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

[User]
ELI5: what was WWI fought over?

It's fifteen minutes into Remembrance Day here, but I don't know what I'm remembering. I know that millions of soldiers and millions of civilians died and that everyone basically pointed the finger at Germany at the end of the war, and I'm somewhat familiar with the Gallipoli campaign and the ANZAC legend, but that's the extent of my knowledge.

What went on there?

[Assistant]
If World War 1 was a bar fight
Germany, Austria and Italy are standing together in the middle of a pub when Serbia bumps into Austria and spills Austrias pint.
Austria demands Serbia buy it a complete new suit because there are splashes on its trouser leg.
Germany expresses its support for Austrias point of view.
Britain recommends that everyone calm down a bit.
Serbia points out that it cant afford a whole suit, but offers to pay for the cleaning of Austrias trousers.
Russia and Serbia look at Austria.
Austria asks Serbia who its looking at.
Russia suggests that Austria should leave its little brother alone.
Austria inquires as to whose army will assist Russia in compelling it to do so.
Germany appeals to Britain that France has been looking at it, and that this is sufficiently out of order that Britain should not intervene.
Britain replies that France can look at who it wants to, that Britain is looking at Germany too, and what is Germany going to do about it?
Germany tells Russia to stop looking at Austria, or Germany will render Russia incapable of such action.
Britain and France ask Germany whether its looking at Belgium.
Turkey and Germany go off into a corner and whisper. When they come back, Turkey makes a show of not looking at anyone.
Germany rolls up its sleeves, looks at France, and punches Belgium.
France and Britain punch Germany. Austria punches Russia. Germany punches Britain and France with one hand and Russia with the other.
Russia throws a punch at Germany, but misses and nearly falls over. Japan calls over from the other side of the room that its on Britains side, but stays there. Italy surprises everyone by punching Austria.
Australia punches Turkey, and gets punched back. There are no hard feelings because Britain made Australia do it.
France gets thrown through a plate glass window, but gets back up and carries on fighting. Russia gets thrown through another one, gets knocked out, suffers brain damage, and wakes up with a complete personality change.
Italy throws a punch at Austria and misses, but Austria falls over anyway. Italy raises both fists in the air and runs round the room chanting.
America waits till Germany is about to fall over from sustained punching from Britain and France, then walks over and smashes it with a barstool, then pretends it won the fight all by itself.
By now all the chairs are broken and the big mirror over the bar is shattered. Britain, France and America agree that Germany threw the first punch, so the whole thing is Germanys fault . While Germany is still unconscious, they go through its pockets, steal its wallet, and buy drinks for all their friends.


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

[User]
[Harry Potter 5] In Harry's trial, why is the fact that Dudley already knows about magic never brought up?

In Order of the Phoenix, why is the fact that Dudley already knows about the existence of magic from things like Hagrid's visit in Book 1, the cake incident with Dobby in Book 2, and Harry's accidental magic as a child not brought up? It probably wouldn't be enough to change the outcome on its own, but surely it might away a few people to know that the Muggle in question already knew magic existed and the secret was kept with him and his family?

[Assistant] Because it's kangaroo court. Harry was a known dissonant by the administration for claiming the return of Voldemort. They gathered a full wizengamot for a minor charge and shifted the time in an effort to trip up the defense. The point was to get Harry on a technicality, and the law is performing magic in front of a muggle, whether that muggle has previously had the same violation occur with them is immaterial to the charge.


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

[User]
[GTA]how many states are there in the US?

San Andreas is meant to be a pastiche of California, with Liberty the same for New York State. However, the songs *Keep On Rocking Me* and *Back(In The New York Groove*) make it clear that both California and New York are actual places in the game world. I'm guessing Vice City, Liberty City and Los Santos are all island cities off the coast but are there parodic doubles of every state? Or are there just the three?

[Assistant] The flag still has fifty stars, so provided they didn't change that tradition there should still be fifty states. That said, could be any number of territories and dependencies that are fictional and not reflected on the flag.


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

[User]
[Star Wars] How was Princess Leia able to choke Jaba so easily?

Are the Hut species physically weak? He knocks over C-3PO with one arm? Wookieepedia tells me, "They were tough and muscular with thick leathery skin, which was wrinkled and slimy." How is a 5 feet nothing, 100 and nothing Leia choking him out? Even if she was strong enough what about leverages? What about just slipping out due to him being a large slimy slug?

[Assistant] She got behind him and got a big ass chain under his chin, such as it was.  From there she had leverage against the back of his platform.  If Jabba struggles forward, the chain cuts deeper.  If he writhes back, she pulls the chain tighter.  With the chain and the leverage, there was nothing he could do.


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

[User]
ELI5: Does sign language provide the predominant message for hearing impaired people?

Or does the lip reading do most of it and the signs are just there for context?

EDIT: Who the fuck is downvoting this?

[Assistant]
Note that there's more than one sign language, just like there's more than one spoken language. Deaf people in the U.S. usually speak ASL (American Sign Language), which isn't the same as what's signed in the U.K., Australia, France, or other countries. Oh, and there are regional dialects, too.

To answer your question, though, all of those sign languages are complete languages, just as rich and expressive as spoken language. There's nothing that can be communicated via speech or writing that can't be communicated between two people who are both fluent in sign language.


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

[User] If an aircrafts cabin is pressurized, why can people feel a significant change in air pressure in the ear drum during lift off and landing?

[Assistant]
**What actually happens:**

Comercial aircraft are pressurized at ground level pressure before take off. After that, the pressure inside the aircraft is slowly (but steadily) reduced to a lower level (Usually around the same pressure as if you were on top of a 2km mountain).

**Why it's done:**

Each time there's a noticeable difference in pressures between the inside and the
outside of a pressurized vessel, it feels stresses outwards or inwards that can help small defects evolve into microscopic cracks. Each load cycle (flight) can make those cracks grow by a tiny percentage. Multiply that times a couple thousand pressurization cycles, and you get cracks so big you can see them with your own eyes and are a threat to structural integrity and safety.

Reducing the cabin pressure to something closer to the outside pressure helps reduce loads on the aircraft structure and therefore increases the life-span of the aircraft in terms of pressurization cycles before those cracks become a concern.


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

[User]
[AMC The Walking Dead] Why does everyone have pearly white perfect teeth 10 years after the zombie apocalypse?

It's been 13 years since the apocalypse started, and everyone still has teeth that's ready for a toothpaste commercial.
None of the children or adults require braces or dental work.

[Assistant]
Lack of sugar in their diet and toothpaste has a very long shelf life. Plus fewer staining drinks and food and luxury items like coffee, tea, and tobacco. You could dig up centuries old skeletons and find nearly complete sets of teeth. It's only fairly recently that we've gotten to having diet's that dissolve our teeth over time.

As for more aggressive dentistry it's pretty manageable with limited knowledge and equipment. Things like braces will be difficult to still do but an infected or broken tooth can be pulled without much skill and recovery from the procedure is minimal. Unless the mouth has some serious problems you can chalk up their full smiles to good luck and good hygiene with healthy diets.


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

[User]
How do virtual photons have a real influence?

My question is, if virtual photons are a mathematical book keeping tool, how do they play a real role in terms of Hawking radiation and vacuum energy?

Thanks!

[Assistant]
They don't. Anything you can describe in terms of virtual particles can be equivalently described without referencing virtual particles.

Anytime you see an explanation involving "virtual particles", you can replace them with "higher-order effects of QFT" (except tree-level diagrams, which aren't really "higher-order", but anyway you don't have to take virtual particles literally at tree level either).


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

[User] [Fallout] What determines whether a person becomes a ghoul versus just being irradiated all to hell?

[Assistant]
It does seem to mostly come down to radiation, plus an unidentified random genetic factor. While the Forced Evolutionary Virus may also be a factor, the existence of ghouls in circumstances where they could not have been exposed (like the Chinese Sub ghouls and the pre-war criminal who deliberately ghoul'd himself to survive the apocalypse in Fallout 4) suggests that ghoulification is a natural consequence of radiation in the Fallout verse. Additionally, there seems to be no distinction on race or nation, as we see Americans, Mexicans, and Chinese folk who have all been turned (with the majority being Americans purely by dint of being set in America).

There also seems to be flexibility in the timing. The ghouls of Bakersfield were exposed to lingering fallout because (by design) the door of their Valut failed to maintain a proper gas seal, while Moira of Megaton and the NCR troopers of Camp Searchlight were turned by being in proximity to a detonating nuke and an improvised radiological attack (respectively). It's possible for a ghoul to be formed by a relatively slow process (Raul effectively died slow of what looked like conventional radiation poisoning before getting back up), or to go from human to ghoul in a matter of hours (Moira can be found almost immediately after the Megaton detonation already notably transformed).


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

[User]
[Hobbit: An unexpected journey] Gandalf and the dwarves are overall courteous and nice people. Yet at beginning of the movie they are uncharacteristically rude.

Gandalf self invited himself and 13 dwarves to someones house who straight up refused. After coming to his house, they throw his food around, treat it like their own house, treat him like a butler by thrusting their weapons and coats on Bilbo. Sure by the end of the journey he got repaid for it many times over but they werent sure that hell accept the invite to the journey from before. What made the dwarves and Gandalf especially act so uncharacteristically?

[Assistant]
Gandalf will do whatever it takes to get this quest rolling. Much like his fellow Istari, including those two blue brothers, hes on a mission from God

The dwarfs are demonstrating that manners can vary by culture. They were led to believe he was a host and that he respected the rite of sacred hospitality. They also didnt break anything and even cleaned everything afterwards.


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

[User]
What foods allowed civilizations to grow so well in the "Old World" before being introduced to food from the "New World" that now seem like staples (corn, potatoes, tomatoes, etc)?

It seems that many, if not the majority, of fruits and vegetables we commonly eat around the world today came from the Americas. What foods allowed  civilization flourish in the Old World?

[Assistant]
It depends on exactly where and when in the Old World we're talking. Some of the first domesticated crops in the Fertile Crescent were wheat, barley, and peas to name a few and those cereals never leave being a staple of the Old World.
Moving west to the ancient Greeks they thrived mainly on barley for a porridge and bread along with olives and grapes.
Moving west again with the Romans and not much changes with wheat, barley, oat, olives, and grapes. Of course other vegetables are grown, but if you're looking for the premiere staple crops of the old world you're looking at the grains for breads, porridge, gruel.
On the other tip of staple foods in the Old World are an array of domesticated animals provided dairy and meat in the form of cattle, goat, chicken, and pig.


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

[User]
ELI5:How do tiny organisms like insects, etc. think for themselves?

Like, how does a mosquito for example, function intelligently? It cannot possibly have a brain or even a similar structure. Yet it knows well enough to avoid my hand and fly above my reach.

[Assistant]
The way mosquitos avoid your hand is known as a taxis. A taxis is a simple response which either moves towards or away from a stimulus. In this example, the stimulus is the hand moving towards the mosquito. The mosquito responds with a negative taxis, as it moves away from your hand.

Both simple and complex organisms react with taxis, some more than others. In humans, taxis are a form of reflex. If you touch a hot stove, you move away your hand away (negative taxis).

Some animals rely on this almost entirely. Mosquitos will use taxis to find food. The stimulus would be chemicals in the air coming from the food, and it's response would be to move towards it (positive taxis). Venus flytraps use this to their advantage, as they lure flies in with smells (a bit simplified) to eat them.

Other animals don't even use taxis that often, and instead use kinesis. When you put a woodlouse into a dry and light place, it doesn't move in a certain direction. It runs around frantically in hopes that eventually it will find a dark and damp place. The woodlouse's behaviour is known as kinesis.

More complex animals can consciously process actions rather than always acting on reflex. However, even in humans all our decisions are based on stimulus - we are simply able to interpret more stimuli in more detail.

Feel free to ask any follow-up questions!


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

[User]
ELI5: does the body really have a starvation mode that kicks in if you eat too little and stops you losing weight?

I hear this from time to time. If you cut your calorie intake too much your body with assume food is scarce and initiate its starvation mode which will prevent you losing weight so quickly. Is that actually true or is it a story told to stop people following unhealthy diet regimes?

And, if it is true, how can the body do this? If the body can suddenly run on fewer calories then why doesnt it do that all the time? I guess it must have to stop burning calories on certain activities?

[Assistant] You'd have to miss many meals for this to start, it's a common misconception that dieting causes it or missing a meal, it's called starvation mode because you have to be suffering from starvation. Several days of no food...


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

[User]
ELI5: Why do dogs have to sniff all over the god's green earth before finally feeling satisfied enough to piss or shit? What are they sniffing for?

It seems like it should be a territorial thing, but this idea seems to fail to me for two ideas:
1. It'll often take 5-10 minutes of sniffing for my dog to take a shit anywhere--including the same backyard he's been shitting in for over 10 years.
2. Since when is poop a territorial marker? I could definitely be wrong about that one, but it's something I've genuinely never heard of before.

[Assistant] Dogs shit in about the same way you surf for porn. They will find a spot that they want to mark to keep other animals away, then they smell a spot where a bitch just did her business. The dog will then look for a spot marked by a bitch and also a pest droppings nearby. The dog finds a good spot, then thinks there must be something better. Again continues surfing until a spot is found that can be marked and get the attention it deserves.


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

[User]
ELI5: Who benefits financially from the anti-vaccine movement?

I have read opposing views on this topic that both site scientific evidence.  Usually when I'm deciding what to believe I like to "follow the money".  For example, scientific evidence will site that oats are good for you but the study might be funded by General Mills.

Who benefits financially from telling people not to vaccinate their kids?  I don't understand a direct money trail for that viewpoint.

[Assistant]
While "following the money" *can* be a good strategy, it's probably remiss to assume that it *must* be a factor in everything.

The anti-vaccine movement is driven by emotional advocates: people who *think* they have suffered (either directly or indirectly) as a result of vaccination, and have access to *just* enough medical knowledge to make vaguely-true-but-misleading claims, etc. They're not benefitting financially from it; they just genuinely believe it's putting people's lives at risk, and they want to stop it.

The only people who'd make money off it are the lawyers (prosecuting the case), and maybe the 'alternative medicine' crowd pushing their alternative products.


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

[User]
[Star Wars] How long did it take for Palpatine to personally call every clone trooper commander about Order 66? How did the Jedi not catch on while the calls were being made?

We see the calls are personal. He starts off with "Commander Cody" on the first call we see. In addition, each time we see the hologram he has a different inflection in his voice.

Nobody else knew about Order 66, and only he could issue it. There were about 10,000 Jedi and assuming each call took 30 seconds, that's 3 and a half days of straight calling to each clone unit.

How did the Jedi not catch on to that? "Hey wow in the last two days half the Jedi were killed by their clones weird huh".

Like Yoda could feel they were being killed, could no one else? Or was he the last one to be killed?

About 100 Jedi survived, you're telling me 9900 Jedi were killed over three days and NOBODY NOTICED? For crying out loud I could notice that and I'm drunk. Actually I'm drinking as I type this so I apologize if this is becoming nonsensical.

TL:DR Why could the Jedi not notice all their friends getting killed over the course of three and a half days? Or how long did Palps actually take to personally call each Clone Commander and tell them to do the deed?

[Assistant] It's likely he sent individual messages to the Clone Commanders accompanying members of the Jedi Council, as they would be the main priority. After that order went out, he sent out a more generic message to the Army commanders who then filtered the order down the chain.


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

[User] ELI5: Why are the storage options for devices like phones or laptops multiples of 16GB?

[Assistant]
computers are based on a binary system so it goes up in powers of 2.

The math starts at two not sixteen but its:

2^1=2
2^2=4
2^3=8
2^4=16
2^5=32

so on and so forth right up to 1024 when we move to 1 Terrabyte.


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

[User] ELI5: An article today said using your phone battery below 20% and charging it routinely above 80% reduces battery life...what causes this and is it the same process at both ends of the range?

[Assistant]
ELI5: Discharging a battery too deeply causes its structure too break down, increasing the potential for a short circuit. Overcharging has a similar effect, but can also result in the battery catching on fire. Discharging from 80-20 slows the breakdown.

Full Answer:
When discharged below its safe low voltage (exact number different between manufacturers) some of the copper in the anode copper current collector (a part of the battery) can dissolve into the electrolyte. The copper ions then in turn can stick on to the anode during charging by chemical reduction and cause dendrites. The dendrites might cause a short circuit inside the battery. So basically discharging too much is as bad as charging too much. But the dendrites caused by overcharging is formed out of lithium.

Normally the battery pack should have some sort of supervisory circuit that disconnects the cells from the charger or load when the cells are above or below the recommended voltages.


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

[User] Is my weight the same if I'm standing on the 1st floor or 50th floor of a building?

[Assistant]
No, your weight would decrease slightly. The reason is that your weight is given by mg, where m is your mass and g is the gravitational acceleration. However the gravitational acceleration is not constant, but depends on your position relative to the center of the Earth. This change is due to the fact that the gravitational pull of Earth decreases as 1/r^(2), where r is your separation from the center of the Earth. As you are moving away from the surface, you can express g as:

g(r) = g0\*(R/r)^2,

where R is the Earth's radius, and g0 is the gravitational acceleration at the surface (on average 9.81 m/s^(2)). Now we can plug some numbers in, the Earth's radius is 6.37\*10^(6)m, let's say each floor is 3m tall, so 50 floors corresponds to 150m, then the gravitational constant you would feel would be roughly: 0.99995\*g0, so your weight will be 0.005% less than on the surface.

To get a feel for how small this change is, if you had a mass of 80kg, your apparent weight 50 floors above the surface of the Earth would be roughly the same as that of a person standing on the surface of the Earth but whose mass was 4 grams less.


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

[User] ELI5: How did we decide how long a second was?

[Assistant]
The Egyptians were the first to split the full cycle of day and night up into 24 hours, a system that was later improved upon by Greek astronomers Ptolemy and Hipparchus who further split it up in a sexagesimal (60 as a base) system, and that's where the second comes into play. First you divide an hour into 60 parts, creating the minute, and then you divide that a *second* time, hence the name, creating 1/60th of a minute. Further splitting up a second in sixthieths is called a third, but that's not really used nowadays.

At the time it wasn't possible to keep time that accurate, but towards the end of the 16th century mechanical clocks were able to measure seconds accurately, which is also when the English word for them came into use.

**Edit: Since so many people ask "Why use 60 as a base?", the answer is because it's easy to divide it by 2, 3, 4, 5, 6, 10, 12 15, 20 and 30, making it a solid base for counting.**


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

[User] ELI5: Why does gorilla glass shatter so easily when you drop your phone but seem indestructible in their demo videos?

[Assistant]
Gorilla Glass is a brand name for Corning's tempered glass.  Tempered glass is very strong when you hit it from the front, but if you make a tiny nick on the edge the internal stresses cause the glass to instantly shatter.

The demos you see always test the front surface and never the edges.  When you drop your phone, it's usually an edge strike that causes the damage you see.


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

[User] If I set my water temperature to 50 deg celsius and have a shower why does the bathroom fill with steam, as this is half of the boiling point?

[Assistant]
Boiling and evaporation are different processes. Evaporation can happen at any time from the **surface** of the liquid, while boiling is a bulk process where all the liquid may turn to gas. This is why you get the bubbeling when boiling, as gas bubbles are formed below the surface and rise.

Evaporation increases with higher temperatures because the energy in the liquid is randomly distributed between the water molequles, giving some of them high enough energy to evaporate from the surface. The reason there is so much steam when you shower is that the evaporation only happens from the surface of the liquid. Small droplets have a large surface area compared to the volume, so naturally this allows for a lot of evaporation.


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

[User] [Kill La Kill] Is Junketsu sentient and able to talk to Satsuki like Senketsu is?

[Assistant]
Satsuki is a normal human so she has to force Junketsu on her, that is why Satsuki calls it Life Fiber override instead of Life Fibers Synchronize, also Junketsu is really feral compared to Senketsu so it is possible that Junketsu just cant speak.

So answer is no.

and Senketsu is Life Fiber-human hybrid so that might be one reason why only Senketsu is able to speak.


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

[User]
How did the black death of the 14th century spread?

If the plague was caused by the bacterium Yersinia Pestis, which was carried by fleas - how did it spread from human to human? Was it flea transmission?

And as far as I'm aware there were 3 forms of the plague in 14thC Europe, was it all spread the same way?

[Assistant]
It's super interesting actually!

So, the disease spread through fleas. Essentially, the bacteria infect the flees, and reproduce around their proboscis and "gum it up". When the flea goes to bite a human, it must "push" out it's blocked proboscis before it can take a blood meal, throwing the bacteria into the person's bloodstream. This is only half the story, however.

Fleas stay on living bodies, so there are a couple of things that happen. If an infected person's body got too hot from fever, the fleas would move to a fresh host. Further, if a person died, the fleas would leave the cold corpse and seek a warmer, healthier body. This is why the disease spread quickly.


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

[User]
[Star Wars] How does a non-Force user ever challenge a Jedi or Sith?

Like Jango or Grievous, for example. Why couldn't Obi-Wan just force-grab them and beat them against the wall a few hundred times? I get why they can't do that to another Force user, but against a regular dude? No weapons or skills they have could really defend against something like that, right?

[Assistant]
we are spoiled because we constantly see the most powerful Jedi using the force like its nothing. However, grabbing a resisting person and throwing them around with the force is something that masters would struggle with. Most could do it, but not while dodging blaster shots. thats why we see force pushes more than grabs - easier to throw a punch than to catch something.

Yoda, the most powerful force user of the Jedi in their peak, was rendered immobile by the need to use the force to stop a column from falling onto some Jedi. The force is hard to use and using it on moving targets while engaging in combat is sheer madness for all but the most powerful of Jedi.


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

[User]
CMV: I don't think affordable housing is important in NYC (and other major cities)

I don't understand exactly what the need for affordable housing is in NYC.

I understand that affordable housing is essential to foster a viable middle class anywhere.  However, I do not live in New York City because I do not have the means to, it is that simple.  Would I want to some day when I have a comfortable enough income? Absolutely.  Do I currently when I do not? Absolutely not.

So what I want to know, really, is what the driver is behind needing/wanting affordable housing in NYC and other major cities.

How does it benefit the economy? How does it benefit the local communities? Is it really that important?

Edit: Another question: Ultimately, if it is so important, how can we go about creating affordable housing?

[Assistant]
It's quite simple, people who work low income jobs need places to live.  There are plenty of low income jobs in cities, from fast food to retail positions. You can't expect these people to commute from outide the city, because even if they can afford a low income home outside of the city, they likely can't afford a vehicle, and minimum wage is not worth an hour + bus ride (if one is even available).

Unless there is low income housing available, most low income employees will basically be homeless.


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

[User]
Applied maths in Economics

I am planning on applying to Cambridge for Economics and need to beef out my personal statement, especially on the maths end. My college offers us an opportunity to present a field of mathematics that is not on the specification to our further maths class. I think this is a good opportunity to explore an area of maths which can be applied to Economics. But what do I do?

I have been suggested Markoff chains and Monti Carlo methods, both of which I have never heard of before. Are these too complex for a first year A-level student and can they be directly applied to economical situations?

I have also heard game theory can be very mathematical and I may do some research into that however, I find many people talk about game theory and Im intrigued in finding something more unorthodox.

Could anyone recommend and interesting side of maths that can be directly applied to economics. It would be much appreciated :)

[Assistant] Is constrained optimization with Lagrange multipliers on the A-level syllabus? If not, that's a foundation of a lot of economic theory - you'll use it all the time in any undergrad course, whenever you want to model an individual maximising their utility with a budget constraint or a firm maximising their profit subject to constraints - and it's not too complicated if you already know how to find unconstrained maxima and minima from calculus.


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

[User] ELI5 why are cars made to be able to go speeds well above any speed limit, when they aren't made for reaching?

[Assistant]
A lot of road cars are designed to be efficient. They want to be working as little as possible at the speeds they are most likely to go at.

An engine that can only get a car to 60mph/100km/h will be working as hard as possible all the time if you were on an open highway. This would wear the engine down and lead to more faults as the parts are pushed to their absolute limit.

An engine that can get the vehicle to 140mph/225km/h will effectively be working way less when keeping at 60/100. This results in less fuel usage, less wear and tear, less part failure and less hassle for the consumer.


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

[User]
ELI5: Why can't aircraft carriers have longer runways?

I was watching a documentary about the US Navy and they talked about the million design challenges and compromises needed for planes being able to take off and land on aircraft carriers.

But i was still left with an "obvious" question, why just not make the runway longer?  Is there a hard limit on how long a ship could be?

Or keep the ship the same size and bolt a longer runway on top of it.

Edit 1: also, how do these pilots train? It seems like there's no room for error there.

[Assistant] You've gotten some good answers. It's really a cost versus benefit. There's a huge cost in making a ship bigger just to have a longer runway. More weight, more operational costs to move the ship, inability to fit in harbors, stronger structure needed to withstand the bending loads from ocean swells, larger radar cross section (easier missile target, and you don't want your expensive carrier to be a "cheap kill" for the enemy). Aircraft carriers already have effective catapult and braking systems, they work well, so there's no good reason to make the ship longer.


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

[User] What causes the Earth to spin on its axis?

[Assistant]
Conservation of angular momentum. The Earth has a kinetic rotational energy it obtained during its formation and outside interacting tidally with the Moon and other celestial bodies doesn't have a way to get more or get rid of it.

So nothing continuously causes it, no force is require to keep it spinning.


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

[User]
CMV: 500 days of summer is the romcom with the most important message out of all the romcoms ever.

Post inspired by a rotten tomatoes tournament where sadly 500DoS got paired against the princess bride and is obviously being crushed in round 1.

Yeah, there's no other romcom with a message as important as The one in 500 days of summer. It's really the perfect romcom, it doesn't have the generic "happy ever after ending" and a lot of people in the world go through the exact same situation (or are going through) so the movie really teaches you that, despite investing all your time and love in a particular person, that person may not be for you and it's not the end of the world because there's still going to be someone else who you haven't met yet.

It's a simple yet important message for a lot of people. I don't even think most romcoms have messages other than just telling a story.

[Assistant]
> It's really the perfect romcom, it doesn't have the generic "happy ever after ending" and a lot of people in the world go through the exact same situation (or are going through) so the movie really teaches you that, despite investing all your time and love in a particular person, that person may not be for you and it's not the end of the world because there's still going to be someone else who you haven't met yet.

This isn't what *500 Days of Summer* is about.

The film is about how Tom chooses to ignore the social cues and conversation that make it clear his relationship won't work out, instead focusing on an unrealistic ideal and superficialities that he sees in a woman he doesn't really know (Summer), all while he ignores his own interests and personal health in the process. And the ending isn't a happy one, we're led to believe Tom hasn't learned anything from the experience and will repeat the same mistakes with Autumn.


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

[User] why are images seen through night vision devices, tinted green?

[Assistant]
Image intensifiers work by having the incoming infrared light strike a photocathode, which releases electrons when it is struck. These electrons are accelerated via a high voltage field, causing them to travel to a second plate and slam into it at high speed. This second plate is coated with a phosphor which glows green in response to the electron strikes, both (in effect) converting infrared photons into visible-light photons and increasing the number of photons (because the fast-moving electrons can spawn many photons).

As for "why green", human eyes are significantly more sensitive to green than any other color, and since the goal is to see dim illumination, green is the obvious choice.


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

[User]
ELI5: Is our real voice the one we hear in our head or the one we hear in recordings?

I've heard that the voice we hear inside our head is actually one octave lower than our real one but when I'm playing online with a mic with friends that I know in real life they always sound a bit different than they do in person and they say the same thing about me, so which projection of our voice is the real one?

[Assistant]
Recordings.

When you're playing online, you're not getting a good, high fidelity recording.

However, if a good mic picked up your voice and filtered and played it back well, that'd be your real voice. It sounds different to you because it travels through all the fleshy tissue and bone in your head before hitting your ears.


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

[User]
[WALL-E] why are the humans fat?

Dear AskScienceFiction, I require some assistance in reference to WALL-E.  We are given to understand that the shipboard passengers' nutritional intake comes solely from the shakes that are perennially squeezed between their little sausage fingers.  My question is, why are they all so fat?  Would it be unreasonable to think that such a self-sufficient vessel would be programmed to serve meals whose caloric input matches the passenger's  caloric output? It seems to me that such a practice would only be more efficient, and produce less waste.

[Assistant] The ship, like the corporation that built it, was founded on consumerism.  The ship isn't going to tell the passengers what to eat just like the corporation wouldn't tell its customers to stop creating so much garbage.  And so the passengers get fat for the same reason that the world became uninhabitable.


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

[User] If it only takes 23 people in a room to have a 50% chance that two of them share a birthday, how many shuffles of a standard card deck does it take to have a 50% chance that two of them are the same (they end in the same order of cards in the deck) ?

[Assistant]
If we assume that each shuffle is "perfect" in that each shuffle is just a randomly chosen permutation of the cards form the 52!  8 x 10^(67) possible permutations, then your question is exactly the same as the birthday problem, but with 52! "days" instead of 365 days. Let p(n,d) be the probability of there being at least one match among *n* "people" in a year with *d* "days". Then if *n* is much smaller than *d*, we have the approximation

> p(n,d)  1 - exp(-n^(2)/2d)

Setting this equal to 0.5 and solving for *n* with *d* = 52! gives

> n = [*d* log(4)]  1 x 10^(34)

So quite a lot of shuffles.

Having said all of that, when you physically shuffle a deck, you are not choosing a random permutation of cards. For instance, people generally divide the deck into two roughly equal parts and then mix them together, roughly alternating cards from each smaller deck. So a given card typically does not move more than a few positions from its current position in the deck. Of course, depending on your shuffling method, a card could possibly move many positions. Your question then has no general solution. For one, we would need a lot more information on how exactly the cards are shuffled. Second, it is not immediately obvious whether every permutation of cards is achievable, let alone in a finite expected number of shuffles.


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

[User]
[Harry Potter] How exactly are some wizards more powerful than others?

In Harry Potter, both Dumbledore and Voldemort are described as being extremely powerful wizards. My question is: how exactly are they more powerful than a regular wizard? Do they simply know more spells? How does a wizard know how powerful he is? Can a wizard become more powerful with time? Seeing as lots of spells seem to have uniform effects regardless of who is casting them, it seems that knowing more spells, rather than any kind of intrinsic power, would be more useful.

Also, a related question, the Elder Wand is described as being the most powerful wand in existence. How exactly is it more powerful than any other wand?

[Assistant]
I believe in HP, at least the books, "Power" Is a combination of two things. Reserves, and Knowledge.

Magic in the Potterverse. Every wizard (probably) has a reserve of magic. Different spells take different amounts of magic. Think of it like Chakra in Naruto. You CAN run out.

Knowledge is just that. Spells you can cast and know how. Dumbledore, having given his life towards The Greater Good, has dedicated his life to magical studies, ever since he was a child. Since he's quite old, he knows a lot. He also has a large amount of magic.

Voldemort, succumbed to the darkest of arts. Dark arts are always more powerful, but they have a cost. Riddle's cost was eventually his humanity.

To prove that it is Knowledge & Power, think to The Golden Trio. Hermione isn't very intristically powerful, but more than makes up for it with her studies. Ron, on the other hand is the opposite. He comes from a very powerful and old wizarding family, but doesn't study worth crap. He relies on his own power to match with Hermione. Harry is just about the balance, except he is more powerful than Ron. He doesn't study as much as Hermione, but more than Ron. This explains how HP is considered the more powerful of the Golden Trio. He has a considerable amount of power, and some knowledge to back it up.

I think that The Elder Wand is a more powerful focus of magic. Think of a wand like a magnifying glass, and then the Elder wand is a VERY powerful one. It also has the ability to be compatible with anyone.

TL;DR - Both knowledge and magical reserves have a part to play in "power" Dumbles and Volde both have a considerable amount of both.


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

[User]
[Star Wars] Is the force against a post-scarcity culture?

The force is balanced nature, so hunting/fishing/scavenging/gathering/nomadic life seems the most in tune with the natural way of the living force. A post-scarcity society has no need, so the natural loop is broken or non existent. Would the force upend this society?

[Assistant]
The Force is not "against" anything, it's impersonal natural phenomenon. It doesn't really act on it's own. Most people treat interactions with the Force as a spiritual experience, but it doesn't exactly *have to be* a spiritual experience.

People in harsh environments have to rely on their wits and strength to survive, and for a Force-sensitive person the Force is an additional edge that allows them to excel. In a post-scarcity society people don't need to fight daily just to survive, so many people won't need help from the Force to sharpen their senses or enhance their strength or speed, but that doesn't mean that the Force is absent in this society. It still responds to the needs of the sensitive individual, but the needs would be different in this case. It could be the source of divine inspiration for arts, supernatural charisma or incredible empathy.


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

[User]
CMV: Adults should be able to Trick-or-Treat if they're willing to put in the effort of dressing up.

Up until I was 19 or 20 years old, I went Trick-or-Treating. I always loved dressing up, and I always made a sweet costume to go door-to-door in. I never got turned away, and a lot of people commended me for going out even though I was out of the "traditional" age group for Trick-or-Treating.

The last few years, though, I haven't gone. A lot of the people around me have strongly discouraged it, saying that I'm far too old to partake in a "kids" event. I've been told that it's extremely awkward, and that it's just not something adults do. Sure, I can dress up and go to Halloween parties if I want, but Trick-or-Treating is a no-no. So I haven't gone, because I feel weird about it now.

But the way I see it is, the world would be a better, happier place if everyone got to partake in "childish" activities. Be a kid again for a few nights a year. Go have fun, without getting hammered at an adult party (unless that's what you want to do of course). If you're an adult and you want to put in the effort of making a costume/dressing up, why shouldn't you be able to go Trick-or-Treating if you want to? Screw those punky teenagers that go door-to-door in nothing but jeans and a hoodie, though. Those assholes don't deserve candy.

[Assistant]
The problem is that the people who would put in the time and effort are those that most love the holiday.

Those are the same people who tend to be the ones that supply to most/beat candy to trick-or-treaters.

It's simple economics. Not everyone can be a taker, there needs to be some givers.


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

[User] [MCU] What material is Thanos' DoubleEdged Sword from Endgame made of? Is it Uru? If so, how was it able to break Captain America's shield, while Mjolnir, which is also made of Uru, was not?

[Assistant]
I don't think we know officially what it was made of, but the likely answer for the damage was impact vs. cutting force.  Cap's shield was Vibranium and that metal is particularly good at absorbing then redirecting shock force.  Mjolnir is an impact weapon, delivering all of its energy via blunt force (exactly what the shield is made to defend against).

The Sword has a sharp cutting edge and, as we saw from Cap's fight with the Black Panther, the shield can be scratched by a hard enough edge.  Thanos just turned that up to 11.


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

[User]
[Jurassic World] But seriously, how would dinosaur soldiers ever be viable, or even remotely a good idea?

Would any real-world government even consider such a thing? Sounds *really* stupid to me.

[Assistant]
The important thing is they're *deniable*. If humans commit atrocities then you can question them, match their faces to records, etc.

Raptors? If you catch one alive it's not gonna snitch. You may have a hunch it was a US government deployed killer raptor but how would you prove it?


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

[User]
[Star Trek] What are the limited resources on Earth? How are they distributed amongst Earth's population?

Money is no longer used due to almost inexhaustible energy and replicator technology to create food/oxygen from energy.

But although energy and food are no longer limited, resources like land space, or access to live renditions of a Mozart concerto would be limited.  What are other resources that are limited, and more importantly how is access to these limited resources determined?

[Assistant]
The biggest thing to remember about Earth in the 23rd or 24th centuries is that Earth is literally a paradise. It's a technological and ecological paragon that most other planets could never dream of equaling. No human living on Earth wants for anything. Even living space isn't that much of a big deal. You have free access to go live on a colony world that's ALMOST as good as Earth, or you could travel the stars as much as you wish.

What is probably the most limited thing left on Earth is society's patience for people who take advantage of this situation. Humanity suffered more than any other species to get to this point, and even centuries later still haven't forgotten the lessons of the 20th and 21st centuries. Everything is provided for an Earth-born human, literally everything. But they're expected to do something with it. Push themselves, be greater than the generation before. They have their material needs taken care of, it's up to the person to give back and show thanks for the gifts given to them by their ancestors. It would be SO EASY for a person to sit around on Earth doing nothing, or possibly sitting in a holodeck forever, but they would face the gentle but inescapable pressure of society at large to break this trend.

Even though humans are beyond petty things like racism or prejudices based on other inborn traits, they can still be pretty judgmental about other people's choices, opinions or ideas. (Just check out how people treat Harry Kim sometimes) If you tried to live in a holodeck on Earth, you'd eventually find it turned off and a medical professional waiting to give you counseling for holo-addiction and ways to cope. It would be friendly and cordial, but you'd get the underlying message: We demand you succeed.


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

[User] ELI5: Why can't our bodies prevent tooth decay without the help of toothpaste?

[Assistant] We eat WAY more sugar than our teeth really evolved to handle. If you look at ancient skeletons (from before agriculture) you find a lot of people with really nice looking teeth. So, with modern living comes modern problems that need modern solutions to fight them.


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

[User]
[Marvel] Just how exactly does Spider-Man ever defeat Sandman?

So I know this guy Sandman exists. I have a vague idea of what his powers are. And I know Spider-Man has fought him a lot. What I can't wrap my head around is, assuming my understanding of Sandman's physiology is correct, just how exactly does Spider-Man defeat him? And keep him defeated?

I'm thinking maybe trap him in an air tight container. But doesn't Sandman have to breath? He could heat him up and turn him into glass. But wouldn't that kill him?

[Assistant]
Wet the sand, turn him to glass, suck him up in a vacuum, disperse him

In his buhjillion encounters with him, Spidey has figured out that Sandman actually has a "core" of a single grain of sand that he uses to control the rest. He's isolated that one grain of sand and problem solved.

And no he doesn't have to breathe.


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

[User]
CMV: The American left is a mess right now, with no clear hope for unified action to defeat the right in sight

Many members of the right have been playing the long game, being strategic, swallowing their disdain for Trump, using churches for community organizing to great effect, and maintaining a unified front and messaging. They just had a huge payout for their patience with the overturning of Roe V. Wade, and they're planning on overturning more rights as soon as they can. Meanwhile, the left (which for me includes liberals, progressives, and socialists) is constantly at war with itself over identity politics. We have no unified and coherent platform of shared positive goals that we can all agree to agree on. We don't have any means of community organizing to compete with churches. We have no long-term strategy. What we mostly have is a burning hatred and rage for anyone who disagrees with us (regardless of what political party they're in), a blindness toward the arbitrariness of our critiques (eviscerating Lin-Manuel Miranda for colorism in IN THE HEIGHTS while championing blatantly racist reality shows made by and featuring white people), and an unwillingness to face the extent to which we're driven by capitalistic greed ourselves. We do share the small sliver of ethics and humanity that enables us to be willing to pay some taxes for the greater good, but that sliver isn't enough to get us all out to vote in the next election. If someone could prove me wrong, I would hugely appreciate it, because I could use some hope.

[Assistant] Dont kid yourself. The right is a mess too. There is a wide swath of the electorate that is swing voting against candidates rather than voting for candidates. Both parties have lost the majority and are pandering to a loud vocal core minority in their party which makes it very difficult to hold anything for any length of time.


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

[User]
[Economics] Do internationally donated clothes (eg to Africa) have a detrimental effect on the receiver's economy?

I once read an argument that the very common practice of donating clothes to Africa have a had a highly negative effect there as the flood of almost free foreign clothes have destroyed, or at least severely hampered, the native textile industries and created a damaging economic dependence on foreign charity. Furthermore, it was noted that the clothes sent over tend to come from Europe and North America, which often have very different climates and clothing than the places they are sent. Is this accurate?

(I think I read this in Paul Theroux's *Dark Star Safari*, so I am using a grain of salt)

[Assistant]
It depends on whether or not they act as a substitution for local producers' goods. There is a case study (will look for a citation at some point) where a large volume of cheap tee shirts were donated to an East African country. The unintended consequence was that local manufacturers experienced a sharp decline in demand, causing job loss and business closures.

A far better approach is to donate by purchasing orders of clothing locally for donation with foreign capital, which acts both to clothe people and stimulate the local economy.

In addition, there is a well-known phenomenon in the aid industry that donations of discretionary goods are less valued than subsidisation of goods. For example, houses in South Africa provided to township dwellers living in informal dwellings like shacks free of charge are typically in far worse condition that houses provided for small costs/low interest loans.

So if you're giving absolute basic necessities (eg shoes, warm clothes in cold environments, all good, but if you're giving discretionary goods, this effect may reduce their functional lifespan).


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

[User]
[Star Trek/Farscape] How might events have turned out differently if instead of Farscape One it was USS Voyager that shot through the wormhole into Peacekeeper territory?

For the purpose of this discussion let's assume that Voyager appears in the same location and situation that John Crichton found himself in and Peacekeeper territory is located in the Delta Quadrant.

[Assistant]
When Voyager appears, much more than one Prowler is destroyed, Voyager being much larger and shielded. Voyager is not captured, and the crew never encounters Moya, which without Crichton is unable to escape and is recaptured.  Voyager warps out of the battle.

The destruction of the Prowler sparks a vengeful response, and their technology is more than enough to spur Scorpius to hunt them, but they have little chance of success. While they have an edge in biotech, Peacekeeper technology overall doesn't seem as advanced as 24th century Starfleet.

They seem to have similar maximum speeds, Janeway thought it would take ~70 years to make it home, Scorpius told Crichton it would take ~60 years for the Peacekeepers to reach Earth. But Voyager definitely has the edge in acceleration and sensors.

Being unshielded, Prowlers pose no danger to Voyager. Larger vessels like like command carriers are shielded, but they are pretty slow and cumbersome. It's an open question whether Peacekeeper shields would block transporters, if not even command carriers are no threat. Even if they do, it would be some time between when the ship is detected and it reaches Voyager, and it takes Voyager only seconds to go to warp.


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

[User]
[Godzilla Against Mechagodzilla] How hard would it be for someone to steal and reprogram Kiryu?

In Godzilla Against Mechagodzilla, Mechagodzilla or Kiryu is built by the Japanese Self-Defense Force as a way to fight Godzilla.

If someone wanted to use Kiryu for their own means, could they do it?

[Assistant]
Given the setting it would be virtually impossible to actually steal Kiryu, simply because one just can't operate it without a military unit supporting and maintaining it, along with a huge maintenance bay. So to take Kiryu home one would have to have might of another country behind them to actually grab and take it away, being chased by JSDF along the way.

More sensible is to try to get into the piloting jet and when the time comes just highjack it... but that's also would be a quite a tall order, since Kiryu is a highest strategic asset, and Self-Defence Force won't let just anyone near it.


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

[User] ELI5 What is a Catch 22?

[Assistant]
Imagine you're a pilot. The only way to get out of flying missions is to be certified insane. Additionally, if you demonstrate concern for your own immediate safety, you are certified sane. Sane people must fly missions.

You and your friend Orr are concerned that the mission you are about to go on is incredibly dangerous.

Orr is a crazy man. He talks to his bed. This means that he could easily get out of flying the mission by claiming insanity. But why would he want to get out of the mission? Because he is concerned for his own safety, and so is sane. So he must fly the mission.


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

[User]
ELI5: why is 9/11 considered such a huge deal while there have been events with much more death since?

I realize 9/11 was a terrible event and all, but there have been other events that had as much death, or more, all over the world, yet they are not recognized in the same fashion. Why?

[Assistant]
1. It was the most deadly attack on U.S. soil since Pearl Harbor (only a few hundred more died in Pearl Harbor, making it one of the most catastrophic events on U.S. soil since The Civil War.

2.  It was an attack primarily against civilian targets in a major U.S. city.

3. It involved a new terroristic strategy. Previously, terrorists relied on bombs or simply hijacked planes for ransom. In this case, the planes themselves became the bomb.

4. It completely destroyed two iconic American structures. Towers 1 and 2 were important symbols of American wealth and success. They were a trademark of the New York skyline and were recognized around the world.

The biggest reason it was so important is because it was an attack from a non-state entity directly on American soil. It wasn't against an embassy or a consulate or a bus full of American tourists. Rather, it was against Americans in America. While this was not the first time such a thing had happened, it was the first time something of that magnitude had occurred and it came completely by surprise.


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

[User]
I don't believe there is an overarching meaning to life. CMV

I don't think there is some thing that humans were put on earth to do. All of the theories I've heard had to do with other people, religion, or egotistical 'we have to fix everything because only we can' stuff. I think that there is no reason for life, and that people should do what they want without worrying about whether or not they're doing what they are supposed to in order to fulfill some higher purpose. It just doesn't make sense to me for there to be some reason we're all here, or even a reason why each person is here. We're here because of evolution and a natural urge to procreate, and nothing else.

[Assistant]
You could perhaps look into the philosophy of existentialism - Jean Paul Sartre et. al. His starting point was in agreement with yours: there is no *intrinsic* meaning to life. However, it is up to you to bring your own meaning to it.

Say you see a mountain. Maybe you take it as a challenge to climb it. Maybe you want to study the rocks that form it. Maybe you want to take the perfect photo. This is the meaning you bring to it.


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

[User]
[Warcraft] How does magic work?

From a spellcasters point of view how does magic work for the "wizard" classes (i.e. mage, warlock, priest, druid to an extent).

Shamen seem to be granted their magics from spirits of nature, druid's have a similar deal going on, but the balance discipline seems to veer into wizard territory.

But of the 'wizard' classes how does the magic work? They shape their mana into spells and release it, but where do these spells come from? Are they incantation based? Is there a "weaving" of their mana into spells? What's the difference between a warlock casting Incinerate and a mage casting Fireball? How do the elements of fire, frost, arcane, holy and shadow relate to the same mana resource innate to the caster?

Is it simply usage that separate a mage, priest and warlock, or are they distinct magic systems?

[Assistant]
The literary examples of how Magic works indicates its something like a circuit. Magic users basically take energy (Arcane being the base, natural magical source. Everything else is a variation of it)and through a combination of gestures and sheer will, shape it into patterns which elicit particular results.

Different types of magical energy (basically wavelengths) have different reactions when harnessed in the same way, and depending upon what they are used. Fel and Holy tend to cancel out violently, somewhat like Matter and Antimatter,  while Holy and Shadow only nullify each other.

In terms of general practice... Most spells are simply memorized patterns that a magic user can easily put energy into, and eliciting a predictable effect. More complicated spells require more time and effort, often using physically reagents and focus points in complex circuits (generally referee to as the Spell Matrix) but incantation is rarely, of eger necessary. It can help novices focus, mind you.


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

[User] ELI5: Could there possibly be any planet anywhere that is warmer during its night period?

[Assistant]
Could be.

If your definition of "night" is "the side of the planet pointed away from the sun", you could have a planet that's far enough away from the sun to not get any heat from it, but that is still volcanically active and for some reason happens to have cyclical eruptions on the far-side. This works better on a planet that's tidally locked to the sun and just happens to have more activity on the opposite side.

There can probably be many other ways to have this happen naturally (maybe very heavy cloud coverage, and consistent meteorite strikes, or a natural satellite that somehow has turned into a huge curved mirror or something).


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

[User] ELI5: How is it possible that China copies and sells copyrighted stuff and be a member of WTO at the same time ?

[Assistant] China are very powerful as an economic entity & the world needs China much more than China needs the rest of the world. Countries that enjoy that kind of political position can get away with quite a lot.


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

[User]
Paper accepted, but I dropped the ball, but they also dropped the ball

Is this normal?

"Check submission emails" is what I put into my calendar for today. I put it on my calendar because it is my first paper, my first conference, and there are just so many little things. And every now and then, there is super important information hidden beneath a wall of text. No system, no reminders, everything is manual, and everything is just a big old mess (and this is in Computer Science)...

I started with the acceptance email and found something right away: something I entirely overlooked, neatly lodged right between the end of the acceptance notification and above the reviewer texts. It reads:

> "At least one of the paper's authors must register to the conference by the camera-ready deadline."

Guess what... DEADLINE'S PASSED! Paper is submitted, but I'm not registered!

Drenched in sweat, I write an email asking for advice, all the while hysterically iterating all the worst case scenarios in my head... am I automatically disqualified? Is my "academic career" in jeopardy?
Frantically, I scour my other emails. I find the relevant submission link email. It DOES NOT EVEN MENTION registering to the conference!

I keep looking... My heart going at 180... Finally, I see the magic words on the registration website:

> "We are working on building the registration system, and the link to the registration system will be provided and updated soon on this website (approximately in late Feb)"

What... just... happened?

[Assistant] I feel your pain... I've missed a couple of registration deadlines in the past. You just have to email the organizers and they will add you in manually, no stress. That being said, it's a lesson you learned in a (not so) painful way.


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

[User] If we find life on Mars, how will we know it didn't come from tiny organisms on any of the rovers?

[Assistant]
NASA has "planetary protection" protocols whereby rovers are meticulously sterilized before being loaded into the rocket, and the payload bays are air-tight.  The protocols are especially strenuous for Mars and other destinations considered prime candidates for exobiology.

The agency is so focused on this principle that, for instance, the Cassini spacecraft will be crashed into Saturn to avoid even the possibility that it will some day crash into Titan or Enceladus and contaminate them somehow.  The Juno spacecraft will likewise be crashed into Jupiter to avoid possibly contaminating Europa.


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

[User] [Stranger Things] How was Will able to survive so long in the UpsideDown, whereas Barbara and a Dept. of Energy worker were killed quite soon after their arrival?

[Assistant] The Demogorgon is *really* bad at finding things that aren't bleeding. Remember how Nancy was like a few feet away from it and it couldn't find her? Will was able to hide once he was in the UD, but Barb had the poor luck to not only have cut herself a few minutes earlier, but was also trapped at the bottom of a pool.


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

[User] ELI5: Why do we need an ISP? Why can't I just connect to the internet without them or act as my own ISP?

[Assistant] There is no "Internet" for you to connect to. What we call the Internet is just the collection of ISPs connecting their networks together, as well as to some other networks like Level 3 that don't sell connections directly to end users. If you formed your own ISP, you'd still have to connect your computers to some other networks in order to have an Internet connection and unless you got really big, you'd still have to pay them to do that.


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

[User]
Is it okay to ask for a copy of my recommendation letter?

I applied to a few programs through an application service that requests recommendation letters directly.

In my email requesting the letters I asked if I could also have a copy because Im applying to a few jobs.

I was notified the letter was submitted via the application service but I havent received my own copy from the recommender.

Did I ask for something thats taboo? I thought I was saving my recommender trouble in the future?

Thanks

ETA: thanks for the replies and consensus! Ugh, I feel like a real dummy now.

ETA2: this is getting a lot more feedback than I expected! Thanks! Just for context: I worked at a lab for over a year a year ago. Im 23 and not sure what I want to do with life but one of the things I was considering was a grad application to a short degree while also applying to jobs (since I dont know exactly what I want). Thats why I asked my former laboratory director to send it to me *and* the application site thing. Hes a bit difficult to get in touch with so I tried to cram a couple of correspondences into one. I explained that Im trying to find what I want. I now realize that looks bad and somewhat intrusive! Darn.

[Assistant] It's generally not ok to ask to see a letter, and most programs will discount letters that students have seen. This is because we need to be able to be honest in our letters, and knowing that the student will see them is likely to change what we will write. Most professors will ask you to provide the email for them to send the letter or ask for contact information so that they can get in touch. This doesn't mean that the professor is writing anything bad or negative about you, but the norms of letter writing strongly favor not showing the student the letter.


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

[User]
[Star Wars] Why did Darth Vader hire bounty hunters to hunt down the Millennium Falcon?

Sorry for another Star Wars question but...

Why did Darth Vader hire bounty hunters to capture the Falcon? (can't remember if he was after Luke or Leia exactly, but I don't think it's relevant)

I mean... I imagine there's got to be some sort of special Imperial SEAL team or something that would be much more suited to the task, and wouldn't involve the likes of bounty hunters.

[Assistant] Because for all the Imperial talk of efficiency, they still floundered in rooting out the Rebels. Not to mention,  stealth isn't exactly the Imperial strong suit, and stealth is what Vader needed in order to lay the trap for Luke.


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

[User] [General] Why is that when a nefarious organisation creates a doomsday weapon or a computer chip that can break into anything, they often try to sell it to the highest bidder instead of just using it to make more money?

[Assistant]
Maybe they don't have the desire to do the legwork. They do R&D and don't really want to bother becoming the face of terrorism that holds the UN hostage for ten billion dollars. Its a whole different sector of the evil villain industry.

In the example of Ant-Man, Cross sold the weapon so he could continue selling the ammo for it. So its a better payout structure for someone who isn't actually focused on running the world.


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

[User]
Why does the color of fire change at different intensities of heat?

Layman here. It also could be cool if someone could maybe relate this to why stars burn at different colors depending on heat.

[Assistant]
Run of the mill everyday fire and the stuff going on in stars are completely different, so they don't have the same answer.

I can answer for fire.  What determines the color of a fire's flame is what chemicals are present in the hot gasses created during combustion.  So take a bunson burner for example, or your gas stove (same thing) these are burning natural gas.  If oxygen is in excess - meaning gas flow is low compared to air flow you will get a nice blue flame.  This flame is hotter than a yellow falme, but being hotter isn't really why the flame is blue and not yellow, it is because the excess of oxygen allows for very complete combustion which makes a hotter flame, also complete combustion gives one specific reaction chain for burning so you get one set of chemical products combusting which give off blue light when they are hot, excited and reacting.

Now if you lower the oxygen vs the gas you will get incomplete combustion and yellow flames.  What is happening here is there are more hydrocarbon compounds in the gasses exiting the reaction and those do not glow blue when they are hot, excited and reacting.  So same story for burning a piece of wood, you will have non complete combustion and so it kicks off a bunch of hydrocarbons from the burning reaction which glow yellow or orange or red, and you will also see a bunch of smoke and soot created.

This also happens with metals, in fireworks for instance.  When metals burn the chemicals produced by the combustion glow different colors because each chemical has electrons in different configurations and energy levels and when they are brnuing they jump around and react and a byproduct of those electrons moving is that they emit light.  Light is a different color for different moves.


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

[User] ELI5: Why does the letter "U" almost always follow the letter "Q"?

[Assistant] Its called a digraph. Qu makes the /kw/ sound in the English language. You can thank Latin origins and the Greeks for that. There are a lot of words that have Q without a U after it, but they are mostly in Semitic languages.  Qatar, burqa, qabab.


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

[User] ELI5: What's the purpose of screensavers?

[Assistant]
Back in the day of CRT displays if you left an image in place long enough it would burn into the phosphors on the front of the display.  So instead of turning it on/off (which also causes problems) when you walk away for 5 mins they would blank the screen.

Then someone got the idea of displaying something (probably to let people know it was still on) and then people used it as a venue for funny shit (e.g. After Dark).

LCD/LED displays don't really need screen savers other than to shut off the inverter (via DPMS).


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

[User] ELI5: What does the letter from 47 U.S. Senators to Iran mean, and why are some saying it's treason?

[Assistant]
The 47 Republican Senators sent a letter to Iran basically saying that any deal they make with Obama (with respect to Iran's nuclear program) will basically be ignored by congress and that those Senators will ensure any such agreement has no effect once Obama finishes his presidential term and leaves office.

Some people claim it's treason because the Senate has no right to interfere with diplomatic negotiations like that. Their job simply involves writing and passing legislation (i.e. laws). Their job does not involve making diplomatic negotiations on behalf of the President / government administration and it's definitely out of line for them to be interfering with diplomatic negotiations like this (especially when they are effectively trying to sabotage those negotiations and roadblock the President's attempts to reach an agreement).

It's a clear attempt to try and undermine the power of the government administration and the consequences (in terms of damage to diplomatic relations) could potentially be serious. In an international context, it frankly makes the US Senate (specifically the Republican Senators) look immature, ignorant, out of control, politically unstable and disrespectful to international law and foreign policy.


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

[User] [Harry Potter] Considering their potential as deadly weapons, why aren't wands heavily regulated?

[Assistant] They are regulated. Rubeus Hagrid had his wand snapped for a crime he wasn't even convicted of. What more do you want? For them not to give them to children? Then children won't be able to use them as well when they grow up.


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

[User]
[Star Wars] Why does the Emperor's face get all messed up?

Palpatine goes from looking like a fairly regular old man to a hideous wrinkled monstrosity after using force lightning on Mace Windu. Why?

[Assistant]
It's because the dark side of the force corrupts not only your soul, but your body. There is a reason why most Sith lords have pale skin or have massive scars.

Also, Palpatine never really got burned by it. He wore a force mask to hide his appearance. That was burned off, not his face like some are lead to believe. He just wanted evidence that the Jedi "assaulted" him.


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

[User]
How to stay up to date with analytical philosophy?

Basically I want to know new, important, discussions, papers, books exc in some areas of analytical philosophy. Should I follow journals? I guess they are not free.

[Assistant]
Philpapers is a great place for staying up to date because of how it is organized i.e. you can follow people, sort papers by posting date, etc.   That said, it can be a bit unwieldy.  Once pro tip, if you see a paper that looks interesting, click on the link, and its pay gated, if you politely email the author(s) they are usually happy to send you a copy.  Maybe a "penultimate draft" that is nonetheless effectively identical to the published version in case they are worried about sending you the published version.

If you're looking for something that is more curated, Philosophers' Imprint is a good, peer-reviewed, open access online journal of philosophy that publishes in a any/all of the main sub-fields.


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

[User]
[Final Fantasy, most RPGs] Why don't Phoenix Downs work on story-killed characters?

How come a major villain can kill off a character and everyone despairs their death, but then my next battle I could have a character get slaughtered and quickly revived with an item/magic?

Sure, the major villain could've stabbed them right in the heart and nothing much could help them. However, someone in my party could've been slapped into the ground by a huge boss 5x their size...it could easily be argued that items/magic wouldn't be helpful for a crumpled heap of a body either.

[Assistant]
(Note: **Final Fantasy V spoilers**)

It's a common misconception that Phoenix Down drags people back from the dead.

That's not its function- when applied in battle, it's primarily useful as a quick fix-up for battlefield injuries, and brings knocked-out individuals back to consciousness. It takes significantly less damage to knock the average Knight or Mage unconscious than to actually *kill* them- with the amount of punishment the average magically-reinforced adventuring party's bodies can take, straight-up death on the battlefield's much less likely an outcome than simply being taken out of the battle for a non-trivial period.

The limits of Phoenix Down have been well-demonstrated- in the event of an individual's being knocked down, thereby ceasing to be a threat, attackers tend to focus their attention on the more pressing threats on the battlefield- but when all of said threats have been neutralised, it's viewed as prudent to go back to the now-helpless unconscious opponents and slit their throats, to be sure that their injuries are fatal.

There *have* been recorded cases of souls with advanced magical abilities' using magical means to keep themselves conscious far beyond levels of trauma that would ordinarily knock them out- the most notable case being, of course, the famous stand of Galuf against Exdeath in the closing months of the War of the Crystals. In a genuinely desperate situation, the mage shrugged off an ever-increasing list of crippling injuries to fight off the tyrant, until, finally his body gave out. It's estimated that the total damage absorbed by his body by the battle's close reached upwards of 25,000 HP units- well beyond the fatal limit for any standard human. Past a certain level of damage like that, no amount of White Magic can bring a body back- and he expired shortly after.


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

[User]
ELI5: If when light ray travels from one medium to other, it's speed decreases/increases, why does the direction of the light ray change?

The question should be self-explanatory, But if any explanation needed, I'll do the needful.

[Assistant] The easiest way to visualise it is to think about a remote control car driving from concrete on to sand at an angle. The wheels that hit the sand first would slow immediately, causing the car to turn. This is essentially the same way it works with light, as the wave enters at an angle, one "side" of the wave will hit the new material first and will slow down or speed up before the other side does.


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

[User]
Eli5: why did dial up modems make so much noise?

Couldn't we just disconnect the speaker that's making so much noise?

[Assistant] We could, and we did once the connection had been established. You could disable the speaker for the dialling and connection process too, but hearing the noise could give you some information if the connection failed - did it fail to get a dial tone, did it get an engaged tone, did you input a wrong number and a human picked up?


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

[User] Why is chickenpox more dangerous for adults than for children?

[Assistant]
Simply put, the ability of cell-mediated immunity to resist intracellular pathogens decreases with age, so become more susceptible to new viral infection and reactivation of latent infections (like Varicella-Zoster virus AKA Chicken Pox/Shingles).

With age, thymic tissue is replaced with adipose tissue so ability to produce new, mature T cells in the thymus is eventually lost.
Therefore, a decreased ability of helper T cells to proliferate in response to antigens. So, antigen exposure produces fewer helper T cells, therefore less stimulation of B cells and effector T cells (so both antibody-mediated immunity and cell-mediated immunity response to antigens decrease)
Also, primary and secondary antibody responses decrease (decline is most evident after age 60).


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

[User]
CMV: Cars should have right of way unless at pedestrian crossings.

So many instance where driving around a carpark or something similar and pedestrians who walk right infront of cars without looking up ot pay attention to thiet surroundings. This forces the driver to slow down or stop complete halting way of traffic. Cars are 1000kg to 2000kg metal objects + they move faster than people. I think in situations unless at pedestrian crossing where pedestrians actually have right of way, people need to stop thinking they have more priority than cars cause cars can kill you. And its not my fault that you werent looking or paying attention i manage to hit you. It should be both parties looking and paying attention to hazards around you. We need to stop this culture of being too arrogant for your own safety.

[Assistant]
So there are two different things here - the cultural expectation of how different people behave in various situations, and the legal concept of 'right of way'.

In terms of cultural norms, yes, pedestrians should be more careful around cars, and more conscientious of not getting in the way of traffic.

In terms of the legal concept of 'right of way', it's very important that the person who is in a position to kill people has the legal responsibility to not kill people, rather than that the person who is in a position to get killed, has a legal responsibility to not get killed.

That is, we don't want everyone who runs down a pedestrian to be able to say 'I had right of way, so it was their fault' and get off scott free.  Partially because this leads to more people being killed, but also because, once you've killed someone with your car, they're not there to testify about whether or not they were *actually* violating right of way, or not.


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

[User]
[Alien] would the Xenomorphs even care about a synthetic?

The movies prove that theyre typically after human hosts so they can either kill them or use them as fodder to increase their numbers.

[Assistant]
There's examples of them both ignoring and attacking synthetics, though the latter was a Queen who had already demonstrated higher intelligence.

That said, all the xenomorphs may have that same higher intelligence, just different priorities. For example, even if the Queen somehow "gave the order" to cut the base power in *Aliens*, the Drones still carried that order out. It is likely that, since the primary purpose of Drones is to defend the hive and expand its breeding facilities, they simply see no reason to concern themselves with a synthetic unless they perceive it as threatening the hive.

The Queen, on the other hand, was seeking revenge when she attacked Bishop. Could Drones also seek revenge under the right circumstances? Hard to tell. The lone Drone in *Alien* decides not to attack Ripley in the shuttle at the end, and that seems to be because either it's too tired at the moment or it wants to preserve her as the only living host it knows about.


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

[User] ELI5: What happens when we feel shivers down our back?

[Assistant]
The arrector pili muscle of each hair contract, making the hair stand up.
It's a vestigial trait from when we were covered in thicker/coarser/longer hair, we would puff up (like cats do) when threatened to look bigger to potential dangers.


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

[User] ELI5: Why does a phone camera flash twice before actually taking the picture?

[Assistant]
> When you press the shutter release, aTTLflash will fire apre-flashbefore the actual shot, the camera will then measure thepre-flashwith the ambient light level to calculate the power needed in the actual flash for the shot.

Basically what you're seeing is a preflash. The camera uses that to measure how much power the actual flash requires.


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

[User]
ELI5: toddlers and their sleep to energy ratio

I just.. I just dont understand. How do toddlers/young children just wake up rudely and abruptly early, ready to run a triathlon whilst doing a speech and debate event. I feel like I need an IV of caffeine.

I can get the same amount of sleep and still be dragging ass. Is it just because as adults we are plagued with stress/responsibilities, etc?

[Assistant]
IIRC up until age three or so the human body is experiencing a phase of accelerating growth. Cells are proliferating at a rate they never will match again basically for a year or so, the lil wee bastards are Wolverine.

It takes a lot of energy to power that, and youre seeing it in all its manic glory. And dont forget they crash hard, too.


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

[User] [general fiction] What would happen if I stuck a werewolf on the moon? Would they also transform at the light of other moons?

[Assistant]
Some stories tell of werewolves having to see (or at least able to see) the full moon before transforming. If that is the case, then if the werewolf were on the moon, it would never be able to see the full face of the moon at once and therefore would never change.

On the other hand, if it's driven by moonlight, then we can assume it's a function of the intensity of light given off by the moon. With the intensity reaching its peak during a full moon. If this is the case, then being on the moon you would experience moonlight of intensity greater than that of a full moon from earth, and so you be a werewolf all the time.

I don't believe you can see other moons without a telescope, so we can rule that out.


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

[User]
ELI5: What biologically prevents interspecies breeding?

I remember learning in Biology that different species could not create offspring. That seems to be counteracted by mules with horses and donkeys. How does the reproductive system determine that there's another species involved and prevent insemination?
Ex: If that same horse from earlier got drunk at a barn party and went home with a cow, how does nature prevent them from making some weird hybrid horse-cow (a corse if you will) baby, and why didn't that same system prevent the mule from being born?

[Assistant]
Two different obstacles to interspecies breeding.

One is physical, where the sperm dies before it can reach the egg, due to different chemical environments in the uterues, or simply cannot reach the egg.

The other is genetic, where either each animal has a different number of chromosones, so the genetic information from the father can't find a suitable match with the information from the mother.


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

[User] [Marvel] Why doesn't Jean Grey just use her telepathic powers to take off magnetos helmet and have the professor get inside his mind?

[Assistant] Probably because the helmet is metal and Magneto would have a pretty easy time keeping it on/around his head with his powers. He probably does this unconsciously to keep it from just falling off during the course of a battle.


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

[User]
ELI5: how did we get to understand any extinct languages?

For instance hieroglyphs or other symbol based languages. How did we find out what those symbols mean, when weve got nothing to compare them to?

[Assistant]
We need something like the Rosetta Stone, a stone that had the same text written in ancient Egyptian, but also in two forms of ancient Greek as well. And since we could compare both forms of Greek and see that the stone had the same text for the two forms of Greek, it was then easy to assume that it also had the same text in Egyptian as well, and we were then able to begin translating by comparing the Egyptian to the Greek.

Without something like that though, we really can't decipher an extinct language with no modern speakers.


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

[User]
Do all planetary systems have orbital planes? If so, why?

My question is this: does every planetary system (even other than our solar system) have a single orbital plane? That is, for all other stars with orbiting planets, do the planets have orbits that all line up within a certain plane? For instance, our solar system has at least 8 planets that all essentially line up within a single plane.

My second part of the question: Why? (Even if other planetary systems don't follow this rule, why does ours?)

[Assistant]
It's because of the way the system was formed. Picture a spherically symmetric cloud of dust. Something sets the cloud spinning along an axis. Centrifugal force will push it out at the equator, this process feeds back upon itself and the cloud collapses into a disc. Various inhomogeneities cause the dust to collapse into planets/stars/etc., but they all start from the same spinning disk.

I believe the reason some orbits end up not in the plane is gravitational interaction with other systems.


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

[User] ELI5: In instances of large crowds at sporting events, how are all those individual voices amplified to near-deafening levels?

[Assistant] Constructive interference. When a group of people are all talking/yelling at once. The frequencies at which their voices overlap will be louder due to the sound waves interfering with each other, increasing the amplitude (volume) where the frequencies match, and decreasing the amplitude where they do not match. To a listener, without focusing on a specific voice, all they would hear is a noisy mess. This is exacerbated in a stadium because of the sheer number of people and the construction of the building caused a lot of reflection/reverberation.


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

[User] ELI5 how do people with hemmoroids not constantly get e.coli infections?

[Assistant]
Physician here. Hemorrhoids are veins that have becomes swollen In the rectum. Occasionally they may bleed which leaves an open communication between the blood stream and the colon but they don't often get infected. Why? Think of it as a small weak fish (bacteria) trying to swim upstream against a fast current.  It doesn't get anywhere right? That's the pressure behind the vein. Now imagine the same stream with a bunch predator fish swimming around eating the small fish.  This is the immune system in and around the rectum.  So we have a two protection systems against infection.

The most common reason hemorrhoids become infected is when the blood supply to the hemorrhoid ceases (strangulated or thrombosed). So now there is a dam, river comes to a standstill and the predator fish can't get in so the little fish (bacteria) can go wherever he likes including right into the now dead tissue of the hemorrhoid and wreak havoc.


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

[User]
Why doesn't lactose function like a prebiotic in lactose intolerant people?

Dietary fibers like inulin cannot be digested by the human body and feed gut bacteria instead and that's generally thought of as a good thing. Why doesn't lactose serve a similar function in those with lactose malabsorption?

[Assistant]
It does, thats the problem.

The presence or lack of certain lactose living bacteria is what determines whether your lactose intolerance is asymptomatic or not.

Its the bacteria that cause the discomfort for people who experience symptoms. They produce gas when they consume lactose and that cause pain and bloating and your body trying to expel things as quickly as possible.

For people who dont have those bacteria and are lactose intolerant the lactose just passes right on through.


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

[User] What would a cup full of viruses or bacteria look like?

[Assistant]
If your cup only had bacteria and no broth, most bacteria would look like slime with a yellowish tinge to it. Some are slightly more granular than others. There's a few types that would be a little red, pink, or a little green, others a stark white. There's a couple of types that would likely look crusty (like those in the Mycobacterium tuberculosis Complex), because of cord factor, they tend to look more chunky and waxy.

No idea what a cup of viruses would look like. That would be SO MANY viruses.


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

[User] Why is the sea level on one side of the Panama Canal higher than the other?

[Assistant]
It's not really - the difference is only a matter of centimeters and basically it's due to currents and weather conditions. There is no significant difference in sea level on each end.

You're thinking about the locks. The Panama Canal isn't just where the Atlantic and Pacific come together - the ships actually travel up to a lake and then back down to get back to the sea. The locks are used to get the ships up to the navigable waterway - they're not equalizing to different sea levels.


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

[User] ELI5: what is the noises our stomach makes?

[Assistant] The stomach is like a big bag, half full of liquid. It's job is to take whats put into it, mix it all up in it's acid pool, and send it down the line to the intestines. To do this mixing and sending, it uses muscles to squash and stretch itself, pushing food around. When you get hungry, the stomach might get excited and churn early, when you haven't given it any food, and the air being squeezed around makes that gurgle sound!


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

[User]
ELI5: Why does music provoke deep emotions in some people yet does nothing for others?

For example, I absolutely love music, I have playlists for every mood. Some music makes me just completely stop what I'm doing and listen, and music can change my mood in seconds. However, my friend doesn't enjoy listening to any genre of music. She doesn't mind it if its playing somewhere, but she is indifferent to listening to it, and despite listening to many songs me and my friends have recommended, she says she doesn't feel any emotions from it.

[Assistant]
The human brain is infinite in its variation. Some people respond most emotionally to their auditory senses (like music), some to their visual senses (like art), some to olfactory senses (smell), some to written language (reading), some to kinesthetics (body movement). And this is mediated through their life experiences which may push them closer or further to interest in one particular area.

Have you cried, or felt a chill, at a short story or painting ever? Why/why not? Have you ever become emotional because of a smell? Why/why not? Perhaps your friend has an emotional connection with another aspect of their senses that means nothing to you.


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

[User]
[WH40K] Was The Emperor's power armour special in any way, other than the fact that The Emperor was wearing it?

Did it have any special properties other than its colour? If you were to compare it to the latest model of power armour, how would it fare?

[Assistant]
It is either the best armor ever created or the worst armor ever.

The Emperor was a big tinkerer and loved to build and develop new technologies. It is very unlikely that he was wearing a mass produced armor and its was probably created by himself for himself. Considering we don't understand most of the technologies he created, it safe to assume his armor followed suit. It is probably still well beyond the highest tech the imperium has to offer.

On the flip side, it could have been completely ornamental and the Emperor's true armor was his psychic power and intelligence. This made any armor void and unnecessary. Granted he did get killed by a mortal blow from Horus, but this was due to him dropping his guard thinking he could save his fallen son.

Either way, he also loved not telling people about what he was doing with his work and things were on a need to know basis (Horus and that golden throne thing). So he probably wasn't too quick to tell people about what his rolling save was on his armor.