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

[User] How would Ancient Stoics deal with people who did not think, even remotely, how they did, and how would they help them if in emotional need?

[Assistant]
Epictetus' Enchiridion chapter 16 has the following advice:

> When you see any one weeping for grief, either that his son has gone abroad, or that he has suffered in his affairs, take care not to be overcome by the apparent evil; but discriminate, and be ready to say, "What hurts this man is not this occurrence itself,- for another man might not be hurt by it, - but the view he chooses to take of it." As far as conversation goes, however, do not disdain to accommodate yourself to him, and if need be, to groan with him. Take heed, however, not to groan inwardly too.

So the basic approach the ancient Stoics used when dealing with non-Stoics was to show outwardly that they were there for a person and to try and comfort them, but to internally remember the Stoic doctrine of the dichotomy of control, and that what was happening to the other person was not a true Evil, but only an apparent evil.

It's also important to note that the Stoic doctrine of the four virtues: wisdom, temperance, courage and justice and the doctrine that virtue is the only true Good, would tend to have the Stoic do the virtuous thing in any situation. If that happens to be comforting a non-Stoic friend, then they would comfort that friend.


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

[User] ELI5: Why do more men seem to snore than women?

[Assistant]
There are some differences in throat anatomy where men often have longer airways and bulkier tissue in their throats and this can contribute to snoring. Men may also tend to have more fat in their chest and neck, pressing on their airway when they sleep on their backs.

While in younger populations men do snore a little more often than women, this actually tends to equalize as people get older.


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

[User]
[Star Trek] How do comms route calls in real time?

When Picard hails Riker with a "Picard to Riker," does everyone's combadge respond similar to an intercom, or is there some sort of intention tracking that occurs so that only Riker's combadge responds. If so, is it not a real time message until the computer works out who it's going to, then it plays catch-up?

[Assistant]
It only routes to the person. Remember the com badges have identifiers in them to say who they are - like when a crew member takes it off so they're not tracked.

And Starfleet computers work at a speed that most lifeforms wouldn't even notice a lag time in routing.


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

[User]
[StarWars] Why do we fight?

I'm a pilot with the Rebel Alliance. I lost my parents when Alderaan was destroyed. That is what brought me over to their side.

But why were we fighting the Empire before that? So what if they killed a bunch of Jedi, those wizards wielded far more power than they had a right to. Much more than the other 99% of us.

[Assistant]
Why do you fight? Why indeed!

Friends, the Galactic Empire means you no harm! We seek only to bring peace and order, and without the so called 'rebellion' - in reality little more than a band of loosely-organised criminals seeking to better their lot at *your* expense - those goals would have been fully met long ago.
Think back to the dark days of our fathers; the time of the Old Republic. A corrupt, bloated organisation, with the noxious Senate as the embodiment of all that is wrong with such a system of government. How much more has been achieved since the dissolution of the Republic and the establishment of the Empire!
As you rightly say, the Jedi wielded too much power without a moderating body. With the Emperor at the head of us all, we can be sure that no such situation can arise again - any power-hungry wizard resurgence would be swiftly dealt with... if there were any possibility of such a thing happening! As you well know, the Jedi are extinct, and thanks to the Emperor, we are all that much safer.

Brothers! Sisters! *Friends!* Lay down your weapons and come to us! If fighting is your skill, then you can fight - the Stormtrooper legions are ever-expanding, and we have the finest pilot training facilities in the galaxy! If engineering is where you are best, then work as an Imperial Engineer - we are working on a number of engineering programmes, the like of which has never before been seen! It pains me, as it pains our Emperor, to see so many walking in darkness, misguidedly believing the lies and propaganda spread by the traitor criminals of the 'alliance'.

Join us. For your own sakes, and for the sake of the galaxy - a galaxy where your children can grow up, safe and secure, in the arms of the Empire.


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

[User] [Marvel/DC] What single event (like doomsdays, extinctions, invasions, etc.) has had the largest impact on the respective universes?

[Assistant]
DC - The Crisis on Infinite Earths.  Literally to the point that events in DC are always referred to as "pre-Crisis" or "post-Crisis".  It involved the Anti-Monitor destroying countless worlds, with many major heroic deaths and long lasting impacts.

Marvel - Probably the Incursions that led to the Secret Wars.  The entire multiverse was destroyed and only managed to survive at all because of Dr. Doom and Dr. Strange.  There were similarly large scale ramifications, but this is less clear cut as THE biggest thing than DC's is with Crisis.


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

[User]
[Dune] How does a Mentat's mind work and how can it be compared to a supercomputer?

I know that they don't just calculate or store data. They also have a human's/a sapient being's capacity to plan and form hypotheses. I'm asking about how much information can they store and process, and how much information and stimuli can they gather as they go on with their lives?

[Assistant] Mentsts are "human computers", so it helps to think of them in those terms. They have the same basic function as standard humans, but with more memory and a much faster processor. This enables them to do highly complex calculations with incredible speed. When they ingest the Juice of Sappho (which is basically super-Aderral), it is like over-clocking an already powerful computer.


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

[User]
[DC Comics] Batman is often shown fighting alongside extremely powerful super-beings - but how is he not immediately ripped apart at super-speeds by the Reverse Flash before he can react, or turned to ash with a look by Darkseid?

Maybe it's a suspension of disbelief thing?

I mean, Batman is cool, Superman is popular - it makes sense to for DC to team up their most popular characters.

But the powers get stacked so absurdly high it's hard to imagine any human not instantly being eviscerated by these super-fast, mega strong flying behemoths.

I know part of Batman's coolness is his minimalist ninja design - stick him in an Iron Man suit and that would take away from the fun of the character.

But if even a stray bullet to the head could kill him, let alone some crazy power blast from a Yellow Lantern or whatever, it strains belief that Batman and Superman and their respective villains can all fight in the same battles and take on the same enemies.

[Assistant]
He generally tries to avoid fighting such people directly. And to be fair to the writers, despite the various batgod memes, whenever he's been unfortunate enough to end up in a straight fight with people like that it's almost always gone exactly as you'd expect.

Rather, he's much more of a planner. His main contribution is taking down minions, laying traps, figuring out weaknesses, finding assets, etc etc. He's much more of a behind the scenes guy.

Basically, he's doing asymmetric warfare. He's well aware that in a fair fight, he's ending up as a batstain on the floor. So he tries his best to avoid getting in a fair fight. He uses evasion, allies, traps, weak spots, schemes and any other dirty trick he can get his hands on to even the playing field.


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

[User] Why do we tend to laugh more when laughing is forbidden?

[Assistant]
One of the reasons is to release negative feelings. It is an automatic reaction from the brain. Exactly the same for when we cry.
It is healthy to react as we feel. Don't beat yourself up for that. Or at least, don't make it too obvious if it is going to REALLY hurt someone.


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

[User]
ELI5 how one third of 100 as a decimal adds up to 100 and not 99.9 recurring

Edit: thanks all for helping me wrap my head around this. 99.9% sure i get it now

[Assistant]
.9 recurring is the same as the next whole number because there cannot be a number in between them. If there was, you couldn't continue recurring and include another 9.

With a number like 99.999 not recurring we can add .001 and reach 100 but if we take 99.999 recurring and add .001 we reach 100.000999 with the nines recurring.

There is no point where you can add a number to reach the next whole number without going over nor a point where you could subtract to reach the recurring number.


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

[User]
CMV: The Trump/Parlor bans are due to free market economics

The recent events of social media companies banning accounts, delisting apps, and pulling hosting is not purely for the sake of safety but is for liability and profitability concerns.

Just like a bar that has a policy to take away a drunk patrons keys these companies have determined the liabilities (drunk driver crashs) out way the possible benefits (sell a few more drinks).

The executives of Twitter, Google , Facebook, Amazon, and the rest don't give two shits about possible incendiary or violence inciting rhetoric that we've seen. Otherwise these actions would have happened long ago. If these companies did not take action this time they would probably face a significantly larger federal response then they will now. This could have other effects such as opening them up for lawsuits.

The other issues was effect on internal operations. Long before Trump supporters stormed the US capitol, groups in these tech companies had submitted petitions or emails on taking action. The events at the US capitol gave a physical display of what these companies were partially responsible for. This makes it harder for employees to stay at that company and even harder to recruit out of college. Unlike 4 years ago, I think college students will pause before accepting an internship or a job from one of these tech giants.

I would be interested to hear if people have a different take on this. Why would executives at these publically traded companies make this decision now if it didn't have to do with profitability of the company? If that was the case why wait until now?

Edit: some of the comments are extensively talking about Section 230-c1. The section in question is shown below. This post was not intended to be a conversation about section 230 but rather my view that tech companies don't really care about issues until it hits or has the possibility to hit their bottom line.

 "No provider or user of aninteractive computer serviceshall be treated as the publisher or speaker of any information provided by anotherinformation content provider."

[Assistant]
Under the law, Twitter is considered a "platform" and not a "publisher" which means they have less legal responsibility for what gets posted.   If someone violates copyright, defames someone, or incites violence, twitter isn't legally responsible the way a newspaper is.   By being a platform, it means they're just hosting other people's content and can avoid legal responsibility for it.

You don't get to have it both ways.  They don't get to both control what gets posted AND have no legal responsibility for what is on their site.  If they control the content then they're a publisher and need to be legally responsible for what is said.

Package delivery services have a similar exchange of rights.  If UPS delivers drugs to your address, your UPS driver isn't in legal trouble for delivering drugs.  These are called "common carrier laws".  And in exchange for those legal protections, package companies don't have the right to open your package.   They legally cannot open anything.  Which is what protects them.  If they can't legally open it, then they can't be held responsible for what is inside.


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

[User] ELI5: How do non-radio objects (eg fans, bed frames) pick up and play AM signals?

[Assistant]
They have metal parts in them that can act like an antenna. If exposed to a strong enough electromagnetic field, they'll begin to oscillate at whatever frequency that field's at. This is essentially how a crystal radio works.

But you'd need to be really close to a really, really powerful transmitter to hear music on your bedframe or water pipes. The origins of this story seem to date back to the 1930s when WLW in Cincinnati opened up a 500kW transmitter. The FCC no longer allows transmitters that powerful. They max out at 50kW nowadays, and they usually aren't built close to residential areas.


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

[User] Will mastering any one programming language allow the person to easily pick up any other language?

[Assistant]
Any is a strong word, but concepts in one language are very common in others as well.

You'll find that some are different. C++ and JavaScript are similar. Python and BASIC aren't. But what you learn in one, such as functions, recursion, logic, data types, variables, etc. will translate to the others.


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

[User] ELI5: why do the sides of your jaw hurt when taking the first bite of certain foods? (and only the first bite)

[Assistant] Whenever you eat something with a lot of flavor (especially sweet or sour) after not eating anything for a while, your salival glands on each side of your jaw begin to rapidly secrete salive to break down the enzymes in the food. Imagine it like a sleepy cop in the security room with all the screens showing footage from cameras. When he finally spots something, he falls out of his chair startled and calls security. Similarly, the spontaneous secretion of saliva makes your salival glands hurt or "cramp" up in a way.


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

[User] ELI5: Do annual flu shots cause a similar evolutionary resistance/mutation of viruses to what we are seeing with antibiotic resistant bacteria? If so, why is there a push for reduction in antibiotics and an increase in flu vaccinations?

[Assistant]
>Do annual flu shots cause a similar evolutionary resistance/mutation of viruses to what we are seeing with antibiotic resistant bacteria?

No.  Vaccines and antibiotics work in completely different ways.

Antibiotics are chemicals that directly kill bacteria.  The danger with antibiotics mostly occurs when people don't finish their treatment regimen.  They take the antibiotics until they feel better and then stop, but all the bacteria weren't dead yet, and the ones left alive are the ones most resistant to that antibiotic.  Now, if the person had kept taking the antibiotic, those bacteria would have died, because "resistant" is not the same as "immune".  But by stopping the treatment early, all of those resistant bacteria have a chance to begin multiplying again, and now the entire infection is composed of antibiotic-resistant bacteria.  And since bacteria have very short reproductive cycles, they evolve fairly quickly, so the chances are pretty good that some of the bacteria will evolve to be even *more* resistant to antibiotics than their "parents", and all of the "parents" are already resistant.

By contrast, the flu shot is a vaccine.  It contains weakened/dead viruses that can train your immune system to fight the real thing.  If the virus can't infect you well enough to get a foothold, there's much less of a chance for it to be able to evolve resistance.


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

[User]
Learning C and C++ as a hobbie. Any leads, tips or perhaps tutorials?

I know this is like the most frequently asked question to the programming community but I dare ask this again because most of the answers on internet do not help. Most of them are demotivating ("You crazy?  Learn python instead), some are simply mocking learning ("Lol, programming noobo wants to learn C, hey chap, lemme tell you how to change the color of your command prompt!").

I want to learn it for the thrill of it. I like challenging myself and positive results make me satisfied. So please don't gate keep me.

I am ready to invest 30hrs each week into learning C++. I even know the basics of the language so I dare say I am above the beginner level. Also, suggest only the stuff on internet because no high level books on C++ are available in my city and Amazon does not work here.

Thank you for your time reading this.

[Assistant] If you like music and audio, that could be a fun area to explore. It is dominated by c and c++, and very interesting. It could keep you motivated. Or build a super duper simple game engine in opengl. In summation, have a direction for your exploration to work towards goals.


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

[User]
ELI5 why do some (most) products say "this product has been known in the state of California to cause cancer?

Why just California?

[Assistant]
California has a state law (Proposition 65) that was passed 30 years ago or so that requires companies to warn consumers if they're selling them any product that contains certain chemicals.

The intentions were good - all of these chemicals might be carcinogenic. Unfortunately, 99% of the time they're perfectly safe when used as intended.

The problem is that the law has stiff penalties for failing to warn consumers, but there's absolutely no penalty for issuing a warning that isn't needed. So most companies add the warning to *everything* that might contain even trace amounts of any of those chemicals, just to be safe.

Unfortunately it just means that those warnings are useless.


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

[User] Eli5: besides safety concerns, what other reasons are there for not using nuclear powered engines in rockets for long term space travel?since they are used in submarines?

[Assistant]
Nuclear power *is* used in space travel. Not in the same form as sub reactors, though.

Nuclear reactors are big and heavy. This is a problem for space travel. They also produce a lot of heat, and if that heat is not shed quickly, the reactor is very inefficient. That means a lot more weight in radiators.

We currently use RTG's, very simplistic nuclear power banks that generate very little power, in some space travel, but they are not ideal when sunlight is so conveniently available.


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

[User] ELI5: Why is it even important for some people that the moon landings were "faked?" How is the idea relevant and meaningful to anyone alive today?

[Assistant]
> How is the idea relevant and meaningful to anyone alive today?

It's about whether or not we can trust what the government says. Getting to the moon was/is a pretty big deal. If they lied about this, what else are they lying about? Global warming? 9/11? Roswell and aliens? (and so on). Is the president's state of the union also a lie?

Similarly, how did they fake the whole thing; the launches, the pictures, the movies, the space rocks, the news coverage, etc.

TL;DR - it's about whether was can trust what the government tells us.


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

[User]
ELI5: So I found out that space telescopes capture "colors" that weren't there to begin with and see in black and white. What colors are really present in our universe?

EDIT:

To clarify, the Hubble colorizes white and black images by adding colors to represent the spectrum. I'm just wondering "what colors are really present in our universe," as in, what colors are actually out there in space? Not how they color it. That's my bad.

[Assistant] You might be mistaking a few things, lots of telescopes CAN capture colour, others do not. When you see a false colour image it isn't that the microscope is detecting something that we dont see, false colours are just substituted for other values to make things easier to see. For example, we cant see infrared radiation, but we can detect it with IR cameras, however in order to make sense of the data we colour different values of IR detection with different colours to create a "predator vision" type of image that can be useful to us. Similarly there are lots of telescopes that dont operate in the visual spectrum, they detect xray, or IR, or gamma bursts or microwaves, or some other portion of the electromagnetic spectrum, and we give these wavelengths false colours so that we can more easily visualize them.


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

[User] [DC] Does Batman know Torquasm Rao and Torquasm Vo? And how much do those martial arts actually help Superman given that ancient Kryptonians couldn't fly and he can?

[Assistant]
Batman certainly knows every technique he's ever seen Supes use to some extent, and more certainly he has video of Supes fighting, even people in his weight class, and he has used that video to recreate moves to see what he should add to his arsenal of moves, as well as the arsenals of his Robins.

Supes can fly, but he very rarely just nukes from orbit.  There are plenty of opponents who are too powerful for range attacks and flying into opponents causes a lot of collateral damage, so on occasion, with the strong enough opponent and in the right circumstances, he is going to stand his ground and pound away in a way that might almost look like a regular fight at high speed, not to mention he takes advantage of various holds and joint locks.  In those situations he'll employ his martial arts.


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

[User]
What's the highest possible IQ?

Now I know IQ measurements are extremely subjective, and no one test can really accurately measure intelligence (if such a thing can truly be quantified), but I was just wondering why some people make ridiculous claims about IQ.

From what I have been able to tell, IQ tests for adults these days generally tend to use a normalized distribution.  The mean is 100, and the st. dev. is 15

So by putting the numbers into a formula, an IQ of 195 would put you in the 0.00000000011 percentile, which would give you an IQ higher than 9 billion people, or more than there are on earth.

But yet some people like to claim to have IQs over 200.  is this even possible, or do I understand it all wrong?  It would seem like if the "smartest person on earth"  had an IQ of 195, then even an omniscient superbeing would only have an IQ of 196.  Is this even close to the correct understanding?

[Assistant]
Theoretically you are correct. But even if IQ scores are theoretically perfectly normally distributed over the entire human population, no test can capture this. People are born and die every second, and there is no way to test every single human.

So, an IQ test's scores has to be modeled on a small population and then that model is extrapolated to the whole population. Tests will often fall apart outside its statistical range; for example, a test for normal ranges (e.g. IQs of 60-150) may be too easy for people with high IQs, so a person with an IQ of 170 may get the same score (100%) as an omniscient being with a theoretical score of 195.


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

[User]
ELI5: using steel to get rid of smell

When I wash my hands with water and soap after handling fish, cutting onions or spilling gasoline, the smell doesn't go away. When I rub my hands agains steel, like the sink that I have in my kitchen, the smell is gone. How does that work?

[Assistant]
Some smells (Garlic, fish, onions) are because of sulphur (sulfur) based chemicals/compounds.

These sulphur compounds bind with some of the molecules of the steel (chromium oxide, produced when the chromium plating on the steel reacts with water), producing new substances which do not smell as strongly.

This only works with sulphur-based smells, but those happen to be some of the strongest smells to a human nose.


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

[User] ELI5: What is the point of a judge in countries where a jury decides if a prisoner is guilty or not?

[Assistant]
Juries decide issues of *fact* (did such and such actually happen).  Judges decide issues of *law* (who is allowed to testify, what questions are allowed to be asked, who has the burden of proof, what facts must be proved to establish a particular crime).

So, for example, in an ordinary rape case, the judge might explain to the jury that they need to decide whether the victim actually consented to a sex act, but in a statutory rape case, the judge might explain to the jury that it doesn't matter whether the minor consented to sex or lied about their age.  These are points of law that you wouldn't expect an average juror to know going into the trial.


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

[User]
[Batman] What is Bruce Wayne like to hang out with? Is he cool, charming, nice, etc - or is he a vapid asshole?

Obviously to keep up the appearance of a social life, he has to spend a fair amount of time consorting with fellow rich folk, going to parties, chilling on yachts, taking girls out on dates, etc.

It's established that this isn't Batman's actual personality, and he doesn't enjoy this sort of thing. Furthermore I'd imagine the rich playboy act rubs some people the wrong way. Nevertheless he needs to maintain social ties. So what impression do his "friends" have of the guy while they're with him?

[Assistant]
To fellow socialites, hes a decent enough guy to drink with but nothing special. Just another rich boy looking for the next supermodel, yet he almost seems to really buy into the charity thing.

To employees in Wayne Industries and those closer to him (but not too close), hes actually a fairly good guy who cares a lot about people and has more depth than youd first think. Just seems like the moneys his real problem.


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

[User] Why does having a bigger particle accelerator help reach higher energy collisions? Can't we just spin around in a smaller one for longer?

[Assistant]
The maximum momentum of the beam in a circular accelerator is set by the maximum main dipole magnetic field strength and the radius of curvature.

Magnetic field strengths are limited by technology, so in order to reach higher momenta, you need larger radii.


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

[User] ELI5:How is it that the US's economy is doing well, but paychecks are growing at a "record low pace?"

[Assistant]
Production per hour of labor is increasing, but the increased income from that productivity is mostly going to the shareholders and company executives.

This trend will continue as long as people are willing to work for the same low wages as before.  And before people start pushing for higher wages, the unemployment rate has to decrease.  It's hard to ask for a raise when you know that there are 100s of people to replace you at your current wage or below.


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

[User] [Dragonball] How is Vegeta's parenting skills?

[Assistant]
By human standards, pretty average on the positive side. Yes mainline Trunks is a bit of a brat but he didn't grow up in the ruined future that Future Trunks did.

Vegeta can be a bit strict but he does in fact spoil his family if given the opportunity & whatever Bulma says is what goes anyways.


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

[User] ELI5: Why aren't women required to sign up for Selective Service in the US?

[Assistant]
Because when the Selective Service framework was actually used, women were seen as weak. Many people don't think there should be a draft at *all*, so they would be very opposed to any change in the Selective Service Act except eliminating it.

e: To be clear for anyone who doesn't know, the Selective Service is America's military draft board. There is currently no draft, and barring World War III there probably never will be; the issues are basically just symbolic.


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

[User] ELI5: If hot air rises, then why are many low-lying areas so hot?

[Assistant]
Hot air rises, but the atmosphere cools the higher up you go. The reason for this apparent contradiction is that pressure decreases the higher you go, which allows the air to expand. And when gases expand, they cool down.

The hottest places on Earth are the result of warm, moist air rising, rain falling on high mountains, and then the resulting dry air falling on the other side. Moist air heats and cools by a smaller amount as it rises and falls than dry air does, so what happens in those settings is you get something like:

30 C moist air -> rises up and becomes 10 C moist air (loses 20 C as it rises) -> rain falls -> now is 10 C *dry* air -> descends the other side of the hill -> heats up by more than it cooled down before and hits the valley as 40 C dry air (gains 30 C as it descends).


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

[User]
[Star Wars] How does a slave come by the name Skywalker?

Sounds like the name of a pilot or stellar nomad.  Was there a Skywalker clan that Shmi came from?

[Assistant]
Shmi is the earliest Skywalker we know of.

In Legends, her and her family were traveling in the Outer Rim, only to be captured by pirates. Whether or not they are named Skywalker is unknown.

In both Canon and legends we really have no idea about the Skywalker name. Perhaps they were from a long line of pilots and adventurers, only forgotten by time around Shmi's birth. Perhaps Shmi gave herself this last name to sound appealing to potential buyers. Maybe one of her master's gave her that last name.

Really the point is that Shmi is the flat out beginning of the Skywalker line in many forms. And for Legends standards, she is quite under developed as a character.


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

[User]
ELI5: What happens when someone gives birth on a plane?

What citizenship does child hold? Does the child also get free flights for life?

[Assistant]
> What citizenship does child hold?

It obviously varies by the laws of each country, but generally the child will get the citizenship of its parents (the same would happen if the child was born while the parents were on vacation).

> Does the child also get free flights for life?

That's up to the airline to decide.


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

[User]
ELI5: How do stores with self-check out lanes ensure that all products bought are accounted for?

Other than an employee or two standing by, it seems to be riding on customer trust. Wouldnt a company want to only have cashier lanes, so they can ensure that all products taken from a store are bought fairly?

[Assistant] Honestly, the money saved by having to hire less people to manage check-out lines ends up making up for the occasional item that doesn't get scanned. The majority of people aren't thieves, and will be honest when scanning their groceries. These stores see how much money they made before and after self-check out, and have found that they are saving money by having them, even factoring in inventory checks to see how much is getting stolen or lost.


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

[User] ELI5:Why does milk become spoiled when left in the heat but not when heated?

[Assistant] Milk is spoiled by bacteria. Most bacteria grows fastest in a warm environment. Leaving milk to warm up over a long period of time gives the bacteria the warmth it needs, and plenty of time to multiply. When you heat milk quickly the bacteria doesn't have enough time to grow to substantial numbers and spoil the milk.


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

[User]
ELI5 How did mankind discover metal?

This has always bothered me. Like how did ooga booga caveman discover that if you heat up yellow rock you get better ooga booga axe. Pls explain I'm going insane.

Edit: Thank you everyone for answering now I can sleep well.

[Assistant]
We would find out naturally that clay left out in the sun would harden.

Putting said clay into a fire would do the same thing, but quicker and produce a more hardened clay that did not revert back when wet (as opposed to just sundried clay).

Clay might have impurities in it, such as trace amounts of ore that, in a hot enough fire, would melt the metal and leak out, which would turn very hard when cooled.

Find concentrated or larger deposits of these impurities and do the same, and you get more of this harder substance.


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

[User]
Does our universe expand faster than the speed of light?

Just wondering if it's possible to ever reach the "edge" of the universe.  If it's possible, what would happen?

[Assistant]
1) According to our best models and data, the universe has no edge. It's either wrapped back around on itself like a three-dimensional sphere or (more likely) infinite in extent.

2) According to our best models and data there are and have always been objects far enough away that their recession velocity as a result of expansion exceeds the speed of light.


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

[User]
ELI5: Why do we use bronze on buildings and statues if they're only going to turn green? Do the creators know the work will turn green or is it a sign of a lack of upkeep?

For example, in Philly there's a building with green roofing because the roof is bronze. Did the architect know his work would change color or what? Thanks!

EDIT: Copper.  Not Bronze.

[Assistant]
It is a choice made in the design of a building...

Originally it had to do with longevity and reliability of the materials - if you look at steel, the rust that forms when it is left exposed is detrimental - as it rusts the material degrades and gets thinner and weaker until it fails. So steel needs maintenance and protection to last long term (such as bridges being painted, or having steel encased in something like concrete to protect it). The green of bronze however is actually helpful - initially it is nice and shiny, then degrades to the green colour we commonly see, at which point that green layer has created a barrier around the metal, so it doesn't degrade any further. So once it reaches that point it needs relatively little maintenance and upkeep - great for a feature dome at the top of a roof you don't really want to have to access regularly.

It is also worth remembering that most of these structures are traditional ones, built when technology and materials were far more limited, so the green roof was a small price to pay to be able to actually build the structure that may not have been possible with other materials.

Nowadays it mainly comes down to architectural reasons - it will be used to give a certain look and design to a structure that the architect desires.


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

[User] [Deus Ex]How does the grey death kill you?

[Assistant]
The two primary symptoms appear to be a progressive respiratory infection and skin discoloration, so best guess is that it kills you by gradual suffocation. Possibly may also result in more conventional pneumonia by compromising the immune system, which leads to the same end.

However, Grey Death is a nanomachine disease, so it *can* kill you in any way it is programed to. Much as Ambrosia will issue a temporary shutdown order to the Grey Death, you could theoretically issue orders to multiply exponentially off the host's tissues, which would lead to a very rapid death.


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

[User]
[Lord of the Rings] Why exactly were the black riders so dang meek?

Currently reading the Fellowship for the ~5th+ time.

The wise say at various points that the black riders were hesitant to commit to any action before all nine were assembled. But why? Why did they need to be so careful and meek?

According to Gandalf's speech at the Council of Elrond, Sauron had already "declared himself" openly some time after returning to Mordor from Mirkwood. And he was already warring openly on Gondor. Why couldn't the ringwraiths just go mess stuff up in the Shire and then Bree? Sure, Aragorn was at Bree, but what did the riders have to lose? And why were they so meek beforehand?

I realize they literally didn't know where the Shire was, but they seemed to get decent enough information when they talked to some folks. Even the Gaffer told them where Frodo was heading. And surely they could've easily tortured the hobbits for more information?

Between Bree and Weathertop, sure, Aragorn's skillful leadership would've led the pursuit astray. But after Weathertop, they took 17 days to get to the fords, moving slower and slower towards the end, and there was no sign at all of the ringwraiths. I know Glorfindel was hanging around as well, but the nine were clearly split up, so surely Glorfindel couldn't keep them all away at once, especially as he didn't actually know where the party was anyways.

Aragorn mentions at one point that, since Frodo was stabbed, they would be content to wait and let him come under the spell, their work nearly complete. So why not just finish it?

And they were there, ready, at the fords, and yet still somehow they don't block it off in time?

Or, to summarize it: Why take so many chances when we're talking about the freaking *ring*? Just get the damn thing.

[Assistant]
I dont know if there's a canon answer, so just spitballing here.

- The Nazgul are ageless, but not immortal.  They can be killed by a good old fashioned stabbing with a magical sword, as the Witch-King finds out.  This makes them cautious to a fault, more interested in preserving their own lives than accomplishing any given mission for Sauron.  Even the most important mission for Sauron.

- Sauron had declared himself, but had not declared that he knew where the ring was yet.  We take it for granted now that everyone knows Frodo held the One Ring, but even Gandalf needed to consult some old scrolls to be sure, and took his sweet time doing so.  They didnt necessarily know that Frodo knew and understood what he had, but they know once they're assembled they'll tip off everyone to the fact that they're after the ring.  Once Sauron's enemies know they have the ring, there is the risk that they might use the ring, and might even master it.

- For a combination of the two points, the Nazgul might not actually care who their master is, so long as they keep their lives.  If Gandalf masters the ring and overthrows Sauron, he'll need lieutenants to spread his glorious perfect order, and the Nazgul will gladly bow to him.  From this perspective time is on their side; they're going to live forever, it doesnt matter who ultimately wins, so nothing, not even the ring, is worth risking their lives.  The idea that someone might actually destroy the ring is simply unthinkable.


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

[User] ELI5: Why do paper cuts hurt so much more than larger cuts? Shouldn't a smaller cut be less painful?

[Assistant] Because they don't bleed. Which means the nerves are open to the air. Most deeper cuts the blood will start to form a clot and protect those open nerves. But with a minor cut like that, the exposed nerves have nothing to shield them.


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

[User]
What makes a colour "neon"?

Is there a special ingredient in neon yellow or neon orange dyes or colours that makes them particularly glowing?

[Assistant]
A so-called neon dye or paint is actually fluorescent, which means that it can absorb a short wavelength photon, such as UV or blue, and emit a longer wavelength photon, such as yellow or orange.  A normal yellow object can only reflect a small range of the spectrum of light contained in the light illuminating it.  But fluorescent yellow can additionally convert the energy in the blue part of the spectrum, as well as any UV, and concentrate that energy in the yellow range, making it brighter than a normal yellow object.

This is the same phenomenon as in a fluorescent lamp where the phospher coating on the inside of the glass absorbs ultraviolet created by the mercury arc inside and converts it to visible light that is emitted through the glass.


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

[User]
[MCU] Why didnt the Ancient One protect all of their Sanctuaries with runes a.k.a the Fundamentals of Magic (note: very minor WandaVision spoiler included)

So in the last episode of WandaVision;

 >!Wanda tries to use magic in Agnes basement and Agnes scoffs at her and talks about how there are runes in each wall which are basic protection spells and how this knowledge is the basic fundamentals of magic. !<

Is there a reason why the Ancient One couldnt have protected all of the Sanctuaries from Kaecilius and his zealots, with something similar?  Kaecilius was able to enter and leave these sanctuaries with impunity...

Does Wizard Magic and Witch Magic work differently?

[Assistant]
The Sorcerers of Kamar Taj work together, so a spell the prevents all but one Sorcerer from using their powers would severely hobble them.

- Strange and Mordo worked together to take on Kaecilius
- Wong and about a dozen students worked together to defend Hong Kong

It's also possible, though unlikely, that the Ancient One was unable to work Agatha's spell; Agatha doesn't seem to use the same sort of sigil-summoning magic as Kamar Taj (and neither does Wanda, for that matter).

Agatha and Wanda seem to use innate magical ability, whereas Kamar Taj *teaches* magic. In D&D terms, Agatha and Wanda are sorcerers, while Kamar Taj are wizards. They might operate under different rules.


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

[User]
ELI5: Why do we make our weekend parties run during the hours we normally sleep? Why not party and disco during the hours we are awake every other day of the week?

I have party/disco thing this weekend and it starts at 10pm and goes until 4am. The most normal sleeping times I would expect are something like 10pm to 6am (maybe 12am to 8am but whatever). The point is that everyone sleeps during these times every night of the week - then suddenly, STOP that, it is time to party when you are meant to sleep! Then sleep when you are meant to be awake for precisely ONE day, then return to your normal sleep-work pattern.

Why not just dance and party during the day?

[Assistant] People in their 20s and early 30s often have to work weekends and may have other errands to run during their days off.  By putting the start time late at night you're ensuring that everyone is actually available.


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

[User]
[Matrix] What does an ordinary mission into the Matrix look like?

Most of the missions we see the crew of the _Nebuchadnezzar_ undertake are related to Neo and the prophecy of The One. In the first movie, we see three such missions:

1) Trinity and Morpheus contacting Neo and helping him escape

2) The crew taking Neo to meet the Oracle

3) Neo and Trinity rescuing Morpheus

In the second film, we meet a number of other captains and crews of other ships, some if not all of whom must undertake their own missions into the Matrix. However, not all of them work with Neo or even believe in The One, meaning their assignments must be completely different to the _Nebuchadnezzar's_. These captains are also still important enough to be meeting with the council and helping plot the defense of Zion.

What does an "ordinary" mission into the Matrix look like, one that doesn't involve The One at all? What are the usual objectives, and the usual amount of resistance met?

[Assistant]
You should look into the game "Enter the Matrix", which follows the crew of the *Logos* before and during the events of "The Matrix Reloaded" and after the Animatrix story "Last Flight of the Osiris".

As we see in the game, typical missions include gathering dead drops/data bundles left by other crew, contacting other ships' operators via coded messages (which gets interrupted when you need to rescue another operative) and generally recruiting other people into the resistance.


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

[User]
Why can GPUs do more floating operations per second than CPUs?

I've read that modern GPU can do up to ~2 Teraflops while an Intel is ~80  Gigaflops, also GPUs have hundreds of cores while a modern CPU around 8 to 4.
Why is the calculation difference between these processors so big?
Why do we not use GPUs instead of CPUs?
Is there other types of specialized processors that give an advantage for a certain type of calculation?

[Assistant] A GPU is basically a big multilevel bank of computation units.  It is made for performing the same instruction many times on slightly different data inputs.  A CPU typically has one or rarely a small number of computation units per core, but is optimized for serial operations.  In practice, it is usually impossible to get the full efficiency out of a GPU because you usually can't fill up all the computation units at the same time.  A GPU is great if you want to quickly do a set of identical operation on a large dataset and you can run those operations in parallel, say when rendering graphics.  However, if you want to just execute a sequential series of operation, then a GPU is unoptimized for that task and you can't use more than a fraction of its power.  An analogy would be to describe the GPU as like a sweatshop, where a massive amount of a specific product is produce by numerous but relatively unskilled labors.  In contrast, the CPU is a more professional firm, with fewer, but better trained workers, capable of only a few jobs at a time, but is better equipped for a diverse set of jobs and the better training can often allow a specific job to finish faster.


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

[User]
[Star Trek] If the Borg incidents with Picard hadn't happened, would Earth have been left weakly defended at the time of the Dominion war such that the Breen attack would have been disastrous?

Would Dominion forces have been able to easily warp deeply into Federation territory?

[Assistant]
If the Federation wasn't so weakened, would the Romulans have felt like joining the conflict when they did? Would the Federation have *needed* to deploy space-AIDS against the Changelings if the war was going better to start with? Would Sisko have ever come to Bajor if his ship didn't get gnawed on by the Borg? The thing is that DS9's plot is extremely tightly wound. There's a lot of interconnected moving parts and changing things would cause this huge ripple.

It could've ended up worse for everyone, it could have gone better. Earth probably still would've gotten attacked because they flat out did not expect it. They might not have gotten so trashed, but it probably would've still happened.


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

[User]
ELI5: Are ISIS the Syrian rebels the US government wanted to send arms to when the Syrian civil war broke out?

I seem to remember McCain and other senators saying they wanted us to send arms to help the Syrian rebels against Assad. As far as I'm aware ISIS is fighting Assad, so were we trying to send arms to them?

[Assistant]
No.  There were several rebel groups fighting against Assad.  The one(s) the US was thinking of sending arms to were largely secular.

ISIS, however, has been more effective at building a solid fighting force in Syria and beyond.  The secular rebel groups are now a small minority of the rebels in Syria, and will probably have little to no say in a new government even if Assad falls.


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

[User] Why do some people, such as medical doctors, use cubic centimeters versus milliliters since they are essentially the same unit?

[Assistant] Simply:  for historic reasons.  It's just something that's endured, like the odd measurements in blood sugars (milligrams per deciliter), or oddball units like mmHg (when in SI, this ought be in pascals (Pa)).


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

[User]
ELI5: "Race is a social construct"

I don't understand this. What is the explanation for race being a social construct if there are observed biological and physiological differences between different races?

Clan mentality certainly is a social phenomenon amongst humans, but the catalyst of that clan mentality is race, and what race a person is is a product of biology and breeding.

So, when I hear people argue "race is a social construct", trying to give it no credence, with an underlying social/political agenda, it makes me wonder how they can make such a claim when there obviously is an innate biological difference among races.

Thank you so much!

EDIT: Thanks for all of the awesome responses. Follow up question, what exactly is the difference then, between race and ethnicity? Thanks!

[Assistant]
The problem is that we divide people based on superficial and largely irrelevant traits simply because those particular traits are easily visible.  As a result, all people from southern Africa tend to get lumped into a single category such as "black", even though most human genetic variation is found in those populations.

To put it another way, two random black Africans are likely to be genetically more distant from each other than either one is from a random "white" European or Japanese, even though the common understanding is that these are different races in some meaningful way.

And aside from that, all the different categories we can construct based on physical appearance are going to shade into each other anyhow.  Humans do vary quite a bit, but dividing them up based on gross physical traits obscures a whole lot more than it illuminates.  For instance, a person with one parent of mostly African ancestry and another of mostly European will generally be considered black in the USA but white in Haiti.  If that doesn't point to a powerful cultural influence on these classifications, then what does?


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

[User]
[Halo] Can fuel rod guns be effective area denial weapons?

So sorry If I'm misusing military terminology... So, fuel rod guns fire a big blob of incendiary, radioactive gel. I remember in "Halo: First Strike" a Spartan commented they couldn't keep using them in a confined space due to radiation concerns, presumably because they had two unshielded, unarmoured humans with them. With this in mind, say I have a fuel rod gun and say, thirty, fifty, one-hundred rounds, could I perhaps plaster an interior space or somewhere somewhat enclosed (so the Covies can't just go around it) and prevent the Covenant from attempting to pass it?

Will they even care? Presumably Elites will be radiation-resistant thanks to their armour and shields, but how will the other Covenant fare? Will they just not care and trample over the lukewarm radioactive gel-covered ground, radiation sickness be damned?

Your thoughts?

[Assistant]
Wouldnt work well unless you wanted to deny an enemy a position *after* the war was over. No one wants to live in a city with high levels of ambient radiation.

If you tried to use it in a confined space all that would happen is in the following days or weeks people might get cancer. Even if it was stupid radioactive you have hours of combat effectiveness.


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

[User]
ELI5: Why hasn't anyone actually attempted assassinations of the North Korean leadership?

With all this talk of how The Interview is now cancelled because of North Korea, I'm curious why it hasn't been attempted? Their citizens are basically starved prisoners, and there are executions frequently. No one is really gaining anything from them, except for maaaaaaaaaybe China. So why has this not happened?

[Assistant]
North Korea is controlled by a bunch of psychos, but in the grand scheme of things, are powerless. They like to make a bunch of threats and bomb a few South Korean ships and islands, but don't actually constitute much of a threat. However, if you try to attack North Korea, you're gonna cause a bunch of problems. They have medium-range missiles that are capable of hitting South Korea and Japan, even though they probably don't have the capability to launch a nuke on these missiles. Also, North Korea has a lot of very poor people. If the country collapses, you're suddenly dealing with millions of refugees.

TL;DR: It's easier to ignore North Korea than to actually fight with them.


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

[User] Why are battery voltages selected at the values they are? What is special about 12, 5, or 3.7 volts?

[Assistant]
First, you should differentiate between battery and cell. A battery is composed of many cells. A cell is an individual electrochemical cell. Thus, battery voltage will always be a multiple of the cell voltage for that given chemistry.

12V is common in vehicles. It's low enough not to be dangerous, and require relatively few cells, yet high enough voltage to crank the engine.

A lead-acid cell has a voltage of around ~2-2.1V, so a 12V battery is composed of 6 cells in series.

Lithium-Ion cells commonly have a voltage around 3.7-4.2V, a bit depending on the exact details of the cell. Thus 3.7V is fairly common for low voltage devices; it's a single cell. Other common voltages is 7.2V.

Basically the cell voltage is *always* dictated by chemistry, and the battery voltage by need.


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

[User] If someone gets a blood transfusion, wouldnt they have a mishmash of genetic material appear in a DNA test?

[Assistant]
From a review of an article in *Scientific American*:

Scientific American explains that when donor blood is mixed into the body with a transfusion, that persons DNA will be present in your body for some days, but its presence is unlikely to alter genetic tests significantly. It is likely minimized because the majority of blood is red cells, which do not carry DNA  the white blood cells do. That publication notes studies have shown that highly sensitive equipment can pick up donor DNA from blood transfusions up to a week after the procedure, but with particularly large transfusions, donor white blood cells were present for up to a year and a half afterward. Still, even in those latter cases, the recipients DNA was clearly dominant over the donor DNA, which is easily identifiable as a relatively inconsequential interloper.

====

This review raises a question for me.   Suppose the white blood cells from the donor, that can persist for up to a year in the blood of the recipient, have a high risk of becoming cancerous.  Is there any evidence of this occurring, that is, a recipient developing cancer of a type of white blood cell that came from a donor ?


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

[User]
ELI5: what does it mean when a game engine is tied to the fps? why is high fps sometimes casuing problem?

playing ff14 atm and the devs said any fps above 90 fps causes game enging problem problem and apparently causing  out of bound issues and stuff, how is that related to fps? isnt that more like model collision?

[Assistant]
So tying a game to frames per second means that certain actions are updated on a per-frame basis. The simplest way to think about this is, consider a ball that bounces up and down. To create this we need to track acceleration, velocity, directional, and current position. Given we have finite resources, we can not track this in a continuous manner. Instead we need to update all these on a schedule. We could set this schedule to be every **X** milliseconds. Alternatively, we can tell the engine to update the numbers every time a frame is rendered. The issue with this, is that as frames increase or decrease, we change how often we update numbers. In this toy example that isn't necessarily a problem.

I will give two real world examples where this does become a problem. The first is Skyrim. Their engine is tied to FPS. In fact, when you go over 60 FPS everything tends to go berserk. But a real issue is with attacking and damage. Attacks occcur and then there is a "cool down" before another attack can happen. At higher FPS, these attacks can occur faster than at slow FPS. On the flip side, the player can take far more damage in the same "wall clock" amount of time. So in a way the game does not have "damage per second" but rather "damage per frame." So at 90 FPS, you can take 50% more damage per second, because there's more frames for this damage to occur in." It doesn't work exactly like that, but you get the picture.

The other example works exactly like that is Call of Duty Advanced Warfare. One of the weapons in that game was a laser cannon that dealt damage every frame. This is fine on consoles which all run the same frames per second. On PC however many players have 100+ FPS. Console generally run between 30 and 60 FPS (I believe AW was locked to 30 FPS.) This meant on PC this laser cannon did over three times the damage it did on consoles.

The moral of the story? Don't use frames to updated your game.


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

[User] ELI5: How do free softwares like VLC Player make any money?

[Assistant] Broadly speaking, they don't, but that's okay because they aren't trying to. VLC is "community-developed" software; it's just a bunch of people who got together to write a video player because they wanted to.


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

[User]
Eli5: How does GoodRx work..?

How are they able to save money for so many patients without going into loses?

[Assistant]
Healthcare gets really weird in the United States. When you look at the price of medications, it usually has very little to do with the actual cost of making the medication, and much more to do with a lot of other things.

Let's make up some numbers and say drug A costs $1 to mass-produce a 30-day supply in a factory in India. Shipping and storage add costs, so the pharmacy pays $2. The pharmacy has to keep the lights on and pay its pharmacists and pharmacy techs, but they do a lot of volume and keep things efficient, so charging $10 for the prescription means they can turn a small profit.

Now, let's say the pharmacy takes Insurance B. Last year, they told the insurance they needed $10 to break even, but the insurance is trying to keep costs down as well, so it said it would only pay 80% of that. The pharmacy is losing money, so this year it claims it needs $15. Insurance cuts their payment to 66%, but that's just enough for the pharmacy. Repeat this cycle until the pharmacy is claiming $100 and the insurance is paying $12. \[In reality this gets even weirder, because a pharmacy one block away may be charging ten times more or less. The contract is actually with something called a PBM, which is a sort of middleman that has been the target of many lawsuits.\]

Now, a customer with no insurance shows up. The pharmacy has sworn in its contract with insurance that the true and appropriate price for drug A is $100, and cannot charge the customer less without getting in trouble.

GoodRx has its own set of agreements with insurance/PBMs. It simply provides a contract-legal way for that patient to access the same kind of "discount" pricing that insurance B offers That's the incredible thing: GoodRx doesn't actually pay for this discount. GoodRx actually takes a cut from what the customer pays (and pharmacies are more or less willing to go along with this since it still means steering a customer towards them, not that they have much choice.) What it does is allow customers who aren't using insurance to access the "discount" that someone using insurance would get. It's a sweet gig that exists because the American healthcare market is seriously distorted.

This same problem exists a lot in American healthcare. Hospitals charge an enormous fee, knowing that insurance will only pay a small fraction (which is closer to what the hospital actually needs to keep the lights on.) Uninsured patients must be charged that full enormous amount, because that's what the contract said.

**TL;DR: GoodRx exploits a sort of contract loophole that allows people to access discount rates, and gets paid to do so without having to spend anything.**


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

[User] [META] Could we keep Star Wars:TFA out for a few days?

[Assistant]
> * Do not put spoilers for recent works in post titles. (6 months should be fine)

Right there in the sidebar. There will inevitably be a metric butt-ton of questions, and it'll be nearly impossible to shut them out in any meaningful way. A more effective solution might be a stickied reminder on the main page that spoilers need to stay out of topic titles.


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

[User]
ELI5: How do researchers decide how big a study needs to be (ie sample size) to give a reliable read on whatever theyre observing?

Ive always wondered this. Ill sometimes see the most random numbers ranging from <10 to >10,000.

[Assistant]
The really simple version: there are mathematical formulas that tell you how reliable the results from a particular sample size (and design) are. This could be in terms of a "margin of error" or it could be a test to accept/reject a null hypothesis (the two are very closely related).

The more complicated version:

The first thing to note is that this only measures the reliability of *random samples*. This could be taking a population of people and randomly picking some to interview, it could be randomly picking out records from a database to look at, it could be repeatedly taking a measurement where your instruments aren't perfectly accurate. (In some cases you can also improve reliability by dividing your sample into groups which are similar and taking a certain sample size from each of these groups.)

It doesn't take into account any other problems with your sample, eg. certain types of people refuse to take part in your research, or with your measurement, eg. your instruments are calibrated wrong so always measure too short.

The second thing is that you generally don't know how big your margin of error will be until you actually do the measurement. Let's say you're getting people to rate something on a 1-7 scale. Your margin of error will be smaller if most people score 3 or 4 than if they're spread all across the scale. (If you have some idea what your results will be, eg. someone's done similar research before, you can estimate this margin of error.)

The third is that you still need to decide how "reliable" you need your results to be. There's a rule of thumb in science that a power of >0.05 is good enough for a result - that means there's a 1 in 20 chance that you've accepted a hypothesis when you shouldn't. Is that good enough? This is a controversial subject. For example, the experiments to look for the Higgs Boson used a much stricter test. If your research comes up with a very unexpected result that seems unlikely, perhaps you should be looking for a more powerful test. If you're expecting to see a small difference, you're going to need to design a powerful experiment to reliably find it.

(I do research in a business and for me the answer to the question "how reliable does this research need to be?" is "what are the consequences of being wrong?" How much money are we staking on this? How easy is it to change course if we turn out to be wrong?)


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

[User] ELI5: Why does outlets have a ground wire if neutral and ground are connected anyway at the fuse box?

[Assistant] They do not serve the same purpose. The white neutral wire is the grounded conductor and completes the circuit. The bare or green ground wire is the grounding conductor that serves as a safe return path should something go amiss in your electrical device or wiring path. So instead of your metal appliance holding an electrical charge that can shock you, that charge returns via the bonded ground. ELI5 version.


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

[User] ELI5: Why are the ceilings in supermarkets so high?

[Assistant]
1) To keep it from being claustrophobic. If it had short ceilings being in isles would feel like tunnels.

2) Heat management. There are dozens if not hundreds of people in the store at any given point in time. That produces a lot of body heat. It is cheaper for them to have high ceilings for that warm air to go to and be replaced by cooled air from the AC ducts that are set lower.


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

[User]
[Harry Potter] Wizard's Woeful Incompetence

How in the world has the wizarding community in general managed to keep itself a secret for millennia when most of them don't seem to know what electricity is? Don't they have a rudimentary understanding of physics and subatomic particles? It seems like everything is rather precariously balanced on the verge of almost-being-found-out-ness. What if a muggle leant on the window into St Mungo's? Mind wipe, yes, but seriously, it must happen every few weeks. What if a muggle found a moving photograph? It seems impossible that absolutely no muggles have ever, *ever* seen a wizard perform magic and told anybody.

[Assistant]
There's a lot of charms to protect witches and wizards. They can make objects impossible to mark on a map, including satellite. They can make it so Muggle minds absolutely cannot focus on, or even see, an object. Of course, there's the memory wipes, but those are a last resort. If a Muggle picked up a moving photograph, the person depicted would probably stop moving or vanish.

Keep in mind also that they work with Muggle governments fairly easily. A dozen people could report seeing a battle over the sky with broomsticks, and most Muggles would think them mad. And, if it were reported, the Muggle Governments would cover it up.


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

[User]
If there is a nothingness that is beyond imagination, wouldn't all attempts to define it lead to a paradox?

Wouldn't it be like writing down a description of a blank piece paper using that same paper? The blankness would be effortlessly self-explanatory and any effort made to write a description, no matter what symbols you use, would work against you. The more symbols you write on that paper the more you have to look past them in order to see the blankness they move upon. Or just erase them all together.

Or what about in terms of sound and trying to talk about silence? Wouldn't it be best to just be silent? Even if you do try to define silence, again it doesn't matter what language you use, whatever you say breaks the silence and moves you away from what you're trying to define. Wouldn't I be better off just ignoring everything you said and waiting for the sounds you made to move on?

Well what about if I was trying to imagine nothingness? Wouldn't it also be best explained by not making no effort to imagine it? And wouldn't anything you imagine about it would just obscure the nothingness that the imagined image moves upon?

[Assistant] It sounds like you might want to look into Ludwig Wittgenstein. In particular he has some ideas concerning, "saying" vs. "showing" in that, some things can't be said, only shown. Also, in his line of thinking, your question might be considered nonsensical, in that it's our lack of understanding of the grammar of our language that allows us to even form questions like "what is the good" or "something beyond thought" (to paraphrase your question). Since for something to be "beyond imagination" suggests that it cannot be conceived of at all. Given that state of affairs there would be no way to describe it with language since that would require a conception of it on our part. Check out a summary of the Tractatus Logico-Philosophicus, it might provide some insight into your question.


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

[User] Do all mammals have a menstrual cycles? Are there any species where the males have cyclical fertility?

[Assistant] There is some disagreement in definitions between sources, menstruation is generally considered to be limited to primates. Females of other species of placental mammal undergo estrous cycles, in which the endometrium (lining of the uterus) is completely reabsorbed by the animal at the end of its reproductive cycle. To answer your second question, there aren't any male mammals with a "reproductive cycle" but there are males that carry offspring and birth them rather than the female i.e Seahorse.


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

[User] ELI5: How do parasites, like tapeworms, manage to survive the gastric juices of the stomach and get to the rest of the digestive tract?

[Assistant] Threadworms or pinworms actually use the stomach acid to trigger hatching. The eggs are ingested and the stomach acid strips away the sacrificial outer layer causing them to hatch later when they have passed through to the lower intestines. The adult worms irritate the sphincter to aid the dispersal of the eggs by scratching so that they are not simply passed into the stools of the host but are instead lodged beneath the fingernails etc.


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

[User] [ELI5] What do CEO's of Forbes 500 companies do exactly and why they are so generously compensated?

[Assistant] Their two key jobs are selling the company to investors and setting the company's strategy.  They get paid a lot partly because the executives are a sort of reward for all the lower level managers, and partly because good strategy earns the investors a phenomenally large amount of money so even a small share is an enormous amount of pay.


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

[User] ELI5: What, physiologically speaking, is a "puffy nipple?"

[Assistant] There's more breast tissue directly under the nipple pushing it out. It's just caused by genetics, and it's not really particularly any more interesting genetically than say having blue eyes, or a large or small nose or whatever.


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

[User]
[12 angry men] But who killed the kid's dad?

It was someone who had the same model knife and stabbed him the exact day that the kid lost his knife. or someone who had access to the kid's knife

also, it was someone who could pass for the kid in front of a woman who may not have (but may have) been wearing her glasses.

Who could have done this?

[Assistant]
Regarding the knife, it was suggested (by the juror going out and easily buying one) that it was exceedingly common and easily acquired.

The racism of the period (again, thoroughly demonstrated in text and movie) suggests the identification of the suspect was of the 'they all look alike,' variety, so almost any non-white male could've been the actual attacker.

Based on what we can infer, it was likely a random crime of opportunity, such as home invasion for theft or a breaking and entering gone wrong, that lead to the fathers death.  Due to the lackluster efforts of the police, it's likely the actual perpetrator would never be found.


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

[User] [Dragonball Z] How would things have differed had Goku not hit his head in infancy?

[Assistant] He would've killed everyone after going ape form. Then Raditz would've scooped him up in a few years and they'dve joined Vegeta to go do some hood rat shit across the galaxy, probably rebel against Freeza eventually.


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

[User]
How does iron exist IN the earth without rusting?

Better yet, how do we have it in our blood without it out oxidizing? There's water and oxygen in our blood.

[Assistant]
Rust is an iron oxide, and iron cannot exist in a pure state in an oxidizing environment--so yes, pure Fe iron is not found in your blood or in the earth. However, iron can form plenty of compounds and complexes in the body and the earth that ARE stable even when water is around to potentially form rust.

Let's start with blood: iron in red blood cells actually DOES oxidize--but it's not a very strong bond. In your red blood cells you have heme complexes, which consist of an iron atom that is strongly stabilized by a ring of nitrogens. Oxygen can still bind, but it's weak, and the oxygen can dissociate from the iron easily--that's how we transport oxygen in our body. Oxygen associates to and then dissociates from the red blood cells, distributing it throughout our body. The nitrogens stabilize the iron enough that it can "let go" of the oxygen.

In the earth, iron can form a lot of different stable compounds--even ones containing oxygen--that we wouldn't necessarily recognize as "rust". For example, pyrite ("fool's gold") is an iron molecule stabilized by bonding to two sulfur atoms. Both sulfur and oxygen "donate" negative charge to the iron atom, making it stable in the earth. Another example is magnetite--you wouldn't look at it and think "rust", but it's just a pure iron oxide. Magnetite is Fe2O3, "rust" is a hydrated form of FeO2.

On a thermodynamic level, iron can form a lot of different compounds besides rust, and many of them are stable enough that they won't be converted to rust, even if free iron (Fe) would immediately react.


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

[User] [My Hero Academia] If there was a Villain Ranking like the Pro Heroes who would be in the Top 10?

[Assistant]
AFO (Obvious)

Shigaraki (Obvious)

Kurogiri (Too much utility and power, not that strong. But even the heroes are wary of his portals)

Gigantomachia

Chisaki (smaller scale but ready to wipe out quirks)

Harima (we dont know much, but hes mentioned with AFO)

Stain (Serial Killer and pretty op power)

Toga/Twice/Muscular in no particular order.


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

[User]
ELI5: how does a smart watch know what phase of sleep you're in?

i imagine it tells rest from sleep by heart rate but how would it know if I'm in REM, or "deep sleep" or whatever other phases it says. are they ALL distinguishable by heart rate alone?

how legit is this readout anyway?

[Assistant]
Your heart rate drops when you are in deep sleep (compared to light) and raises when you are in REM. It might also look at movement and (depending on your watch) skin temperature/blood-oxygen levels which change as well.

It's not as legit as, say, a sleep study where they stick sensors to your head to read your brain waves, but it's fairly accurate for what it is.


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

[User] [Stargate] Why didn't the SGC have the iris perpetually closed until the wormholes where safely open?

[Assistant] Probably got disintegrated every now and then from the unstable wormhole still managing to be occasionally formed. Plus someone might be coming through in a hurry. Safer to have it open and ready then need to open it if they need to come in.


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

[User] [Game of Thrones] Why for 8000 years Night's Watch didn't come to conclusion that wearing black clothes on lands covered with snow isn't the best idea when you try to be sneaky and kill your enemies?

[Assistant]
Back in the day during their creation they had thousands of men and 19 castles to man. It had less to do with covert ops and more to do with identifying your dudes vs wildlings and other evil shit. Those are their team colors.

Additionally if you are sneaking around dont do it during the day, do it under dark where black clothes will help.


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

[User] [Fullmetal Alchemist] Did humans evolve naturally and if so how did the soul evolve?

[Assistant] Ironically for a setting that talks so much about the soul and it's value they never actually establish that souls exist. One person (the father of the faux elric brothers) develops a way to make redwater and therefor eventually a philosophers stone out of plants. So either 1. plants have souls or 2. nothing has souls and the force that animates organic matter is simply extractable by alchemy, the more something can move and think the more you get for melting it.


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

[User] I want a job working on smallish programs like tooling, utility scripts, internal software. What do I look for on job sites?

[Assistant]
Honestly you don't.   Jobs working on smallish programs like tooling, utility scripts and internal software come with the more bigger responsibility like maintaining actual said software your company needs to support.

In a proper company it's part of the job.


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

[User]
IAMA Economic Geographer. Ask me Anything!

Hi everyone. I'm an Economic Geographer whose currently finishing his PhD. My dissertation research looks at how the interaction of local and global economic and social forces affects entrepreneurship in Canadian cities, but I've also done research on innovation, clusters, and the geography of the financial crisis.

I'm just sitting here, waiting out the hurricane and reading about the influence of the American oil industry on Calgary, so I'll try my best to answer all the questions I can!

[Assistant] How do you think fair trade policies has influenced the growth of local economies in developing countries? Do you think that fair trade policy is an efficient way to influence development, or do you think that the majority of gains from the fair trade label go towards the businesses that market them?


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

[User] ELI5: Why do some airplanes have the wing tips folded up at about 80 degrees and some planes do not?

[Assistant] A wing provides lift because it creates low pressure on top of the wing, and higher pressure below. As a side effect this causes the air to swirl around the tip of the wing in an effort to equalize the pressure as air on the high pressure side tries to reach the low pressure side. This is undesirable because it screws up the airflow around the end of the wing, and also creates dangerous vortexes that trail behind the aircraft. One way of minimizing this problem is by using "winglets" that serve as a fence to block the air under the wing from being able to curl around the end. This makes the wing work more efficiently and reduces those vortexes.


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

[User] [Warhammer 40k] Is there any possible scenario where the Imperium of Man can return to it's past glory?

[Assistant]
No. Mostly because there was no past glory for the Imperium of Man. Even at its height, before the Horus Heresy, the Imperium controlled less worlds than present. It had a lower overall military strength than present. It's technology was barely any better than present.

The high point of human civilization was during the Dark Age of Technology, and even then it peaked with the creation of the STC systems. In fact, the STC's are one of the main reasons why human technical development went into decline, having machines make everything for you leaves little need to knowing how to do anything yourself.

There are several possible scenario's in which things can get better for the Imperium of Man, but almost all of them require a major social and ideological shift, not only in Humanity, but in the Eldar, Tau and many minor species.

Ironically, the Emperor isn't the answer here, since his rebirth would likely destabilise the Imperium, something extremely dangerous given the current delicate balance of power in the galaxy. Really, the Emperor's time is done, and the only way to actually save humanity is for it to stop following him.


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

[User] Why is Lead a good radioactive shield?

[Assistant]
Lead (and other dense metals like cadmium) are good at shielding gamma radiation because they are dense. High atomic number and relatively short bond length means there are a lot of electrons for incoming photons to interact with. When the photons that make up the gamma radiation interact with the electrons and transfer energy to them. The same will happen with any material with electrons, but dense metal has more electrons, so better attenuation.

Lead is not so good for other types of radiation. Alphas are massive and have high charge so are stopped by almost anything, including lead, but also paper and several centimeters of air. Betas will be stopped by lead but produce x-rays in the process (Bremsstrahlung radiation) so they are better shield by a lighter material like tin or plastic.

Neutrons are a different story. They are uncharged and don't interact with electrons. To shield neutrons you must get them to collide with a nucleus and transfer energy to it, slowing the neutron down. The energy transfer happens best when the nucleus is of similar mass to the neutron (ie, a H nucleus). For this reason, materials with lots of hydrogen are best for neutron shielding. Paraffin wax is often used.


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

[User]
ELI5: How does RAM work?

I mean I know how to put it in, but like what does the ram chip actually do? I know it increases RAM storage, but how does that storage work?

[Assistant]
Heres an analogy comparing a computer to an office desk

Obligatory edit: the context here is OP's question, this is not nor ever was intended to be the end all perfect analogy. Remember ELI5 guidelines folks.

The hard drives are long term storage, like file cabinets

The RAM is how big the top of the table is, like how many papers you can look at face-up at the same time (after you're done 'loading' it into the table from said cabinet)

The CPU speed is how fast you can move your hands to flip papers over and do stuff

The GPU speed is how fast a printer can print out high definition pictures on a sheet of paper

Edit: RAM doesnt store things long term cause the "office" has a clean desk policy, all desk papers gotta go to the file cabinet at end of day (when the power is off) cause the janitor will just throw away anything that isnt nailed down.

A bigger file cabinet (high capacity hard drive) does hold more but isnt faster, one heavy-ass cabinet sure does hold a lot but it's hard to move. An SSD is like one of those tiny desk organizers with lots of little drawers, you can move stuff much quicker but it doesnt hold as much

Dual core CPU is like having two arms, quad core like 4 arms etc. You can imagine that so many arms wont always be useful, which is why a 16-core CPU (lots of skinny spider arms) might not play games as well as a few beefy hulk arms.

Hope this helps :)


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

[User]
CMV: The argument, "There is a large consensus in the scientific community," is a valid point to bring up in an argument.

Now, I'm not saying that scientists can't be wrong nor am I saying that a majority of scientists can't be wrong. However, I am often told that "there is a consensus" is not an argument and should not be brought up in a debate. But the fact that there is a consensus, in my opinion, should carry weight. Scientists are men and women whose job is to hypothesize and test those hypothesis and determine if their hypothesis was tested to be right or wrong; their secondary, but just as important, job is to call and point out the bullshit that their peers may say, to find the mistake in the experiments if there are any. So saying "there is a consensus" isn't just saying that some smart people believe something; it's saying that there is a wealth of evidence to so support an idea that the most skeptical people in the world have come together and said: "all the evidence we have is pointing to this being right."

I am not saying that we shouldn't look into the things that scientists say nor should we trust everything they say but the very fact that there is a consensus should hold a lot more weight than it does today.

_______

So I've seen a few counterarguments that keep coming up so I'll address them here.

1. You cannot use the fact that "there is a large consensus" to prove something.

Well...yeah. I know. I never said that the fact that there is a large consensus should be the end all be all, simply that it shouldn't be seen as worthless. I don't understand why the fact that there is a large consensus is just shrugged off with a  "whatever"

2. Science can be wrong.

Again, I did admit that the consensus can be wrong. But to logically follow this argument is to say that you cannot trust science at all, that you should interpret everything yourself. The point of specialization is that if you have not specialized in something, say a field in science, it should not be your job to know about that field. Why should I, a non-scientist, be able to talk about astronomy as well as say Neil deGrasse Tyson?

3. By saying that there is a consensus, I'm using an asshole argument

I would argue instead that by saying that there is a consensus, I am merely asking you what makes you doubt the consensus? If you have had a different experience, that sucks. And I admit that there are places in which saying that there is a consensus adds nothing to the conversation/argument but why is it dismissed all the time?

4. A consensus means nothing

Saying that a consensus is nothing is like saying "the theory of evolution by natural selection isn't true because it's only a theory." But the fact that this is a theory implies that there is so much evidence toward this hypothesis that the scientific community has agreed that there is a low likelihood that new evidence will come to light to disprove this hypothesis. A consensus is similar in that there is evidence implied in the word, that for the consensus to have existed that there is evidence for it!

5. You're appealing to an authority

Yes...I am because they know more than me and know more than the average laymen. When a plumber tells me that I need to fix my plumbing, I'll probably trust him. If I feel I need a second opinion, I won't go to a doctor, I'll go to another plumber. I am trusting in the people who know about the subject matter to tell me about it.

6. A scientist studying A won't know about B

Of course, that's why I'm trusting the people studying B when I say that there is a consensus on B. I'm talking about the relevant academics.

7. Some comparison to religion

The difference between religion and science has always been that the former doesn't look for proof. And that's okay, that's what a religion is. It's a moral guidance and it's unlikely that science will ever come up with a "we have proved what is right and wrong."

Edit: Not sure how formatting works.

[Assistant]
> So saying "there is a consensus" isn't just saying that some smart people believe something; it's saying that there is a wealth of evidence to so support an idea that the most skeptical people in the world have come together and said: "all the evidence we have is pointing to this being right."

I think the problem with this is that, if there is a wealth of evidence to support an idea then it's almost always better to point out the evidence itself, rather than just saying it exists and that most scientists see eye-to-eye because of said evidence.

If all you do is say there's evidence without actually showing what it is, then you're basically just telling them to "Google it". And that is not really a "valid point" to make in an argument.


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

[User]
[Star Wars] Why is Grand Moff Tarkin not afraid of Vader?

We see on screen that when he commands Vader to let go of the force choke, he asserts a sort of sternness. This makes me think Vader was lower than Tarkin in the chain of command. Does this mean even in a room with each other, Tarkin was fearless of Vader? Or was it just a meeting room thing?

[Assistant]
Tarkin and Vader are longstanding colleagues and have worked together since even before the end of the Clone War. They're almost friends, and essentially equal in the chain of command, both second only to the Emperor.

Tarkin is also one of very few people who know the true identity of the Dark Lord.


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

[User]
Why does light travel the same speed for all observers?

To my understanding, if something (say a ship in a vacuum) is travelling away from a light source it would observe photons reaching the ship in [time=d/c], while a stationary observer (with respect to the light source) could theoretically observe photons reaching the ship in [time=d/(c-v)] (where d=initial displacement from ship, c=speed of light, v=velocity of ship).

I use this concept whenever I want to remember the implications of time dilation for something travelling near the speed of light, but I realized that I do not understand why this phenomenon should occur at all.  My limited search on the subject found only that this is a mystery of nature and has been proven by experiment.  Does any have some insight on this matter?

[Assistant]
I wouldn't classify it as a "mystery" of nature. But it is a postulate, something assumed to be true, based off of a lot of observations.

The postulate arose because people were playing around with the equations that govern electricity and magnetism. You can test each of the 4 equations independently, they're called Maxwell's equations. And when you put them together in the right way, you get a wave that has some velocity that's equal to 1 divided by the square root of the electric permittivity constant multiplied by the magnetic permeability constant. But as you look at the equations, no where in there did it mention the speed of some observer. Each observer would necessarily come to the exact same conclusions based on the same laws of Electricity and Magnetism.

So Einstein ultimately becomes famous for saying "fine, let's just make this a thing. This speed of electromagnetic waves is a constant value for all observers. And no physical experiment can distinguish between a frame at rest and a frame in uniform motion." Take those two postulates and you get the whole of special relativity.


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

[User]
ELI5: Why is it that the United States is falling so far behind in education compared to many other countries?

Is is bad American policy and politics, is it skewed information based on statistical differences such as population size, what's going on? Does America really just suck at education?

[Assistant]
All the money being pulled from education.

Religion dictated curriculums.

Poor teacher training.

Poor teacher pay resulting in all the good teachers quiting.

Over crowded classes and schools.

Outdated and out moded standardized tests.

Oppressive school environment resulting in student apathy and depression.

Take your pick from the above.


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

[User]
Should I read Leviathan if I am interested in contemporary political philosophy?

Just wondering if the book has value besides being part of the interesting history of philosophy. Thank you!

[Assistant]
Certainly it isn't strictly required reading but it is a kind of shared cultural background which could make work in the field easier to understand, plus it is a good book.

EDIT: Part 2 will make much more sense if you read part 1 as well.


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

[User]
What is the energy need to take 1 kg of mass to the sun?

Was wondering what is the energy need to take 1 kg of mass to the sun?
Also how much difference does it make with gravity assist or similar methods?

What's the ratio of energy needed to escape earth gravity to the energy needed to reach the sun?

Thanks in advance...

[Assistant]
Earth velocity around the sun is 30km/s. If you zero this, the object would fall straight into the sun. We don't need exactly that since sun radius is 695000 km, so an orbit with periapsis lower than that would already be enough to impact the sun, but this is still about 28.5 km/s of delta-v.

So you need to decelerate your 1kg by 28.5km /s and energy is `(m*v^2)/2`, assuming this object is already in earth orbit.

Reaching LEO requires about 9.5km/s of delta-v.


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

[User]
(WH 40k) Does the universe timeline continue and evolve or is it stuck in a purgatory state?

By purgatory state I mean something like the Simpsons where there's endless adventures and happenings but the actual time period never changes.

I don't follow the story religiously (obviously) so I may have some details wrong, but last I heard the Tyranids are basically going to overun the galaxy and the various other races and factions are struggling to stop them.

So does the time period ever change and will the great Tyranid threat ever be beaten or subdued or is is stuck in a romantic eternal battle situation?

I assume the tabletop rules and statistics come into play here and demand a fairly unchanging, level playing field for players, lest their  army of choice is suddenly useless due to a change in the Lore.

[Assistant]
Allright due to the nature of the post i'm breaking character.

Due to GW's beliefs, the timeline does not advance.  To do so would mean them thinking up some galaxy shattering events, such as the fall of the imperium, resurrection of the empera and the return of the primarchs.

In fact, the timeline has regressed, the 6th edition sort of retconned the 13th black crusade, cadia still stands and eldrad is still dicking around.

So yeah, romantic eternal battle.

Fortunately they are progressing the Horus Heresy cannon by using their novel series.


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

[User]
[Arkham Games] Are there other heroes in this universe?

The stories have focused entirely on Batman and his allies/enemies. We know that Metropolis exists (it was a password for one of the Riddler boxes). Magic is also apparently present, as the Lazarus pits are used frequently and Solomon Grundy exists, so this world isn't bound to the laws of ours (unlike Nolan's movies, but even those weren't entirely realistic).

I'm just curious if this is a world with Batman only (like the recent films) or if he's part of a much larger DC Universe and he simply hasn't interacted with the other heroes.

[Assistant]
(I assume the Arkham games are part of a larger DC universe, not just a Batman-only one. The Arkham aesthetic fit very well into Injustice: Gods Among Us. Seeing Arkham scarecrow randomly show up after knocking someone through a wall is always great.)

Batman is notorious for working alone. We know for a fact he's barely tolerant of direct allies like Robin and Alfred because he wants to shoulder the entire burden by himself. The nights we follow him through the Asylum or the city are just those nights where he's out by himself while the League handles global crises on the other side of the world or out in space. Batman helps out with those now and then, but his mission will always be just Gotham.


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

[User]
How does omniscience interact with randomness?

What are the implications of God's omniscience for randomness? For example, could God create a truly random number generator, such that even He doesn't know what number it will generate? I know nothing about quantum physics, other than that it's supposed to be probabilistic rather than determinate; in this case, does he know the outcomes of quantum events (I am using that phrase not really knowing what that means; I apologise if it's completely incorrect to use it!)?

[Assistant]
What you've stated is essentially an articulation of the classic Omnipotence Paradox, but restated to be about knowledge (omniscience) rather than power/ability (omnipotence). There are a variety of responses to these kinds of challenges, but common answer is that omnipotence only covers that which is *logically* possible.

The existence of *truly* unknowable numbers is logically incompatible with a God that knows absolutely everything. Therefore, either the numbers aren't truly unknowable, or God isn't truly omniscient.