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

[User] ELI5: My 4yr old is fascinated with dinosaurs and evolution. I am trying to explain the concept to her, but seem to keep going over her head. Help me explain evolution, specifically human evolution, at her level.

[Assistant]
She is not exactly like you. You are not exactly like your parents. They, in turn, are not exactly like their parents.

Because of this, she is not exactly like her first cousin. And she's even less like her second cousin. And even less like her third cousin.

That might well be enough for her. But if she wants to know more, then try this:

Now, what about her dad's dad's dad's dad's dad's a thousand times' dad? He'd look nothing at all like you or her.

And what about a monkey's dad's dad's dad's dad's dad's a thousand times' dad? He'd look nothing at all like the monkey.

In fact, her dad's dad's etc dad and the monkeys might even have been the same monkey-person. She and the monkey could be cousins!


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

[User] What makes online forums so prone to disinformation?

[Assistant] Don't really have time to explain them, but you might be interested in the disinhibition effect, affective communities (Papacharissi), and how  algorithms encourage/facilitate the formation of echo chambers.


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

[User]
How do villages and civilizations become buried?

Archeologists dig up bones, objects, even entire villages 10-20 feet underground. How did they get that far down? Where did all the dirt that is covering them come from? Why aren't we being buried?

[Assistant]
Dirt is produced by erosion of rocks and decaying plant matter that constantly shifts with wind and rain. Ive watched a brick slowly get covered by a 1/2 inch of dirt in just a single year within a fenced in backyard. Now extrapolate that to a structure left in the open and undisturbed for a century or two with things like floods, major storms, and mudslides.

This also why you wont see much except foundations as well.


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

[User]
ELI5: Why does it cost upwards of $50 to ship from USA to Australia, yet I can get the same thing from Amazon with $10 shipping.

Looking to buy a few things that I can't get from Amazon and the shipping is upwards for $50 for something that is $20, yet I bought something on Amazon last week that was significantly bigger and heavier and it only cost $10 shipping.

[Assistant] Amazon ships in bulk, literally by the truckload/shipping container, which saves both you and them money. The other shipper probably doesn't have the kind of volume to negotiate the same level of shipping discount.


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

[User]
Could Earth acquire another moon? If so, what would be the implications?

Would it be possible for a asteroid, meteor or comet to become trapped in orbit around Earth? Obviously it would depend on context and mass but what would the implications be?

[Assistant]
Well, it's not *im*possible, but it's very, very, very unlikely - so unlikely that the chance it would happen is probably longer than the Earth would be around.

But, anyway, if it's asteroid/comet sized, probably minimal to no noticeable effects. Even something the size of Vesta probably wouldn't do much but mildly affect the tides (unless really, really close).

And if Earth gets this new moon the same way it got the current one - by a Mars-sized body ramming into it - the effects are the extinction of all life, the complete erasing of the surface of the Earth, and basically setting the whole "clock" back to 4 by ago...


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

[User]
[World of Warcraft] Why are the people of Azeroth successful in repelling and ultimately defeating the Legion when countless other worlds have failed?

Like...what's special about us? Did the other worlds just not try or what?

[Assistant]
One answer is practice.  Prior to fighting the Legion directly, the residents of Azeroth fought among themselves *a lot*.  They also got plenty of practice fighting demons, fel magic users, undead swarms, dragons, shadow magic users, Old Gods, weird ancient bug peoples, Pandas' inner demons...boy it's a long list.

Another answer is allies and awareness.  The forces of Azeroth received help from people like the Draenei, who had encountered the Legion before, and the Army of the Light, who had been fighting the Legion for ages.  There's also Illidan and all his angsty warnings.

Yet another answer is that Azeroth has always been a distinguished place.  It drew attention early on for having a very powerful Titan soul growing within it.  Old Gods flocked to the world, and the Titans came to its defense.
 Sargeras and the Old Gods/Void Lords have long been after Azeroth, seeking to corrupt and/or destroy the planet and its denizens.  The peoples alive on the planet today are survivors and heirs to a long lineage of fighting evil stuff.


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

[User] ELI5: If medical evidence suggest that the Helicobacter Pylori Bacterium is responsible for peptic ulcers, why do many doctors still advice patients to avoid spicy foods and citrus juices?

[Assistant] Spicy and acidic foods can irritate the lining of your stomach, both making you more susceptible to infection and worsening infections that you already have. Avoiding these foods also reduces the discomfort that comes from ulcers, which helps the patient.


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

[User]
ELI5: Why do we have the right to life but not the right to death?

We never consented to being born so why do governments not allow us to be euthanased as we please? I mean we are all mostly the "consequence" of sex or just exist to serve our parent's (perhaps selfish) desire to lead a happier or more fulfilled life by having a family.

Am I missing something obvious here or has this not crossed anyone's mind?

Edit: Thanks guys for responding.

[Assistant] In most parts of the world suicide is legal, the only reason (in most places) that assisted suicide is illegal is because it's so difficult to put in place safeguards to prevent people from bumping off their ill relatives and then pocketing their cash safe in the knowledge that the euthanasia laws will protect them.


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

[User]
ELI5:Can a quantum computer solve problems that would be impossible to solve using regular computing; or human thought?

I was interested if computers could get so much smarter than humans that it would be logically impossible for us to compete at some stage either with or without the help of non-quantum computers.

[Assistant] In theory, no.  In theory, humans could eventually solve the same problem, but quantum computing is so much faster.  For a difficult problem, a quantum computer might solve it in seconds while humans might take millenia to solve the same problem.


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

[User] [WH40k] Is there anyone with enough fincnaial wealth and personal elan to gain access to the Golden Throne?

[Assistant]
Short version: No, the Custodes wouldn't let you in no matter how rich or impressive you are.

Longer version: Yes, but not directly.

Basically, if you're rich and powerful enough - and we're talking owning multiple gigantic spaceships, and possibly one or more worlds - and also smart enough, you could theoretically get in with the Inquisition. If you can persuade an Inquisitor to make **you** an Inquisitor, then you can petition the High Lords of Terra for an audience with the Emperor. But you'd need a very good reason for them to let you in.

Alternate route: Bribe the right people and have them slip you in with the regular tithe of psychics who are sacrificed to keep the Throne functioning. You'll die pretty much instantly, but the last thing you will see is the Throne. Probably not the part with the Emperor on it - it's a massive device housed in a building the size of a small country - but you'll be closer than the billions of pilgrims who will be crowded outside.


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

[User]
Is multiple databases logical?

very noob question. But let's say some has these features; the ability to send and display currency, a user's profile info (name, photo, uploaded photo/video), and a catalog of videos accessible throughout the platform. Would multiple SQL databases and a CDN make sense? This is a general question but I simply chose to highlight the specifics.

[Assistant] It depends on the scale. Using separate databases (and microservices) for all of those concerns allows you to upgrade and scale them independently. This means that e.g. if video streaming is very popular, it won't impact currency transactions, for example, because the infrastructure is separate.


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

[User]
Would a large enough explosion disperse a tornado?

I was thinking perhaps you could fire a rocket/bomb into a tornado, and it would explode causing the tornado to be destroyed? If this is possible how big of a blast would be required? I suppose it would depend on the tornado's size and strength.

[Assistant]
A large enough explosion would disperse the solar system etc.

A proper question is how large of an explosion would you need. Somone that would be able to answer this is someone versed in fluid dynamics. A tornado is a heat transfer machine based on the differential of two temperatures. You may be able to ignite the atmosphere above the tornado to balance the temperatures. A like others have said, it'd only be localized and most likely temporary. Another one would just popup further away.


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

[User]
How do we differentiate the Earth's magnetic field weakening due to a pending reversal instead of a complete shutdown like is suspected to have happened to Mars?

From my understanding, it is suspected that Mars once had a magnetic field like ours, but because of its smaller size, the core eventually cooled and stopped its movement, causing the field to "turn off".

How do we know the current weakening of Earth's field is not a similar process, but instead just a reversal?

[Assistant]
Loss of magnetic field is a gradual process which results from the cooling and solidification of the liquid outer core. We know from seismic studies we are nowhere near that point - it is still large and molten.  Turning off of the magnetic field is *not* a rapid on-off process.

The reason we're so far from it happening on Earth is the much bigger volume of our planet in comparison to Mars, hence the cores are bigger, better insulated, and the much higher volume to surface area ratio which means that cooling is less quick.


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

[User]
(LOTR) Could Sauron take physical form without the ring?

The movies seem to stay that Sauron was only a spirt and he was the Eye of Sauron himself. And even the Hobbit seemed to show him as the necromancer as simply a spirt as well. I haven't read the books in quite some time but from what I remember, the necromancer was and actual physical being, and after Gandalf chased him away Sauron fled back to Barad-dr and was too weak to fight for himself, so he created the eye of Sauron.

[Assistant]
In the Red Book of the Westmarch, we find Gollum, recounting his captivity at the hands of Sauron, telling how Sauron has "Only four [fingers] on the black hand, but they are enough." This is widely accepted as convincing evidence that the Dark Lord had taken physical form again during the later years of the Third Age, which the Wise had already feared was happening during the rise of the Necromancer at Dol Guldur.

He was not able to take fair form again after he fled the Ruin of Numinor, but he had a physical form. The "Eye of Sauron" was already terrible to behold and hard to endure during the First and Second Ages, also it was taken up as a symbol by all servants of Mordor, so that it's hard to distinguish between the actual, physical eye and gaze of Sauron and its metaphysical use as a symbol for Sauron and his power.


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

[User] [Final Fantasy VIII] Why is Esthar so much more technologically advanced than the rest of the world?

[Assistant]
Different cultures progress at different rates. Asking why they are so much more advanced is like asking why we (the West) are so much more advanced than central African hunter-gatherers.

Availability of resources

Fostering of particular attitudes

Random dumb luck in the birth of technical genius

The key factor, however, lies in the fact that Esthar is highly insular. To the point of xenophobia. They do not, under any circumstance, like to deal with outside powers. Their technology, their culture, their resources, everything in kept within their borders. This means they likely develop independently from the rest of the world, and due to the aforementioned factors, have progressed faster.


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

[User] Do all known species exhibit an approximately 50/50 distribution between male and female offspring or are some weighted toward one sex over the other?

[Assistant] Haploid diiploid insects(bees and ants) are a good offhand example. Instead of using sex chromosomes, they rely on an egg to hatch in a fertilized or unfertilized state. Males having half the chromosomes as females do.


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

[User] [GoT show] How would things have worked out if Tyrion had after killing Shae not gone on to face Tywin but instead had gone straight onto the boat leaving Tywin alive?

[Assistant]
Tywin quashes the Sparrows' movement before it gains traction. He forces Cersei to marry Loras and sends both of them away to Highgarden so he is free to educate Tommen. He limits Margaery's control over Tommen, but is careful to keep the Tyrells in the fold.

Before he can turn his attention to Stannis in the North, he has to resolve issues with Dorne. Qyburn is Cersei's pet, without her, Tywin puts an end to his research. Gregor is left to die and his skull is sent to Dorne as an apology. Tywin offers Oberyn's seat on the Small Council to another Dornish representative. Doran keeps Ellaria and the Sand Snakes in line while sending Trystane to take Oberyn's seat, while Myrcella accompanies. Tywin encourages King Tommen to spend time with his sister and with Trystane to foster good ties with Dorne and to limit Margaery and the Tyrells' influence over him.

In the Riverlands, House Frey quashes revolts with Tywin's support. Jaime is probably still sent to retake Riverrun from the Blackfish, this arc doesn't change much. Not sure what Jaime and Tywin's relationship is like now, but Tywin probably forces Jaime to take on more responsibility to make up for freeing Tyrion. Jaime is tasked with assembling a force to oppose Stannis in the North.

Littlefinger would be stupid to continue his treacherous alliance with the Boltons with Tywin still alive. He keeps Sansa in the Vale and focuses on consolidating his power in the region.

With Lannister and Frey support, Roose easily crushes Stannis. The Lannister army continues to the Wall and demands the removal of the Wildlings, ignoring Jon Snow's pleas and warnings about the White Walkers. The Watch is helpless to stop the massacre of the Free Folk, many of brothers are even pleased with this turn of events. Jon is shattered and resigns his command to Thorne.

Ramsay is unable to betray his father, who has powerful allies in Tywin and Walder Frey. He is forced to watch his trueborn brother grow to become a rival despite his father's reassurances. Theon remains Reek. The Umbers give up Rickon to Tywin to earn his favor. Tywin keeps Rickon as a hostage to keep the Boltons in line and to make up for the loss of Sansa.

The Brotherhood without Banners and any remaining dissidents and insurrectionists on the mainland are hunted down. In a scandalous, unprecedented appoinyment, Tywin has Olenna Tyrell appointed Mistress of Whisperers since he desperately needs to replace Varys.

Mace Tyrell and Meryn Trant are never sent to Braavos to treat with the Iron Bank, so Arya continues to train with the Faceless Men.

As he rebuilds the royal fleet in preparation for finally dealing with the Greyjoys, Tywin meets with Littlefinger to return the Vale to the fold. Littlefinger stalls, quietly keeping Sansa in his custody and denying any knowledge of her whereabouts. He is forced to reach out to Varys in an attempt to coordinate, since they share a common enemy in House Lannister and House Targaryen is the only piece left in the field. Varys rebuffs him for now.

Tywin personally commands a grand coalition to attack the Iron Islands once again. Jaime and Kevan serve under his command, this force is composed of Lannister, Tyrell, Martell, Frey, and Bolton bannermen. The Greyjoys are crushed and their castles torn down. Tywin puts many thousands to the sword in order to ensure the Ironborn will never be a threat again.

A portion of the Iron Fleet under Yara manages to escape to Mereen to join House Targaryen.

Tywim begins a vast rebuilding program to restore the war-torn country, while preparing for the inevitable threat of Daenaerys. He makes common cause with Qarth and Yunkai and funds the Sons of the Harpy, hoping to keep Dany tied down in Mereen for as long as possible.

The Night King cannot breach the Wall without Viserion, so he sits around waiting.


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

[User] ELI5: Why are the traditional blueprints blue?

[Assistant] Despite most people using the term Blueprint to mean an original design or plan on how to build something, a Blueprint is actually what it means, a print. A printing of an original design, usually to print a bunch off to give to all the workers that require a copy of the plan. Back before photocopiers, scanners and printers, they had many techniques of duplicating a drawing. One was placing the original drawing (drawn on a translucent layer), on top of another layer with chemicals that when exposed to light would turn another color, that color just so happened to be blue, and leaving the areas covered by the drawing white.


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

[User]
Eli5: Why do earthquakes devastate Haiti but not the Dominican Republic?

The two countries share an island, and neither is that big. Why do we hear about earthquakes in Haiti causing massive damages and loss of life, but almost nothing about the DR?

[Assistant]
1) Haiti has a higher population density. Both countries have about 11 million people, *but* the Dominican Republic occupies a larger part of the island and the population is spread out over a wider area (for the Dominican Republic the density is about 220 people per square kilometer while for Haiti the density nearly 415 people per square kilometer). That means that you have more vulnerable people crammed in a smaller area.

2) Haiti is a poorer country and cannot afford to build sturdier structures to withstand quakes.

3) The main faultline that triggers a lot of earthquakes in the area happens to run across the southern part of Hispaniola... *right through* Port-au-Prince where nearly 2.6 million people live. So the DR might experience the initial shock and aftershocks but those are not going to be as severe as what Haiti experiences.


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

[User]
ELI5: Why are sports injuries allowed to be reported in detail

How does that not violate HIPAA law? And if it does, does no one care?

[Assistant]
> How does that not violate HIPAA law?

HIPAA would prevent a doctor from just handing out detailed information on the injury of a patient, sports icon or otherwise. What HIPAA *doesn't* prevent is the sports organization which employs that patient releasing details on their injury as per their prior agreement in their employment contract.


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

[User]
[Batman] Why do the Joker and other Batman villains go to Arkham Asylum when legally they arent insane?

Insanity is a legal term meaning someone committed crime without knowing what theyre doing is wrong. Joker knows hes doing something wrong as do most Batman villains. Just having a vendetta or general hatred toward humanity or getting your kicks from hurting people doesnt qualify you as insane. There are lots if criminals in jail like that. So why do these criminals go to Arkham Asylum?

[Assistant] Theyve been declared not competent to stand trial. Arkham serves to determine if and when they become competent. Couple this with the rampant corruption throughout Gotham and it becomes clear why they end up outside of prison, and why they keep escaping.


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

[User]
What's the point of a repo?

If I understand correctly, A repo is when X gives some assets to Y, and Y gives like 10 dollars to X. However X is comitted to buy back that asset, but for a higher price. Hence Y is essentially lending money to X, receiving interest and using the asset as a collateral. I guess I understand that, but I read that most repos are done in a short timeframe. What's the point then? Why don't the buyers like X just borrow money through the traditional channels?

[Assistant]
Typically the repo market that you see discussed in the news is for banks. Banks have collateral requirements and must have certain levels of assets on the books at the end of every day to comply with federal regulations. Traditional lending would be too slow; often a bank needs to balance its books and gather additional collateral only an hour or two before COB. The repo market provides liquidity so Bank A can hold Bank B's extra assets overnight and not violate the law. Bank B makes a little money, but not a ton. The real value is that when Bank B has too many liabilities, it can tap the repo market to balance its own books.

There are other repo market examples, but this is one of the most common.


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

[User] ELI5: why do smelling salts wake you up as they do? And what are their limitations?

[Assistant] Smelling salts are basically a really strong smelling powder, which irritates your nose, making you take a big breath. They were used for rousing people who had "fainted" from a shock, a bad smell, or the sight of blood. They can occasionally make people focus on the smell or simply breathe more deeply, which can prevent a syncope. They don't do anything when someone is actually unconscious though, and they can cause irritation of the airway if used frequently.


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

[User] ELI5: How does an optometrist create prescription lenses for an infant?

[Assistant] Lenses work both ways, so the Dr. can use a scope to look in the infant's eyes and try lenses to bring the back of the eye into focus. It won't be perfect, but if the infant has bad enough vision that they can tell the infant needs glasses, you'll be able to make a huge improvement anyway.


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

[User]
ELI5: Game Theory

After seeing the golden balls split standoff,  I understand what he did but don't understand the wider concept.

[Assistant]
Game theory is a branch of math built around something called games. There are multiple players, and they each have some strategy to try to get the most points. You try to find something called the Nash equilibrium, where each player's strategy is the best possible strategy given their opponent's strategy.

For example, if you're playing rock-paper-scissors, if you always pick rock you opponent can beat you by always picking paper. If you always pick paper they can always pick scissors. And if you always pick scissors they can always pick rock. But there's a Nash equilibrium if you randomize it. If you pick rock one third of the time, paper one third of the time, and scissors one third of the time, then no matter what strategy they use, they'll win one third of the time, lose one third of the time, and tie one third of the time. If they're using that strategy too, then there's nothing you can do to be more likely to win, so that's the Nash equilibrium.

You can also look at subtle variations, like what happens if you count rock as two wins instead of one. In that case, you should pick paper half the time and rock and scissors one quarter of the time.

Also, games aren't necessarily zero sum. The Prisoner's dilemma is probably the most famous example of a non zero-sum game.


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

[User] ELI5: Why dont you feel the effects of a car crash (like sore muscles or strain) immediately instead of a day or two after?

[Assistant]
I'll second what the other poster said about adrenaline keeping you going for the first few minutes, but there's more to it than that. First, you most certainly *can and will* feel pain from a traumatic injury right away, even with adrenaline. This happens when severe structural damage has been done -- for example a broken bone, a ruptured muscle body, torn ligament/tendon, or large amounts of blunt force trauma. Adrenaline will only cover up so much in these situations. You will be in immediate pain, and as the adrenaline wears off the pain will get worse. Adrenaline diverts blood flow away from your (potentially damaged) extremities, but it also puts your brain into fight-or-flight, where the instinct to stay physically active overrides the debilitating effects of pain.

As for the pain that presents a day or two after -- this is due to inflammation in the tissues which gradually builds up as part of the healing process. Your damaged tissues release inflammatory markers that promote blood flow, and that swelling is painful. This is no different than how your muscles don't immediately hurt after working out, but the next day may be extremely sore.


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

[User]
Do fans increase the temperature of the air they move?

As I understand it, increasing the movement (or vibrations) of the molecules in a gas increases the temperature of a gas.

Would the propulsive action of a fan on the air moving through it have any kind of effect on the actual temperature of the air as it leaves?

[Assistant] Yes, but the effect is so slight that it would be almost impossible to measure. A fan is basically a high flow low pressure compressor. It works by slightly increasing the pressure on the surface of the blade. And from the ideal gas law, PV=nRT, temperature is directly related to pressure. Since the pressure change is low and the volume is very high, the temperature change is very low.


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

[User]
[Batman] How long could Batman go on vacation before Gotham is completely inhabitable?

One morning, Batman decides he needs a break from crime fighting and goes on vacation to Cancun or the Bahamas or somewhere tropical, so he's far enough away that he can't intervene with anything Gotham related until the vacation is over.

How long before Batman's enemies terrorize the city to the point of total inhability? One week? Two weeks? More?

[Assistant]
Tbh, as long as he wants assuming a global, or city wide threat doesn't hit.

For one, he's cleaning up the streets on a very miniscule level. While he's stopping 15 or so crimes a night, he missed about a hundred. And had he stopped those, the city as a whole would have been no worse for the wear, just like New York or Chicago is with the crimes that go down there.

On a second note, he's not the only hero in the world. If anything were to be threatening enough that the whole city was in peril, the whole Batfamily, Batwoman, or even one or several members of the Justice League could come down and help out with.

Batman is at base street level, and street level isn't going to ruin a city entirely.


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

[User]
ELI5: Why does major chords sound happy and minor chords sad?

Why does major chords sound happy and minor chords sound sad? Is there any real science behind it, or is it like that because it's always been that way? I also wonder about humanity's fascination with rythm. I have some theories but I wonder what you guys think/know.
Would appreciate if you could give an actual ELI5 explanation, I'm going to try to explain it to some kids at work.

[Assistant] It's cultural. Major chords sound happy to you because you've been told it's happy since your early childhood. That said, Pharell William's "happy" is in minor chords (Happy Together by The Turtles too), whereas REM's Everybody Hurts is in major chords and Creep by Radiohead is mostly major too.


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

[User]
ELI5: What happens with the remaining cavity when someone donates/loses a body organ?

Do they stuff it with something or is there left air? Does the body fill it up with new tissue?

For example, it seems a lung might leave a fairly big *hole*. They don't just leave it and staple it closed, do they?

Please assume a good process of healing without problems for this example. No need to go into a (mine-)field of medical what-ifs.

[Assistant] There is no air or fluid that fills the space. The organ is removed and depending on the organ, its size, and its location there are internal stitches put in to hold the walls of the organ cavity together. Like all tissue the flesh surrounding the organ will eventually grow together. Basically after it is healed it is like there was never an organ there to begin with. From the outside there may be a noticeable "dent" or cavity. It is very easy to feel when an organ has been removed if you rub over the scar. it sort of feels like a hole but it is solid.


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

[User] ELI5: why are tornadoes so rare outside of the US?

[Assistant]
The US has a perfect breeding ground for them.  Cold, dry air comes down from Canada and meets up with the warm, most air from the Gulf of Mexico.

Mix in some instability from a warm spring/summer day, and youve got the makings of a hellfire and brimstone tornado producing thunderstorm.


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

[User] ELI5: Why is backwards compatibility for consoles (like playing PS3 games on PS4) not possible?

[Assistant]
There are 3 ways to achieve backwards compatibility:

1) Make the new console essentially a more powerful version of the old one. This is why the Wii could play GameCube games, and the Wii U could play Wii games. They used components that were compatible with software made for the previous console. This is kind of like how a new PC with the latest CPU can play games that were made for PCs 10 years ago. The hardware is fundamentally backwards compatible.

The problem with this approach is it limits the options for designing a new console. You can't necessarily use the latest and greatest CPU if it's not compatible with the CPU in the old console.

2) Include the hardware of the old console in the new one. This is how the PS2 had backwards compatibility with PS1 games, and how early PS3s had PS2 compatibility. While the new console was significantly different from the old one, they still incorporated the hardware necessary to run the old games.

The problem with this approach is that it makes the console more expensive because you essentially need two consoles in one. That's why they dropped PS2 compatibility from later PS3s.

3) Software emulation. This is how the PS3 could play PS1 games, and how the Xbox One can run Xbox 360 games. The new console doesn't have compatible hardware, but instead it has a program that pretends to be that hardware so it can execute programs written for the old console.

The problem with this approach is that your new console needs to be significantly more powerful than the old one. Emulators take a lot of processing power to be able to run games at a playable rate.

The PS3 used a very unusual CPU called the Cell. And Sony's plans for it didn't really work out. Developers found it hard to use, and although it theoretically had a lot of power, games typically performed better on the Xbox 360 which had a more normal architecture.

So Sony didn't want to use the Cell again. They wanted to use a more typical PC-like architecture that developers know how to use effectively. So option 1 was out.

Having the PS3 hardware alongside the PS4 hardware would have been too expensive, so option 2 was out.

Option 3 isn't viable because the PS4 just isn't fast enough. Thanks to the weird architecture of the PS3, emulating it would be very complicated. So there's very little chance of them making a PS3 emulator that performs well enough.

Microsoft have had success with option 3, but that's because the Xbox 360 had a more typical hardware architecture. So in a sense it's easier to translate software instructions for the Xbox 360 into ones that the Xbox One can understand.


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

[User]
Coding Bootcamp Vs. Associates and Beyond

Hello all,

I'm wondering if going to a coding bootcamp would be worth the 11,000 I'd have to drop to get in. Are any of you employers? Or does anyone know from experience, can a 3-6 month bootcamp get me a job in CS fields or will my certificate be laughed at. I know that an associates and definitely a bachelors will give me a great chance of landing a job with all the openings out there. My dilemna is spending 2-4 years to get one. I'm 24 and for some reason I feel like getting an associates/bachelors and starting over my career at 26/28 is too old? I know that's ridiculous but...Anyway, what is  the best route to go. What will really land me a job upon completion.

Thanks everyone!

[Assistant]
Go for the degree. Gives you much stronger foundation and covers core concepts much deeper. Bootcamps teach you tools/frameworks but they don't focus much on the CS fundamentals.  CS programming courses focus on applying the programming concepts to problem solving and the questions are usually difficult; thus to a recruiter you are more likely (based on you passing the course) to be a better problem solver than a bootcamp grad. In the long run the degree will be more beneficial than a bootcamp. And with a degree you can always study further (formally) if you want and go into more complex topics.

Imo it's never too late to start a degree.


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

[User] [Dungeons and Dragons] What does being under the Charm spell actually feel like?

[Assistant]
Ever met someone who you've just really clicked with? Someone who you suddenly feel really comfortable with even though you've only known them for an hour or so? Someone who's got  that certain *je ne sais qua* that leaves you nodding along with everything they say?

Like that but artifical.


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

[User] ELI5: Why was the AIDS epidemic in America more prevalent among gay men in the '80's?

[Assistant] Because anal sex is more likely to transmit AIDS than vaginal sex.  At the time, they didn't really know as much about STDs as we do today, so gay men, knowing they had no risk of pregnancy, didn't use condoms.


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

[User] ELI5: Who wrote the bible?

[Assistant]
Hundreds of people. Then their writings were rewritten, edited, translated, retranslated, thrown away, made up from memory, etc. It's basically like wikipedia.

Many of the councils were convened to decide which parts to cut out or include.


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

[User] ELI5: How do self healing phone screen protectors work?

[Assistant] "Self-Healing" is just a fancy buzz word for elasticity. What you are essentially doing when you scratch the screen protector is putting a shallow dent it in. Over time, the elasticity of the material allows the dent to return to normal.


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

[User] ELI5: There are about 900 Channels on my TV. Who is running/watching all of these obscure channels?

[Assistant]
Many of those channels are:

HD versions of normal channels, with the exact same content.

Robo channels that don't have content, such as a "TV guide" built
into your cable box.

Robo channels with music provided by your cable co.

Alternate language versions of normal channels.

Foreign channels.

What's left is just a bunch of channels, and TV companies run them.  Many of them play simply syndicated shows that are all repeats and don't actually produce any content.  There are dozens of crappy news shows for specific subjects ("TechTV", etc).  Then there are channels which literally just show infomercials 24/7 (Home Shopping Network).


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

[User] (Predator 2) How did the predator know what to say when he said "moutherfucker"?

[Assistant]
The Predator had been watching in the area for days, if not weeks, and had plenty of opportunities to overhear people talking, it could have easily picked up the term from listening in on peoples conversations. Swear words are often the first words people learn from another language, not just out of juvenile amusement but because they are usually used in a very specific, easily recognisable context. e.g. Confrontation, Pain, Anger.

If you consider other evidence, e.g. the Civil War era pistol or the complex later discovered in Antarctica, it's clear the Predators have been coming to Earth for a very long time, and to North America specifically for several centuries at least. They've had ample opportunity to learn English.

They probably don't speak much because their vocal tracts are very different to ours, and it's very hard for them to speak clearly in our languages. Secondly, they probably consider it below them to try to communicate with 'prey'. In our context, a big game hunter may learn the meanings of different animal calls, but he's not going to sit down and try to have a chat with a Lion.


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

[User]
eli5 Why can't we just drop rocks on landmines to make them explode?

ok. this might sound stupid but in area with a high number of landmines. can't we just load up a lot of rocks on a airplane and drop them on the area to make them explode? you dont even need airplanes, just a catapult looking thingy to chuck rocks at the landmines to trigger them?

[Assistant]
In WWII they had flail tanks which were basically tanks that hit the ground with big chains, hoping to set off land mines. You can also use a big roller like a steam roller. However, these are not reliable for clearing all the mines, only clearing "a lot" of mines. For a unit moving through a mine field, that might be enough. For kids playing or farmers farming, not so much.

There is a charity (HeroRats) that trains rats to sniff out mines. Rats are cheaper than dogs, and they are too light to set off mines.


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

[User] [Children of Dune] Why does Alia have the personality of the Baron? Aren't Reverend Mothers supposed to only have access to their female ancestors?

[Assistant] She and Paul are anomalies in the whole Kwisatz Haderach breeding program.  Alia is probably closer to being a true Kwisatz Haderach than Paul was as he never seemed to manifest the ability to access the pasts of both gender bloodlines like she eventually did.


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

[User] ELI5 why are mercury containing amalgam tooth fillings considered safe despite mercury being extremely toxic?

[Assistant] The properties of elements change wildly when those elements form chemical bonds with other elements. It's why hydrogen (a flammable gas) and oxygen (a flammable gas) are not flammable when they are bonded in water, and why sodium (a violently reactive metal) and chlorine (a poisonous gas) are not deadly to consume as table salt.


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

[User]
CMV: Student loan forgiveness is unfair and unjust; people who take out loans should pay them back themselves.

It seems there is a push to forgive student loan debts by democratic candidates like Bernie Sanders, Elizabeth Warren, Pete Buttigieg, and Kamala Harris. I completely disagree with that. It is unfair, unjust, lacks accountability, lacks integrity, and places the burden of the irresponsible on the backs of all.

Id like to provide three personal examples of students taking loans, then Ill go into into the matter itself.

I went to a state school where tuition was 12k a year. After using scholarship money for tuition, books, rent, food, I had to take out loans I had the choice to work, but I took out loans, instead. I chose the hardest major there is, graduated with 20K in debt, and landed a job with excellent pay nearly ~70k (I also own shares in a business that brings it up, but thats besides the point).

My best friend went to the same school, had a little less scholarship money, and he worked throughout school and graduated with $0 in debt and landed a job making ~60k. (He also owns shares in the business we co-run.)

I have another friend who had nearly the same amount of scholarship funding as I did, but she decided to go a private school with a tuition of $30k a year. She will certainly graduate with  ~100k in debt. Given her major, she wont break 40k. To make matters worse, she rents rather than living at home which is only 15minutes away; and she will graduate this December as a 5th year senior.

If the government forgives her loan, it will be as if she suffers no consequence of her choices and actions,  but rather, it is my best friend and I who will pay for her choices and actions. How is that fair?

Do we really want to live in a society where people can take out loans without having to pay them? The lender suffers, honest people suffer, and the irresponsible profit. This is completely unjust. (Loans should be based on major choice. The higher the salary for that major, the higher the loan amount.)

There are thousands of students out there who take the risk and invest in themselves. But when they graduate, they loathe the idea of giving back what they borrowed. That sort of behavior should not be rewarded at the expense of the students who are honest, the lender, and the American tax payer.

There are many people out there who want people to be given a free pass on loans and Im sure they have their ideas, so please, change my view!

[Assistant]
Student debt is a burden on the economy. Not only do people in debt obviously spend less money, but they also have fucked up credit so they can't even get certain jobs (no matter how qualified they are, and most majors are pretty much bs anyway), can't build wealth through homeownership, etc.

This many people should not be in college and the government enabled this huge mistake by instituting FAFSA. Government loans drove up the cost of education because it's guaranteed money for the schools. So we've had a system for like at least 25, maybe 35 years where the prevailing logic has been that in order to be successful, you need a 4-year degree. This completely illogical and incorrect mindset made the demand for these schools skyrocket, and in order to make sure as many people could afford to go to college as possible, the government just kept accepting that universities would increase tuition.. This is a pretty noble goal until you realize that the system of guaranteeing money, for what have basically become research corporations, is fucking stupid.

We have a whole generation and more in more debt to the government than has ever existed in history. Maybe outright forgiveness isn't the move and some of the money needs to be paid back, but we all just need to accept that the FAFSA system needs to go and as a result the people who already harmed themselves with it need to be made right by the government that has been screwing them over.


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

[User]
ELI5: Why is it a huge deal that John Boehner stepped down? Something about the Pope?

Maybe I'm missing the whole controversy and reason he's stepping down.

[Assistant]
It's a surprise, because he's the Speaker of the House (the highest position in the House of Representatives, which is half of the U.S. Congress). He's resigning as Speaker and as a congressman.

It very likely has almost nothing to do with the Pope, but it's all about Planned Parenthood.

Republicans want to defund Planned Parenthood. The most conservative members of the House are threatening to shut down the whole government until Planned Parenthood is defunded.

The problem is, the whole "shut down the government until we get what we want" thing has been tried before, and it doesn't work. Democrats refuse to give in because it would set a horrible precedent. Last time they tried it, the Republicans gave in and suffered horribly in the polls.

Boehner wants to defund Planned Parenthood too, but he knows they don't have the votes and he knows shutting down the government would be a terrible idea. So he doesn't want to fight this fight. He's smart and pragmatic.

Unfortunately what most likely happened is that the more conservative members threatened to vote him out of the speakership if he didn't go along with shutting down the government. He decided to resign rather than be ousted.

Of course it might not have played out exactly like that. Nobody knows yet, and we may never know. But for sure defunding the government was the main reason.

Note that he isn't resigning until after the vote, though. Possibly he was able to work out a deal to keep the government running in exchange for resigning.


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

[User] In Aliens vs Cowboys, why can't the aliens produce gold when they can travel trough space?

[Assistant]
we can grow food in our own back gardens yet we still feel the need to import food from countries on the other side of the world.

why do we do this? because it's cheaper.

i'm sure the aliens are capable of producing gold but it's probably cheaper for them to just retrieve it from less evolved planets.


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

[User]
ELI5: Why do we spend billions and billions of dollars on cancer research, and still use Chemotherapy as the most widely used treatment.

After having people come to my door asking for support in Cancer Research, I asked them how much further we've come in the last ten years, and they couldn't tell me.  And they said that Chemotherapy is still the most widely used treatment in America for Cancer.  After having multiple family members who have died from Cancer after going through Chemo, I am just curious how effective Chemo is against Cancer cells, and where is all the money going that we donate if it's not making any widely known progress.

[Assistant]
Cancer is a broad spectrum of diseases that involve uncontrolled growth or production from your own cells.  As broad a term as cancer is, chemo might be even broader.  Chemo is medication that kills cells or targets them for killing, but does so preferentially to cancer cells than non-cancer cells.

Cancer research and effective chemo is making a lot of progress, as pretty much everyone on here is saying.  Money for cancer research goes toward staffing cancer research centers/hospitals, testing chemo drugs, and testing cancer screening strategies, just to name a few things.  There are MANY cancers that we have developed a very effective chemo regimen for.  Testicular cancer is one that we are able to very effectively treat with chemo.  More recently, a specialized chemo drug for Her2 positive breast cancer has been developed.  This form of breast cancer used to be a death sentence, now it's one of the more favorable breast cancer diagnoses because of the efficacy of our available chemo.

You'll never turn on the news to a headline of "chemotherapy stops all cancer all at once."  What's unfortunate is that the many small victories in cancer research don't receive the attention that they should, leaving the lay person to believe that there hasn't been progress.


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

[User]
Does monkeypox leaves scars forever? What are the risks of contracting it and can it kill you?

Is there a vaccine to prevent it?

[Assistant] The smallpox vaccine is effective protection from monkeypox. The scars can be permanent. It can be lethal, around ten percent of the time. The varieties we already know about do not spread easily, but the current cases might be different.


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

[User] I've read a lot of speculation about the future of the world's water supply. How serious is the issue, and what is likely to occur over the next decades?

[Assistant] The main thing to remember about this is the interconnectedness of resources in general. There's plenty of water in the world; it's just not potable. The availability of cheap energy would solve this issue, as that's mainly what makes it expensive to, say, desalinate seawater.


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

[User]
Can Superman get fat?

What I mean to ask is: If Superman didn't work out, didn't move around a lot, ate a ton, etc. could he get out of shape? He would still have all of his powers, he wouldn't be any less powerful, but could he lose his muscular physique?

[Assistant]
I would be willing to bet he has some form of super metabolism - which would also make him immune to poisons, etc.

In Lois and Clark: The New Adventures of Superman, they point out that Clark eats like an 8 year old but has the body of Hercules.


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

[User] ELI5: How can a knife be sharp enough to cut to the touch or without even being felt?

[Assistant] Your skin is filled with nerves to detect damages. If a nerve cell is damaged it will tell the brain about it. But cells are actually bigger then people imagine. And sharp knifes have a very thin edge. Most microscopes can be used to see individual skin and nerve cells but even electromicroscopes might have issues seeing the edge of a sharp knife. So it is possible to use a knife to cut though the skin without hitting any nerves or to cut though the nerve without allowing it to fire a signal.


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

[User]
What causes all living things to die of old age?

What exactly causes any living thing to cease living simply from old age? Why can't cells perpetually replace themselves and continue to grow and live?

[Assistant]
Once the germline is established an organism begins to die, due to the loss of cellular quality control. After you have offspring, you are no longer important (evolutionarily speaking).

Your genome is also limited in the number of times it is copied, due to sequences known as telomeres. These get shorter and shorter with subsequent divisions and the grnome will begin to deteriorate after further replication. Telomerase is an enzyme which repairs these regions but it is not expressed after a certain stage of embryonic development.

Both of these processes are often reactivated in cancer cells, allowing them to grow out of control.


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

[User]
CMV school in the first world has become sexist towards boys

I am currently in high school, and I cannot help but see a repeated favoritism in favor of girls in my school. Girls are given the advantage in everything be it college admissions, internships,there are even girl exclusive internships, etc. Teachers also seem to favor girls for awards. For example, there is an awards ceremony in my city where every school sends a nominee. For our school there is a kid who applied for technology, who started the robotics team, took 2 AP computer classes,does all of the lights and sounds for our theatre program, and got the only internship ever to a , multinational, credit card processing company in our area. But he,a guy, didn't win. The person who had won was a girl whose only qualification was being in a club called girls who code. How is this not blatant favoritism

Edit:  I thank you for all of your responses and have a greater sympathy for the girl now, and many of my words were a little bit extreme, but one place I did not exaggerate was the girl's accomplishments . And this though is simply not true. Literally all she has done in the field is the aforementioned club and I even overplayed,it as the club only met once last year. Thank you for all of your responses.

[Assistant]
So you're saying that there's a boy who

* Got to start a robotics team

* Got to take two AP computer science classes

* Was given full responsibility for all the lights and sounds in the theater program

* Got the only internship ever to a major corporation

and on the other hand there's a girl who

* Was in a club

* Won some award

and this comparison somehow reveals sexism against boys?


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

[User]
[MCU]Why aren't Iron Man style suits used by advanced aliens?

Iron Man is "only a genius on earth".  So why don't advanced aliens have combat suits like Iron Man?  The closest is Star-Lord, but his suit doesn't hold a candle to Iron Man.

[Assistant]
Honestly, because Tony isn't only a genius on Earth.  Rocket was roasting him, but Rocket is also a notorious dick.  Tony Stark accomplished things that no other species had ever done before because Tony is exceptional at building upon other's tech.

Tony is the only person in the universe to master time travel by building off of the work of Hank Pym and Bruce Banner.  Wizards could time travel with the Time Stone, but that's a very different technique.

We know that aliens do use high tech gear, Star-Lord does and so do the Nova Corps, the Kree also have equipment that they use.  While Star-Lord's tech is better than what Tony was using in Iron Man 1, Tony's suits from Infinity War and Endgame truly put him in a league with the intergalactic heavy hitters.


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

[User] ELI5: Why do space vehicles need so much heat shielding for reentry but not so much for launch?

[Assistant] When going up, they are accelerating at a fairly slow rate, they only get to very significant speed once outside the atmosphere. When they return however, they are immediately coming in very fast, and the slowing by air resistance is very significant, and causes heat.


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

[User] ELI5:How can microsd cards be so much smaller then a 2.5" ssd and still store the same amount of data?

[Assistant] An SSD will last a lot longer. The problem with flash memory is that it degrades when you try to rewrite data: the technology does not like it when you change bits. SSDs have an internal chip which scrambles to minimize the amount of damage you cause by making rewrites, whereas SD cards will just crap out because they're kind of dumb.


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

[User]
Adjuncts of reddit, how did you become an adjunct, what are your plans for the future, and how is your financial situation?

I've been contemplating a PhD in comparative literature for a while, and the only thing that's keeping me from taking the plunge is the very likely prospect of becoming an adjunct or having to change careers when I'm 35. I'd love to hear any stories from actual adjuncts, in literature or otherwise! (If you post to judge me for wanting a humanities PhD, that's cool too.)

[Assistant]
> If you post to judge me for wanting a humanities PhD, that's cool too.

:(

(There's nothing wrong with wanting a PhD in the humanities! It sounds like you're being realistic about your job prospects, which is really important.)


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

[User]
ELI5: Why can large loans (e.g. mortgages) be structured so that your first several payments are mostly interest and little principal?

Is there a better reason than, "Because they can"? It seems so unfair to the borrower.

[Assistant]
Loans do not have to be structured that way; that's just the result of homeowner's desire to have a stable payment for the life of the loan.

If your payment is fixed, some of it must be allocated to interest and some to principle. Early in the loan the principle is large, so the interest is large, and the interest has to be paid every year (this is what you're paying the bank to have the loan). As a result, once you pay the interest, there isn't much left over for paying principle.

Over time, as the principle shrinks, the interest gets smaller but your payment is the same size, so more goes to principle.

If you don't have fixed size payments, you can do whatever you like after you pay the interest. You can structure a loan so that you pay the same amount of principle on every payment, but then your total payment will be much larger early on when the interest is also large (many home equity line-of-credit loans can be paid this way).


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

[User] Why does getting too much sleep make you feel tired?

[Assistant]
We have four different stages of sleep that repeat every 90min. The first three are progressively deeper, more relaxing stages of sleep. The fourth stage is called rapid eye movement (REM). This is when we dream, and it's actually not too restful- your brainwaves are similar to when you are conscious, and arousal and oxygen consumption are higher than when you're awake. As you stay asleep longer, REM becomes an increasingly large portion of your sleep time. So it may be that if you sleep too long you are actually experiencing so much REM that you're tiring yourself out.

I think no one actually knows the answer to your question, but that's one theory.


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

[User] ElI5: Why cant we smile in pictures for passports and other official docs?

[Assistant]
You're supposed to look the same in your picture as you look when you present your ID to someone for inspection.  That makes it easier to quickly confirm that you're the same person as in the ID picture. Usually this happens when you're pulled over by the police, going through an airport checkpoint, etc.

People usually aren't all smiles when talking to police or airport security.


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

[User]
How does the stomach know when to let the food through to the intestine?

Q1- What triggers the opening of the pyloric valve?

Q2- If you eat continuously over a long period of time. Does it wait until all the food is digested to the same level before opening?

[Assistant] There's also a mechanical factor to this - the food needs to be dissolved into small enough pieces to pass through the pyloric sphincter. Contractions in the smooth musculature surrounding the stomach continually work the larger pieces towards the top of the stomach while the smaller pieces pass through the sphincter.


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

[User]
ELI5: How does my TV 'translate' the signal it receives into images and sounds?

Thanks for all the responses everyone! Looks like I have a lot of reading to do and videos to watch!

[Assistant]
Back in the old days, CRT TVs would sweep an electron beam across the screen, line by line,, with the amplitude of the video signal translating to the intensity of the beam. Things got a little more complicated when colour was added, but it largely works in the same way. Just with a few more parts.

Digital video signals are a bit different in that they're a series of 1s and 0s. With a digital LCD or OLED display, you can control each individual sub pixel with precession, with an intensity value anywhere from 0 (off/black) to 256 (full intensity). By varying the intensity of each sub pixel, you can mix red, green, and blue to make various colours. Millions in fact. A computer inside your TV or monitor processes all this data. The video signal though may not actually contain all the information the TV needs, in order to save bandwidth. So the display does some fudging that exploits limitations with human vision.


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

[User] ELI5: why is Greenland not its own continent?

[Assistant]
Most maps accidentally make Greenland too big. It's an oddity of projecting a spherical globe on a rectangular map, thee is always something out of place.

Greenland is about ~2 million square kilometers. Australia being an island-continent is ~7.7 million square kilometers. So the cut-off, while not being readily defined, is somewhere more than two million square KM but less than 7 million square KM.

Also, basically zero people live in Greenland.


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

[User] ELI5: Why do dogs react a certain way when you scratch certain spots?

[Assistant]
It's stimulation of different sensory neurons.

It's like when a woman holds your hand vs. your penis.

Yes, holding your hand is nice. You like the feel of it and you smile. But when she's holding your peniseven if the same grip and pressureyou get a happier, more pleasant feeling that makes you pant loudly and your leg wiggle.


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

[User] ELI5:What is happening when you see the air ripple on a hot day?

[Assistant] Light travels at different speeds through different mediums, and as the density of the mediums vary. The air is being heated at different rates between you and the horizon creating different air densities, like ripples on the surface of a river. Light from the horizon refracts as is passes through the different boundaries of densities, just like looking down into a river bed or sea shore through the water.


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

[User] [Harry Potter] What exactly is the nature of the "contract" of the Goblet of Fire? What would have happened if Harry just decided not to participate in the tournament?

[Assistant] We don't know the specifics, but it's likely that it would have become impossible to carry on with at all. This would have caused a major diplomatic incident between the British, French, and Norwegian (probably, the exact location of Durmstrang is secret) wizarding governments.


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

[User] ELI5: Why is front wheel drive preferred to rear wheel drive on most cars?

[Assistant]
It's cheaper and easier to make. The engine, transaxle is all one unit and easier to manufacture and install.

Rear wheel drive requires running the drive shaft under the floor which removes footroom in a small car.


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

[User]
Does actual Marxism have anything in common with what is commonly called Marxist by people on the political right in America?

Basically, I see things called Marxist indoctrination all the time. Teaching LGBT history in school? Marxist indoctrination. Toppling confederate statues? Marxism. Taking funds from the police? Marxism. Any American who has watched Fox News or reads popular right wing blogs or subreddits will understand what I mean with frequent accusations of Marxism.

My question is, does this idea these people have of what Marxism is even vaguely resemble actual Marxist thought?

[Assistant]
> does this idea these people have of what Marxism is even vaguely resemble actual Marxist thought?

It's hard to answer this plainly, because "Marxism", in the sense you describe, is used so broadly that it can describe just about anything -- and so might also describe things we'd be inclined to call "actual Marxism"!

But if the question is something like, "Does this use of 'Marxism' I've described aptly convey what actual Marxism is, albeit perhaps in a shallow or caricatured way?", then the answer is -- nope.

Indeed, sometimes conservative polemics complain about things they call Marxist but which are also things *actual Marxists* complain about -- for instance, there are significant Marxist critiques of postmodernism, "callout culture"/"cancel culture", "identity politics", "political correctness", etc.


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

[User]
If genetic mutations are random, why are some (nonhereditary) mutations so common while others are rare?

For example, why do some types of cancer account for the majority of cases while others are rare? What is stopping more people from getting those rare cancers more often? I know environmental influences + cell type + other genes/genetic predispositions are definitely big factors, but it almost feels like a paradox to just call all mutations random, even though I know that to be true.

To clarify, I'm not trying to challenge the idea that genetic mutations are random, I'm just trying to understand the framework, especially in the broader context of evolution.

Edit: Thanks everyone who's responded! This has pointed me in the direction of thinking more along the lines of distribution of cancers + mutations in general in different types of cells + in specific genes and considering the complex environmental causes/risk factors (?) of cell mutations, which feels more comprehensive and like I'm on the right track. I feel like I may need to go more in depth to understand this in the broad context of genetics + evolution, so I might have to look for some good (maybe basic, for now) reading materials or something.

[Assistant]
Just adding this: although genetic mutations are random in the sense that whether they happen or not in an individual is, effectively, a roll of the dice, that doesnt mean the dice are equally likely to land on all numbers.  For example, its known that one nucleobase (cytosine, C) has an outsized tendency to mutate to thymine (T) because it only has to lose one amino group to turn into uracil, which looks to many enzymes indistinguishable from T.  This even happens when you heat DNA in a test tube - a very small fraction of the Cs in that test tube will lose an amino group and become U.   (Edit: and if the C was already methylated, it will turn into T if it loses the amino group.)  This is actually a nuisance when you are looking for rare mutations in a sample, and can lead to false positives unless you correct for it somehow.

There are many other examples, but even at a chemical level certain DNA bases and sequences are more susceptible to mutation than others.  This is at least part of the answer to your question.

Edit: So, while the occurrence of a mutation or not in an individual can be considered an essentially random process in most cases, not all random mutations are equally likely.  Its like if you had a hat full of names and drew a name at random: the likelihood that the name begins with S isnt the same that it begins with X, just because S names tend to be more common (at least in English).  The process can be random and still generate certain outcomes more than others.


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

[User]
Are all problems that can be solved recursively, be solved iteratively?

Is it true that if a problem is solvable through recursion, will ALSO be solvable through iteration? Is there any case where you could do something with recursion, but not with iteration?

Sorry for my noob question, I just studied about recursion.

[Assistant]
If you allow generic iteration (e.g. while(condition)) and not just elementary iteration (e.g. repeat N times), yes.

You can explicitly transform a recursive program into an iterative one by creating a single struct containing all the variables in one function call, and a stack that contains these structs. In a loop, push or pop from this stack when you would call or return, respectively. This is what the language is ultimately doing in memory anyways.


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

[User] ELI5: How can gravity be so weak (10^29 times weaker than the weak force) at the subatomic level, but at the same time be the dominant interaction at the macroscopic scale?

[Assistant]
Because everything that has mass exhibits a gravitational field and the gravitational field is purely additive.

Contrast that with the electromagnetic force. Not everything has an electromagnetic charge and for the things that do, there are roughly and equal amount of positively charged things as negatively charged things, so they cancel out. At macroscopic scales, things are neutral.


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

[User]
[Greek Myths] So... the river Styx is rather deadly to the touch, and Achilles was dunked headfirst in it. Why didn't this kill him?

It's all in the title.

[Assistant] Achilles was half immortal, to begin with; which was a virtue of his mother Thetis.  So anyone fully mortal would surely die, but for Achilles the river washed away his mortality (except for his famous vulnerability) so to speak.


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

[User] Eli5 - Why does the dryer shrink wet clothes after they've been washed, but does not shrink dry clothes thrown in for a wrinkle release?

[Assistant] Heat causes shrinkage. Water has a high latent heat of vaporization (which means it it can "store" a lot of heat before it evaporates) which causes the moisture on your fabrics to retain more heat in the dryer. And with more exposure to heat, the more shrinkage you get.


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

[User]
Why do lower frequencies seem to travel through materials easier?

You can hear the bass in a song throughout an entire house basically. Why is it that the higher frequencies seem to get lost?

[Assistant]
When sound, or any wave, travels through a medium, it loses energy by transferring it to the medium. For sound, this usually means kinetic energy - the medium vibrates with the sound, which robs the sound wave of energy. Each time the wave cycles through the medium, some of that energy is lost. Since lower frequencies of sound have a longer wavelength, it takes fewer wave cycles to make it through the medium, therefore less energy is absorbed by the medium.

Say you're using a piece of material that matches the wavelength of a 20 Hz sine, i.e. 1 cycle of a 20 Hz wave takes up the width of the piece of material. At 40 Hz, it takes two cycles for the wave to make it to the other side. At 80 Hz, 4 cycles, and so on, all the way from 20 to 20,000 Hz. By the time you've reached 20kHz, your waves are having to cycle through 1,000 times to make it to the other side, compared to just once at 20 Hz, meaning much more energy is being lost from the higher frequencies.


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

[User]
ELI5: Is there a surface on a gas giant?

I always hear "gas giant" when referring to Jupiter but wonder if the whole thing is actually gas or if I can find some resemblance of surface.

[Assistant]
Seeing as the only other answer got downvoted to oblivion, I'll try to explain. The short answer is: yes. Gas giants are so large and have such a strong gravitational pull that their cores usually exist in the solid state of the gas near the surface. For example, Jupiter's core is (mostly) solid Hydrogen, which takes either extremely cold temperatures or (in Jupiter's case) extremely large pressures to form.

However, the gradient between solid to liquid to gas isn't as clearly defined as it is on a rocky planet like Earth. If someone dropped you from the upper atmosphere of Jupiter, you wouldn't fall then suddenly splat against a hard hydrogen surface. Instead, you'll be falling into material that gets denser and denser, and eventually you'll stop falling when the density is great enough.


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

[User]
How do we know fossils are the same size?

If fossilization is replacement of tissue with minerals, how do we know that this replacement process doesnt change the size of certain features?

[Assistant]
One part of it comes from recent fossils.  Some older species are actually present in the fossil record, and in sufficient numbers that we can compare size distribution.  We have Nile croc fossils from >5 million years ago (exact same species), and more recent fossils of other taxa, and all seem to be around the same size.

Another is from complete fossils, like those magnificent *Archaeopteryx* fossils.  If they shrunk after burial, either the bones would separate from each other as each bone shrank, or some unknown force would have to pull them all together as they shrank in a strikingly uniform way, despite the tremendous pressure from the surrounding dirt/rock holding them in place.


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

[User]
[Harry Potter] How come nobody arms themselves with a bunch of medical spells? They could've come in handy SO many times yet everyone is too busy learning combat/utility spells.

Hogwarts has a medical wing, but I never understood how the students there couldn't pick up tons of medic-based spells. You'd think in a world with magic, the no.1 priority would be to learn a handful of medicinal spells/charms. Its like having a basic first aid kit....but only better since its MAGIC.

I was just looking back at how Snape heals Malfoy when Harry used Sectumsempra on him. Couldn't Harry just ask "Hey Professor, what is this spell?" or you know, just remember it from his incantations? Would've come in handy to save Dobby or someone else injured in the battle of Hogwarts. Made me realise that in general, everyone prioritizes combat and utility spells.

They desperately needed a medic class in their team!!

[Assistant]
Some magic is easy, some... less so. The only background we have on medical magic is that the requirement to become a healer are two of the higher marks (Outstanding and Exceeds Expectations) in five NEWTs; Potions, Transfiguration, Herbology, Charms, and Defense Against the Dark Arts.

Most people have an aptitude for one or two subjects, but being able to achieve that kind of level for five subjects is only attainable for the truly exceptional. Hermione was able to learn the basics, using a charm and some magical herbs to heal Ron after he'd splinched himself escaping the Death Eaters in London.

Healing magic is also the sort of thing that seems like it could backfire with horrific consequences, so it makes sense that they don't even try to teach the basics at lower levels.


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

[User]
Why is Samsung, HTC and LG making their own Android skin? Why not just release their products with stock Android?

I just don't get it. I mean EVERY tech-journalist loves stock android and everyone hates those custom skins.

[Assistant]
Because then there would be little to differentiate the phone from each other, especially to less tech-savvy people who might not care about megapixel this or gigabyte that, but just want something that looks nice.

By putting their own skin on it, they are making it their own product - one which they hope will be better (including to non tech-savvy people) than the competition, rather than the same as the competition.


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

[User] ELI5: Why does time seem to move faster late at night?

[Assistant] Perhaps you do more interesting and varied things during the night than during the day. Also you spend more time awake during daylight hours than *moonlight hours so you remember days as being longer than nights.


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

[User] ELI5: How do we know that there is an unobservable universe beyond the observable universe if we cant see it?

[Assistant]
We can't know with 100% certainty, but all evidence points towards the universe being pretty much the same everywhere that we *can* observe, so it would make sense to be pretty much the same where we can't.

It is a simpler explanation to say that it simply is infinite and homogenous at large scales (which is consistent with what we observe) rather than having to come up with some reason there might be nothing past what we observe.


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

[User] ELI5: In the United States why do kids under the age of 18 still have to pay taxes when the country was almost built on the motto "no taxation without representation"

[Assistant]
Well, for one, I'll point out that felons also have to pay taxes despite not getting the vote. There are legal restrictions to the vote that we've agreed on. One of them is that you have to be 18.

Second, there is far more government spending supporting those under 18 (schools, etc.) than those 18 and up, so it's not like you're paying for nothing.


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

[User] The James Webb Space Telescope is incredibly precisely made. But it will be mounted on top of several tons of rocket. How do they make sure it doesnt get warped in flight?

[Assistant]
Very careful simulation based on testing data. Engineers have experimentally gathered data about all the different materials used to make the telescope. This data includes failure points given applied loads, vibrational frequencies, etc. They can use this along with a computational model of the sattelite to predict how it responds to the forces of launch. They design can use the results of these models to improve/change the sattelite design so that it can withstand the forces of launch.

That said, It probably takes some clever engineering on the part of the mirror to make sure that forces are applied evenly to it during launch.


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

[User] ELI5: Why is there so much oil in the Middle East?

[Assistant]
There isn't more oil in the middle east, it's just that it's the most convenient place to extract it.

Oil come from dead organism, but not just that. You need :

1) Have enough organism concentrated together.
2) Have them slowly heat up over time.
3) Have them trapped so that the oil/gas doesn't escape.

The best place for that to happen is on continental margins. That's why you so often have offshore platform to extract it.

Not what make the Middle East special? The middle east was a continental margin in the past. The Persian Gulf is what remain of that ancient sea separating the two continent. The Arabian peninsula itself used to be at the bottom of that sea and rised up as that sea closed with the movement of the tectonic plates.


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

[User] [Watchmen/Marvel] Part of Dr Manhattan's condition was his sense of isolation due to his unique nature. Would he have been better off in the Marvel universe, and which people/entities might he hang out with?

[Assistant]
Unlikely. The disconnect was for two reasons (likely related): the atemporal nature of his perception of the universe and his apathy toward human concerns. Neither of these would be significantly changed in the Marvel universe. People still experience time in the same way as us and they are still primarily concerned about mundane human affairs.

While most people would be keen to associate with Dr. Manhattan would probably see little reason to care about them. If he can't muster concern over death vs. life, why would he be concerned, for example, over Homo sapiens vs. homo superior?


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

[User]
ELI5 Why have we not run out of ip addresses?

With the massive growth in internet devices, shouldn't we have used up all possible ipv4 numbers?

[Assistant]
We did, sort of. We have way more devices than ipv4 addresses, but a lot of them are using the same address and hiding behind a local network. For most broadband setups, your entire WiFi network is only consuming one public IP and it's using a whole bunch of local IPs behind your router.

This bought us some time. Ipv6 was invented to make sure this "never" happens again, it has a far (far far far) larger number of addresses.


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

[User]
ELI5: what is happening inside our bodies when we hear 'cracks'?

My back cracks all the time!

[Assistant] If you're wondering how you can hear the noise, it's that your body is almost entirely water and sound travels very quickly and very efficiently through water compared to air. So you are hearing the crack through your own tissues. The water in your body is carrying the sound internally to your ears.


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

[User]
ELI5: Why do we use total internal reflection for fibre optics instead of just ordinary reflection?

I'm a teacher and I gor stumped by this today, couldn't find any answers with Google.

[Assistant]
At ordinary reflection angles, there is both transmission of light and reflection of light at the surface between the two types of material.

At total internal reflection angles, there is no transmission of light, only reflection.

This is important for optical fibers because ordinary reflection will mean light is lost when it transmits through the fiber rather than remain reflected within the fiber. Since optical fibers can span thousands of miles, any little bit of loss per reflection will greatly reduce your optical signal over a distance.

With total internal reflection, you don't get losses from transmission. Interesting enough, if you bend an optical fiber too much, the light going through it doesn't reflect at the internal reflection angle. If the light is visible, you can actually see it transmitting through the bend in the fiber. Optical fibers cannot do the sharp bends possible with metal electric wires.


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

[User]
[Star Trek] what's the regulations on using replicators to replicate living organisms?

like klingon *gagh* for example, it's near worthless dead. and most klingons prefer it as fresh as possible. but it seems like replicating living organisms would be taboo. even if it's technically possible.

[Assistant]
There aren't any regulations because it's not actually possible.  Never in the history of Trek have we seen someone successfully replicate something which was alive.

If replicating living things was possible, the Dominion wouldn't have to clone and grow soldiers.  Massive armies could be built up in almost no time.  Also replicating Worf's spine in the episode "Ethics"  (TNG 5e16) wouldn't have been such a big deal.

Now duplication of living organisms via transporter accident has happened a few times, but each time was a surprising miracle.

If Starfleet ever figures out the way to replicate actual living things, it will open up a whole host of questions.  Getting fresh *gagh* would be the least of one's issues compared to, say, the ethics of replicating a family pet... or a recently killed officer.


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

[User]
eli5 Why do we read from left to right?

Unlike Hebrew which is the opposite. But they're both read from top to bottom. How was this established as the "natural" way to read?

[Assistant]
Short answer: because most people are right-handed.

For the first written languages such as Hebrew, people started writing by engraving letters into stone. Since most people were right-handed, it was easier to hold the chisel with the left hand and hammer it with the right hand. If you think about it, it's a lot easier to do this right to left and would be uncomfortable to do it the other way unless you hold the hammer in your left hand. Eventually, Hebrew and other ancient languages moved on to be written on animal skin, but people were already used to writing right-to-left.

When Indo-European written languages such as Ancient Greek and Latin came about, papyrus and ink was already the common medium for writing. Since most people were right-handed, they would get ink smudges on the paper if they wrote right-to-left. Writing from left to right eliminated this problem.


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

[User]
ELI5: How come the Zimbabwe dollar inflated so fast? How do people survive in a country with such hyperinflation?

Basically those two questions. I'd also like to know what's going on there right now - if your 100 trillion dollars is only worth 10 trillion tomorrow (lol) how can people even work and expect to survive?

Is the situation resolved? If so, how? If not, why not?

[Assistant]
Hyperinflation is typically caused when a nation goes through a major crisis (war, political turmoil, etc) and has a simultaneous need to spend large amounts of money. The tax base has collapsed and the uncertain economy makes international borrowing unavailable, so the government starts to print money.

The sudden, huge increase in the amount of money in circulation makes the currency less valuable. With the value of money shrinking, the government has to print ever more of it to meet its commitments. Very rapidly this turns into a spiral of hyperinflation.

In the case of Zimbabwe specifically, the country entered into a plan of forced land redistribution. At least initially, the idea was to confiscate farms from the descendants of former European colonials and give the land to the poorest indigenous people. There were many problems with this plan. Chief among them, the recipients of the land knew very little about farming so productivity collapsed. Foreign investors saw property being confiscated and left the market. To make matters worse, the land grants were frequently awarded to cronies of the Mugabe regime. The government printed huge volumes of money to try to make up for the lost tax base and foreign investment.

How do people survive? Well, you may have heard of other cases of hyperinflation from history where people try to adapt. In the southern US after the Civil War and in Weimar Germany after World War I, there were stories of people bringing cash to the markets in wheelbarrows to try to buy food. In some families, there are stories of people burning bundles of cash for heat in the winter because it was cheaper than buying fuel.

In Brazil there was a saying that you should always take a bus instead of a cab because on a bus you pay when you get on; in a taxi, you pay when you get out and there is no telling how much the currency may have devalued during the ride.

As others have said, many people turn to barter or other types of trade that are not dependent on currency. Sadly, in most affected countries, this also means a large increase in crime.

The interesting thing is that barter holds the key to how Brazil finally managed to beat decades of hyperinflation. Economists noticed that people bartering would settle on fairly standard relative values of goods: just as an example, imagine two potatoes for one tomato. These same ratios held for the prices in the markets. If a potato was $50, a tomato was $100. When potatoes hit $50,000 tomatoes were $100,000.

The economists called this "real value" and started referring to prices in units of real value. Storekeepers started putting units of real value in ads and on shelves and just posted an exchange rate between the currency and the real value (this was also much easier than re-pricing everything in the store every day).

Eventually, after a few years of this, the country just switched to a new currency. Each unit of the new currency was equal to one unit of real value. The currency was even called the *real* (in Portuguese, the plural is *reais*). The switch was remarkably smooth, since everyone was already thinking in units of real value.

It's kind of fascinating from a psychological standpoint as much as an economic one. You wouldn't expect that you could simply swap out a failed currency for a stable one, but in this case (with the right preparation) it actually worked.


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

[User] [Watchmen] Did anyone try to replicate the accident that gave Dr.Manhattan his powers?

[Assistant] Yes. The US and USSR governments tried this repeatedly. No success. It requires someone with a very precise mindset, a masterful knowledge of physics, and the steady and patient attitude of a watchmaker. Otherwise you just get disintegrated.


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

[User] ELI5: The saying goes never add water to acid. How come your stomach acid does not react when you drink water?

[Assistant] You don't want to add water to acid because some strong acids can react violently to the water, heating it quickly and causing it to boil, splashing acid out of the container. In the stomach there is both no danger of the acid splashing out, and also the acid employed in the stomach simply isn't that strong so there is no danger of that level of reaction.


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

[User]
ELI5: Why are celebrity autopsy records often made public? Don't HIPAA laws protect their medical records?

I'm just wondering why you can often find coroner's reports and autopsies giving every last detail of a dead person's body. Aren't medical records supposed to be private?

[Assistant]
HIPAA protection does generally apply after death, but an autopsy is not heathcare. The rules governing release of autopsy reports is different in every state; some make it a public record, and others do not.

Trials are also public, and if the death becomes part of a court case the autopsy report may be entered into evidence, and thus the public record.


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

[User]
What happens when an electron hits a positron when they both have different momentum?

I know that after the annihilation when they have the same momentum, or no momentum there are 2 photons emmited in 2 different directions, due to conservation of momentum, but what happens when they hit eachother with different momentums?
Will they be emmited at an angle other than 180deg to each other, or will one have higher frequency than the other, or something completely different?

[Assistant]
There are a number of possible processes that can happen, regardless of their momenta.

At high energies, they will just scatter elastically off of each other. This is called Bhabha scattering.

At lower energies, they can combine to form a bound system called positronium, which will eventually decay, or they can just annihilate each other outright.

The probability that they annihilate is largest when they are not moving relative to each other.


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

[User]
How can the average consumer figure out if a commodity they want to buy is overinflated (like diamond jewelry is)?

Edit: I think the question I meant to ask is "how can the average consumer figure out if a commodity they want to buy will appreciate or depreciate in value?"

[Assistant]
You don't. As value is subjective, whether or not a commodity is priced too high is a personal call.

If, however, you mean whether the price you're paying is higher than other parties, you have to carry out your own research: at what price does a given producer sell, what is the *world* market price and what is the market price in your country. Then find all the taxes and trade treaties that bring about any disparity should you find one.

If the commodity is produced locally, I'd also look into any regulatory agencies, the subsidies and licensing laws pertinent to the good/service and the market concentration to get an idea of how competitive the market is. (Technically, competition is not a feature exclusive to higher numbers of competitors; its behaviour. A handful of large businesses can be cutthroat competitive against one another: market concentration is just a good rule of thumb.)


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

[User]
Reading about bhangmeters and the 'double flash' that occurs with a nuclear detonation. Question inside...

The wiki article has this line in it:

This signature, with a double intensity maximum, is characteristic of atmospheric nuclear explosions and is the result of the Earth atmosphere becoming opaque to visible light and transparent again as the explosion's shock wave travels through it.

Can someone explain that statement?

[Assistant] The shock wave from the explosion ionizes air molecules, and basically turns air into plasma. Photons can't pass through plasma very well, as they like to interact with charged particles, and so for a short time, all light emitted by the blast is trapped inside the shock wave sphere. After the shock wave has passed, the ions recombine into atoms and molecules quite quickly, and the gas becomes transparent again. The shock wave also dilutes away, so after a few seconds it's not able to ionize enough particles to turn the gas entirely opaque.


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

[User] ELI5: What happens to my body when I drink alcohol whilst on antibiotics?

[Assistant] Some antibiotics shouldn't be mixed with alcohol because the alcohol impairs a step in the breakdown of the alcohol leading to a build up of acetaldehyde which gives you horrible side effects. Not all antibiotics, only some. The alcohol doesn't make the antibiotics not work - they will still work if you drink alcohol but some antibiotics with alcohol will make you feel very sick.


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

[User]
ELI5: Why isn't lice a problem in adulthood?

It seems like people had lice all the time in elementary school and then no one had lice once we were like 12. Why is that?

[Assistant]
Headlice has nothing to do with hygiene. You can be the cleanest person on earth and still catch lice.

The reason they spread more in younger kids, is because the kids play and tumble with each other, making it possible for the lice to spread from person to person.

If a kid has lice for a few days undetected, the parents and possibly siblings are likely to get them as well.

But because an adult is not as likely to go and rub their heads together with coworkers, no one at work gets lice.
And so forth.


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

[User] [Tenacious D and the Pick of Destiny] How did JB's dad not know about the Dio poster? Where did JB find money for all the rock memorabilia in the first place, if his parents didn't pay for it? How was Kyle paying rent in Hollywood? Was that record executive/producer actually Beelzebub all along?

[Assistant] For the first 2 questions, he likely had an allowance that allowed him to buy the posters. The Dio poster was on the back of the door that you could only see when it was closed. JB's dad didn't see it cause the door was open.


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

[User]
I have a ring made of Tungsten Carbide. It has some scratches on it. How could this have happened?

I don't own or handle any diamonds, and my understanding is that Tungsten carbide is one of the hardest substances around. Is there anything that I may encounter in my every day life that has the ability to scratch my ring?

[Assistant] You have to remember the pressure applied to the ring can overcome the point at which cleavage occurs. You can smash a diamond with a hammer and some force. You can scratch a ring with the right amount of pressure even with an item that is not as hard as the material that the ring is made out of.