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

[User]
CMV: Libertarians are often times naive about how the world actually works.

I have a few friends who are Libertarian.  It often times annoys me because they all voted for Trump, not because they actually like Trump but simply because between him vs. a Democrat, they felt like Trump's America would be less intrusive to the "free market" they imagine exists and to individual liberties.

I think what Libertarians often times fail to grasp is that without sensible regulation and government intervention, the nature of wealth is to concentrate in the hands of a very small group of individuals.  They like to imagine this fair, egalitarian playing field where the opportunities and obstacles we all face are the same, and where outcomes are determined by individual merits.  Work ethos, intelligence, education, etc.  I think that point of view is hopelessly naive.  Previous generations of people have set up a society where (to use baseball metaphors) some people are born on third base, and other people are born at home plate, and some people are born in the parking lot, etc.  And the people born on third base have used their individual liberties to set things up in such a way that people who were born into less fortunate circumstances will always be fighting an uphill battle, not because of regulation or government interference in the market, but simply as a feature of market capitalism.

Also, the idea that "taxation is theft" is, to me, a horrid misunderstanding of what society is, what money is, and what taxes are.  If we're talking about 2,000 years ago where there were some people who had to be 100 percent self-reliant, I could get behind the idea that taxation is theft.  However in 2018 America, no one is anywhere near self-reliant.  There are schools and roads and police and a military and a host of other national institutions that constitute this society we live in, and none of our lives would be possible without those things.  Well, maybe one or two of us, but the exceptions prove the rule.  If we go to work for a company that pays us a salary, Libertarians imagine that they "earned" 100 percent of that money, when in fact they didn't.  That company could only exist in the first place because of the society built around it, and that employee can only access that company and the benefits from working for it because of the society built around it.  So to earn that money without paying anything back to the society in order to sustain it, is actually theft.  Taxes are not theft, but earning money and not paying taxes on it, is theft.  Your'e stealing from society if you don't sustain the society that enabled you to earn the money.

Further, the one area where I tend to agree with Libertarians is in the realm of social freedoms.  Ie marriage laws, freedom to smoke pot or use drugs, reproductive freedom, etc.  However, Libertarians either A: Vote Republican because they care more about economic freedom than they do about social freedom, or B: Vote for a Libertarian candidate, who if elected would have no choice in congress or the senate but to end up backing Republicans in most cases in order to get anything accomplished.  So by throwing their political support behind Republicans, Libertarians are actively contributing to a party who wants to erode social freedoms in favor of religious-themed regulation and intrusion into our social lives.

In short, I see Libertarian ideology as an ideology that may have made some sense at different points in history, but is fundamentally incompatible with life in 2018 in an industrialized nation.  And I see most Libertarians as confused and uninformed as to how modern life actually works.

[Assistant]
The first rule of libertarianism (and most other isms) is that whatever you think libertarianism is is wrong. The second rule of libertarianism (and most other isms) is that it's nearly impossible for more than 3 libertarians to agree on anything except a list of non-libertarian things they disagree with.

That being said can you provide an example of a large ideological grouping that doesn't have at least some portion of people who self identify as that group who are a bit naive about how the world works?


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

[User]
ELI5: Waking up from a coma - why could that person not wake up earlier and what happens to the brain during recovery and at the time of waking up?

EDIT: thank you for all the awesome answers. However, please note that I am still looking for an answer that includes what happens to the mind when you wake up.

[Assistant]
Drug-induced coma can be used to rest the body  or to sedate a person to the point that they can be mechanically ventilated efficiently.
People can be in coma as a side effect of brain trauma- in which case swelling can cause compression of the frontal lobe (partly responsible for assembling reality) and in bad swelling, the hypothalamus in the brainstem. The hypothalamus is responsible for your level of alertness and the brainstem as a whole isn't fond of being compressed. We can use drugs to reduce swelling in the brain but often mild swelling just needs time to go down and the person can have a varied level of consciousness while they recover.


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

[User]
[LOTR] Can orcs be happy?

Asking for a friend.

[Assistant] I guess they can be momentarily happy, in the manner of a miserable bully who gets a bit of a reprieve by picking on someone. But Tolkien's forces of evil cannot create, only twist and pervert. The orcs are fundamentally broken, wretched creatures.


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

[User] ELI5: Why does colored plastic turn white/lighter when you bend/stretch it and stay that way? What happens to the paint/coloring?

[Assistant] When you bend plastic, it forms teeny-tiny fractures throughout the bent area. These fractures scatter the light that passes through them, causing a surface to appear translucent or even opaque when bent.


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

[User]
[General] What's fusion like for fused characters?

Basically asking this for series where fusion is possible, such as Steven Universe and DBZ, what exactly does fusion feel like? Do the characters sort of blank out when the fusion occurs (Goku comments at some point he's himself again after unfusing and SU fusions seem to have independent personalities)? Is it like dreaming, you see yourself acting but can't control it? Maybe it's like some Power Rangers esque robot where two parties are controlling the fusion at one time? Basically, what's it like to fuse? And also, do the minds fuse, like, do fusions consider themselves "I" or "we"?

[Assistant] They create a whole greater than the sum of it's parts. While there is definitively two(or more) separate personalities in there, an additional "unified" one is created that more or less governs the new form.


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

[User] [Star Trek TNG] I'm a crewmember on board the enterprise, in my downtime would I be able to recreate the original 5 year voyage of Kirk's enterprise on the holodeck with myself in Kirk's place?

[Assistant]
I don't see why not. Historical re-enactment seems to be a pretty popular genre of holodeck program - Doctor Bashir and Chief O'Brien regularly participated in programs like the Battle of Britain and the Alamo, and Commander Riker and Counselor Troi also once participated in a simulation of the Enterprise NX-01.

The 1701-D's holodeck is also capable of rendering the Enterprise NCC-1701 (no bloody A, B, C, *or* D) for you, as it did for Montgomery Scott when he was discovered. You might need to do some work recreating the crew members, but the computer is capable of creating simulations of real people from records. Geordi once did it with warp physicist Dr. Leah Brahms, and Data has played poker with simulations of Albert Einstein, Stephen Hawking, and Sir Isaac Newton.


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

[User] [Spider-Man] What if Spider-Man really did whatever a spider can?

[Assistant]
Well, he'd be able to molt, and he could inject venom into enemies to dissolve and drain their internal organs. Plus, he'd probably be covered in stiff, irritating hairs that made him difficult to grab or bite. And he'd have palps on his face that would help groom himself and manipulate food or silk. Real spiders depend heavily on vibration to understand what's around them, so he'd probably have certain touch-based enhanced senses in addition to his danger sense.

Basically, just imagine if Stephen King wrote a Spider-Man MAX book.

**100% ARACHNOLOGICALLY ACCURATE**


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

[User]
[Star Wars] Why are all stormtroopers humans, or races close to humans?

I know that we dont see stormtroopers faces other than Finn so we have no guarantee of this, but given their height and build its a pretty good guess. It seems like theres a lot of other species that would be excellent candidates for warriors.

Im sure some of them wouldnt join the empire because of what the empire has done to their planet and people, but there would have to be some outlying people who just want to go kill things.

Can you imagine going up against a squad of armored Wookie stormtroopers?

Fuck that...

[Assistant] The Empire had a very strong bias against non-human intelligent species. It would take an individual of a different species with exceptional competence and loyalty to the Empire (see Grand Admiral Thrawn) for the Empire to even consider allowing them to join the military.


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

[User] ELI5: why do you groan when you carry out physically challenging tasks?

[Assistant]
when you flex your muscles intently for a task, you may indeed squeeze the air out of yourself while your throat is configured in a neutral state that would construct a glottal stop when given breath.

and so, you wince "hnng" as this is the sound of an aspirated glottal stop.


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

[User] [Halo] Hello, my name is Ung'phie the Grunt. I am currently sitting as the last survivor in a massive battle field. I hid fir very long time and when the last Spartan killed my Elite master, I shot and killed the Demon! What kind of Awards awate me when I return to High Charity?

[Assistant] Immediate promotion to a prominent posting on an out of the way habitat for grunts.  You'll be given praise and assured a position of honor among your peers and possibly a position within the special forces.  In actuality you'll be a king of the littlest hill in the covenant until you die in battle alongside an elite commando that may give you some modicum of respect.  Most covenant will assume the elite struck the fatal blow on the demon and you merely survived to tell the tale of his heroism but among your own kind you'll be seen as a hero.


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

[User]
CMV: In table tennis a net - or edge ball should count as a let

__Background:__ A "let" in table tennis is when the point s re-played which can be caused by any number of things such as obstruction by external factors, the ball breaking or a net ball (the ball making contact with the net) during a serve.

Currently when the ball makes contact with the net outside of a serve or touches the edge of the table it is not a let but the point just goes on. Net - and edge balls (when the ball hits the edge of the table) tend to alter the trajectory of a ball in unpredictable ways making them extremely hard to return. This is such a narrow thing that even on the pro level no player actually consciously _aims_ for a net - or edge ball and it's generally perceived as being lucky when one hits one and it puts the opponent in a significant disadvantage. Even _if_ the opponent manages to correctly return the ball it will be generally returned in a very sub-optimal way which heavily swings the rally in favour of the other player. Players typically get frustrated and annoyed being at the receiving end of a net - or edge bal and players that win a point via a net = or edge ball tend to feel that they did not deserve the point that almost always follows from it. In table tennis etiquette it is even customary to apologize to one's opponent for such a ball as people generally agree that it is not a deserving point but merely being lucky.

Not replaying a net - or edge ball simply takes the enjoyment out of the game for both players and spectators.

[Assistant] I disagree at least with the case of edge balls, because they are very hard to discern at the speed balls are moving.  It's a lot easier with regard to the rules to say "if you hit the table on the opponent's side, it's good".


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

[User]
[General sci-fi] Why does shooting the door control panel always do exactly what you want it to do?

Sometimes when the door is closed and you shoot the panel, it opens.  Sometimes when it's open and you shoot it, it closes.  Sometimes when you shoot the panel and the door is closed, it stays sealed closed.  The only difference is what the person shooting the panel wants the door to do.  Why does shooting the control panel always work?

[Assistant] This theory doesn't work on spaceships because you would want them to be air-tight in case of a hole somewhere. But what if the default setting was door open in case of a power failure. You would want people to be able to get out of a building. So shoot the lock, power is disconnected and the door opens.


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

[User]
ELI5: Why is it bad to let your car get below 1/4 tank of gas?

I've always been told it's bad to let your car get lower than a 1/4 of a tank or be on E with the gas warning light on. Is this them being paranoid or are there actual detriments to your car?

[Assistant]
This is one of those things where there are no absolutes.

There are obvious risks to running out of gas when driving with a tank that's nearly empty, namely running out of fuel or having insufficient fuel to make it to the nearest gas station.

The bottom of the tank, especially in older cars may have sludge, dirt that fell in to the tank, flakes of rust, or water that may have condensed in the tank. Additionally in many modern cars, the tank is usually shaped to conform to some void in the vehicle's frame. Depending on where the fuel pick up is, and where the gas gauge is, it might not register the same levels.

So refill the tank when you feel the risk of running out of fuel justifies a stop at a gas station.


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

[User] [Star Trek VI] Lt. Valeris could not bear to take the life of her mentor, Spock. Knowing she was the only link to the conspiracy and future of the Federation depended on her silence, why did she not kill herself rather than risk interrogation or torture? To not do so seems highly illogical.

[Assistant] Because she presumed that she could hold out against whatever interrogation techniques Federation officers would use long enough for the assassination to happen and the conspiracy to get her out of Kirk's custody. She's not in Klingon or Romulan custody, after all; she's not expecting knives and pain chambers, she's expecting being stuck in a room while Kirk and Spock play emotional cop/logical cop until the deal goes down, which was quite imminent. She wasn't counting on Spock grabbing her by the head and mind-melding the answer out of her as move one.


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

[User]
[Warhammer 40k] Do I as a Space Marine of the Dark Angels chapter get free time and if so are there limits to what I can do?

For example could I socialise with humans outside of my chapter if we were stationed on a planet, could I drink or practice hobbies?

[Assistant]
In the Dark Angels it would be unlikely, the Astartes are characterized as "warrior-monks" with the Dark Angels in particular embodying that "monk" part.

It's telling that when Interrogator-Chaplain Asmodai punished the Dark Angel's 7th Company with a year long penance of silence that the punishment wasn't challenged or overruled. The 7th Company's crime? Laughing.

> "...upon hearing the frivolity of laughter in the halls of The Rock, [Interrogator-Chaplain Asmodai] placed the Penance of Silence upon the 7th Company for a standard Terran year."


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

[User]
CMV: I'm terrified of dying because I will stop existing

I'm not scared of my method of death or pain or discomfort (I would rather burn in hell for all of eternity and maintain consciousness than have my consciousness end), rather, right now, while I still AM conscious, I'm terrified of it ending.
It's not the potential discomfort that I might feel, as discomfort has oddly never been a problem for me (so please don't use the regular "You won't know you're dead when you're dead" excuse), but rather the knowledge that I will die, that I won't exist anymore.
Please try to CMV on this fear!

[Assistant] Not to make anyone afraid of dying also afraid to go to sleep but when you sleep, you lose consciousness, and when you wake up you are a slightly different person. In a sense the person who went to sleep died and never woke up.


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

[User] How are nerve agents such as Novichok so lethal? How does such a small amount of vapour spread in the body?

[Assistant]
Some molecules, like some gases, have fairly unrestricted diffusion through the body.

Toxins often have fairly tight binding to their targets, and what looks like a small amount is actually a considerable excess of molecules compared to the number of their targets in specific organs.


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

[User]
2 x Tesla: 1) How feasible and safe are Tesla's ideas for wireless electricity? 2) How much truth is into that particle beam weapon?

I already knew a lot of stuff about Tesla but I just watched a documentary about him and I got interested in his work again. Halfway through the "documentary" I saw that it was mostly conspiracy stuff about HAARP and particle beam satellites, concealed as part of Tesla's mysterious life story.

Now seriously, regarding wireless electricity transfer... How feasible would it be for use at home or office? To keep your phone and laptop charged without plugging it in anything for example... Or having a wireless mouse that does not require batteries.

And about the weapons developed by Tesla, how much truth is in the stories about these things? I understood only that his idea of giving free electricity to everybody by tapping into the ionosphere was then used as an idea for just developing powerful weapons. I think these conspiracy guys are using the fact that Tesla was both a genius and a mysterious man, as a way of manipulating people into thinking crap like the secret weapons: HAARP and particle beam satellites...

**Later Edit**: Thank you very much for the responses. It seems to me that Tesla's ideas are great and even if they could be applied, they're not better and they are certainly not more efficient than the current ones. I guess that Tesla wanted to give free energy to everybody by spending a huge amount of others' money. Also, it might be that some ideas were more feasible in the past, when the energy demand wasn't as large as now and you didn't have dozens of electronics and appliances around the house to power constantly...

[Assistant]
The example of wireless charging is already in use. Over very short distances for very small loads, it's a convenience. Anything farther than that and it becomes a power sucking parlor trick. (not a problem when you're Tesla and have your own generators.)

As for particle beams, it suffers from the same basic problem. When using radiation as a weapon, increasing the distance to target increases the energy needed exponentially. It's probably possible (to some degree), but not efficient or useful. Remember that plane that fires a laser? It took 10 seconds of tracking a standstill car just to set its engine on fire. The plane could only fire it once per flight.


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

[User] What actually happens when you get the wind knocked out of you?

[Assistant] funnily enough they taught something different to the other comments in med school this year. when you breathe it's a balance of plural cavity pressures plus the effect of the lung called the elastic recoil resisting the expansion of the langs. this recoil is due to the surface tension of water in the alveoli and is greatest at the smaller volumes of the alveoli because the water is closer together. also there's a volume of air in the lungs called the residual volume that cannot be exhaled which really aids in maintaining the elastic recoil not being too high. when you're winded it can pushes out the residual volume so you need to overcome the higher than normal contracting force of the surface tension to inhale and that's why it's harder to breathe. or that's what was taught to me anyways.


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

[User]
ELI5: Why hasn't anyone else been to the moon? It seems like something that super rich people would do for fun, like James Cameron going to the Mariana Trench.

[title]

edit: I appreciate all the responses, and while you all explained like I'm five, you weren't rude and that's appreciated

The general consensus is that it would be a stellar (lol) waste of time and money, only to do something we've done before.

[Assistant] If' Elon Musk has taught you nothing else, it's that getting to space is really, really hard and expensive. Getting a submersible that can withstand the depths of the ocean is small potatoes in comparison. Least of all that you're not sittin on top of a giant bomb that can go off if something goes wrong. The worst that can happen is that you spring a leak and are crushed like cotton candy in a fat kids fingers.


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

[User] [General] Is there an alternative to time travel that accomplishes the same goals that time travel does?

[Assistant]
Dimension Hopping

Some attempts to change history / set things right only end up creating an alternate timeline, not changing the origin time line.  This prevents paradoxes, but really does not change the situation for the traveler.

Dimension hopping will allow many people to observe a historic event without altering history by having thousands of onlookers, just making thousands of timelines that may converge back together soon after.

Dimension hopping also handles traveling into the future, since its traveling into alternate possible futures.  Someone returning to the present with future knowledge only would know what might happen, not what will.  This allows the traveler to take action, instead of being locked in.


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

[User]
CMV Statues of confederate heroes should not be "taken down" but relocated to museums detailing the tragedy of the Civil War, where people would have to chose to see them

They should not be on general public display along with those who have made significant contributions to the history of the United States of America.  By being in the general public eye this implies our elected representatives support the view that these "heroes" and their ideals, did something to make America great.  These "heroes" did nothing to make America great, rather they put their considerable talents into an attempt to tear America apart.

I also think that even these confederates, whom these statues are images of, would be appalled at the ideals of white supremacists who have adopted them as their icons; projecting their hate based ideals on them.  Confederates did not hate Jews, they did not attempt to create a society ruled by a few with absolute power,  storm trooper, jackboot fascist. They elected a president of their own, but they still attempted to tear the United States of America apart, they failed, Hitler and the Nazi party failed, and that is the "real story."

[Assistant]
So, this is a great idea. Except that most confederate statues arent what you think they are. If they were historical artifacts, that represented the civil war, this would be the obvious best choice. But they aren't.

These statues arent "history". They don't represent reality like a photograph would. Not are they artistic representations of how people felt. They were actually created fairly recently as an attempt to reinvent history.

Lee statue is from about 1924 and was created to celebrate Jim Crow. Other statues being removed are from the 70s in an attempt to react to the civil rights era. These are recent narratives dedicated to white superiority.

The real historical artifacts and statues *are* safe. They are in the national archives or in the Smithsonian. Ready for anyone to view incontext.


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

[User]
[Halo] What exactly happened to Pvt. Jenkins in Halo: The Flood?

In the book it only mentions that an ancient flood took him over and it partially failed, but did they ever expand upon his unique situation in later entries? Barring Sgt. Johnson's immunity, were there ever other known occurances similar to Pvt. Jenkin's possession?

[Assistant] Nope, there's no more lore about Jenkins's time as a partial-infected. The other similar case would be Captain Keyes, who was infected immediately in the same room as Jenkins and Johnson but the infection form chose to torture him for information and then transform him into a proto-Gravemind instead of just transforming him into a combat form.


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

[User]
Why were Apollo astronauts weightless on the way to the moon? If they weren't orbiting shouldn't gravity have still affected them?

I get the basic physics of microgravity in orbit but no one has ever explained to me why you don't feel gravity's pull as you travel AWAY from the Earth.  Shouldn't the astronauts feel a pull like they did when they launched off the surface? Please help me get my head around this.

[Assistant] You will feel weightless whenever you're travelling in an inertial path - that is, free of any external forces. An orbit is one such example, but there are many other trajectories that are also inertial paths. For example, if you were to free-fall in vacuum and plummet towards Earth, you're experiencing the "pull" of Earth, yet you'll be weightless.


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

[User] ELI5: How did people in the middle ages not die due to dehydration from drinking alcohol, given that drinking water generally wasn't safe?

[Assistant]
People were not subsisting on hard alcohol back then. They were drinking rather dilute beverages. Ciders and beers have very low alcohol content and they do not dehydrate you when you drink them. In wine growing regions like the Mediterranean, the wine was diluted with water.

Plus, when you consume alcohol all day, every day, your body grows accustomed to breaking it down; the liver produce more of the enzymes needed to metabolize it snd the kidneys adjust to keep the body in tonic equilibrium.


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

[User] Assuming all life on Earth descended from a common ancestor that existed almost 4 billion years ago, what generation are we, approximately?

[Assistant]
There is probably no sensible answer to the question, because the very earliest life may not have had discrete generations - it may have just been chains of molecules that broke off and replicated that way, with no clear cutoff between that and discrete generations. In fact there probably isn't going to be a clear cut-off between "living" and "non-living".

A better question might be starting from the first single-celled life. Seeing as the first single-celled life may have replicated very quickly, the answer is going to be a very big number.


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

[User]
[MCU] so someone unworthy can still move Mjolnir by pushing or punching it rather than by grabbing it as long as they are strong enough right?

Thanos punched it away. His intention wasnt to wield it but get it away. So...

[Assistant] If you're talking about when he seemed to punch it out of Cap's hands, then most likely he either punched Cap's chest or hand/arm so hard the hammer flew out. The hammer is still subject to the movement of the weilder.


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

[User]
Why is it that when I touch the end of an aux cord with the other end plugged into a speaker a loud buzzing occurs?

I have a Logitech S-00067 and when I touch the aux cord I keep plugged into it a loud buzzing occurs. This happens even if I step on it with sock on. If anyone needs to hear the sound I can add a link to the sound the speaker makes.

~TT

EDIT: Thanks guys for the help!

[Assistant]
Your body acts as a circuit that picks up RF signals from your mains. The signals get transmitted to your speakers and amplified to cause the hum.

Edit: You can test this by listening to a clip of a 50/60 Hz test tone and comparing it to the noise.


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

[User]
[DC Comics] How does Batman and Green Arrow protect their entire cities?

They've got allies sure, and they've got the police on their side also but these guys can't fly. They can't move faster than normal, short of a vehicle. So how do they way up what's important and where they should devote their time?

Gotham at least has shown to have several islands, so does Batman just protect each island on a rotating roster, stopping any crime he sees or hears on a police scanner?

[Assistant]
They don't. While Batman is stopping maybe Bane or the Riddler on one side of Gotham, 13 people just got mugged in a straight line leading up to the Killer Croc.

He does a great job relatively, but he is ultimately a human and can only cover but so much area.

This was actually a plot point one a Batman/Superman comic where Bats ended up with Supes' powers. **SPOILER** He hovered above the planet, and marveled on how he could now stop all crime. **END SPOILER**


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

[User]
Why is blue the last color to fade in sunlight?

I often see posters in shop windows that have been faded by the sunlight that hits them every day. Blue always seems to be the last color to fade  out, so you're left with this strange blue/white picture.

Why is this? Is it something about a common blue dye that is used in printing? Is sunlight weaker in that part of the spectrum?

[Assistant] Because the blue coloring agents *reflect* the higher-energy light from the blue end of the spectrum rather than absorb it, and so they avoid being broken down into colorless molecules longer than the others.


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

[User] ELI5: How do we keep air in space stations breathable?

[Assistant]
It's mostly made from water.

Water as H2O can be split and create 2H2 + O2. That hydrogen is then actually combined with waste CO2 from breathing, creating CH4 (methane) and H2O (more water, fed back into the system).

There's loss everywhere in the process no matter how efficient the reclamation systems are. We send constant supplies of water up to the station.

Similar systems already existed on submarines. Of course, they could provide their own water.


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

[User] ELI5: Why should a car engine be left to idle for a few moments after starting?

[Assistant]
For the most part you don't need to, in reality on a modern engine the oil pump is pumping the oil where it needs to be within a couple of seconds, and the oils required by the engine are selected such that they work properly in your engine when cold (that's why there are two numbers in your engine oil spec, 5W-30 means it's a 5 when cold and 30 when warm, so the engine designer would design it to run ok at 5.

You shouldn't run your engine hard when cold because things are not the optimal size and it doesn't lubricate optimally. But idling your car for a minute isn't going to get the oil meaningfully warm, you really need like 5-10minutes of actual driving to get there. But if you're planning on racing, yes, you could drive a few miles before you actually start racing.


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

[User]
[Star Wars] Can someone who is not "Powerful in the Force" still potentially use the Force if trained enough?

So, most Jedis we hear about or read about or play as, are the "Exceptionally strong in the force" types. Is it possible for anyone to use the Force though, given enough training? The Force surrounds all living things right, surely that means anyone could tap into it, just that some people have easier access to it and are naturally savants with it?

[Assistant]
This is something that's changed over the years.

It used to be something akin to athletics. Some people are just natural born athletes, whatever little mutations involved make them better than the average folks for athletics. This doesn't stop average folks from working out or exercising, but they'll never be setting records.

Now, Force sensitivity is a thing that's rare and inherent, and if you don't have it, you won't be able to use the Force. You might potentially be able to feel something, but you won't be able to pick things up and move them with the Force, basically.


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

[User]
"How will you help the university reach its goal of 50% female faculty in six years?"

I'm interviewing for a job in a couple weeks and I this will be one of their questions. In order to reach their goal, they would basically have to hire only women during this window, which means I stand no chance if that's their decisive criterion, but I'm curious how men and other non-female identifying people would answer a question like this.

I usually do just fine responding to diversity questions because I can speak about my experience as an immigrant and other relevant areas. In the last offer I received, they said my diversity statement was the best they've ever read, but I'm really at a loss about how to tackle such a targeted kind of diversity.

[Assistant]
I would think one thing you could talk about is how you support the goal of hiring more female faculty and how you would take action in that direction if you were in a faculty role. You could also come prepared with stats about the ratio of women to men in your field and why there is a need to support women.

There is also the problem of retention of female faculty for various reasons, mostly related to unpaid and unrecognized labor and the challenges balancing work and family. So you could talk about how you would help cultivate a workplace climate that is supportive of women in terms of retention and promotion, not just hiring.


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

[User]
If a supermassive black hole (for example Sagittarius A*) consumes one hydrogen atom, how much this would increase black holes event horizon circumference?

Would this make black holes event horizon circumference increase at least one Planck length in size?

[Assistant]
This is a fun one, because normally there isn't a single answer for this question. For planet or a star, it depends on the radius and the density, both of which change as you add more mass.

However for a (simple non-rotating) black hole, the event horizon radius is just directly proportional to its mass. That means that each time you add a single hydrogen atom, it really does increase its radius by the same amount.

The Schwarzschild radius is 2GM/c^(2), where M is the mass of the black hole, G is the universal gravitational constant, and c is the speed of light. So if you add some small mass *m*, you increase the radius by 2Gm/c^(2). If we set m=1 amu, about the mass of a hydrogen atom, we get an increase in radius of about 10^-(54) metres, which is almost 10^19 times smaller than the Planck length.


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

[User]
ELI5: How much time has to pass before discovering and studying an old civilization/settlement/etc is considered Archaeology?

For example, studying Egyptian pyramids and ruins is Archaeology, but studying a mid 20th century warzone is not. At what point can we consider the study of an event, Archaeology?

[Assistant] Archaeology is the study of history through artifacts.  If people don't actually remember what happened there, requiring other ways of studying it, then I'd say we have archaeology.  Paleo-archaeology would be the study of ancient (whatever that means) history.


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

[User] ELI5: Why do we instinctively rub an area that gets hurt?

[Assistant] From the standpoint of the nervous system: distraction. Rubbing the area around an injury stimulates sensory neurons and creates a sort of "background noise." You'll still feel the pain from the injury, but it's sort of muffled.


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

[User]
[Avatar: The Last Airbender] What was the point of aangs journey

The avatar state gives the avatar the skills and knowledge of every previous avatar, so what was the point of aang learning the other 3 elements in such a short time? Did his 1 year of training and and becoming proficient with the other 3 elements really turn the tide of his battle with Ozai where the other 1000s of years of experience didnt it or would have it been easier to just go after the fire lord the moment he woke up and beat him before Sozins comet?

[Assistant]
Aang wasn't in the Avatar state for most of that fight. Without the experience and training he'd had over the course of the year, Ozai would have taken him out before he could even enter the Avatar state.

It's also possible that if he had not been a fully-realized Avatar he would not have succeeded in energybending Ozai's chakras.


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

[User] ELI5 How video editing softwares change the FPS from ~29.87 FPS to 30 FPS. Where do the extra frames come from?

[Assistant] There are no extra frames. Imagine a video has 1000 frames. At 10fps, it'd be 100 seconds long; at 30fps it'd be 33.3 seconds long; at 29.87fps it'd be 33.48s long. The difference between 10fps and 30fps is very noticeable, but the 0.18s difference between 29.87 and 30 isn't noticeable.


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

[User]
[Multiverse] What other fictional properties' canonical multiverses, outside of DC and Marvel's, also establishes specific designations for each of their universes (whether it's numbered or whatever)?

What I mean is, when a fictional TV show, movie, comics, games, books, etc. etc. (whether it's sci-fi, or fantasy) establishes more then one universes, then that's when a multiverse is established, right? And for each universes that are totally different from one another, they require specific designations (say universe 1, universe 2, universe 3, etc.) so that we the viewers, AND our heroes (or villains) will know exactly which this universe is which when talking about where this character is from, or where that device is from, etc.

The most famous example are DC and Marvel with their multiverse designating each of their realities by earth numbers, like DC's Earth-1 or Prime-Earth, and Marvel's Earth-616. Here's a list of few examples I got:

**DC**

* Earth-1 (Pre-Crisis) = Home of the Justice League of America (^(E-1 Superman, E-1 Batman, E-1 Wonder Woman, Flash Barry Allen), Green Lantern (Hal Jordon), Martian Manhunter, etc.))
* Earth-2 (Pre-Crisis) = Home of the Justice Society of America (^(E-2 Superman, E-2 Batman, E-2 Wonder Woman, Flash (Jay Garrick), Dr. Fate, Specter, Green Lantern (Alan Scott), Green Arrow, etc.))
* New-Earth = Home of the Justice League of the Silver Age, and the Justice Society of the Golden Age, Post Crisis
* Earth-12 = DC Beyond (which is NOT the DC Animated Universe, BTW)
* Earth-19 = Gotham by Gaslight
* Earth-22 = Kingdom Come
* Earth-30 = Superman: Red Son
* Earth-31 = The Dark Knight Returns (and all of it's sequels, and ASBAR)
* Earth-C/Earth-26 = Captain Carrot and His Amazing Zoo Crew!
* etc.

**Marvel**

* Earth-616 = Marvel Universe
* Earth-1610 = Ultimate Universe
* Earth-199999 = Marvel Cinematic Universe
* Earth-8096 = Wolverine and the X-Men/The Avengers: Earth's Mightiest Heroes
* Earth-51778 = Japanese Spider-Man (1977)
* Earth-13122 = LEGO Marvel Super Heroes
* Earth-26496 = The Spectacular Spider-Man
* Earth-30847 = Marvel vs. Capcom
* etc.

But with other fictional properties with an established multiverses outside of DC and Marvel, they also tend to designate their realities specifically, but they do it more differently (sometimes even more complex then just "Earth-1" or whatever). Take for instance...

**Rick and Morty**

* Dimension C-137 = Former home of our Rick and Morty before it got "Cronenberged"
* Dimension J19 Zeta 7 = Home of "Doofus Rick"
* Dimension 35-C  = Where the Mega Seeds originated
* Dimension 46'\\ = The Universe of Gravity Falls (believe it or not!)
* etc.

**Ghostbusters**

* Prime Dimension = Ghostbusters (IDW canon)
* Dimension 68-R = The Real Ghostbusters
* Dimension 68-E = Extreme Ghostbusters
* Dimension 68-Q = Slimer!
* Dimension 11-W = Ghostbusters: The Video Game (Stylized Version)
* Dimension 80-C = Ghostbusters (2016) (^(A.K.A. Ghostbusters: Answer the Call))
* etc.

Hell, even...

**Transformers** (and brace yourselves for these ones!)

* Primax 984.17 Alpha = The Transformers (1984 - 1987) (^(including The Transformers: The Movie, G.I. Joe: A Real American Hero, Jem, Inhumanoids, and COPS))
* Primax 496.22 Alpha = Beast Wars/Beast Machines
* Primax 984.0 Gamma = The Marvel US Transformers comics (^(including the G.I. Joe comics, the Generation 2 comics, and Simon Furman's fanfiction, Alignment \[which IS canon, BTW\]))
* Primax 1005.119 Gamma = The 2005-2018 IDW Continuity (A.K.A. Hasbro Universe)
* Viron 901.8 Alpha = Transformers: Robots in Disguise (2001)
* Aurex 802.23 Alpha = The Transformers Armada, Energon, and Cybertron cartoons
* Tyran 707.04 Delta = the live-action Transformers movies (^(Transformers, Revenge of the Fallen, Dark of the Moon, Age of Extinction, and The Last Knight))
* Malgus 1207.27 Alpha = Transformers Animated
* Uniend 911.05 Alpha = Transformers Prime, Rescue Bots, and Robots in Disguise (2015)
* G1 World (Primax 785.06 Alpha/OG World) = Fight! Super Robot Lifeform Transformers
* Nexus 208.0 Epsilon = Axiom Nexus (TransTechs)
* etc. (Sorry if Transformers multiverse's one was convoluted as hell, it's gonna take a lot to get use to, I guess. Also, why doesn't Reddit.com have an Underline feature? That would've been easy).

But yeah, you get the idea. These are the popular fictional franchises with multiverses that specifically designates each of their realities (both for viewers, and in-universe). But now **THIS** is where I ask for OTHER franchises, purely out of curiosity (and fascination, I guess): What about the the Teenage Mutant Ninja Turtles multiverse? What about He-Man's multiverse (as first established within DC comics in recent years, I dunno which issue)? Scooby-Doo's multiverse (first established in Scooby-Doo! Team-Up #100 - Crisis of Infinite Scooby's)? Star Trek? Doctor Who? Archie Comics? Gundam? Dragon Ball? Digimon? Ben 10? Power Rangers? ANY fictional properties with a canonical multiverse? Any ones besides them, even?

If the one's I'm asking for **do** have specific designated realities in each of these multiverses (IF they have an actual multiverse established in canon, rather then theorized by fans, mind you), like numbered or whatever, what're these universes called in canon, exactly? Please let me know.

Thank you in advance. :)

[Assistant] The Long Earth series of books. Uninhabited parallel worlds are discovered, you can go through them like moving through a stack of pages in a book. You move to the same location you're already in but 1 universe along the stack. Starting from our universe these are labelled "East 1, East 2, ..." as you continue going in one direction, and "West 1, West 2, ..." in the other direction.


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

[User]
ELI5: What is Californi suffering from huge wildfirs every single year?

There are many methods to wildfir prevention such as controlled forest burnings. Why are wildfirs still happening and seem to be getting worse every single year?

[Assistant]
Several reasons. First, California is a chaparral ecology, meaning that it has dry shrubs, thickets, and trees that go through natural cycles of infrequent fires and regrowth -- some of the vegetation there has evolved to require those periodic fires.

Second, the climate in California is changing. Drier conditions and higher winds are effectively making the conditions more favorable for fires, and they are becoming both more frequent, and more severe / fast spreading.

California is undergoing a process called "desertification" - the conditions a re favoring a decline in the chaparral and replacing it with desert.


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

[User]
ELI5: how do sodas travel the country all carbonated but as soon as you get one alone and it shakes up, its flat?!

Im confused and have been thinking of this for a while. They get shaken and dropped all across the country on their wooden pallets and in trucks and crates and are just fine. But as soon as you get one, of you shake it it gets flat! Is this like how when bicyclists ride bikes in close proximity, they use less energy or something? So maybe because all the sodas are all close together they absorb all the movement or something?!

IDK! Lol just throwing it out there!

[Assistant]
I would like to add that soda in its final form rarely if ever makes a cross-country trip. What happens with the big companies is they stir up the beverage base at their own place (this is JUST the flavorings and stuff), then ship *that* to the various regional bottling factories who then mix it with carbonated water, and then ship the final product out.

This is why when you see Coke and Pepsi delivery trucks, they're *always* driving a "day cab" semi, which doesn't have the sleeper area in the back. Don't need the sleeper area if you clock in make your rounds and clock out and go home each day.


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

[User]
I believe that further extension of human longevity through the advancement of medicine is detrimental to the human race. CMV.

Dan Brown's novel, Inferno, proposed an interesting idea.
It's simple math: the global population is expanding at an exponential rate. Exponential growth in a system of finite resources (the Earth) is unsustainable.

 More people living longer puts huge stress on the environment (let's be honest, we're already not doing a great job with that - google "cancer-causing lake in china")and drains basic necessities such as clean water and food. Increasing human longevity makes the extinction of our own species more and more imminent.

Edit: for clarification: people living for 90, 100 years thanks to medicine take up way more resources over their long lives than people who die younger. Since this exacerbates our already grim exponential growth situation, it is not desirable.

[Assistant] That's assuming people continue to reproduce at the same rate as their longevity increases. Current statistics do not support this, in fact countries with higher average lifespans have lower birthrates than those with lower lifespans, if the two are directly correlated then the problem will correct itself.


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

[User]
[The Lego Movie] The man upstairs calls Emmet "a generic construction worker."

If he is generic, then why does he have an exclusive hairpiece and a nametag on his legs with his name on it? Do all the construction workers have the same nametag, giving all of them the name Emmet? Or do they all have different names, making them not generic? Also, where did Finn's father/Finn get all of the hairpieces and parts that are exclusive to the characters in the movie? For example, President Business's hair, helmet and armor, which have never appeared on any other minifigure?

[Assistant]
Its possible the names for the name tags are picked from a small pool, making them both distinct and "generic"

Lord Business' armor/helmet were constructed out of other pre-existing pieces by the kid.

Other exclusive parts were probably 3d printed or otherwise custom ordered.


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

[User]
ELI5: Why does the body keep demanding I take deep breaths after hard running?

Just had to bolt for the train and was wondering why after I had finished running my body wanted me to keep breathing at that rate instead of immediately calming down to normal breathing.

[Assistant]
Your body is reoxygenating your blood. Imagine your blood is like a battery, when you run, you drain from that battery really quickly. After a while, it runs out (you feel 'puffed') and you consume oxygen as you breathe it. When you stop running, you replenish your battery (reoxygenate all your blood). When it's full, you feel normal again.

Edit: Note about carbon dioxide: When you 'drain your battery' you are left with the nasty byproduct of carbon dioxide. That is the nature of aerobic respiration to produce CO2 as a byproduct. However this does not change the fact that your lungs (the 'charger') have limited capacity for gas exchange, which causes the effect OP observed.


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

[User] eli5: How do we experience Temperature?

[Assistant]
For the most part, you don't really feel temperature, your senses feel the flow of heat.

If you touch something cold, you feel the heat leaving your hands, if you touch something hot you feel the heat enter your hands

This sounds similar, but explains some of the quirks and flaws in the way we experience temperature.

Metals feel colder and warmer than ceramics at similar temperatures cause they are are thermally conductive.

Also, if you cool your hands with ice water, then pick up something cold, it will feel warmer than it should be, because the temperature of your hands means less heat can leave your hands.


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

[User]
ELI5: Why do lightbulbs go out, but not the lights that illuminate screens on TVs and phones?

Is it even possible for them to go out?

[Assistant]
it is, DLP tvs for example used a honest bulb (though very bright and powerful), and it had a life of a few years.

LCD screens use edge lighting, most are LEDs these days (all cell phones), but they used to use compact florescent lights (rarely still do).  both have absurdly long lifespans, longer than the devices they are in.  but its possible for the backlight to fail.

the newest phones (and some TVs) are OLED, which means the screen itself are itsy bitsy LEDs that generate the light themselves.  again, super long life.


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

[User]
Recommendations to start with Camus?

I have read about a fair share of philosophers, but I have never read anything from Camus. Any recommendations on where to start?

[Assistant]
Tbh Camus isn't that difficult to read, so if you've read other philosophers i think you can start anywhere with him.

I started with ''The Stranger'' and i thought that was a good start. Loved it!

Have fun!


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

[User]
[Resident Evil] How cost effective are Umbrella's bioweapons in the first place?

Manipulating biological contaminants like the T and G viruses probably costs enough to outfit a Delta Force team. Given the end products, just how cost-effective are these monstrosities when used against trained military forces?

[Assistant]
Not very effective, it turns out. Or very effective, depending on how you look at these things. An uncontrolled T-Virus outbreak completely destroyed Raccoon City; it was so bad a nuke was required to contain it. If you WANT to do that sort of thing to the enemy then yeah, it worked pretty well. No loss of life for your soldiers, and an immensely scary display of power for yourself.

The problem is that the whole point of warfare is, when you are fighting for something, you generally want to be able to use it afterwards. Which isn't easy when the entire thing is covered in zombies and monsters. While T-Virus is great for killing off civilians and enemy combatants the bad news is that the same thing that makes it dangerous to them also makes it dangerous to the people you send it to occupy it. It's a double edged sword, most of the creatures don't follow orders and will attack you as easily as the enemy.

Umbrella was experimenting with creatures that could follow orders. The Nemesis was basically a Tyrant with some very low-level mental conditioning to hunt specific targets. However, it wasn't perfect. Nemesis wasn't intelligent enough to distinguish friend from foe and couldn't do anything more intelligent than blindly pursue targets.

In short, the T-Virus creations have a high success rate against most military and civilian targets, especially those without prior experience or training in combating them. However, like most biological weapons they are uncontrollable and the clean up is a bitch.


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

[User] Why do videos with a high frame rate appear unnatural to look at? Why does it appear to be a "higher frame rate than real life"?

[Assistant]
High frame rates are closer to life than low frame rates. If high frame rate video looks strange it is either how you have been conditioned to certain frame rates subjectively or there is a problem with the video that would not be present in ideal playback.

Pixel response times are more of an issue with high frame rate causing the screen to spend more time slurring between one image and the next and less time showing undistorted frames.

You are also used to seeing lower frame rate video and the change is distracting. You might associate low framerates with expensive film based recording which is usually high quality. High frame rates might be associated with electronic recording which is cheaper.


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

[User]
Does i^i have a fixed, real value?

Given that you can use the identity  e^ix = cos(x) + isin(x) to prove that i^i is real (by letting x=pi/2 and raising both sides to the power of i) that would suggest that i^i = e^-pi/2, however since there are multiple values of x which could work just as well (5pi/2, for instance) and these would give different values, does i^i have a set real value or can it vary or is it just not as simple as I think it is?

[Assistant]
Since we use the natural logarithm to calculate this exponential, and the natural logarithm is a multi-valued function, you should expect multiple solutions. i^i represents all of these values, so in a sense it's a set (e^(2pi k - pi/2) for all k in Z), but more correct is to think of these points as lying on a twisted surface that revolves about the origin infinite times in both directions. Think of an infinitely tall helical parking building - these solutions represent the same parking space on each floor.

Edit: Coming to think of it, the parking space analogy breaks down because the solutions are in different places from level to level, although always on the real line. The point is that each solution is on it's own level.


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

[User] What happens to forgotten memories in your brain chemically and energetically, or however?

[Assistant] Memories are believed to be "recorded" as distributed synaptic changes in cerebral cortex neurons, and some aspects of this are understood (e.g., dendritic changes, post-synaptic densities, pre-synaptic modifications), very little is know about how these many changes are encoded as memories or how they are later recalled as memories or modified behavior. It's possible that these memories (as synaptic changes) still exist, but our ability to recall them changes. That would explain why some people with advanced degenerative diseases like Alzheimer's start to recall old memories even while they're forgetting more recent ones.


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

[User] Particle entanglement says distance between particles is irrelevant for one to affect the other instantaneously. What if the particles are a light year apart? Does that mean the speed of light really isnt the universal speed limit?

[Assistant] It's arguable if "one particle affects the other", since entanglement can't be used to send information faster than light. In the back of Griffith's QM book, he says it's analogous to a planet passing in front of a star. The planet's shadow moves faster than light, but it's irrelevant since no information is transmitted.


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

[User] ELI5: why do you feel nauseous or sick after staying up too long?

[Assistant]
During sleep, our bodies replenish a lot of key substances which are necessary for the normal function. This is regulated by the 'circadian clock' which is just a fancy word for our bodies' sleep/wake clock.

When there's sleep deprivation, we have an absence of these key substances being replenished, and that in itself can cause some of these symptoms like nausea/headaches.

Alongside this, it creates stress on the body, and that activates our 'fight vs. flight' response. One of the effects of this response being activated is also having feelings of sickness/nausea.

It's a lot more complicated than that because there are so many things that work together, but this is the very basic gist of it.


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

[User]
[Xmen: Days of Future's Past] What would be the future Sentinel's counter to Quicksilver?

They said that the Sentinel's can transform to adapt to different mutants. So what about Quicksilver?

Whats gonna stop him from running to each Sentinel and plant bombs or something.

Or, he could gather them one by one and throw them towards Blink's portal directed to space.

[Assistant]
They seem to have a shared ability pool so even though quicksilver could destroy a good few, eventually they would show up ready for him, probably with a sonic cannon or another incapacitating AoE ability.

Sentinels aren't slow. They'd only have to stun Quicksilver for a few seconds to at least trap or limit his movement to open up a kill shot.


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

[User]
Engineers: Can we solve greenhouse emissions by solidifying them at the point of creation?

I'm curious if it's possible to collect the dangerous emissions of cars and lump them together into a solid rather than as greenhouse gases.  Basically, if the gaseous emissions of fuel consumption are the problem, is there a way to convert the emissions to a solid (or liquid) before expelling them out of the exhaust system and thus side-step the issue?

The ELI5 version of this question would be:  Why don't cars poop?

[Assistant]
Our feces is all the things we don't digest. The fuel part of food gets turned into energy sources the body can use, which are used up and produce energy, water, and CO2 as byproducts.

Similarly, when gasoline is burned in the presence of oxygen, it produces energy (heat), water, and CO2 (along side with other side reactions such as NOx compounds). There is some soot which is not combusted would be the automobile equivalent of feces, but modern vehicles are quite efficient and the fuel is a relatively pure compound, so there isn't much in the way of other side products.

CO2 is a very stable molecule and doesn't react with much; and the reason we get so much energy out of burning hydrocarbons is that CO2 is such a stable, low-energy molecule and we get to use the energy difference for heat engines. You can catalyze CO2 back into carbon and oxygen, but it requires an energy input to do so, which defeats the purpose of burning it in the first place. You could conceivably burn hydrocarbons in the presence of some other oxidizer to produce a solid waste product, but then you have to carry your oxidizer with you and will probably suffer a performance loss and it will be more expensive than using atmospheric oxygen for free. You could capture the CO2, filter it out, compress it and store it as a liquid, but this also requires energy to do and is expensive.

So there are physically a number of things you can do to prevent CO2 emissions from entering the atmosphere, but they are not practical to implement.


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

[User]
[Fallout: New Vegas] So, I am a legionnaire, stationed in Cottonwood Cove. Last night, some unseen person managed to write "People called Romanes, they go the house" on the side of our communications building. What does this mean, who could have done this, and why on earth would they do it?

So when I woke up in the morning, the message was just there, written in red paint. Its definitely not blood, just paint, and I have no idea how it got there. It couldn't have been the captures, since there's no way any of them could get access to paint without their heads blowing off, and none of them would know how to write, the filthy profligates. Furthermore, none of the Captures have told us anything about the message, even after we tortured them - they said the message appeared as they slept, as well, so someone must have done this without waking the captures in the pen beside them.

It could have been an NCR profligate, but if one of them could make it into the middle of Cottonwood Cove, I would think even those empty headed swine would have the good sense to plant a bomb and leg it, or at least slit a few throats before they ran, instead of standing and fighting.

I suppose one of the Followers of the Apocalypse would be foolish enough to creep into the camp, and yet cowardly enough to not dare to spill any Legion blood, and may know enough Latin to write a message, but even if that were true, why would they be near Cottonwood Cove when they stick near Vegas?

And what on earth does the message mean? "People called Romanes, they go the house" - its just gibberish.

[Assistant] Probably some loyal Legionnaire, maybe that new one called "Bigus Dickus", using his weak Latin skills trying to show the wasteland who will be taking out Mr. House. Who knows, it sure is a wacky wasteland.


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

[User]
[DC] Superman and Supergirl?

We all know how powerful Superman is, but what about Supergirl? Could she be as powerful, if not more powerful then Supes if she had been on Earth as long as him?

[Assistant]
Not sure about the latest canon (New52/Rebirth), but story used to go that Supergirl is perhaps a tinsy bit stronger, faster etc. Their rationale was that

A) Supergirl took a longer trip from Krypton to Earth (sent as a baby, arrived as a young adult), thus soaked up much more sunlight enroute. More energy = more power.

B) Supergirl does not have the same degree of control as Superman, who'd spent 30 some years to 'hold back' even when fighting a super robot made by Lex Luthor (or whatever). Less control/finesse = more power.


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

[User] ELI5: why is it that big dogs drool alot while small dogs tend not to drool at all?

[Assistant] Larger animals have to work harder to keep cool. Volume, which determines the amount of heat produced, goes up with the cube of the length of the animal but surface area, which determines the rate that heat is lost, goes up with the square. Dogs cool off by panting while producing drool instead of sweating. Large dogs have to drool more to maintain their body temperature in the same way that overweight humans sweat more to keep cool.


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

[User] [DnD]I'm on a low budget here, is there any way to weaponize a bag of holding placed within a portable hole?

[Assistant] ... yea you can send everything in the area into the astral plane. You can turn it into a ranged weapon by rolling up the hole and putting it on the tip with the bag under it. But frankly if you are on a budget there isn't a lot of reason you shouldn't just sell one of them and use that money to buy like... a weapon.


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

[User]
ELI5: Why are the four parts of the UK defined as countries, but the fifty parts of the US are states within one country? What makes the two different when it comes to unified governing?

Ive always found it difficult to understand what the difference was between the US and its states (or Canada and its provinces) and the UK and its kingdoms. England, Wales, Scotland, and Northern Ireland are all defined as countries, but make up parts of a larger entity, whereas the US is one country. Do the countries self-govern in worldwide matters, such as war, trade, diplomacy, etc. or do they have to come to a decision as a group? What are some of the major political/government differences between states/provinces in the US/Canada and the countries that make up the United Kingdom?

[Assistant]
In theory, US states and Canadian provinces are more independent than UK countries. This is because the US and Canada are federal states (power is shared between central and state/provincial governments) while the UK is a unitary state (all power is vested in the central government).

For example, the UK government dissolved the Northern Ireland government during the Troubles and ruled directly from London, which is legal under their system of government. Meanwhile, in the US, there is no legal way for the federal government to dissolve a state government. Not sure about Canada, but its probably the same.

In *practice*, however, the Home Countries of the UK (except for England) have a lot of power devolved to them by Parliament and they function much like American states or Canadian provinces. Theyre called countries for historical reasons, it has nothing to do with how independent they are.


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

[User]
CMV: the electoral college completely undermines democracy

I have thought that the electoral college is ridiculous for years, but after I have grown up watching it be used as a tactic to sway several American elections it has made me and lots of people in my generation not trust the American democracy. It absolutely should not exist and the only reason it still does is because it is just another tool corrupt Republican politicians are using to sway elections. And the worst part is that the only argument people have for it is that it doesnt matter because it doesnt actually affect elections which we have all seen to majorly wrong.

[Assistant]
Thats the purpose of it. The founders were trying to guard against the tyranny of the majority. Also to ensure that small states would still have a say in the conduct of the national government.  There are many elements of our constitution that are designed to restrain pure majority rule, mainly by establishing a Federal government only empowered with specific, limited, enumerated powers.

Pure democracy is 2 wolves and a sheep voting over what to have for dinner.


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

[User]
ELI5: What do people mean when they say that a music album is 'overproduced'?

Some examples too would help.

[Assistant]
Let's say you have three musicians. A singer, drummer, and guitarist. If they were to play some music live in front of you it would have a natural sound to it. What this means is:

* Large dynamic range: The volume of each instrument would vary. For example the volume of the drums differ by each hit since a human will never strike exactly the same.

* Pitch would vary too: All instruments are tuned, but it's never perfect simply because of the nature of them. They might get warm, humid, de-tune while playing etc. The musicians playing might make small mistakes here and there. The singer will of course not be pitch perfect at all times either.

* Timing: Ideally the drummer would keep a constant tempo and the other musicians would follow this exactly. But this is impossible to do in a live setting. There will always be some off-timing of everything here and there, even if it's just for some milliseconds.

All of these effects are subtle, but give rise to a "natural" sound. However when recording an album you are free to 1) do as many takes as you want to get that perfect crisp take, and 2) polish it in the mixing.

For example you can put autotune on everything, guaranteeing that nobody ever goes off-pitch at all. You can slide and adjust every take to have perfect timing with the drums, which themselves can be perfectly fit to one tempo through the song. And lastly you can apply compressors to everything. These make everything have the same volume (the loud parts get quieter, the quiet parts get louder). This completely destroys dynamic range.

All of these things are part of what makes something sound "overproduced" i.e. it's been "produced" beyond anything that might sound natural. It ends up sounding artificial because in many ways it is. In the end it's of course a matter of taste what you think sound better. Overproduced music tend to be more favourable with today's younger generation, while natural sounding music is more favourable to older generations. In the past the technology to overproduce this way simply didn't exist.


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

[User]
ELI5: The "Economic gap" between the "1%" and the "99%"

So I hear about this a lot. The increasing difference in wealth between the supposed 1% and the 99%. So why has this occurred? And why is it increasing so drastically? Additionally, I often hear about how bad it is for the economy. Why is this? I know this may be a bit of a loaded question, so any info you can provide would be welcome.

[Assistant]
This is obviously a very complicated question, ~~Nobel Prize winning~~ economist Thomas Piketty set out to explore it in his book Capital.  What it comes down to is this:

If you make enough money (and only enough) to keep you alive, you will never get any richer.  Every day you will earn $5 and at the end of the day you will have $0 left, and so the cycle repeats until you die.

But if you earn $6, you can put away some of that money.  You can save $1 a day and put it in a bank account.  You can set the money to work, *to make you more money*.  For the super-rich, this is even more extreme.  The more money you make, the more you can invest, and the more you make off of those investments that you can then re-invest.  It's a positive feedback loop.


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

[User] ELI5: Why do I never feel "fully awake" until evening?

[Assistant] I notice exercise is not mentioned in your basic description above. If you are not getting some form of physical activity that gets your heart and lungs working and little sweat going, that could be the key to your issue. It can be surprising to people how a little bit, everyday will change your alertness levels to be more in tune with the daily cycles of day and night. Not to mention the other good "side effects" of regular exercise.


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

[User]
Why can I see star clusters better when theyre in my peripheral vision?

I oftentimes find that I can see clusters of stars (sometimes just a couple slightly larger ones) better out of the corner of my eye. But tonight I observed what Im assuming is part of the Milky Way better when not directly looking at it. In fact, when directly looking at it, I really couldnt make out many stars.

Why might this be?

Edit: this has been super informative, thanks for all the insightful answers!!

[Assistant] There are 2 types of photoreceptor cells in the eye: rods and cones. Rods are more sensitive to light than cones, and they are more concentrated on the edges of the retina. Thus peripheral vision is more sensitive to faint lights. When you look straight at the stars the light falls on centrally located cones which are less sensitive to light, and you can't make out the stars.


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

[User] [Avatar] What's the state of Earth?

[Assistant]
In short: Overpopulated, not enough resources, polluted, bleak, dirty and depressing.

They go into it in great detail in the original script of Project 880. Which is the original script by James Cameron that eventually turned into Avatar:

It is a century from now, and the population of our tired planet has tripled. Finally, drowning in its own toxic waste, starvation and poverty, the population has topped out at a nice even 20 billion. The Earth is dying, covered with a gray mold of human civilization. Even the moon is spiderwebbed with city lights on its dark side. Overpopulation, overdevelopment, nuclear terrorism, environmental warfare tactics, radiation leakage from power plants and waste dumps, toxic waste, air pollution, deforestation, pollution and overfishing of the oceans, global warming, ozone depletion, loss of biodiversity through extinction... all of these have combined to make the once green and beautiful planet a terminal cess-pool.

Josh lives in the urban sprawl which has grown like kudzu over the whole eastern US. His particular part of this undifferentiated concrete rat- warren is Charlotte, NC, but you could be anywhere. Its the same crowded, gray, trash-strewn high-tech squalor. The walls are gray, the sky is gray... the people are gray. They shuffle past each other in dense crowds, shoulder to shoulder, unwashed because of the water shortages, and sickly looking from the bankrupt diet of cheap carbohydrates and synthetic proteins.

It looks like a cross between THX-1138 and a Calcutta train station. Josh has it a little worse than most because of his involvement in a stupid little war people barely remember. He is paralyzed from the waist down, and his useless legs hang twisted and shrunken down the front of his wheelchair. Josh still wears his army jacket, and with his unkempt beard and hair, and surly eyes, he is pretty much ignored by the crowds which buffet him like surf.

Just another angry vet, a piece of discarded human trash. Josh fights his way to work every day on the crowded subway. And every night he goes home to a tiny cubicle of an apartment in a vast government housing project. The room is reminiscent of a cell at a federal prison, which is pretty much what it is. The amenities look like they are from a 747, which is to say they are efficient, space conscious, and are about a hundred years old. There is a single fluorescent fixture, which casts a sterile light over the grimy walls. It flickers constantly.

One entire wall (all seven feet of it) is a TV screen. On it we get a wider view of the world, and it's nothing to write home about. There is a breaking story about a fire in a Boston subway which asphyxiated over a hundred people. Not unusual these days. This is followed by a feature about the death, in Kenya, of the last lion living outside captivity. This leads to a recap of the state of the environment overall, and it's grim.

The oceans are overfished and barren, poisoned by toxic runoff. All whales and at least half the Earth's fish species are extinct. On land over half the species extant at the beginning of the century are now gone forever, with most of the remaining endangered. The human race, using its technical ingenuity, has learned to keep itself alive, but it has lost almost all contact with the natural world, which it has strangled and crushed out of existence. There are no national parks left, only housing projects and protein farms. Yosemite is an upscale condo development. Most ocean-front property is used for mari-culture, since the only food source efficient enough to feed everyone these days is spirulina.


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

[User] ELI5 what is Gauge Symmetry?

[Assistant] Imagine you're trying to measure the length of a piece of string using a ruler. You place one end of the string at one end of the ruler, and the other end reaches the 10cm mark. However, you could also put the first end of the string at 10cm, and the other end at 20cm, and work out the difference. You still get 10cm, as the place you start measuring from does not affect the result. This means that the length of the string exhibits gauge symmetry, as it's unaffected by moving the scale that you're using to measure it.


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

[User]
CMV: the stormcloaks are the better side to choose in the Skyrim civil war

The main argument against the stormcloaks is that they are racist, but I dont think that the entire rebellion is racist. Ulfrik stormcloak and the people of Windhelm are largely racist, but not the whole rebellion.

Every place in Skyrim has racism, but the cities under stormcloak control dont have any less racism than the imperial cities. Not only this, but the empire doesnt care about the racism and, after the events of Skyrim, wouldnt do anything to stop it.

The stormcloaks are also the best choice for Skyrim to be independent of the Aldmeri Dominion. The empire is falling apart. At the time of Skyrim the empire is just Cyrodiil, Skyrim, and Morrowind.  The empire is falling into chaos with the death of the emperor (dark brotherhood quest line) and Skyrim needs to get away from the empire as soon as possible.

[Assistant] The Empire and all other non Aldmer realms face a huge threat in the Aldmeri Dominion and the only way to face such a threat is with unity. The Empire barely survived the previous war with the Dominion how is Skyrim going to survive the Aldmeri onslaught going at it alone?


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

[User]
[DC/Superman] Why is Superman a public figure? Did he set out to be a beacon of hope?

So why did Superman decide to be a public figure?  Did he set out to be the beacon of hope?  Did he realize that the people of the world need it?

Like every other hero baring Flash need to be public figures but he and Flash are fast enough to get through with their conflicts without needing to talk to people.  So why become a public persona?

[Assistant] He didn't fully set out to be a beacon of hope, just to be a good person saving lives. Lois Lane is the real reason that people think of Superman as this symbol of hope, she was a cornerstone on propaganda for him. Without her glowing reviews, Superman might have been less welcomed to the world at large.


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

[User] ELI5: the difference between using "who" and "whom"

[Assistant]
Restructure the sentence to talk about a specific person. Use "who" when it's "he" and "whom" when it's "him".

"*Whom* will you be meeting there?"
"I will be meeting *him* there."

"*Who* will be meeting you there?"
"*He* will be meeting me there."


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

[User] ELI5:How do commerical passenger aircraft generate enough AC power to accommodate every passenger seat plug and for Inflight Entertainment Consoles? What would happen if every single plug was used and drew max amperage?

[Assistant]
Jet engines produce an enormous amount of power. In an aircraft, some of that power is used to run electrical generators. The jet engine (in a 777 for example) could produce enough electricity to, if the generator was large enough, power something like 75,000 homes.

The actual generator and electrical system is sized appropriately for the expected load, which is likely something less than every passenger using the maximum rated power at the same time. Although airplanes are overbuilt so it might even handle that. But engine wouldn't even blink.


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

[User]
ELI5: Why are battery arrays (ie: AA-style) designed to alternate the + and the - positions when lined up next to each other?

I mean, in rechargeable packs, you line them up identically, but then you put them in a remote control and they have to alternate. Why?!

Edit: Thanks all! Happy to learn this random bit of information after a lifetime of blindly accepting it!

[Assistant]
Because it's a simple way to wire the batteries in series rather than parallel.

There are two ways to connect batteries.  In series (which adds the voltage) or in parallel (which adds their amperage).  Many battery powered devices could simply use a single larger cells for more amperage, so wiring in series (to increase the voltage) is much more common.

Putting the batteries in alternating sequence means that one end of the array only requires a single connection between the two ends to maintain them in series.


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

[User]
ELI5: When playing roulette at a casino, what's the strategy of those folks who are putting chips on a large portion of the individual numbers?

Is this strategy better than just playing the outside?

[Assistant] There really is no strategy to roulette, it's all just guessing. Every dollar you bet has an expected return of 93 cents, slightly more if there's only one zero. It's the most transparent gambling game there is.


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

[User]
ELI5: How do self driving cars work? Are their only approved routes where it can be on autopilot (more details inside)?

Would self driving cars only be able to auto pilot on "identifiable routes". For example, are essentially all roads programmed so that the car knows the amount of lanes (for lane switching, etc)? What about speed limits? Do they always know when to slow down/speed up? Merging with traffic? So many questions.

[Assistant]
Lots and lots and lots of data and sensors, and programs smart enough to understand it all and react quickly to changing circumstances.

GPS is a basic requirement, telling the car where it is down to a meter or so of accuracy. That's not enough to necessarily distinguish lanes apart, though, much less know when another car is nearby.

Most roads in the US are mapped, either by government or private agencies working for/with the government. Sometimes this will include speed limits. You can see this in some current car nav systems that tell you when you're going over the limit for this part of the road.

Traffic data is collected both from transportation agencies that monitor congestion through cameras and the like and also from analyzing cell phone users on highways and seeing how they slow down.

Cameras in different parts of the spectrum (visible, infrared) record the surroundings, and advanced machine vision programs identify shapes and patterns to distinguish between signs, pedestrians, cars, lane markers, etc. You can also see this tech in action in current systems like the Subaru Eyesight safety package. Much of this technology was adapted from military use, where it was used to track enemy combatants and vehicles as they move.

When vision isn't enough, cars have other sensors to help cope. Radar, sonar, and lidar (lasers) work together to calculate distances and speeds of nearby objects both stationary and mobile. Onboard software classify them based on their size and motion (house vs car vs bicycle vs unidentifiable object) and try to react accordingly, either keeping pace with the car in front or emergency braking to avoid hitting the unknown obstacle up front.

Internal sensors on the car like accelerometers and gyroscopes and wheel sensors also help it figure out where it's going relative to where it wants to go, and the computer makes changes several hundred times a second to correct course and ensure stability and safety, far faster and more reliably than any human could.

Each and every one of these problems were very difficult to solve, and combining them into a self driving car is the culmination of decades of research across multiple industries. A lot of it comes from the military and aerospace, and a lot of it had to be purpose built for consumer use on highways.


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

[User]
[Star Wars] So, it has been established before that sometimes, especially when a Jedi feels emotions like anger, hate, fear, etc., that they start hearing The Call of the Dark Side. Under what circumstance would a Dark Jedi or Sith Lord hear The Call of the Light Side?

I've been wondering this for a while. I can see why a Jedi would turn, but why would the opposite happen? The Jedi use the Force with a calm, clear mind, and strive for peace and justice. Whilst I can kind of see a Sith Lord wanting peace and justice, would that be enough to make them hear the call of the Light side?

[Assistant]
In the strictest sense of the term, there is no "light side", simply the natural will of the Force, which one may follow harmoniously with little effort. The Dark Side is not a side of the Force, but a side of one's self-- the selfish destructive urges that compel one to try to force (pun not intended) the universe to follow their desires rather than acting in accordance with the natural way of things. If you're familiar with Taoism, it's a bit like that.

To answer the question more directly, a Dark Jedi constantly hears the call of the light as a result of being Force-sensitive-- they have simply trained themselves to ignore it and prioritize their own negative feelings.


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

[User] Why is it with viruses you often cease to be contagious well before your symptoms go away?

[Assistant]
There are two immune responses. One is a general response, the other is specific. The specific one, where antibodies are made to destroy the specific virus, takes longer to come into effect. The general response (cough, runny nose, fever) can kick in without the need for specific antibodies and sticks around longer to make sure you got rid of all of whats left of the infection.

This also means that the typical symptoms of a cold are actually symptoms of an active immune system.


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

[User]
[DC] Batman Beyond (Terry McGinnis) lives on Earth 12, which supposedly is the near future of Prime Earth. In Bendis Legion of Superheroes run, Terry is shown to exist in Prime Earths future. How is Earth 12 a separate universe if its literally just the future of Prime Earth?

Sorry, that title wasnt very concise. What Im wondering is how Earth 12 could be considered an entirely separate, alternate universe if its just Prime Earth in about 40 years. Thats just the future, not an alternate history or fundamentally different reality. Is it just that Earth 12s universe is about 40 years older than Prime Earth, so their clock runs a few decades ahead of time? Even that doesnt seem like a good justification for E12 being an alternate universe.

[Assistant] Universes are weird. Theoretically, you could have a universe that is exactly the same except George Washington faces right on the US quarter. So it makes sense that E12 could be running on the same happenings as Earth Prime but 40 decades earlier. Or it could be a nearly totally different universe that happens to have a similar Gotham and Terry McGinnis. Or anywhere between the two.


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

[User]
ELI5: How do erasers work

.

[Assistant]
Erasers pick up graphite particles, thus removing them from the surface of the paper. Basically, the molecules in erasers are 'stickier' than the paper, so when the eraser is rubbed onto the pencil mark, the graphite sticks to the eraser preferentially over the paper. Some erasers damage the top layer of the paper and remove it as well. Erasers attached to pencils absorb the graphite particles and leave a residue which needs to be brushed away. This type of eraser can remove the surface of the paper. Soft vinyl erasers are softer than the erasers attached to pencils, but are otherwise similar.

Art gum erasers are made of soft, coarse rubber and are used to remove large areas of pencil marks without damaging paper. These erasers leave a lot of residue behind.

Kneaded erasers resemble putty. These pliable erasers absorb graphite and charcoal without wearing away. Kneaded erasers may stick to the paper if they are too warm. They eventually pick up enough graphite or charcoal that they leave marks rather than pick them up, and need to be replaced.


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

[User] ELI5: Where does morning breath come from?

[Assistant] Basically when bacteria eats the leftovers on your teeth and in your mouth, it creates a yucky smell. Your saliva usually takes care of some of that bacteria, but when you are sleeping you produce less saliva. Thus the bacteria gets to run rampant, and thus you have morning breath.


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

[User]
ELI5: Why, when a person freaking out or panicking, is it good for them to drink water?

I have a few theories regarding this that I'd like substantiated. Does focusing on drinking take their mind off whatever is causing them stress? Perhaps it makes them regulate their breathing? Or does hydrating a person somehow calm their nerves and allow them to think more clearly? Maybe all of these?

Edit: grammar, etc.

[Assistant] It's beneficial because it forces them to slow down and take a short break.  We all have to focus a little while drinking, we have to swallow and breath carefully to be sure we don't choke.  Since we can't fidget or talk while drinking, it gives a moment for thinking to ourselves.  If a person is panicking, that little break may be helpful instead of pacing, talking or yelling.


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

[User] [Fiction] Why do hulking, strong monsters like Nemesis or the Terminator seem to have a fighting style that consists of throwing the protagonist away from themselves as opposed to just crushing them in their grip like an egg?

[Assistant]
If you're melee fighting something smaller than you, but is still able to damage you, than throwing it into things is a good way to hurt it while putting yourself out of range of counterattack.

Also, you won't get viscera all over yourself.


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

[User]
What makes the sound of a stomach grumble?

I assume it has something to do with liquids moving and such, but how can it get so loud sometimes? Why do we not hear the same sounds on a full stomach?

[Assistant]
It's called borborygmus and it's caused when the muscle contractions in your upper gut push its contents against the walls, sometimes causing pockets of gas or liquid to move and bubble around.

It's louder and more common when you're hungry because after your stomach empties, shortly after eating, the srong muscle contractions stop and don't restart until a couple of hours later to prepare for the next meal.


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

[User]
If you scaled an ant up to the size of an elephant, would it still be able to carry an object five times its own body weight?

In other words, is an ants apparent strength only due to its tiny size?

(Bonus question - who would win in a fight, an elephant or an elephant-sized ant?)

[Assistant]
No.  In fact, if you scaled up an ant to the size of an elephant, it would die.

Ants breathe through spiracles, tiny holes which cover their body.  As you scale up, these holes become unable to provide enough oxygen for their body mass; an elephant-sized ant would suffocate.

The reason is simple; as the size of the ant increases, the volume (and hence the mass) of the ant increases much faster than the surface area.  As a result, the air provided by the spiracles decreases as compared to the mass of the ant, as it grows.

This is the same reason why an insect can survive a fall from dozens of times it's own height, but larger animals cannot.  The ratio of mass to surface area is not held constant as we increase a creatures size.


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

[User]
Why do we sweat when we're scared?

Surely you'd want to *not* smell strongly when a predator is trying to find you.

[Assistant]
The sweat that is excreted by humans due to the fear response contains certain hormones and pheromones that, when inhales, heighten another person's alertness. Basically, what we sweat out of fear is to help other people in our situation escape whatever it is is causing us fear.

Stress sweat is meant to help our species survive by increasing our awareness of a given situation. The glands that produce stress sweat are different from the glands that produce normal heat-related sweat, and only activate in response to the "fight or flight" response.


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

[User] ELI5: If two people suction their mouths together and breathe in and out simultaneously, how long will they survive under water?

[Assistant] Approximately as long as one person holding their breath. They have the same amount of lung volume per person either way, so the only difference is the effort expended in breathing which is fairly low.


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

[User] ELI5: Why do candles only make smoke after I blow them out?

[Assistant]
That's not smoke. Its vaporized parrafin wax. It is to wax as steam is to water.

You see, when a candle burns its not the string that is burning, but rather the wax of the candle. Candle wax is quite flammable, but only when vaporized. The melted wax is absorbed by the candle wick, and then burned. When you blow the candle out, for a time the wax in the wick continues to "steam" causing a trail of what appears to be smoke.


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

[User] [Vampires] In a universe where Vampirism is totally scientific (a different species/virus/mutation), how can blood be nourishing to them? Besides containing water, does blood have any nutritional value?

[Assistant] Perhaps the virus itself feeds on the vampire's own blood cells, making it more difficult to circulate oxygen throughout the body. By feeding on the blood of others, the vampire is able to stave off the debilitating effects of the virus.


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

[User] [HP] Do students still get the class credit for the classes that were taught by Prof. Quirrell or by Barty Crouch Jr. when he posed as Mad-Eye Moody?

[Assistant]
I think the NEWTs and OWLs are the important factor, not the classwork. If you can pass the Ordinary Wizarding Levels in fifth year and Nastily Exhausting Wizarding Test in seventh, you're good to go.

There's also no indication that any of the main three characters had to repeat the class, and Ron would have certainly complained, and Hermione would have been apoplectic is she had been held back.

Finally, some leeway was probably extended to the people in Potter's class, too. They might not have completed all of the requisent coursework, but they *did* manage to once and for all defeat the Death Eaters, which the whole of the Wizarding World had failed to do for decades. That probably earned them some bonus credits.