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

[User] ELI5: How did English become the universal language of science and aviation?

[Assistant]
The International Civil Aviation Organization, a UN agency, simply chose English, or rather a subset of English called "Aviation English", as the recommended language for pilots and controllers in 1951.

While it was just a recommendation it was widely adopted as post accident investigations before then had found language and communication in general was a big contributor to accidents.

So, the main aviation organization just chose it. ICAO even offers Aviation English proficiency tests.

As for science papers, that arose somewhat naturally. Many papers coming out from research during post-WW2 were written in English. To read those papers, you had to speak English, and most prestigious journals were in English. If you wrote papers in other languages, they wouldn't be cited as much. So, English became the de facto language for reading and writing.


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

[User]
eli5: Why do kids struggle with the volume of their voice?

It seems like every kid I've ever met has to scream everything at every one. I taught elementary school, and noticed that they seem to have no idea how loud they are talking at any given time.

[Assistant]
Kids are far less self-aware than adults.

This is why you'll see them doing things like "sneaking" to get a cookie while you're watching them and it's quite obvious that you are and that they aren't being very sneaky at all. Or, like, picking their noses in public or some such.

Children also lack a fully developed brain, especially the part of the brain that does behavioral control. This is why a kid will just burst out crying or start hitting another kid, often with little to no reason. This lack of behavioral control (and emotional regulation) means that kids will get excited and they literally won't be able to moderate their emotional response which feeds into their behavior, which they also won't be able to regulate, which leads to loud voices.

Last of all, kids are still learning things. While it seems obvious that you use your inside voice when you're inside, kids often have to go through a process of learning (meaning lots of mistakes and corrections and feedback) before they learn what is and is not acceptable in any situation, especially novel situations.

Obviously this depends on things like the temperament of the child in question and especially their age and level of development.


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

[User] ELI5: Why is it so hard to use your fingers to pick something small out of a drink?

[Assistant]
You know how when you plonk a rock into a lake, it creates those circles of little waves moving outwards? Those little waves like to push things away from the middle of the circle.

In this instance, your finger is the rock and the 'something small' you're trying to fish out is being pushed away by the little waves made by plonking your finger into your drink.


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

[User]
CMV: We should normalise single people asking friends to be set up

Background:

Many people seem to feel that dating is "broken", and that dating apps are partly responsible. Whether this is because dating has always been rough and dating apps are just making a difficult experience more accessible, I don't know. I do think that apps aren't ideal for a number of reasons. Companies' motives lean towards monetising loneliness rather than enabling matches, which is an indicator of success that's hard for them to advertise. There's a big gender imbalance in the userbase for popular apps, which reinforces unhealthy behaviours among several (esp. heterosexual) users, e.g. people using the app mostly for validation; people basing their self-esteem on their number of matches; people making faster, more superficial judgements than they would when meeting each of these people IRL.

Proposal:

People should play matchmaker for their friends/acquaintances more often. Obviously, I don't mean that people should try and set up unwilling/incompatible single friends freely, or that people should constantly bug their friends to set them up. Rather, people seeking to date should mention to their friends more often that they would be open to being set up on dates. Going through your friends means there's some level of screening for safety, which is more than you'd get on a dating app (although it is biased towards matching people who are more socially similar).

Reasons I think I need my view changed:

I'm a Redditor. I honestly don't know if I'm describing a social phenomenon that already takes place pretty often and just isn't as wildly successful as I think. I'm also not sure if this sort of trend would be somehow socially detrimental.

[Assistant] Friends already do this if they have a potential match. But if you have to ask, they don't have someone for you at that time. If you pressure them to find someone, they might do it, but it probably wouldn't be a good match.


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

[User]
[Injustice 2] Why not ask the Prime Universe for help?

So, in injustice 2, Brainiac is coming. One of the big conflict in the plot is whether to release the tyrannical Superman to help, risking him taking over, or not, and fight Braniac without their heaviest hitter. It's a real dilemma. If only they had a backup Superman, you know? Like the one they summoned during the last crisis?

They know Earth Prime exists- they've already summoned heroes from there, and in Aquaman's ending he goes there. It's the DC universe, they'll find *someone* who can dimensionally travel. And while I'm sure the Justice League probably don't want to be called over for every minor issue, I'm sure any annoyance would be overshadowed by "GIANT SPACE SKULL SHIP EATING CITIES HELP". They are, after all, heroes, and they know this world has limited abilities to protect itself at the moment.

You get the help of a genuinely heroic Superman (and Wonder Woman, Flash, Cyborg and so forth to boot), the Regime stays safely imprisoned, everyone is fine. So why not do it? Why not at least consider it? You need help. Why go to guy who burnt a child's eyes out when you can step through a portal and get his heroic twin to help?

[Assistant]
IIRC: The heroes dont find out Brainiac is behind all the supervillains until hes already almost arrived. By then, its too late to start experimenting around and trying to jump into the Prime Universe. Its not a full proof method and even if you do get there, how do you know theyre not dealing with their own big problem? Yea, the payoff is big, but if you mess up youre taking at least one of your most powerful heroes out of the fight to try to get allies. It doesnt help that half the justice league gets brainwashed by brainiac at one point or another.

Better to just release Superman and keep an eye on him (which Batman does the entire game) than go on a mission that might fail.


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

[User]
CMV: Washington DC should have been set up as an independent geographic zone with no residents

One of the chief concerns of the residents of Washington, D.C. is that they reside within the district but have no representation in Congress. Technically, they do have representatives that can do quite a few things (vote in committees being a very important one) but they can't do other core functions such as voting for final passage of bills. They also do not have Senators representing them either.

There is a push to grant them statehood and I won't speak to whether or not I think that is a good idea. What I would like to propose to CMV is the hypothetical situation that the District of Columbia should have been set up as a completely independent geographic zone bordered by Virginia and Maryland with no residents whatsoever.

The boundary of the District of Columbia would be exclusively zoned for governmental and business construction only, no homes would be allowed inside the perimeter and the workers and politicians would commute into the city.

The cost of running the district would be drawn from the tax system (both federal taxes and, assuming non-government businesses and organizations are allowed, taxes paid by those organizations directly to the district). Utilities would be provided under contract from the neighboring jurisdictions outside the District. Services such as law enforcement, fire, sanitation, maintenance, etc. could be provided either as functions of the District or under contract from neighboring jurisdictions.

In this fashion, there is no such thing as no representation. People who work in the District are residents of Virginia or Maryland and have the representation and rights accorded by their home state, just as people who work in one state but live in another are accorded.

I'm sure there would have to be some specific provisions on things like taxes, jurisdiction for crimes (immediate extradition perhaps? a special district court that just handles DC crimes?), and the like.

Edit: Note, this is a hypothetical and would have required this set up from day one. I'm not sure it could be done today without crazy upheaval, so this CMV is about the hypothetical, not about trying to do this today.

I am presently in the middle of an argument with my girlfriend over this topic and I'd like to spar it out with you good CMVians to see if you do any better of a job of convincing me than her. Change My View!

[Assistant]
Since your idea is about hypothetically having done this way back when DC was first established...

You have to remember that for the first 130 years that DC existed, cars didn't. Commuting in from the suburbs was a HUGE undertaking. Even today with a car it takes a long time because of traffic, but it would have taken much longer by horse or foot.


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

[User] [DC] Im a paraplegic speedster. What are some cool things I can do?

[Assistant]
Closeup magic is the first thing that comes to mind. You'd be a world class sleight of hand artist after a few hours of research...

A custom engineered carbon fiber (or other suitable material) wheelchair might make supersonic ground travel a possibility, (stairs still a problem...)

If you had other skills to combine with your powers it would be helpful, you could be a speedforce Macgyver, improvising gizmos on demand with a backpack full of electronic parts... Or real time coding/hacking with a sufficiently powerful computer.

Edit: Wait! You could have foldable wings that anchor to your back and attach at the elbows... Flap your arms like a chicken and you can *fly*, bitch! You're ***The Hummingbird!***


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

[User]
[A Quiet Place] What is life like in Japan, Hawaii, New Zealand and other island nations? [Spoilers]

**SPOILERS FOR A QUIET PLACE 2**

Islands are safe from the monsters.

Assuming that no monsters drifted to them, the inhabitants of islands can make all the noise they want in safety.

With the rest of the world in shambles, what is it like to be the inhabitant of an island sanctuary?

[Assistant]
Every nation is tied into international trade. No man is an island, and these days, no island is an island either.

Places with enough agriculture to sustain their population probably crashed a century or two in terms of standards of living - which carries a death sentence for thousands of not millions by itself. (Those dependent on advanced medical care likely perish. Many Hawaiian islands are dependent on oil shipments for power generation. Nobody anywhere drives a car after six months; nobody is getting replacement computers.)

Those places are basically pastoral now. Think medieval level technology with a few exceptions - we know the germ theory of disease, and dental treatments are better.


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

[User] [Halo] Has humanity found any alien civilizations that weren't part of the Covenant or Forerunners?

[Assistant]
Depends on how you define "part of the covenant". You got species like the Yonhet who were collectively considered a part of the "Covenant Fringe" they were discovered by the covenant, but were simply too few or otherwise not considered worth the bother of fully integrating into the Covenant millitary forces. They were mostly left alone, but the Covenant did trade with them.

Haven't heard of other species than the Yonhet in specific yet, though. The part of space where they are located are quite a distance from Human-controlled space, and when cutting through the red tape, even the ONI have barely begun catalogueing the amount and significance of the sapient species there.


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

[User]
[Jurassic World] Was the Indominus Rex really a sadistic monster who killed for the evulz, or was that just humans anthropomorphizing her behavior?

If the latter, what was the motive behind the dinosaurs overly-aggressive behavior? Was she really insane?

[Assistant]
So like the whole point of that series was that the scientists were designing bigger and badder monsters for two reasons.

1. So they could attract people to the dinosaur fun park

2. So they could sell the dinos to the military/highest bidder.

And what kind of dinosaur does the military want? One that kills to kill. Without justification, morals, or need. Drop an Indominus Rex into a civilian population center, and let it have some fun.


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

[User]
Where do you see academia in ten years?

With the value-added model of neoliberalism shrinking state funding budgets, shrinking tenure, and increased automation, where do you see the social sciences in ten years.

Is it totally and absolutely foolhardy to go into research in this day and age? Are researchers pushed to produce more and more at their own cost? Tenure was always what made academia worth it - you got paid less but could pursue what questions were important. With tenure dropping at ever increasing rates, what will the academic lifestyle be like in ten years?

[Assistant]
Aging adjuncts everywhere replacing graduate labor, with fewer new scholars. Research subjects more and more limited by their attractiveness to external funding bodies. Grade inflation increasing as the "consumer" model for student engagement continues to take hold and student evals replacing research output in continuing employment decisions in the absence of tenure.

The upshot: hopefully also we'll see the key text in critical theory that will signal the eventual end of the Derrida/Foucault era. We might also see the beginnigs of a real commitment to grad programs training students to teach instead of treating them like apprentices.


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

[User]
[HGttG series] Do the problems avoided by the Somebody elses problem field *literally* become somebody elses problem?

The Somebody Elses Problem field allows the user to not have to worry about such things as airlessness or high levels of radiation. These problems become Somebody Elses. Would widespread use of the technology lead to pandemics of people spontaneously suffering random, gruesome deaths?

[Assistant] Not really. The SEP field is only a cloaking-device substitute based on the principles that getting people to ignore something is a lot easier than, say, transforming every ray of light into a form of EM radiation that can penetrate the object when it enters the field on one side while keeping all the information it contained and transforming it back on the other side. It doesn't literally create problems, nor does it magically resolve any problems apart from the problem that people might notice a spacegoing Italian bistro that wasn't there yesterday. That one it resolves simply by making any passers-by think that such a structure is... well... somebody else's problem.


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

[User] [Terminator] What is life like in the future AFTER the war and humans have won? Is humanity united and rebuilding under John Connor? Or does the post-war future not exist somehow because of all the time-loop shenanigans?

[Assistant] In the new canon evey time they beat one AI threat another rises. Skynet and Legion may be dead but another will always replace it and push Humanity to the brink again and there goes another time loop.


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

[User]
How do computers initiate the boot process when you turn them on?

I understand that the BIOS POST is basically the first thing that runs when a computer is turned on, but I have a really tough time grasping just *how* a computer knows where to look for instructions on how to boot, and how it is able to interpret those instructions.  If pressing the power button simply causes an electrical current to be initialized, how does that electrical current know where to access the BIOS POST, and how does it translate the information in the POST if there are no other programs being run at that time?

**tl,dr;** How does a computer translate and interpret the instructions contained at the beginning of the boot process if no programs are running yet?

[Assistant]
I think you have the misconception that computer software program interprets instructions; which is not true at this level.  CPU instructions are run by the CPU directly, not more software interpretation needed.

And usually computer hardware is wired to start executing instructions stored at certain address in the ROM upon boot.


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

[User] ELI5: Why do worms come out from the ground all the time when it rains?

[Assistant]
The simple answer is "because they can"

Normally a worm near the surface would turn back because it was too dry.

But when it's wet their adventures can bring them to the surface.

And for every worm who makes it to the surface there's about a hundred more that don't bother. If the rain really chased them upto the surface the ground would be covered in worms, there's a *lot* of them down there!

So, no, they won't drown when it rains!


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

[User]
[DC]How does the richest human beings' wealth fare on a galactic/universal/etc. level? Is there a way to measure and compare wealth across different planets?

To illustrate the title with an example: we all know Bruce Wayne is one of the richest people on Earth, but is he also a one\-percenter in the entire Sector 2814?

[Assistant]
On a wide scale, money probably does not matter nearly as much as your material resources and your people.

Gorgolons from sector 50000330 don't want dollars, but might happily trade a few warp drives for DNA samples, art, science, borium, that iron asteroid over there, a bunch of venusian methane, or maybe even anglerfish livers, which are rumored to work as aphrodisiacs for them.

Aliens capable of interstellar travel either want energy, matter, or something that they can only get from living planets. Earth's "wealth" would be our ability to produce rare items not found elsewhere. DC earth has a variety of resources, such as capes, magic, lazarus pits, geniuses, and more. Does DC have an equivalent to adamantium/vibranium? Aliens could want that too.


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

[User]
How to refer my previous work without breaking double blind review process?

I'm about to submit a paper to a CS conference that has a double blind review process, and that rejects papers that expose the authors' identity in the text.

However, the work is an extension of a previous work we published last year in the same conference. We will be referring to that work a lot, write a similar problem formulation, show new results on the previous datasets, and in general it is clear that the current work extends the previous one and should be read with that in mind.

how should I refer to the previous work throughout the paper? I find it hard to believe the reviewers won't guess that the work is from the same lab, and don't want to be rejected solely because of that.

[Assistant] It is a bit difficult to manage, but you have to write the paper as if that previous work was someone else's.   While that seems like an unnecessarily burden, this paper must stand on its own regardless of whose work it builds upon, so it's a good practice to think that way even when the process is not blind.


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

[User]
Eli5 , How do windsurfers get back to where they started if the wind is only blowing one way?

The only way I can think that this would be possible is if the wind was blowing directly onshore?

Edit: thanks for all the well thought out replies. I think Ive got it figured out know,  Ive always Been a bit confused about ships tacking into to wind and I think the key thing I was missing was the sail being using like as an airfoil creating pull, used in tandem with with the fins/keel .

[Assistant]
Sailing ships, and windsurfers, can make progress upwind by tacking.

Say the wind is coming from the north. The ship can sail as close to the wind as northeast or northwest. So if it alternates, first going this way and then that, the *net* movement will be north.


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

[User] ELI5: Why do great QB's like Geno Smith, Christian Ponder and Vince Young play bad in the NFL even though they were the best in college?

[Assistant] College football players are the top 1% of high schoolers, and NFL is the top 1% of college players.  Most college teams will only have a couple players (if any) who may make it in the NFL, so truly good superstars can usually run roughshod over the competition in HS/college.  Once they get to the NFL however, everyone is a superstar.  The game is so fast at that level that some people can't adjust.


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

[User]
ELI5: Why is there only one internet?

With all of the problems with our current internet, why are we unable to just "create a new one"?

[Assistant]
Think of it like roads. Roads connect locations to each other, much like the internet connects computers and networks.

You can get from one place to another via many different routes, but they're all part of the same system of roads.

When one town has its own system of roads and builds a road to a freeway or something, it's connecting its "network" to the greater "internet."

Creating a new system of roads would require creating connections between towns that don't use the same roads that we already have - like building a second set of roads on top of our current set of roads. It would be redundant and expensive, and we wouldn't really gain much from it.

And, to answer your question, if we connect that series of roads to the current set of roads, they join the "internet" that already exists.

It makes a lot more sense to improve infrastructure that already exists, rather than building a new one. It's like the difference between filling potholes in the road you already have, instead of building a second road that takes a different route because the current one is a bumpy ride.


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

[User]
ELI5: How is it possible that my car keys unlock only my car and not all the others? Is it theoretically possible that my key could unlock a second car somewhere on the world (given I'm close by)?

Edit: Apologies for the poorly phrased question. While the mystery of mechanical keys is fairly interesting I always figured that there would be a limited amount of key/locks available. My question was particularly referring to the (new) wireless keys!!

[Assistant]
Most modern cars have 3 layers of security when it comes to keys.   Remote Identification, Physical Identification, and Encryption Identification.

Remote identification is your keyless entry.  Its like when you yell for your mommy outside a locked room, if she recognizes your voice, she will respond and unlock the door to let you in.  Voices can be similar, so if in the rare case some other kid sounds like you, she could be confused and let the wrong kid in.

Physical Identification is the cut key itself, or in the case of Push Button start, the physical proximity of the key.   When your mom opens the door, she would make sure you look like her child.  You have a unique face but doppelgngers or your twin brother could fool her into thinking another kid is you.

Encrypted Identification is the RFID chip inside the key that the immobilizer has to sense to allow the car to run.   Even if you can duplicate the remote entry or physical key, the RFID reader will still need to read the encrypted code programmed to each key matches to the Immobilizer before the car is allowed to remain running for more than a few seconds.   This is extremely difficult to duplicate and very short range, so the real key would need to be within a few inches of the ignition to work.  Its like your mom verifying your fingerprint or DNA to make sure you are you, even if you look and sound like her child.


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

[User]
ELI5: Why are Andy Warhol's Campbell Soup paintings so highly regarded as amazing art?

Went to the Andy Warhol museum today. Some stuff I thought was really cool, other stuff I definitely didn't get. What am I missing?

[Assistant] One aspect of modern art is its timing (media presentation). Warhol's concept was about icons. The Campbell Soup can. He presented the image as an 'iconic familiarity' that because it was so ubiquitous, it had transcended its ordinariness. For Warhol the soup can's image become iconic while for the public it was Warhol's IMAGE (the actual artwork) of a soup can that BECAME the icon. Which it is and a quite famous icon of modern art too!


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

[User]
[Dresden Files] With what do the other wizards earn money?

Harry proudly proclaims himself the only freelancer wizard (at least at the start of the series, later Elaine does the same). Monoc Securities seems to be another workplace for mages, but what does the rest of them do? Magic alone doesn't pays bills or feeds you.

[Assistant]
The Wardens and other "White Council employees" are directly employed by the WC and get their money from there.

Other freelance wizards have mundane jobs, made slightly easier by their powers, but usually stick to jobs that do not require prolonged contact with technology. The popular jobs are librarians, antique dealers, farmers, animal breeders, jewellers, and people who do traditional rustic crafts: potters, smiths, woodworkers etc.

Essentially, any kind of job where you do not need a computer, but can use a little bit magic to work faster and better, without getting caught by normals.

Plus, wizards live very long lives and very often inherit wealth and property from their wizard ancestors. Which means that a lot of them are independently rich and can live off the wealth.


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

[User]
ELI5: Whats the difference between counting cards and just being really good at a card game?

I understand why casinos kick out card counters, the casino wants to make money and card counting is "cheating". But if you are able to do it all in your head, is that not the same as being really good at poker? Knowing whats left in the deck and estimating your opponents cards based of that info and by reading your opponent. How do you prove counting vs skill? Is it just a way for casinos to weed out people who would take a lot of money?

[Assistant]
Counting cards is, indeed, just being very good at a game.  It is not "cheating" in the sense of violating the rules.

Casinos kick out card counter not because they are cheating or doing something illegal, but because the casino is losing money on them as so has decided to decline their custom.  Think "we reserve the right to refuse service."  The casinos, which are private businesses, are using that right.


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

[User]
[Star Trek Into Darkness] Surely they were breaking the prime directive even if they weren't seen?

At the begin where spock uses that cold fusion device to cap the volcano it freezes in a very unnatural fashion.

Assuming they develop an understanding of geology before they achieve warp they will know something funny has gone on and a pre-warp civilization will know it has been interfered with.

So why was spock so hard on Kirk when he was already breaking the PD anyway?

[Assistant] The reboot movies show time and again that Kirk makes awful decisions that only pay off due to unforeseen circumstances out of his control later on, and that Spock is the one that should be in command of the Enterprise.  He simply didn't care that they were breaking the Prime Directive, or that both he and his second-in-command were placed in direct danger for the sake of a thrill.  Seriously, what was with that bullshit where Kirk and Bones decided to engage the natives and steal the scroll they were worshipping?


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

[User]
[LOTR] Just how deep did the Dwarves dig in Moria?

Rewatching The Two Towers right now, and watching Gandalfs fall while battling the Balrog popped the question into my head. Now I realize that is certainly a natural chasm, but the Dwarves were living there for a very long time before awaking the Balrog.

Watching the fall made me realize that I'm bad at math and physics, trying to do that calculation and guesstimate the height and speed and such from that one scene. So hoping someone else is able to do that better also as a secondary question.

[Assistant]
>'Deep is the abyss that is spanned by Durin's Bridge, and none has measured it,' said Gimli.

Even the dwarves don't know about the extent of the natural tunnels they pierced when they set free Durin's Bane, and they don't talk about the deepest levels where they dug for mithril, only that it was found "at the root of the mountain".


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

[User] [Starbound] Why do the Glitch suffer Hypothermia/need to eat?

[Assistant]
Batteries cannot store power efficiently when they get too cold. Oil also becomes more viscous at lower temperatures and eventually turns into a kind of tar-sludge if it gets too cold.

A Glitch, being a machine, does not generate its own internal body heat like a warm blooded animal does. It does generate some heat due to internal processes but this is a side effect and not enough to keep a Glitch warm in the middle of a snowstorm.

If a Glitch gets too cold its systems fail, it shuts down, and thats it. This is a hazard space probes have long experienced. Rovers on other planets routinely freeze to death at night or during planetary winter. If the heaters fail or there is not enough power for the heaters to function then cold will kill a machine. The machine will fail.

Food is organic in nature. Organic compounds are very useful for machines. Organic compounds can take the form of fuels such as gasoline, or lubricants such as oil. Petrolium products are wonderful for machines. They are a very dense energy source. While a Glitch has no living organic body it still needs energy. It has a "digestive" system that breaks down organic substances (food) into a fuel that can be burned as well as lubrication for its joints. Metal grinding against metal is a bad thing.

This is also why a Glitch requires air. No oxygen means no combustion of its organic based fuel, and no combustion means no power. No power means no activity, which is "death" for a Glitch.

Fortunately, a Glitch can be repaired relatively easily. If found, damaged parts can be repaired or replaced and the internal power source can be refueled and reactivated. Batteries can also be recharged.


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

[User]
What's the problem with infinite regress?

A large number of philosophical arguments for the existence of God seem to rely upon saying something along the lines of 'since there cannot be infinite regress...' to prove their point. I don't see why it should be so obvious that infinite regress is impossible. Can someone explain?

[Assistant] It's not that no infinite regress is *possible*, it's that any infinite regress fails to serve as a justification for the conclusion.  If each step in your justification appeals to the truth of another claim, whose justification requires an appeal to the truth of another claim (and so on), then at no stage in the argument is the truth of any of these claims established --  although they may well all *be* true.


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

[User]
Access denied to the last version of a paper when I am first co-author

I worked in a lab with a toxic PI until the end of 2020 and we try now to publish a paper with my work. We wrote the manuscript and at one point, the PI deleted the Dropbox we used and send me a pdf version of the article saying that the submission will come very soon and that there are some formatting issues to address but he will manage it alone. I received few months later the notification from the journal to accept that I am a co-author of the paper. I accepted (but I didnot have access to the version submitted). Now we have the comments of the reviewers and the PI ask me to answer to the comments but, despite my request, he is denying me access to the version that was submitted. Do we agree that it is illegal and unethical ? My suspicion is that he tries to hide the fact that he changed the positions of my authorship (from co-first author to second author) but I have no proof of that. What can I do ? Many thanks for your advices.

[Assistant]
Illegal - no.  Unethical - yes.  In breach of the journals publication requirements - almost certainly.

Check the journals "Instructions to authors".  There is almost certainly a statement or statements about authors agreeing to the submission and having seen the last version.

If the PI is not in a retaliatory position, you can be quite tough on this.  The PI almost certainly had to make a statement that all authors agreed to the authorship listing during the submission process.

Lastly, you have a 100% right to NOT approve submission until you are happy.  You can make that clear to the PI and if they go ahead without your consent, you can get in touch with the journal.


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

[User] ELI5: Why some YouTube videos can be accessed via PC while the same website cannot be accessed via a mobile device.

[Assistant]
Most of the time it is due to copyright. If a video contains an audio track YouTube thinks is copyrighted, it is blocked from mobile since the mobile player is not designed to show the advertisement ("Buy this track link").

Other times it is because when you upload a video you have an option as an uploader to block mobile devices.


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

[User] ELI5: Why are boogers and ear wax two seperate things when they have the same purpose?

[Assistant]
Lets say you have two classes of students, and you give them the same problem to solve- how to clean a chalk board. One class is sent to the library, and the other to the auditorium.

The class in the library learns that they can take all of the books and fan the dust off of the board.

The class in the auditorium learns that the curtains can be used to wipe the board clean.

Now, lets say you ask these classes the same problem again the next day.

Each one now knows a way that works to do this, and will just repeat it like they had before- the books are still laying out in the library and curtain is pulled up to the board in the auditorium. They quickly solve it using the same method, maybe adding a small change but mostly just using what works and is already available.

The classes can't just tell the other "Hey, just use the curtain!" or "Use all of the books as fans!", because what works in a library might not be doable in the auditorium, even if they're solving the same problem.

This is similar to how different pieces of your body developed over millions of years.

Ear wax is the product of millions of generations of solving this problem one way, as are the parts of your ear that make and regulate it- the same goes for your nose's snot, which solves the problem another way.


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

[User]
When we are young, we pee the bed.  Why and what causes us to stop doing that?

I was just thinking about how I sleep and I'll wake up in the middle of the night to pee sometimes. I don't know exactly what wakes me? (Without any looking into it, I assume that at the end of an REM cycle, your body does a self check and wakes you up if you have a full bladder, etc).  That eventually led to the thought process of wondering why children eventually "grow out" of it?

[Assistant] In the urethra of a human we have 2 sphincters. One of which is under our voluntary muscle control. When we are younger we don't quite have complete mastery of "holding it in." As they get older they're able to hold it even when they sleep.


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

[User]
Why particle accelerators are so huge? Wouldn't be possible to crush particles in a smaller and spiral structure?

sorry for the dumb question, my knowledge of electromagnetic fields is restricted.

[Assistant]
The vast majority of accelerators are not that big (they can fit in a garage). It sounds like you're specifically asking about the few very large colliders around the world. So why are *those* so large?

You use a collider rather than a fixed-target machine when you want to reach higher energies. Kinematically, the thresholds for interesting processes are lower with a collider than with a fixed target because with a collider, *all* of the kinetic energies of the two beams is available in the center-of-mass frame (because the center-of-mass frame is the lab frame). In a fixed-target experiment, there's nonzero total momentum in the lab frame, so some of the beam energy is "wasted" on the motion of the center of mass.

So you build a collider when you want to study extremely high-energy processes, which generally means you want the beams to have as much energy as possible too.

And with a collider, you'd prefer it to be circular rather than linear, so the beams will circulate around many times. If the beams circulate some thousands of times before the fill is dumped then each particle has thousands of chances to do something interesting, while in a linear collider it would only have one, so to speak.

But if you want your accelerator to be circular, you need to steer the beam in a circle. For beams at high energies you do this with magnets.

The radius of curvature of the accelerator (), the momentum of the beam (p), and the magnetic field strengths of the main bending magnets (B) are all related to each other by

B = p/q.

That says that the magnetic field times the radius of curvature equals the momentum per unit charge of the beam.

So if p is fixed by your desire for maximum energy, and q is fixed by the type of particle you want in your beam, then the radius of curvature of the accelerator is inversely proportional to the magnetic field strength of the dipoles. But field strengths are practically limited by what technology is available. Superconducting dipole magnets for accelerators can currently give sustained fields on the order of ~ 1 - 10 Tesla. So if your dipole field strength is limited, but you want to maximize the energy of the beam, you need to increase the radius of curvature accordingly. That means that the collider ring needs to be bigger.

If the magnets were stronger, you could have a beam with the same p/q (we call this the "magnetic rigidity" of the beam) at a lower radius. But currently we're limited by the strength of the magnets, so we're stuck with these huge rings, *if* we want to reach the highest possible energies.


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

[User]
[Star Wars] Why would 360 degree turns ever be performed in lightsaber duels?

I haven't watched all the movies in a while, but I've seen in a bunch of the fights that duelists would turn around during fights frequently. It's not like it would help put it momentum for the next blow, since lightsabers can cut through pretty much anything with no force needed. It's a huge danger to have your back turned to another lightsaber user even for a split second, isn't it? What's the advantage when it's just a one-on-one fight besides looking flashy?

[Assistant] 99% of a lightsaber duel is mental, it's a battle of agility and precognition. All that flipping and spinning and juking and stuff is each of them trying to either find an unexpected angle of attack, taking the first path they see that gets them out of the way of an attack that won't come until a few seconds later, or trying to trick their opponent into a possible future where there is no way for them to win.


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

[User] [Middle-Earth] If dwarves build their cities underground, what do they usually farm/raise for food? Do they have crops that grow underground?

[Assistant]
Cave-fish and eating cave critters, mushrooms grown with waste product, and while they had large cities underground, many of them were situated near good pasture lands or rivers where the dwarves could come out of the city to tend to the fields, raise animals, or fish.

As they developed better relations with humanity. They would often exchange craftworks or labor in exchange for food as well.


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

[User] [Lord of the Rings] What happened to Mordor and the Orcs after the end of the War of the Ring?

[Assistant]
Mordor was conquered by Aragorn in his campaign to eee re-claim lands lost to Arnor (he was crowned king of Gondor and Arnor) - just to put it in a timeline context - this makes about as much sense as if Italy started to re-claim Europe bcs of the roman empire.

As for the Orcs without Sauron's unifying presence to guide their action, they scattered unable to organise on a larger scale never to be a significant threat again, with Aragorn's forces killing whatever stronghold of theirs they found on their 're-unification' campaign.


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

[User]
Is Wittgenstein's Tractatus just saying the same thing as Plato's divided line?

Aren't they both saying the same thing?

[Assistant]
And for that matter, isn't Nietzsche saying the same thing as well, with his line: "We have to cease to think, if we refuse to do it in the prison house of language; for we cannot reach further than the doubt which asks whether the limit we see is really a limit.

Are these guys all just restating the same proposition?


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

[User]
ELI5: How are Molotow cocktails effective against armored vehicles?

I feel like these very robust vehicles should withstand some fire on the surface of their armor. Isnt this what they are designed for?

[Assistant]
Fire on armor isn't the problem. All of those vehicles are going to have various orifices for things: Hatches, optics, and most importantly ventilation. The crew inside will need constant air supply along with the engines.

It turns out that the air intake to an APC doesn't do very well when it is covered in flaming gasoline. They suck in smoke and air with most of the oxygen combusted out of it. Engines can be stalled, and crew tends to react poorly to being inside a metal box full of smoke and low oxygen air.

Various gaskets can also be damaged by the high temperatures, and the view outside temporarily obstructed. Hitting an armored vehicle with several Molotov cocktails isn't going to *destroy* the vehicle in itself, but it might force the vehicle to stop and the crew to get out. Outside the vehicle the crew are much more vulnerable, both to small arms fire and more Molotov cocktails.


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

[User] Theoretically, can all elements become stable if you add or subtract neutrons to it?

[Assistant]
No. Some elements have no stable isotopes. The heaviest known stable nucleus is lead-208 (bismuth-209 is *almost* stable).

Every known nuclide heavier than lead-208 is unstable. It's possible, maybe even *likely*, that there are no more stable nuclides.


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

[User]
Future grad student here. Any books recs/suggestions on how to approach reading?

Hello!

I'm a future graduate student, and I really want to learn some new or better ways to approach my reading prior to starting school. When I am reading, I can't help but feel that I'm not getting as much out of the texts as I could be and that I'm not doing it right.

I was just wondering if there are any books, scholarship, or anything else really that anyone on here would suggest on the topic of reading (particularly academic/complex texts). There seems to be a lot of books on how to improve academic writing, but the only one I see commonly suggested for reading is Mortimer J. Adler's "How to Read a Book". While I do intend on picking that up, I would prefer to start with something more recent.

Any general suggestions would be appreciated too!

EDIT: I am beyond happy and grateful for the responses this got! Thank you all so much for all the amazing suggestions. I am definitely going to be a lot better off in grad school now :)

[Assistant]
I teach reading seminars for undergrads and usually assign *How to Read a Book* by Mortimer Adler. You want the c.1970 2nd edition co-written by the infamous Quiz Show contestant Charles Van Doren. The first half of the book teaches active reading strategies in general and the second offers some discipline-specific techniques.

It's old, yes, and it's still the best book on the subject. It's also available all over used for $1. Probably the best investment you can make in preparation for grad school.


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

[User] Did the Big Bang start time or does it just mark the start of time?

[Assistant]
Time, as it is understood in General Relativity, is simply a dimension through which things travel within the universe (although not one of the three spacial dimensions, it can be easily pictured as being simply another axis through which things travel). In this way it is best to think of time as being part of space-time, rather than being a completely separate entity--it is as much a part of the universe you travel in as space is.

Thus, since space-time, which makes up all of the universe which we can interact with, was created in the big bang, time as we understand it would have come into existence along with it. That's not to say there was nothing "before" the big bang (we don't know for sure yet), but however you might try and understand that period, it was not likely "time."  We are, unfortunately, forced to describe the "before" using time-like terminology simply because that is how humans think and understand, given we exist in a universe with time.


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

[User] ELI5: Where do all the insects and bugs go in the winter?

[Assistant]
There are several wintering options:

Plan A: Pop those wings open and fly to Mexico!  Grasshopper fun in the southern sun.

Plan B: Huddle under a log until spring!  Spiders dont have wings and its a long walk to Mexico, so lurking in your basement all winter will have to do.

Plan C: Die.  Those eggs will overwinter alone and hatch in the spring to repopulate the next generation of mosquitoes.  Its hard out there for a bug.


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

[User] [Norse Mythology] What do Odin and other gods do nowadays since nobody genuinely believes in them?

[Assistant] Aspects of them manifested in every country that norse believers travelled to. Being manifestations of belief, each aspect is slightly different based on the local beliefs.  Please read the document American God's for further details.


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

[User]
ELI5: When I'm in a crowded room and want to focus on one conversation happening across the room, why does that conversation seem to become more audible, or more easily discerned?

Mostly just curious about how your body knows to essentially block out, or make most other sounds fade out as you focus on that one particular sound, conversation, etc.

[Assistant] It's called selective focus or sometimes it's called the cocktail party effect. There is a difference between perception (actually putting brain power to interpret stimuli) and simple detection by your senses. So when you focus on this one conversation, your brain only interprets signals here and effectively ignores the rest of the sounds in the room.


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

[User]
[Warhammer 40000] What should I, a Rogue Trader, know when clearing out a ship wrested from a Space Hulk?

In this case I can count my lucky fortunes. After three months of tracking preceded by another three months of investigation I have discovered the location of a Space Hulk in the Koronus Expanse.

In fact one that's never been seen before. My crew has slowly been dismantling on Light Cruiser from the mass of warp trickery and will be done in another few months time.

However I am currently considering what I should do to make sure the Space Hulk Ship is safe for sale.

It's not too bad. There's no Xenos on it. But there are thousands of Ghilliams and dozens of Hullghasts at least that I light have to kill. From what my junior officers have also said they have also reported some Gloom haunts and skin takers on it.

But it shall not discourage me. Agreeable a light cruiser is a prize worth fighting for.

Given these threats what should I do to clear it out properly?

[Assistant]
(Both are mutant human types, found in the 40k RPG books from Fantasy Flight Games).

Once the ship is freed, move it to a quiet spot and open all airlocks, purging the ship's atmosphere to the Void.

The mutant can survive in many environments, but few can hold their breath for a week.

After a week, send in some mercenaries with flamers and stubbers, followed by a tech-priest or enginseer and a member of the Ecclesiarchy and some more mercenaries.

You'll have to purge and resanctify step by step, soothing the Machine Spirits and erasing any signs of Warp-taint.

Don't close the locks or repressurize until multiple sweeps have shown no activity and you've put together updated schematics for the entire ship.

You'll lose mercenaries, but that's to be expected.. the hardest part is going to be waiting a week guarding those airlocks and killing anything that tries to close them.

You might also want to use any connections with a PDF or local Astra Militarum to present this as a 'live-fire training opportunity'- the more squads they send in, the fewer mercenaries you have to hire.

It takes thrones to make thrones.


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

[User]
ELI5: How does an SD card become write protected when you slide the little switch down on the side?

How does moving the little switch on the side of an SD card write protect it when accessing it from a computer?

[Assistant] This was also done with floppy disks, music cassettes and VHS cassettes, and they made it work the same way on SD cards as they did on those older media: depending on the position of the switch, it either trips or doesn't trip a little microswitch inside the card reader, telling the card reader whether it's allowed to write to the card or not.


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

[User] [The Office US] If Creed were ever investigated would he end up in jail?

[Assistant]
You think Creed is the kind of person that would leave any clues about his shenanigans?

This is a guy that never does his own job and when problems arise as a direct result of that, other people are blamed. This is a man that is so sure of himself that he can get away with pretty much anything.


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

[User]
What is the Philosophy behind the Litany Against Fear from the Dune Saga?

The Dune series by Frank Herbert is one of the most popular sci-fi series ever created. It has become more and more popular throughout the years. One of the most famous sayings in that series is known as the Litany Against Fear which reads:

"I must not fear.
Fear is the mind-killer.
Fear is the little-death that brings total obliteration.
I will face my fear.
I will permit it to pass over me and through me.
And when it has gone past, I will turn the inner eye to see its path.
Where the fear has gone there will be nothing. Only I will remain."

On the face of it, it sounds very deep, interesting and comes across to me as very philosophical and psychological. I dont quite grasp though its full meaning and what it is trying to communicate to the reader. I am mainly interested though in what is the philosophy behind this litany? What is its true philosophical and psychological meaning? Some people Ive spoken to said it embodies Stoicism, Zen Buddhism, Ancient Greek Ethics etc, but Im not sure about this. Is it good psychology or is this actually bad psychology (maybe even dangerous)? Is fear the mind-killer? Thanks.

[Assistant] The philosophy within the Dune universe is intended as a fusion of Zen Buddhism and Sunni Islam. However that particular quote seems more influenced by classical Stoicism or Nietzsche's views on confronting suffering.


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

[User] ELIF: What is the link between heart problems and teeth?

[Assistant] Bacteria can very easily enter the blood stream through the gums. Most of the blood vessels in the human body have one way valves that allow blood to flow one direction but not back the other way. This prevents blood from getting trapped in our limbs. The blood vessels in our head and neck don't have one way valves this makes it easier for bacteria get from the mouth to the heart. Also the route from the mouth to the heart is very short compared to other routes blood takes in the body. This means that our body doesn't have time to destroy the bacteria before it gets there. This is where the science gets a little foggy. We don't know exactly why there is a correlation between gum/tooth disease and heart disease but there is. The best theory I've heard goes as follows. There is plaque in our arteries. Not the same kind of plaque on your teeth, this plaque plaque is made up of cholesterols that bind together and attach to the arterial walls. This is what causes strokes and heart attacks when it completely blocks off arteries. It has been shown that people with gum/tooth disease have more of this plaque build up in the carotid artery. Samples of this plaque have shown that bacteria from the mouth ends up in these plaque deposits. The leading theory is that the bacteria grabs onto these cholesterols and plaque buildups and makes them larger and more potentially dangerous if the break free and go to the brain or heart where they can block the artery and cause a stroke or heart attack.


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

[User]
ELI5: How do our bodies know when we've had enough sleep and wake us up?

I'm about to go to bed and then I started to wonder, how the body measures how much sleep it has and how it just wakes itself up.

Edit: Thanks wow that makes sense considering i sleep with the window open.

[Assistant]
You have an internal clock of sorts, the circadian rhythm, so your body knows more or less what time it is. This is partially controlled by sunlight and will go all out of whack if you live in a cave.

The pineal gland, towards the end of the day as determined by the circadian rhythm, will produce a chemical that makes you sleepy. Early in the morning, you're asleep but the circadian rhythm knows it's time to get up and the pineal gland stops producing the chemical. After a while it dissipates and you wake up.

If you've ever had to get up very early you may have noticed you're exceptionally groggy for a while, this is because you're still full of sleep hormones as your internal clock can't predict a change to your routine. After a few days of getting up at 3am you do adapt, but it's always a little harder to go against the natural sunlight hours.

As for how the circadian rhythms are driven by biological clocks, that's a bit more complicated and afaik, invloves timing how long it takes for DNA instructions to be read inside the brain.


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

[User]
ELI5: Where does dirty money go after getting confiscated by the police?

According to the law, what will happen to the money?

[Assistant]
When the police department seizes money, it gets spilt among the agencies helping with the criminal proceedings (original PD and if any other police agencies helped with the investigation and the county attorneys office or attorney general, whoever will be prosecuting). Once criminal proceeding are done and if the money is forfeited, the money will be used within the police department for new equipment, etc.

Most guns seized will get destroyed if illegal.

Cars will be sold by the police department at auction or if the police dept want to keep a car, they have to file with the court a request and reason (undercover use, etc).

Most houses that are seized are still under loan so they go back to the lender.


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

[User] ELI5: Why are you supposed to safely eject a memory stick before taking it out?

[Assistant] That process is basically making sure that no data is being written to the stick while you pull it out. If you remove the stick while it is saving something, the data being saved and possibly the whole stick will be corrupted.


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

[User]
ELI5: How can people upload premium adult videos without the DMCA busting them? [NSFW]

Example hdpornbase.com, premium stuff, no sponsor nothing, and obviously they are making money off of ads, with content they clearly do not own.

[Assistant]
The video content is actually supplied by the producers/owners of that material to their affiliates and "tube" site owners as a method of marketing.

Imagine if a new porn star arrived on the scene, and the company that produced her content added clips of her work to the popular adult tube sites. Visitors would find the clips, a percentage of them will really like what they see, and either click through directly from the tube site (which makes the tube site $$$ in affiliate revenue) or Google that porn actress; either way, they end up on the producers website ready to sign up and make the company money.


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

[User] ELI5: When looking at the nutrition facts on a food, what am I supposed to be looking for that would indicate it as a healthy food?

[Assistant]
It's a bit of a moving target, since you need to look at *everything* you eat, not just one item. Furthermore, your requirements will be different depending on age, gender, type of activities, and many other factors.

As a rule of thumb, though, check the ingredients and make sure it's not mostly junk. Anything that's mostly sugar, for example, is out. Anything with a lot of sodium is probably out too. A lot of things that people assume are healthy (e.g., cereal) are really just sugar delivery vehicles.

After that, try and find out what *your* nutritional requirements are. Once you have that, you can look at calories and make sure you're not far exceeding your needs. You can also look at vitamins and all the other good stuff.

The real trick, though, is *moderation*. If you generally eat healthy and don't have other health issues, the occasional soda (while unhealthy) won't really hurt.


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

[User]
ELI5: If the universe is expanding, but the amount of matter in it remains constant(ish), does that mean the 'average density of the universe' is decreasing?

Not sure this question makes a ton of sense period, let alone from an actual physics standpoint. But in general terms, is this a valid question and if so, what's the answer and its effects?

[Assistant] Yes, the universe is becoming more diffuse, in mass and in energy. If you measure energy density as a temperature, it's only a few degrees (Kelvin) on average now. It dropped very rapidly during the big bang and initial inflation of the universe and has been declining more slowly ever since.


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

[User] [Star Wars] How did turning the Republic into the Empire change the galaxy's economic state?

[Assistant]
Massively. The Old Republic wasn't in *debt*, per say, but the economic state was hardly improving by the time of the Clone Wars. Plenty of people were almost glad to see a war, since it meant business. As it turned out, however, the war went on a lot longer and was a *lot* more expensive than pretty much everyone thought (excluding Sidious, of course), so by the time of Palpatine's Declaration of a New Order, you couldn't throw a rock across the senate hall without hitting someone who was deeper in debt than they could possibly repay.

One of the first things that Sidious did after the end of the war was declare any debts owed to "former Seperatist allies" to be void. This included the Intergalactic Banking Clan, though both the Confederacy and Republic had borrowed heavily from the IGBC to fund their respective war efforts. Though the Banking Clan suffered heavily, it eased some of the fears that the Empire would quickly fail thanks to a postwar depression.

As the Empire's true power became more obvious in the years after the war, they started getting aggressive about centralizing the economy. A new Credit standard was introduced, and smaller industrial firms would have been absorbed into the Imperial engineering corps, or more likely, "encouraged" to be bought out by larger corporations that the Empire had close relations with. Seinar Fleet Systems and Kuat Drive Yards, for example, were massively bolstered in the post-Clone Wars era. They also weren't afraid of intentionally organizing monopolies, either. The Bacta Cartel was an agreement between the Empire,and  Xucphra and Zaltin corporations on Thyferra, which gave the companies exclusive rights to produce Bacta, an essential medical salve used galaxy-wide.

Last, slavery of was made implicitly legal by reclassifying some non-human species as "lower life-forms". This probably had the biggest impact on most Imperial citizens' quality of life, both directly and indirectly.

To summarize, if you were a powerful corporation, you could expect to see higher profit margins, more production, more legal latitude, and the impossibly large military-industrial complex that was the Empire to always order more of what you were selling. As for everyone else, food and other immediate essentials would've slowly gotten more affordable, along with minor luxuries like fancy holosuites, fast speeders, and big houses. For a healthy chunk of the population, you were probably better off than you had been in generations...

Assuming you were human.

Or weren't living in the outer rim, or anywhere far from "civilization". Or didn't try and even *suggest* opposing anything the Empire was doing.


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

[User] Eli5: How come the human body doesn't try to reject donor blood like a donated organ?

[Assistant]
It does!

Even when transferring blood from let's say an O Negative person (the so called universal donor) to another person, a test is performed (Usually Combs's test) to determine if it will be rejected or not.

Since you are only transferring red blood cells, which are much less metabolically active and have less antigens, if you pass the coagulation test then there will he no "rejection"

Otherwise the person dies.


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

[User]
Why was the top quark easier to discover than the Higgs, even though it has a significantly higher mass?

I attended a talk about the Higgs discovery today, and I had a questions I didn't get a chance to ask the speaker. The top quark was discovered relativitly, recently at the Tevatron at Fermilab, and it has a mass of about 170 GeV. However, the Tevatron was not energetic enough to discover the Higgs (or "Higgs-like boson" if you'd prefer), even though it had a mass of 126 GeV. Why was the Higgs so much more elusive, or why was the Top quark easier to find?

[Assistant]
One reason the Higgs is so difficult to detect is because you're working against an enormous background.  The Higgs decays the vast majority of the time to b-bbar pairs (a bottom quark and an anti-bottom quark), but these pairs are produced regularly in collisions where the Higgs is not involved.  The next most likely decay channel, Higgs -> WW (from which we detect two muons and some missing energy from escaping neutrinos) is also up against a very significant background.  This makes seeing an excess of events in any specific energy range very difficult.  In addition, because of the many decay modes of the Higgs, a signal needs to be seen in all of the modes for it to be consistent with theory.

In contrast, the only known decay mode of the top quark is t -> b+W (the top decays to a bottom quark and a W boson is released).  The signal that is sought is generally t+tbar -> b+bbar+W+W because top quarks are produced in pairs.  For various reasons, it is easier to observe an excess in that decay channel than in the various Higgs channels.


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

[User] [Star Wars] How does your training in the Force equate to your skills using a lighsaber?

[Assistant] There are some separate skills to be sure, but a major aspect of lightsaber combat is precognition.  Oh and making sure your opponent can't use the force to just yoink your lightsaber as Ventress learned when dueling Yoda.


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

[User]
I mug old ladies in Gotham, but I feel like my career has stalled. Which supervillain's crew should I join and why?

By day I'm an honest, hardworking longshoreman, like my father and his father before him. But legit work doesn't pay the bills like it used to and I ain't enough of an egghead to get fancy work at one of those places like Wayne Industries.

Now, I started swiping purses on my own, so for me an ideal crew would allow room for advancement with that kind of initiative. Maybe a pension or 401(k) matching too.

Work-life balance can be whatever (as long as I don't lose my life at work!).

Dress code can be whatever, long as I don't have to wear it off the clock or undergo any freaky permanent changes.

I'm 6'2", 250 lbs, and could pass for Italian, so maybe I should start off as just a mob enforcer and see how that goes?

[Assistant] Go Penguin. He's not about playing games, he's all about the money. Sure, double-cross the man and he'll break out the buzz-saw umbrella or some nonsense, but do good work and you might get moved into one of his legit operations like the Iceberg Club. Besides, everyone looks good in a tux.


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

[User]
ELI5: Why can our eyes look inward, down, and up together but not outwards?

Bonus: Can your eyes get stuck? If so, why?

[Assistant]
The eyes are designed so that they both look at the same object.  For very close-up objects they need to converge (look inward) to do this.  For distant objects they're parallel, i.e., looking in the same direction.  There are no circumstances where having the eyes diverge (look outwards) will have them both looking at the same object.

Our brain is only trained to deal with a single image at a time.  Having two eyes is mostly to help with 3D perception and it gives us redundancy (in case one is lost or fails).  It's not so we can look at two things at once.


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

[User] ELI5: What happened to chat rooms? How did they go from such popularity to being virtually non-existent?

[Assistant]
Chat is still popular and easily accessible, IRC, chat roulette, ect
. Some chat host have folded, which might give the impression that chat is dead, however that is far from the truth.

I think it might be more of a case that you out grew chat. Looking back on time you think about how much chat used to be a part of your life. You went back to your favorite server but the rooms are mostly empty, and you don't recognize any of the names. Don't fret, chat is still going, most of your old chat buddies have just moved on in life and have different internet habits.


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

[User]
I believe that all single-user bathrooms should be unisex. CMV.

To clarify, I'm talking about public bathrooms meant to be used by one person at a time. These bathrooms generally have deadbolt locks on the doors, have a toilet but no urinal, and (with the exception of maybe specialized waste receptacles) don't have anything that you wouldn't find in both types of bathroom. Given this, I don't see a reason why you would label that sort of bathroom specifically for men or women.

If the goal of segregating these bathrooms is to keep differently gendered people from seeing each other, it's single user, so that's not an issue. If it's to offer specialized equipment, most of the single user bathrooms I've encountered (for both sexes) don't do this anyway.

Edit: Wow, there is, um, a lot of stuff here! In case anyone is interested in whether my view has actually be changed, so far it has not. The three most common comments I've seen by far are:

1) "[GENDER X] is dirtier and I don't want to deal with that."

Let's presume that one gender is dirtier in general than another. Does that mean that we should essentially quarantine that gender into their own space? The implication there is that, as a member of a gender, am somehow responsible for messes that I didn't make and should be subjected to them based on that? Doesn't seem right to me. Also, in cases where you have 2 unisex restrooms, everyone will be able to hop over in the event that one is just *completely* trashed.

2) "[GENDER X] takes too long in the restroom, I don't want to wait."

There's some great math on this further down the thread, but the consensus is: while have two unisex restrooms and one line might make *your* wait a little longer, depending on your gender, it's going to make the *average* wait time lower overall. Sounds like a good tradeoff to me.

3 "I treat restrooms like this anyway!"

Great! However, not everyone does, and more important, not everyone has the expectation that others do. Without everyone being on the same page, we lose a lot of the benefits of unisex restrooms, so I think changing the labeling is relevant even if, say, 40% of people already treat restrooms this way. Wouldn't we want 100% instead?

[Assistant]
This would be fine, except that in this case one gender is much filthier, smelly and prone to make a mess everywhere.

So yes, until women learn to leave the bathroom clean, we'll have separate loos, thanks!


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

[User] ELI5: Why/how is it that, with all the incredible variety between humans, practically every body has the same healthy body temperature of 98.6 F (or very close to it)?

[Assistant]
Because all of our tissues/proteins/enzymes have very similar structures. Temperatures can drastically affect how a protein works; higher temperatures can render a protein completely non-functional, if not outright destroying the protein.

A narrow temperature range provides the best performance for the body's proteins. This temperature is maintained by the hypothalamus, which tries to keep the body at peak performance: in that narrow temperature range.


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

[User]
[Star Wars] What would have happened if Anakin had not stopped Mace Windu from killing Darth Sidious?

I'm rewatching all six in chronological order, and the thing that stands out to me about the prequels (apart from how bluntly they have shoved every single character in there) is that Sidious took a pretty big risk during his confrontation with Windu.

In order to appear weak and get Anakin to commit an act of murder, Sidious lets Windu beat him. What if Anakin had followed his orders and not intervened?

[Assistant]
Either A) Sidious just amps up his attack and kills Windu

B) He's so taken back that his toy doesn't work as intended, and his throat is slit.

However, one part of Palpatine's plan (downfall of the Jedi) would still go on, due to there being a schism between the Jedi and Republic, most likely leading to civil war.


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

[User] [Myth] Which legendary city would be wealthier, El Dorado or Atlantis?

[Assistant] Atlantis. El dorado was built of gold being a much higher value on paper but you can't expect people to start tearing the city apart to trade with others.  Atlantis is more advanced and capable of projecting it's wealth and influence beyond its city limits.


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

[User]
[LoTR] Galadriel accepts the Ring from Frodo. What happens next?

"Instead of a Dark Lord you would have a Queen! All would love me and despair!"

What does that mean exactly? Super mind-control powers? How would the rest of the White Council, Saruman or even Sauron react for that matter? Has Gandalf been resurrected yet or would he be returned even more powerful to combat this new threat? Could Mordor and Rivendell even join forces if this new threat was so terrible? And if she wins this new War of the Ring, what would this new Galadad-ocracy look like?

[Assistant]
According to Tolkien's letters, if Elrond or Galadriel took the One Ring they would have used the same general strategy as Sauron was using: "they would have built up an empire with great and absolutely subservient generals and armies and engines of war, until they could challenge Sauron and destroy him by force." While her control would be incomplete, Galadriel would be able to use the Ring's ability to influence and dominate the minds of others (especially those connected to the Rings of Power) to a much greater extent than Frodo or Sam ever did.

Sauron would be seriously worried, and would probably send his armies against Lothlorien as soon as possible to prevent them from becoming strong enough to challenge him. (This is also why he responded to Aragorn's attack on the Black Gate; he suspected Aragorn or Gandalf had the One Ring and had arrogantly decided to attack Mordor directly.) If it ever came to a direct confrontation of wills between Galadriel and Sauron over the Ring, Sauron would win. Sauron is not only incredibly powerful but also the rightful owner of the One Ring, and that counts for a lot in Middle-earth.

Saruman would be even more worried than Sauron, since both sides deeply distrusted him and the possibility of stealing the One Ring was pretty much the only hope he had. Who knows, he might even pretend to side with Galadriel in the same way he pretended to side with Sauron.

Gandalf actually returned to life on the same day that Frodo offered Galadriel the Ring. It's hard to say what he would do; he usually tries to confront even enemies who seem completely lost (as with Saruman in Isengard after the ents attacked), but it would be potentially dangerous to enter Lothlorien with Galadriel in possession of the Ring. There's also the fact that Gandalf himself has one of the Three Rings, so it's quite possible Galadriel could exert some influence over him. (Rivendell is also in trouble, since Elrond also has one of the Three.)

Even if Galadriel did conquer all her foes, she would still become irreversibly corrupted by the Ring. She would never willingly give up her power. Like with Sauron, she would at first want to have authority to order things for those who have less power or wisdom; later, this goal would become lost beneath the desire of power for its own sake. Her own power combined with that of the One Ring would make her presence and sense of authority so awe-inspiring that none could oppose her (as she says, "beautiful and terrible as the Morning and the Night!"), but she would still be an autocratic despot running what would quickly become a police state.


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

[User] ELI5 - how come we can remember lyrics of songs heard 10, maybe 20 years ago but we forget to remove the tea bag from the cup ?

[Assistant]
One is long term memory, and the other is working memory.

Working memory is flushed unconsciously, meaning you dont know when its being erased and replaced with something new. Whatever you pay attention to dictates the contents of your working memory. As the innkeeper in Bree constantly reminds everyone, One thing pushes another out.

You forget to take the teabag out of the tea because other things filled your working memory.

You should set a timer for the tea. Over-brewed tea is nasty.


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

[User] ELI5: Since magnetic north is not the same direction as true north, when and how did navigators figure this out, how did they compensate, and does the advent of GPS navigation render the magnetic compass completely obsolete?

[Assistant]
> Since magnetic north is not the same direction as true north, when and how did navigators figure this out

Quoting Wikipedia here:

> The first expedition to reach the North Magnetic Pole was led by James Clark Ross, who found it at Cape Adelaide on the Boothia Peninsula on June 1, 1831. Roald Amundsen found the North Magnetic Pole in a slightly different location in 1903. The third observation was by Canadian government scientists Paul Serson and Jack Clark, of the Dominion Astrophysical Observatory, who found the pole at Allen Lake on Prince of Wales Island in 1947.

Navigators use a number of different tools. A sextant can be used to determine latitude by looking at stars, specifically Polaris. When explorers found the magnetic North Pole they found that their compasses spun because they couldn't find north. But a sextant measurement would have shown they weren't at true north or ~~0 degrees~~ 90 degrees latitude.

But navigators knew there was a deviation between compasses and true north for a while before that.

> how did they compensate,

Once Magnetic north was discovered they could adjust, maps will often have the declination adjustment written on them that tells you how to adjust your compass to point to true north. But navigating up north is still a challenge because of it. Markers like Polaris are unaffected by magnetic north. Which doesn't really help when you have constant daylight during parts of the year.

> and does the advent of GPS navigation render the magnetic compass completely obsolete?

No, compasses are still widely in use and navigators and soldiers for example are still widely instructed on their use. A compass is tiny and doesn't need batteries so it's still a very useful tool.


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

[User]
I think that government employees should never have the right to strike, CMV

Striking is an important negotiation tactic, but it's balanced by the risk that a company owner will remove their capital and reinvest somewhere else, so the strikers will lose their jobs. Or that their demands will make the company uncompetitive and it'll go out of business, again leading to no jobs. Thus the demands of strikers in a private business are tempered by the need to account for what's best for the business as well as its workers.

In the government sector this balancing force does not exist. The state does not typically run organizations to make short term profit; they're run for the benefit of its citizens. It rarely has direct competitors, and often cannot exit the market because it provides key services. Thus, striking government sector workers (who already have relatively better job security) are not taking on much risk and have little reason to produce reasonable demands.

While I strongly believe in the right to strike for other workers, and feel that everybody deserves reasonable pay & working conditions, government employees should not have the right to strike. This includes police officers, firefighters, soldiers, teachers, transport workers et cetera. They need to negotiate using other methods more appropriate to the state sector.

I feel this is sensible but there is often widespread public support for government sector strikers, so I'd like to hear some opposing arguments and get a feel for where there might be situations where my approach is inapplicable.

[Assistant]
Everyone should have the 'right' to strike, in so much as they are not slaves are are free to make their own choices about who they work for and when they work.  If they choose to stop working and protest their work conditions,  it is imperative from a free-speech and anti-slavery perspective that they not be prohibited from doing so.

As citizens running a government, we should immediately fire striking workers... for all the reasons you mentioned.  It should be our policy as 'employers' to pay competitive wages, but not to allow disruptions to our critical functions.  Workers should be free to strike, and we should be free to (and would be wise to) fire them.


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

[User]
[Breaking Bad] How famous is Heisenberg?

Would you have to be involved in the meth trade to have heard of the local drug lord behind the blue stuff? Or is he like an American Pablo Escobar, someone whose name any teenager would know?

[Assistant] For most the series, youd have to be connected to the criminal underworld or law enforcement to have heard of him. But after Heisenbergs identity is revealed he becomes Public Enemy No.1 and is known as the most notorious drug kingpin in the nation.


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

[User]
CMV: Listening to audio books is not as good as reading books

Okay, this may sound controversial, but I have my reasoning for saying this.

First of all, this doesn't include people that ~~cannot physically read~~ find it easier to listen. Obviously audio books are better for them, and that's fine.

You cannot simply sit down and listen to an audio book, you can only listen to them when you are doing something. This is because they are often read at a very slow pace, far slower than anyone actually reads, and it would be better to just read the book if you have time (rather than just sit there and listen to someone read it). This causes some issues to occur, starting from this dilating your attention span. You begin to do multiple things at once, which inevitably means that the effectiveness of one action becomes worse. You can't focus on one thing while simultaneously doing another, unless you want to have a worse result. Let's say I was both reading about a concept in physics, and listening about a concept in chemistry. I could either entirely ignore one and get a better understanding of the other, or get a worse understanding of both. This means that by listening to an audio book you aren't actually appreciating the book itself or any meaning it may have, you are simply understanding it on a surface level (that deepens depending on how little effort you put into another activity).

I would like for you to try to convince me otherwise, or tell me some uses for audio books that are beneficial. More beneficial than reading books that is.

[Assistant] If you have a commute, listening to an audio book can be a great option as it's one less thing to carry, you can listen and drive, or if you are on mass transit, you don't have all the disruption of bouncing around while trying to read the page (which lowers the chance of eye strain and motion sickness).


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

[User]
ELI5: How do Icebreakers work?

With the new recently about a ship being stuck in the ice, and three "Icebreaker" ships being sent to rescue it, one is now also stuck.

How do Icebreaker ships work, and what are their limitations?

[Assistant]
Their hull, especially the bow (front) is made much thicker and heavier than normal and their engine/s are more powerful than you would expect on a craft of that size.

In very thin ice (1m ish) they bash through it.

As the ice gets thicker the bow rides up it and the weight of the ship crushes down and cracks it.

Different ice breakers have their own limit. Unfortunately, the ship stranded in the arctic is in ice just beyond the capabilities of the ice breakers sent to help.


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

[User]
What the hell happened to the academic job market in the past ten years?

I've heard all of these mythical tales about the bygone era of 2001-2007, when new graduates, PhDs in hand, would get some postdoc fellowship straight out the gate, and go on to some tenure track position thereafter.

Nowadays, I see people graduating with PhDs from top ten universities with mile-long resumes who send out more than a hundred applications and still can't find a job.  I've been told that the financial crash in 2008 had something to do with it, but what exactly? What changed in university departments that led to the job market being so awful?  Why does it continue to remain awful?  Will it continue to remain awful?  Or do you reject the premise of my question, and conclude that the academic job market is just fine?

Mainly, I've heard about this in the humanities, since that's roughly where my field is.  I'm not sure how it is in the natural or social sciences.

[Assistant]
(This is purely anecdotal; someone else can research the data and see whether these guesses are right.)

I would hypothesise two effects in the United States:

  * The Great Recession leads to an increase in unemployment in many industries.  Fewer jobs available to college graduates means more people go to grad school instead.  More people in grad school means, a few years later, more people with PhDs chasing the same number of positions.
  * The Great Recession, along with the ascendance of Tea Party or other anti-tax politicians, leads to a drop in state and federal revenues.  A drop in state revenues leads to less funding for public universities; a drop in federal revenues leads to less grant funding.  Less funding for universities means fewer new positions get created, and some retiring scholars are not replaced.  So there are fewer positions available for the PhDs to chase.


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

[User] ELI5: Why do soldiers bother taking POWs?

[Assistant]
In addition to laws and conventions, it's also a tactical decision.

If you're a soldier, and you know the enemy are about to overwhelm you, you have two options. Surrender, or go down fighting and take a few more of the enemy with you.

If you know the enemy is likely to accept your surrender and take you prisoner, you're probably a bit more likely to go with that option. By taking prisoners, armies save the lives of their *own* soldiers, too.

There's a story that during WWII, German parents would tell their children to surrender to Americans, because they take prisoners and treat them well. Much safer than actual fighting.


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

[User] [John Wick] What if a man I owe a marker to demands I kill someone else I owe a marker to?

[Assistant] I doubt markers are the kind of thing that are just given out willy-nilly. Hell, there seems to be a sort of registration for them and records are kept on who owes who what and what favors have been called in. With that in mind it's reasonable to assume that, since the Continental is involved in the processing and handling of Marker debts they can regulate their enforcement and prevent this sort of scenario from occurring. Hell, maybe a person can only have one marker on them at a time. You'd need to keep their circulation at a minimum to maintain the gravity of the bond, after all, otherwise people would be trading in them like candy.


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

[User] [LordOfTheRings] Why men never tried to eradicate everything in Mordor and claim it as another of their territories?

[Assistant]
Mordor doesn't have much going on, for the time period we'd be speaking of, it's a barren depopulated wasteland. While Sauron was not there Orcs likely hid themselves rather than openly occupy Mordor. There's a valuable agricultural region in it's far south east, Nurn, but it's never explicitly said to come under the sway of anyone except Sauron or the native population.

Numenor, at its zenith, had colonies all over the world, but the colonies that we see, Gondor, Umbar etc, are never very far inland, or broach mountain ranges like those that guard Mordor. Later, Gondor at it's respective noontide, had its hands full managing other territories. They may not have seen the gain in making a large extension of their empire to capture the fields of Nurn. In anycase, it would have been short lived. In between the machinations of Sauron during the Third Age, and Gondor's own infighting, they wouldn't have held onto it for long.


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

[User] [Ghostbusters: The Video Game] If the Ghostbusters had hypothetically succeeded in trapping Stay Puft, would Gozer be eternally trapped in this form in the containment unit, or is Stay Puft only a manifestation and not Gozer itself?

[Assistant]
Stay Puft is Gozer's destructor form. An entity's destructor form appears to be the actual entity itself, taking a shape more suited to invasion / conquest / destructoring, rather than a dimensional extrusion or avatar (see also: Shandor).

When Gozer turns up as Stay Puft for a second time, it leads Ray to theorise that there's a limit of one destructor form per god per dimension. If Ray's right, then it would be Gozer itself stuck in the containment unit, stuck in the form of Stay Puft.


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

[User]
ELI5: Why has there been a vinyl resurgence in the music industry?

What's the deal with vinyl records making a comeback? I feel old when I say that I don't really "get it." But, as a music lover, why should I care?

[Assistant] You can get them cheap. They have a slightly different sound quality, and many people enjoy that difference. Album art is pretty great in and of itself. You can roll a joint on an album cover, but you can't on digital music. People like actually having physical items. They have a cool factor that dates back more than a century (the term groovy specifically refers to the grooves in an album, for example). If you are into certain scenes, 7" singles are a great way to pick up and try out new music in a more interactive way than simply going through youtube. Many people enjoy the nostalgia factor. You can give them away as physical objects to people who also enjoy albums, and that beats the hell out of just sending them a link. You can leave them to your kids. You can get them from your parents. People like them.


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

[User]
I think the idea that today's youth are all "entitled" is completely bogus CMV

All the time I hear people say that young people are "entitled" and lazy. What is the evidence for this? Young people today volunteer more and graduate college more than the previous generations. They take internships with no money so that someday they can hope to get a paying job. They indebt themselves thousands of dollars and go to graduate school and work their asses off so that they *might* get a job in their field.

I'd also like to argue that young people under 18 *are* entitled to a healthy home environment with basic necessities. And young people over 18 are entitled to believe that if they work hard that they will eventually earn a living wage.

I'm not saying that no young people are spoiled and lazy. There are spoiled and lazy people in every generation. Why is our generation (i.e. the millennial generation) being singled out?

[Assistant]
The entitlement comes from expecting the same things as the previous generation. The boomers are an economic anomaly, riding off the waves of post war prosperity while rest of the world suffered. Europe was in ruins, slowly recovering and many parts of Asia were still developing. Minority groups were disfranchised. There was no globalization or competition like today.

The extremely high standards of living the boomers had with relative ease did not continue as America faced similar problems as rest of the world, and the world became smaller. The American youth today now face the same problems of unemployment and competition as the rest of the world from Spain to Korea. We're just not that special anymore. An average student who went to an average college, studying a fluff major could still find a high paying job with great benefits, live in a nice house and support a family of four. Many youths today are shocked after graduating and facing the real world that this simply isn't the reality anymore, thus the accusations of being "entitled".

But if it makes you feel better, the previous generation was just as lazy and entitled, just a lot luckier.


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

[User] ELI5: Why do older bath towels absorb water so much better than brand new towels?

[Assistant]
Brand new cotton fibers have a layer of natural oil in them that improved softness. New towels may also be treated with oils or waxes to enhance the softness of the cotton fibers. These oils prevent the fibers from absorbing liquid efficiently.

After several washings the oils no longer remain. The towel dies not feel as soft, but it gets you dry quicker.


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

[User] ELI5: Why can people understand languages, but not speak them ?

[Assistant] Because recognition of language is a lot easier than generation of language. If you've ever studied a language, you've probably noticed that you have more trouble thinking of the foreign word when presented with your native word than you do if you're presented with a the foreign word and have to come up with your native word for it. Then consider grammar and sentence construction. Even if you don't know how to construct a sentence in the language, if you understand the words you can probably get the gist of what they're saying just because you recognize the verb and nouns that are there. But if you had to create a well-formed sentence on your own, you'd have no idea how to do it.


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

[User]
Why do tidal ranges in different parts of the world vary so greatly?

I understand the basics of how tides work with the sun and moon causing neap and spring tides, but why does the tidal range vary so greatly in different areas? (from as little as 1m to 17m)

[Assistant]
Resonance based on shape and depth of the basins.  Tides are essentially very large waves which travel around an ocean basin. Unlike the waves you normally see at the beach which have a wavelength of 1-10 meters, the tidal wavelengths are 1000s of km. For a place with large tides, such as the Bay of Fundy, the natural unforced period for a wave to travel around the basin is very close to the period of the gravitational forcing of the sun/moon (~12 and ~24 hrs). Therefore the sun/moon are very effective at driving a large tidal response.  Other basins, such as the Mediterranean, have a natural free wave frequency which is different from the sun/moon forcing and thus ineffective at transferring much energy into tidal motions. In order to get large tides, the size and depth of the basin have to be in the sweet spot for resonant excitation.

You can create a similar resonant wave in your bathtub. If you swish your hands back and forth you can create a standing wave where the water sloshes back and forth from end to end. The period of this wave depends on the size of your tub and the water depth. If your hands move back-and-forth at just the right frequency, you can excite a large sloshing with very little effort. But if you move your hands too fast or too slow, you will still create lots of small waves and ripples, but it's only when you force at the resonance frequency that you can create the really large response.