolverine, why do they keep showing up with guns?

Especially when the people in question are highly trained and well funded, why aren't there more specialized weapons to detain or explode him?

[Assistant] Because guns are useful for anyone not him that could screw up the mission. If Wolverine is amongst a bunch of people without healing factors, then the bullets would work on anyone not Wolverine, and that would be one part of the mission solved.


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

[User] How far away from the sun do you have to be before it's not the brightest star visible?

[Assistant] The sun's absolute magnitude is 4.8 (defined by brightness at a distance of 10 parsecs), which means that it will appear to be fainter than the current brightest star in the sky, Sirius A, at a distance of 1.8 light years. If we travel towards Sirius, it will get brighter, but not as fast as the Sun gets fainter at this point, so it won't be much different (1.8 light years is not nearly as big compared to our current distance to Sirius A as it is compared to our current distance to the sun). Traveling towards Alpha Centauri doesn't make it appear brighter than the sun until a bit over 2 light years either; even though it's closer, it's intrinsically much closer to the sun's luminosity. So it seems that, in any direction you travel, after ~2 light years the sun will no longer be the brightest star in the sky. A bit less if you don't head directly away from Sirius A.


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

[User]
ELI5: Why is California in a water crisis?

I heard that starting next month they're going to begin state wide water sanctioning which is pretty insane. How have we not fixed this yet? I've heard tons of people say it would be super easy to fix if they would just build purification plants and pipelines etc, which obviously cost money but I think water is something that we can afford to spend money on.

[Assistant]
Most folks here aren't addressing the underlying reason *how* California got to this point of "crisis".

The evidence suggests that California is recently exited a particularly wet period that lasted roughly 300 years. And during that period of time California has seen a huge influx of people who were attracted to the possibility of developing agriculture in the area (think forty-niners turned farmers). But now that the rain has stopped you are left with the population that settled the land with the expectation that it would be sustainable but with no more rain to sustain it.

The fact is California is a high-desert and there is a significant probability it will never go back to seeing the amount of rainfall that it did in recent years.  There is also a chance that what's going on is caused by cyclical climate changes and if that's the case California may see the rain return in several 100 or perhaps a 1000 years.


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

[User] ELI5: Why do manufacturers use Allen wrench screws for self assembled furniture instead of Phillips or flathead?

[Assistant] Theyre just easier. On the assumption that youre provided the correct Allen wrench, hex screws are less likely to strip, you get free leverage from the shape of the tool. The tools themselves are super cheap to make, so compared to the hassle of dealing with customers so are mess up their cross head screws, its probably cheaper too.


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

[User]
[ELI5] How do deep-sea fish get displayed for public view with lack of pressure?

If something, say an angler fish or a chinese spider crab, were suddenly hauled to the surface and captured-- wouldn't they die from the sudden lack of pressure? Like an astronaut with no space suit? How do public aquariums display the creatures of the deep? (Like, the DEEP-deep of the sea) Are their tanks pressurized?

[Assistant] Good question! Actually, deep-sea fish's eyes burst when they get taken up to the surface (but that can also happen with regular food-fish). Blobfish also don't look like that floppy pile of meat when they're in their natural habitat, they are kept neat and round by the high water pressure. Also: cells are pretty magic so they can withstand huge pressure differences which means the fish will not completely burst when you take it up.


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

[User] [ELI5] Why are planes' engines slightly tilted down?

[Assistant]
They are tilted down and also left or right.

The reason is that:

engines do have a torque and the torque will try turn the plane left or right. So you point the engine in a way to cancel a bit of that.

Engines will pitch the nose up the more you ask power from them, they are tilted in a way to counter the nose up they give.

These angles have the purpose to cancel the effect of engine thrust, this makes the plane deviate less when the pilot changes the throttle, and makes the plane save fuel because you need to use less flight control surfaces to keep it straight.


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

[User]
[The Culture] What's with all the humans?

So I'm listening to *Consider Phlebas* and it seems almost everyone except the Iridans and their companion race are some subspecies of human, but the book is listed as taking place during the earth date of 1381. Where'd all the people come from?

[Assistant]
Humans is a broad, more understandable term for warm-blooded intelligent beings with primate ancestry. The 'humans' you speak of evolved similarly to those primates detected on this 'Earth' planet, but Culture Normal Humans are closer to Peak Human than they are to Earth Human. As you make your way through more of the Culture's history, you'll discover more Humanoid/Human species. The Culture itself was formed by several groups of Human species, each evolving separately on their own worlds.

Evolution, it turns out, is far from unique.


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

[User]
[The Flash - Comics] How can he see?

Right so this might be a really dumb question. It was fifteen years since I last took a physics class and I remember nothing from it. I've also been googling but not found exactly what I was looking for. So, I apologize if this is dumb but consider it your good deed for the day.

A friend and I was talking about the Flash the other day. The comics that is. It's well established that he can run faster than light. And then my friend asked: "but how can he see?" which I reckon I didn't quite get at first. But then I remembered: Sight is based on the interaction of light, eye and brain. So if he's dependent on light hitting objects to see it, how can he see? I'm not talking about the times he runs a tad faster. At one point Wally West runs several million times faster.

I don't really know how light works, which is why I'm asking. Are there gaps between photons?  If you're running at many times the speed of light would these gaps not be visible, or rather, would these gaps not make things invisible?

[Assistant]
The Speedforce handles any hassle tin regards to superspeed. This is why friction doesn't impede him. This is why he can pick up and carry people at FTL speeds. This is why his legs don't break when he moves them so quickly.

Speedforce. It negates conventional physics. If he wants them to.


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

[User] [Pokemon] How did the battle rules come in place, and why do criminals follow them? How come criminals don't kill people and steal their pokemon? How come cut is the only thing that can destroy small trees?

[Assistant]
I assume the battle rules are on the Pokemon's part, given wild pokemon also follow them. Your Ekans is going to politely wait its turn in battle however much you yell at it to justt spam acid.

As for why they don't just attack people? Pokemon are loyal to their masters, and an angry pokemon is very dangerous. You need to show your worthiness in pokemon battle.

Basically, pokemon are powerful and weird. A lot of the pokemone world revolves around dealing with their inhuman psychology.


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

[User]
Can fads or trends propagate in non-human societies?

For example, let's say a Gorilla (or another social animal) sees another Gorilla getting attention from many females. Let's also assume the successful Gorilla has something unique about him - a limp or leaves in his hair. Could the Gorilla (or another social animal) decide to copy the other male in order to be more successful?

Are there any animals that will naturally copy another individual to appear more attractive?

[Assistant]
Yes.  A small band of monkeys in Japanese started salting their food.   It started with one monkey washing her yams in salt water and others copying her (1965 Masao Kawai published in Primates)

People used to say- learned culture separated humans from the animals.  Then people started observing apes learning and passing culture/skills onto others and the next generation.  Like using tools (sticks to catch ants)


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

[User] ELI5: How do our stomachs know when we've eaten something bad and need to vomit?

[Assistant]
There are several ways to induce vomiting in humans. Without getting too specific, they are all linked through the "vomiting center" of the brain, also known as the area postrema. This center is capable of responding to many different types of poisons, toxins, conditions, etc. In the case of eating something bad, remember that the stomach is a highly vascularized zone that also happens to have a massive nervous structure, called the enteric nervous system.

Usually food poisoning that involves vomiting is caused by organisms that have preformed toxins, including but not limited to B cereus and S aureus. Meaning that delicious looking potato salad is teeming with toxins that have been pre-made by the bacterial species to wreak havoc on the consumer. This is why they work so fast (hours). These toxins cause inflammation in the gut and this information is transmitted back to the area postrema.

After the brain realizes something is not right down there, it stimulates muscles including the abdominal musculature and diaphragm to propel the harmful substance out of the body via forceful contraction. Of course, the cardiac sphincter must be opened (top of the stomach), and pyloric sphincter must be closed (bottom of the stomach) in order to create enough pressure to blow chunks.

Related: The overwhelming majority of taste types our species is capable of tasting falls in the "bitter" category. This is because throughout human evolution, we have come to realize that bitter tasting food and vegetables are often poisonous. Thus we feel a sense of disgust in response to bitter foods as a protective mechanism to prevent swallowing.


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

[User]
[Star Wars - KOTOR] How much damage on the whole has Revan's little bid for galactic power has caused?

And what's the comparative technological and military status of the Republic at the beginning of the Great Galactic War several centuries later?

Specifically I'm interested whether they've become as demilitarized as in the movie era, and whether *Wh40k*-style archeotech becomes a legitimate concept.

[Assistant] Between the Mandalorian Wars and Revan's Crusade, the Galaxy was left in a pretty sorry state.  Whole worlds were turned into irradiated wastelands and trillions upon trillions of beings died or were permanently displaced.  It left the Republic broken and virtually bankrupt to the point where they could not support reconstruction efforts on more than a handful of worlds.


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

[User]
[Fallout 3] What will the Capital Wasteland look like in 50 years? Did it really make a difference what the Lone Wanderer did with Oasis and Project Purity?

Phrased another way, what will the Wasteland look like in 50 years if the Wanderer fixed Purity and allowed Harold the god-tree to spread, compared to if the Wanderer sabotaged them?

[Assistant] Yes, it definitely made a difference. The sparse access to clean, usable water is a large factor in why the Capitol Wasteland has never grown beyond a handful of isolated fortified towns like the Mojave or California. Project Purity has greatly increased the wasteland's ability to support life, and perhaps even to resume agriculture and trade if the East Coast Brotherhood and/or the communities of the Wasteland choose to put some time and effort into creating a canal infrastructure.


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

[User]
[The Walking Dead (TV)] Why aren't the suburbs more overgrown by now?

It's been a couple of years since the world ended, and people still have fairly nice-looking lawns and shrubs. Are some of the walkers vegetarians?

[Assistant] Those are the remnants of short-lived communities of survivors. The main groups rarely run into them, but there are dozens of small groups spread out over the area in Georgia where the main group is situated. Sometimes they settle enough, and try to restart the old world. Lawns get mowed, grass planted, all the silly bullshit, because their leader is convinced that everything can go back to how it was if we try hard enough. Then a passing herd hears the lawnmower going one sunny Sunday afternoon, and that's that.


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

[User]
I don't believe taking a human life is inherently wrong. CMV

I bring this up because I recently got into a debate with someone on reddit about the moral justifications of taking a human life. He argued that killing another human is never morally justifiable, no matter the reason. However, I lost interest when he started talking about killing being ok if robots do it. I believe that killing another person is completely justifiable and "right" if killing that person saves other innocent people. If a man is holding a detonator rigged to blow up a building with 1000 people in it, and the only way to stop him is to kill him, I see nothing wrong about taking his life. If a man is about to take one innocent human life and I could stop him by killing him, I see nothing wrong with that. So please, show me the other side and CMV.

[Assistant]
I think your problem stems from the fact that you justify murder by preventing another murder or murders. Both are wrong, but one seems to be outweighed by saving another life. Therefore, a more morally coherent approach would be that killing, while always evil, is sometimes necessary or preferable.

A necessary evil, however, is evil nonetheless.


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

[User]
ELI5 - How do Actors hide their limbs?

In Movies/Television shows where an Actors character loses a limb, say a leg or an arm, how are the future episodes/scenes filmed without showing the real limb?

I'm assuming most Actors aren't committed enough to actually lose a limb for their job.

[Assistant]
In some movies, it's CGI - for example in forrest gump, lieutenant dan wore blue stockings and they edited them out with photoshop.

But in older movies, they used special costumes and creative camera angles to give the illusion of no limbs.

You can do it yourself with a loose fitting shirt and large cuffs, so you can pretend to be luke skywalker.


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

[User]
[Mythology] Why does the Kraken attack ships?

If we were to take the kraken seriously as a real animal for a moment, what motivation would it have to attack pirate ships? I mean, wooden hulls can't be very nutritious for a giant octopus/squid.

[Assistant]
Could be they just attack any large object in the sea because, odds are, it'll be some kind of food.  Ships are just unfortunately similar to whales in size and shape.

Could be territoriality.  The kraken doesn't like intruders and defends its home turf.

Then there's also the possibility that they're just plain mean.  Evil creatures who like to destroy.


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

[User] ELI5: Why do we make cars that easily go way faster than the speed limit?

[Assistant]
Well, all countries have different rules, the same goes for speed limits!

The best example is Germany, they are known to have roads with NO speedlimit, meaning you can go as fast as your car (and your bravery) will take you!.

That also explains why there are many sports cars in that country too.

How about other countries with speed limits?, well to be honest. People who buy such cars just do it because....well they can!
Think of it as a show of status rather than practicality.

Its like why people buy virtual clothes or cosmetics. Theres no advantage to getting them, the only difference is that you are now seen as a richer person!


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

[User]
Could arguments to ban crypto mining also be applied to gold mining?

It's an orders of magnitude larger industry, and also seems rather pointless. There should already be enough gold out of the ground for all practical purposes, and it works as a reserve currency however much of it there is. If a ban was possible, would it be a good idea?

[Assistant]
While gold mining and its processing can be quite bad for the environment (e.g. using Cyanide), it is not the case that there is currently enough gold just lying around that people would want to give up to be used in manufacturing processes for things like circuit boards and satellites. Additionally, expropriating the gold off people is probably a bad idea. For this reason, gold mining makes continues to make sense.

The crucial distinction between crypto and gold is that gold has other uses aside from being a store of value. In addition, more people believe gold to be a store of value. The same cannot be said about crypto.


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

[User]
Is all research experience good experience or should you not work in areas that you may not be fully interested in anymore?

So I got an offer for a research assistantship at my undergrad institution for some work in an area that would be my second-third choice if I were choosing it for grad schools. I'm not sure if I'm 100% interested in that area anymore, but I believe it might help me with applications this year, as I'm taking a gap year to improve my profile before applying again. Is it worth it to take up the offer?

(Also as a small side question, if the asking professor asks for a list of the courses you've taken as an undergrad, do you give them your transcript or just actually send them just a list without any grades?)

EDIT: Thank you everyone for the comments!! I think I'll take up the offer then and try to learn something out of it, hopefully it'll help my apps and I'm starting to think I'll enjoy it too!! Thankss!!

[Assistant] I think all research experience is good experience, particularly for undergrads. Honestly unless you have a better offer lined up, you cant really be that picky when it comes to your research topic. There are so many factors involved thats it not reasonable to expect everybody to only research topics they are extremely interested in. You research what you can get funding to research, and hopefully this lines up somewhat with what your interests are.


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

[User]
[The Lord of the Rings/Tolkien] Is the Edoras and Minas Tirith surrounding areas seen in the films at all correct?

It always bugged me that in the Peter Jackson films Edoras and Minas Tirith have nothing surrounding them for what seems like miles and miles.  No huts, no houses no towns.  Wouldn't kingdoms of that size have much more stuff happening?

[Assistant] The kingdoms of Men are fairly unpopulated as it is. For one Rohan was decimated by Uruk Hai and Gondor is sort of waning. Dont even get me started on Bree Land, that place hasnt recovered sincle the fall og Arnor. The 3rd Age was not a fun time to be a Man.


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

[User] ELI5: If a completely undocumented person from e.g. a poor tribe in Africa/Asia, managed to get to e.g. western Europe, he never said a word and it was 100% impossible to track his country of origin, what would the authorities do?

[Assistant]
Assuming they were somehow mentally impaired and was incapable of answering any questions about where they were from and they could not find anyone who knew them, they would be assumed to be a foundling and they would acquire the nationality of the state that found them.

>Article 2    For the purpose of assigning nationality, a foundling shall be considered to have been born in the State where it was found and from parents of that State's nationality. That presumption may be displaced by proof to the contrary.


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

[User]
What kind of bacteria would grow in the glass of water I leave by my bed overnight?

Is it a harmful amount by the time I wake up and need a sip of water.

Assume average temperature is 10 degrees Celsius, in the range for bacteria growth.

[Assistant]
The use of chlorine and chloramine in drinking water render it free of pathogens at the point of delivery (your tap); other areas use ozone, which does not have as strong a residual effect. These products are added in order to get rid of potentially pathogenic organisms; much of the rest of the world does not enjoy assured freedom from nasties such as cholera, dysentery, giardia, typhoid fever, hepatitis A, leptospirosis, and so forth.

However, these organisms do not spring from empty space; they come from biological sources that contaminate your water. These are unlikely to be present in your room, barring any afflicted housemates coughing in your glass of water.

So, while spores and the occasional live organism might find their way into your drinking glass, these are ubiquitous and you inhale them with every breath anyway. That they have found a glass of water to land in is hardly exceptional; there is little else in there to inspire spore germination and subsequent growth. Plain tap water is pretty good at keeping organisms from growing, unlike (for example) a glass of lightly sugared water with some chemical fertilizers added.

So- between residual disinfectant levels, and that there are no nutrients to inspire bacterial or fungal "blooms," your tap water on the bedstand is safe.


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

[User]
What will happen to New Horizons after the Pluto fly-by?

Do scientists know where it will be drifting?

How much power does it have left?

Will it continue to send us data? And if so, for how much longer?

Is the NH team planning at all to examine other Kuiper Belt objects with it? And if so, how are they going to get to them? Does New Horizons have still-working engines that can propel it, or is it entirely relying on the gravitational pull of planets/other objects to slingshot its way around at this point?

[Assistant]
> Do scientists know where it will be drifting?

Yes.

>How much power does it have left?

According to the Wikipedia page, 228 W. This matches closely with the expected 5% power drop every 4 years.

>Will it continue to send us data? And if so, for how much longer?

Yes. It's power supply should be good for about 10 - 11 more years.

> Is the NH team planning at all to examine other Kuiper Belt objects with it?

Yes, this was one of the primary objectives.

>And if so, how are they going to get to them?

Doing nothing would result in passing through the Kupier belt, so the key is adjusting trajectory to fly by objects of interest.

>Does New Horizons have still-working engines that can propel it, or is it entirely relying on the gravitational pull of planets/other objects to slingshot its way around at this point?

It has 16 primary thrusters and 8 backup thrusters, using hydrazine propellant.


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

[User]
ELI5: Why the West is friends with something like Saudi Arabia but always hostile towards Russia

On paper, it's all about democracy, human rights etc, but why being friends with medieval country? Not only Russia, but Iran, China and other countries.

[Assistant] I don't want to be *that* guy, but honestly it's oil. Saudi Arabia has access to a valuable material and Russia's oil access doesn't meet our standards. Not to mention the whole Cold War so tensions are still icy between the West and Russia.


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

[User] ELI5 : How does our brain store information and how does it search for it when I'm trying to remember something?

[Assistant] This isn't completely understood but we know some things about how it works.  We have 100 billion neurons that any one can connect to multiple others.  Any sensory input we have can make many connections.  But any single neural connection doesn't amount to anything mentally tangible and can be undone (short term memory).  Repetition makes multiple connections that basically maps out some concept in your brain.  Then, as you repeatedly traverse this mapped concept, or map whole other concepts together, the brain also processes these signals to form shortcuts for those "mapped concepts" with even more neural connections, so that accessing that stored information is faster.  The brain is continuously reconfiguring these connections based on the input it receives (what you are doing) so whatever is repeated most could be retrieved the fastest.  Trying to remember something is basically your brain looking for those shortcuts and if you were providing other sensory input, the reconfiguring to optimize whatever you were attentive would have used some of those neurons. Things you remember very easily, the connections were repeated enough to make so many connections that they'd never be completely undone again in your lifetime.


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

[User]
I got a new deodorant recently that says that it has no aluminum or parabens. Is there research showing that aluminum and parabens are harmful in the quantities that they usually come in in deodorant?

I.e. when you consider the concentration that they're in in deodorant and when you consider that people use a tiny amount of deodorant once or twice a day, are those amounts of aluminum and parabens harmful to humans?

Edit: WOW this blew up while I was at work. Thanks for all the replies, everyone!

[Assistant]
Not so much harmful, but some people have skin reactions to either aluminum or parabens (or both), so there's a market for deodorants/antiperspirants without these additives.

Aluminum is added to some deodorants as an antiperspirant (helps you sweat less).

Parabens are not commonly used, but they help reduce bacterial and fungal growth (on both the body they are applied to and on the deodorant stick itself), which is part of how those products work, since body odor is often the result of surface bacteria byproducts.  Kill the bacteria or fungus, and the odor "problem" is solved.

Neither substance has been shown to be harmful in the amounts encountered in deoderant products.


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

[User] How are meteorites dated if they don't develop in Earth's conditions?

[Assistant]
This is a great question and it turns out the exact same techniques work for both terrestrial and extra-terrestrial samples assuming they all come from our solar system.

There is a technique for dating where you need different minerals from the same rock (or meteorite) and then you can setup an isochron where you plot the isotope ratio of the daughter (e.g., 206Pb) to a primordial isotope of the daughter element (something with no radioactive decay input so 204Pb) versus the ratio of the parent isotope (so 238U) to the 204Pb. If these plot on a line the slope of that line is the age of the sample (basically things that have higher 238U/204Pb should have higher 206Pb/204Pb because the ingrowth is faster) and from this the intercept tells you the original 206Pb/204Pb ratio the sample had. This is the safest and best way to date samples where you don't know the isotope composition of the daughter ahead of time.

Now you can also go another route and try to find phases to date where the initial amount of daughter (e.g., Pb) is so low that you don't need to correct for it. For example if you find a mineral called zircon in your meteorite you generally can just date it without correcting for initial Pb because it was so low.

I hope that helps.


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

[User] ELI5 why do modern battleships only have one small canon compare to old battleships that had at least 9 huge ones?

[Assistant]
Air power:

In 1950 it became obvious that guided missiles and bombs could hit a ship easily. At that point the aircraft bombs and missiles were available in massive sizes compared to 10-20 years before. For massive, to be clear, it means bus size. Those bombs/missiles had the capability to make a hole in a 30 inch thick armor plate. The only ship big enough to carry such armor would have been a super battleship 1km long and 10 time the cost of ww2 battleships. Even if you armor against the missile, your armor bent can make a bigger missile quicker than you can build the new bigger battleship.

Logical solution was to give up armor completely, make cheaper smaller ships and use the space and displacement to carry the biggest possible punch. The biggest punch you can get, is a cruise missile, there is no gun that can punch that hard.

Still, an enemy can hypothetically jump you at close range using an island as a cover, or whatever sort of ambush you could plan. So you still need something to insta-kill at close range (naval point blank range is 10km nowadays, for scale). But as we said, there are no armored ships around, whatever ship ambushes you, will be unprotected as you are. So you just need to mission kill your ambushed before he fires. To mission kill an unprotected ship, you can just use a small fast firing gun.

And there we are, all missile cruisers carry a single (or double) turret with a fast firing gun, that is 5-6 inch in caliber, more than enough to cripple a 300m long cruiser in 1 minute, by shooting few dozens 10kg shells.

For comparison, this cannon is super tiny compared to ww2 battleship guns, which shells weigh 1-2 thousand kg, and were armor piercing up to 16-20 inch of armor. And because the fight were at 20-30km range, they needed many guns to spray the area and maybe get a kill at that range. That range is non existent now, because a missile can go 200km or more, again, the only gunfight you can get is a strange ambush that never happens, the tiny gun is there just in case.

Minor editing for clarity.

Thanks for the award!!!


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

[User]
ELI5: Why blood bag that isn't completely filled up cannot be used?

So I remember a friend having this really large bruise on her elbow pit. Apparently she donated blood but the nurse said her vessel popped so the needle had to be removed. She was informed the blood can't be used for donation and would have to be discarded because it wasn't completely filled up. Even tho it wasn't full, the bag had lines to measure the amount of blood, so why?

[Assistant]
Blood bags are pre-filled with chemicals to prevent clots and extend the shelf life (most commonly CPDA). These also affect the acidity of the blood. The amount is calculated assuming the bag is filled to a certain volume.

These remain in the blood when it is transfused, so if you used a bunch of partial bags instead to transfuse someone, you would be transfusing them with a bunch of excess anticoagulatant and also messing with their pH. Since they are presumably sick enough or bleeding enough to need a transfusion, they might not be able to handle this.


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

[User]
ELI5: How are people like Jim Jones (Jonestown Massacre) able to influence people to such a degree that they not only take their own lives but also their childrens.

What events can lead up to someone thinking "you know this guys on to something, I *should* take my own life" and how is this process influenced?

[Assistant] Jim Jones had charisma, he had the ability to make people believe anything. He picked people who were looking for something, vulnerable and he knew how to build them up into his ideal. Once they had moved out of the US he had complete control. They had given up families, jobs, homes. Everything. He was really all they had left, even if a part of them was doubting they had to keep going because they had no way to leave. 24 hour a day indoctrination and isolation. If you remove someone from reason and create a new reality for them, you can become the reason they live, or die. They took the children because they were lead to believe that life for the children would be suffering without them. Would you die willingly thinking you would be going to a place of salvation without suffering and leave your child behind? Because of the size of the group it became epidemic, they could not fight it. Mob mentality if you will, they were scard to be left behind and those that did fight it were injected. Jim Jones created a reality for these people that revolved around him, he was the only one that could save them.


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

[User] ELI5: Why would anyone dig their own grave? Seriously, let's say you put a gun to my head and tell me to dig but I refuse to dig. What are you going to do - shoot me? Well shoot me then and dig your own damn hole.

[Assistant] In a lot of cases like this, such as the people who read the scripts before being beheaded by ISIS, the person has been tortured extensively. If they don't comply, they get tortured more. If they do, they get a quick death.


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

[User] [Star Trek: TNG] Why didn't they clone Geordi new eyes? It seems like great strides toward this field are already being made in the 21st century. We never see any other blind people with visors. What gives?

[Assistant] Replacements of failed body parts are one of the few socially acceptable forms of transhumanism in the federation(and IRL). So given the opportunity to have better vision, Geordi or his parents chose the visor.


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

[User]
Does special relativity have any flaws?

We know that the theory of general relativity has its shortcomings, but what about special relativity? Are there any circumstances under which special relativity falls short or fails altogether?

[Assistant] The special theory of relativity is, as the name implies, a special case of the general theory of relativity. Specifically, it's what you get from the general theory of relativity if you assume there are no gravitational sources present. As such, any physical situation that can't be described using the general theory automatically can't be described using the special theory. Moreover, the special theory doesn't work in any case where you have gravity, though it can be used as a very good approximation when gravity is fairly week and uniform (like on the surface of Earth).


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

[User]
[LOTR] What would happen if Elven Ship and Human Ship sailing to the west together?

Since only elven ship are allow to reach valinor, what would happen to both ship? Would the elven ship stuck in curvature with Men or would it just disappear a la bermuda? What if Both ship are connected by mithril chain?

[Assistant]
IIRC, the elves can still travel the straight line that leads West, while men are stuck following the now-natural curvature of the Earth, so from the human's point of view the elven ship would slowly take off into the air and cruise off into the clouds.

If the ships are connected, the chain pulls on the human ship until *something* breaks, most likely the part of the human ship it's secured at. Unless the human ship was purpose built to suspend it's entire weight by a single connecting point, nothing good comes of the attempt.


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

[User]
ELI5 why can NASA get super high resolution images of galaxies hundreds and thousands of light years away, but struggle and cannot get even a decent image of Pluto?

I did the Google-ing like the rules say but the journal articles are very complex with equations and "refraction property data of heat waves through various gasses", and the science news articles don't really say why either. So, I have come here for some dumbed down science and explanation.

[Assistant]
The same reason you can get a brilliant image of the mountain 100 miles away in the day with your camera phone but a professional photographer wouldn't be able to make out the detail of a flea across the room in the dark

It's easy to take pictures of huge bright things, even if they're far away.  TINY things are hard to get a picture of, even if they're relatively closer, especially if they don't give off much light.


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

[User] [The Princess Bride] Why was Westley able to defeat Inigo, who had studied swordplay for much longer?

[Assistant]
They're both phenomenal swordsmen, and the fact that two people with such a transcendent talent actually met it, to coin a phrase, inconceivable.

Inigo worked and trained *very* hard to achieve the level of Wizard. But as he himself has said, he's been "more pursuing than studying" lately - in other words, he's reached his peak-level, and probably has many years ago.

Westley pretty much got tossed in the deep-end, and had to get really good really fast. He also seems to be one of those one-in-a-million people who has a crazy innate talent. Combine those together, and you get someone who made it to Wizard-level really, really fast, and probably has a higher level cap than Inigo.

They are probably the #1 and #2 swordsmen in the entire world, though. Which made them both cocky as all hell.


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

[User]
ELI5: How does a change in the number of protons/neutrons/electrons drastically change a molecules properties?

It's like I add a few electrons and neutrons and protons and BOOM, went from hydrogen to copper or copper to neon.

How does a simple change in a molecule's structure determine the chemical and physical properties of an atom?

[Assistant]
The structure is what determines how it interacts with everything around it.

Think of a molecule like a key, and the rest of the universe is a set of keyholes.  The protons and electrons and neutrons---their positions, charge, number, and other properties---are like the grooves and teeth on the key.  If you change those things in even a small way, it will dramatically alter what keyholes the key will fit.