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

[User]
ELI5: Whats the use of tachometer?

While driving my car, I use speedometer to see the speed but never check and understand the tachometer. I keep thinking it occupies lot of space unnecessarily.

[Assistant] For most cars with automatic transmissions, the tachometer is largely useless except as a way to indicate a problem with the transmission or other part of the drivetrain (although on modern cars, the computers cover that regardless).  On manual (aka standard) shift cars, a tachometer can provide a good visual cue to know when to shift up or down, although most experienced drivers rely on feel more than the visual of a tachometer.  In high end sports or performance cars or heavy duty trucks, a tachometer provides precise information that tells a driver how hard they are pushing the engine.  But in most cars for most conditions, they are pretty much useless.


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

[User]
What is the rationale behind the theory of the island of stability?

Is there any evidence that suggests that the existence of superheavy stable elements is more than wishful thinking?

[Assistant]
If an atom has a certain number of electrons in its outer shell, it is expected that it will be chemically stable. Thus element 118 is expected to behave like a noble gas even though its chemistry hasn't been tested.

Likewise, there are certain numbers of nucleons that impart nuclear stability. These are called nuclear magic numbers.  For example, 50 is a magic number, and element 50 (tin) has more stable isotopes than any other element. It applied to neutron numbers as well. The next nuclear magic number is 126, so it's plausible that nuclei around that size would be more stable than those below.


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

[User] [Halo 5] Why does Spartan Kelly-087 speak with a British accent? All Spartan IIs spent most of their formative years only communicating with each other and their trainers. Shouldn't they share a standard accent?

[Assistant]
She wasn't taken into the program until she was six, and an unusually intelligent six at that.  She was already fully articulate and would have already developed her accent.
Not everyone loses their accents when separated from people who share it, and it's also entirely possible that she likes her accent and keeps it as an affectation.


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

[User]
[LoK] Could Kuvira have successfully invaded the Fire Nation?

While she certainly could have overrun Republic City had it not been for the Avatar, I don't think that would have been enough for final victory for the Earth Empire.  While Izumi refused to support a preemptive strike, I don't think she or her father would be willing to let the country he founded with the Avatar be conquered, and would fight for its freedom.  Could Kuvira fully defeat her enemy across the sea, or would it just be a matter of time until her regime collapsed under the pressure of war?

[Assistant]
Provided the Fire Nation kept a sizable military, not a chance.

The Fire Nation is anapeggioo, which means that the Earth Empire would have to cross an ocean to fight a nation that can defend it's borders from all sidesand. Historically, aagains island nations go poorly for the attacker and The Fire Nation has had time to prepare. The Fire Nation has also spent the last century perfecting navel combat so keeping a steady supply line is going to be tricky.

Plus, the Earth Empire has never really conquered anything in the traditional sense outside of Republic City. Most places they've annexed were beaten down towns and groups of bandits.

The Fire Nation is a stable country of proud people that would fight for their beloved Fire Lord/Lady.

Even if the Earth Empire does manage to land and take territory, it'd only be a matter of time before they're driven from the mainland.


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

[User]
[American Gods] can atheism be a new god?

I'm new to this serial, I only watched some episodes of the TV show, but there's a question that's bugging me.
Since people in America started to believe that there is no God, can a new god derived from there, like atheism??

[Assistant] Yes, but it would be born from those who treat atheism like a religion and who believe with absolute, unquestioning certainty that there is no god.  The atheist god born from this zealotry would be a self-loathing, hypocritical god.  It would look down on the fervent believers of other gods as deluded idiots but then demand that same level of blind devotion from its own followers.


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

[User]
ELI5 If no one knows about your dirty money why do you need to launder it

I know money from drugs, robberies, stolen goods, etc is dirty but, how does anyone know its dirty? Why cant you just spend your money?

[Assistant]
People, particularly tax authorities, start to get suspicious when you somehow start spending many times the amount of money that you make.

Basically, if the money is dirty, it can't really be used for large purchases because the mere fact that you possess that much unexplained cash would raise suspicion of you.


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

[User]
Where does the CO2 absorbed by trees end up?

What is the final destination of the CO2 captured by trees? Their bodies? If that, is it released back into the atmosphere if the woods happen to burn down?

[Assistant] Yes, trees turn water and CO2 into wood and leafs. If the forest burns the carbon turns back into CO2 again. Also, if the tree dies and is digested by insects etc that will also release the carbon as CO2 again. So a forest keeps a certain amount of carbon bound as biomass, but it's a steady-state, it doesn't keep absorbing carbon on net. If e.g. farmers burn down the forests to create fields this releases some extra carbon to the atmosphere, because the field has less biomass than the forest.


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

[User]
[Star Wars] What if Vader killed the Emperor in ROTJ using another method? What do you think would happen next?

I'm not exactly sure how to word my question, at least for the title so let me explain better first. Okay, so when Luke and Vader are in the Throne Room on the Second Death Star, the Emperor is sitting in his throne and practically goads Luke into giving in to the dark side. The Emperor released his restraints, ordered the Commander to fire on one of the Rebels capital ships and the battle over Endor begins. Luke noticed his lightsaber and the Emperor notices it too, he tells him, "take your weapon! Strike me down with all of your hatred and your journey toward the dark side will be complete."

Luke was tempted too, knowing that he had to die and he did grab it with the Force and went in for the fatal strike. Then, Vader blocked the strike locking their blades together before beginning their duel. This was the perfect opportunity to kill the Emperor, the one shot Vader was waiting for and this was Darth Vader, not Anakin Skywalker, he wasn't redeemed yet. So, what if Vader killed the Emperor then?

Let's say he did. He swung quickly and sliced the Emperor in half and doesn't duel with his son. What do you think would happen after that? Vader didn't get electrocuted, so he won't die and I don't see him and his son dueling over the situation. He also doesn't know about Leia then, he only found out when dueling with Luke. The story after this point would obviously be different, we know how Vader feels about the death star but we also know how he feels about the Rebellion, then on top of that we know he wants his son in his life, his family was the reason he became Darth Vader in the first place. Would he keep his promise and offer his son to rule as father and son again, do you think Luke would even want that?

I hope I better explained my question, and I am curious to hear what you think of this what-if scenario. Let's also assume he remains Darth Vader, he stays rooted in the dark side and proclaims himself Emperor of the Galactic Empire.

[Assistant]
Vader is a brilliant military tactician, but a horrendous politician. Even with his son neither have the skills to lead a galactic empire. The Moffs and Admirals would quickly turn against him and the Empire decends into chaos.

Also Luke was intent on saving his father. There wasn't an option to join the Dark for Luke, it was save his father or die. Would Vader be able to strike down Luke? Maybe, but Vader never wanted his son to die. If he somehow comes back to the light side he would go into hiding, never to be seen again. He's already caused too much damage.


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

[User]
CMV: there are no good reasons for going to Mars and we should not do it.

I'm a scientist myself and I'm very passionate about space exploration and science in general. I think the time, money and human effort that would be spent on a manned mission to Mars would be largely wasted.

Some of the arguments I hear in favor of a human mission to Mars are often related to having a "backup planet" or exporting our civilization elsewhere. I will just dismiss these arguments as ludicrous immediately: Mars is a barren rock with no hope of sustaining life. As a species, we currently have no clue how to keep this planet inhabitable, we have no hope of ever populating Mars with any decent numbers. A scientific base? Maybe, sure, an actual colony? That's science fiction.

As far as new scientific knowledge that could be gained from a manned Mars mission, I doubt the enormous resources required for a scientific base on Mars couldn't be spent on having the same or better results with an unmanned probe. Curiosity has been roaming the surface of Mars for 9 years. It needs no food, no water, no human relationships or mental health assistance, and if after all this time it falls in a crater and breaks, no human life has been lost. I find it hard to believe that an automated mission designed to bring back samples from Mars would be harder to realize than a manned mission, and it would be infinitely less dangerous.

I think the idea of a Mars mission is largely a romanticized "to set foot where no creature has ever set foot before" glorification of the human species for some, and a publicity stunt for your garden variety billionaire like Musk. There is little practical reason to do it.

That being said, I love things that are done with no reason other than advance our knowledge and culture, but poetry, art, music, pure mathematics or quantum gravity don't cost billions and don't put any human lives at risk for the romantic ideas of a country or the profits of a billionaire.

[Assistant] Projects with a lot of prestige, like a manned Mars mission for example, can serve to excite a large amount of people for the cause of scientific exploration and as such create more resources for projects that actually have a big projected return. This sometimes makes flashy, but questionably effective projects like this worth it.


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

[User]
[Alan Partridge] Why, in Partridge's universe (which seems almost indistinguishable from ours) isn't he a success?

 Considering he's a cultural icon in our world, what is it about the people in his world that causes them not to appreciate him, even for ironic value?

[Assistant]
Partridge has been a particularly toxic individual with an over-inflated sense of ego and a desire to rise in fame. He was fired from the BBC and blacklisted from television after an incident where he attacked a producer during a Christmas special and was forced to work as nothing more than a local radio presenter.

After that, he's been prone to mental breakdowns and has been forced to change career a number of times, but he's been somewhat redeemed after the incident where a fellow DJ took the station hostage. Although the BBC probably didn't want him on *This Time*, they didn't really have a choice since the original host fell ill and...


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

[User]
[Warhammer 40k] So why don't the humans just crank Space Marine production up to 10000000000% and crush every other race?

I think the reason was something to do with a hard limit on their numbers set by the Emperor, but there have been plenty of times when the powers that be have decided to disregard his orders, why not in this case?

[Assistant]
Most of the gene seeds have become weaker or corrupted over the millennia. This is due to genetic mutation, Chaos influence, or radiation exposure. Several of the gene seeds had flaws from the beginning. Gene seeds need to be screened for flaws and culled if they are unsuitable. This is problematic because a Space Marine only produces two sets of gene seed in his lifetime (and if he falls in battle the second might not be recoverable), so the supply is extremely limited.

Furthermore, the recruitment process to turn a human into an Astartes does not have a 100% success rate. Some chapters are lucky enough to have a 1 in 10 success rate. Some have such a flawed gene seed that they can only manage 1 in 100. Some gene seeds are so failure-prone that their chapters are actually shrinking, each gene seed is producing less than 1 Astartes on average. Space Marines are created at a very slow rate, which limits their numbers greatly.

Finally, the last time the Emperor sanctioned an accelerated Space Marine program there were severe Chaos mutations. Corax had to personally give the Emperor's Peace to many of his own Astartes.


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

[User]
[Batman] Has it ever been explained or touched upon as to how the Joker and other Batman villains are able to escape from Arkham so easily?

* Is there like a secret escape route that they have or something, or do they use different methods to escape every time?

[Assistant]
Arkham is shit.

It's not the most complex explanation, but yeah. Arkham's a corrupt, crumbling, incompetent, possibly literally cursed institution. It's simply not suited to contain people like the Joker, hence how they keep escaping.


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

[User] ELI5 : Why is 32 bit sometimes referred to as x86?

[Assistant]
The first mainstream 32-bit processor Intel made was the 80386 (often just called 386) and it was an architecture improvement over the 16-bit 80286. A few years later they do another upgrade to 486 and then to 586, a.k.a. Pentium, which dominated the 1990s, then the 686 Pentium Pro. These chips were mostly backward-compatible, so software written for an earlier version would usually work on later ones.

Come the late 1990s, there were grumblings about various reasons to upgrade to 64-bit chips, but this sort of upgrade tends to break backward-compatibility, so there was a lot of feet-dragging. Intel decided that the right thing to do was to just suck it up and use the switch to not need to support 1980s-era software forever; they developed their Itanium line of 64-bit processors.

Intel's main rival at the time (and in some ways continuing), AMD, had been licensing Intel architecture to make competing chips, but they developed an architecture called AMD64 with a 64-bit mode *and* could still run software built for the older 386, 486, 586, and 686 (collectively called x86) processors.

This fight went on for a while, but AMD64 ended up winning and Intel finally licensed it. For various boring and silly reasons, people tend to drop the AMD portion and call this x64.


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

[User] [Game of Thrones] Tywin Lannister said a Lannister always pays his debts. Was this a matter of honor for him and always followed, or was it more of a matter of public opinion of his family? If rather than pay a debt, he could have the debtee secretly murdered, is that something he has done?

[Assistant]
A Lannister pays his debts isn't really referring to the idea that Tywin pays his credit card bill on time.

Its a threat.

Its a polite way of saying that if you embarrass them, or slight them, or do harm to them they will absolutely get payback. They owe you an asswhooping after all, and they pay their debts.


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

[User] Why do loud noises and other disturbances seem to work themselves so perfectly into your dreams while you're falling asleep?

[Assistant]
Well, it's not that they work themselves in any better than any other time during alpha wave brain processing, it's just that they're less inhibited during REM sleep.

Quick background: Essentially, when you're awake, your brain is going through alpha wave and beta wave oscillations. If someone strapped you up to an EEG, these frequencies of oscillation would be seen while awake with eyes closed, and awake with eyes open respectively.

REM sleep (the stage of sleep that allows for dreaming) is primarily made up of alpha waves (unlike other stages of sleep which go through much slower frequencies). Parts of your brain are active during these stages of sleep, most notably your occipital lobe (visual processing centers) and secondary auditory cortex (sound processing centers). This means that things you see and hear are available for processing much like when you're awake and contrary to when you're in deep sleep. Now, since your eyes are only flickering when in REM sleep, you're not seeing much, but sounds are freeably available to process and that may work itself into your dream in your reduced state of conciousness because you don't have much of your pre-frontal cortex (inhibition center) to filter it out like you do during wakefulness.


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

[User]
[The Last of Us] What ever happened to the military, government and society?

In the beginning Joel is living in a protected zone with a lot of signs about quarantine, but whatever happened to the government and military? did they just dissappeared? dissolved into factions and smaller groups? why did radio broadcasts and other communications stopped? Did the disease spread overseas or is America under quarantine?

[Assistant]
The spores are airborne and change people into murderous carriers. That makes quarantine zones and the like practically unmaintainable. All it takes is a few spores crossing the boundary and quarantine zones turn into meat grinders.

The population simply got decimated to the point where there's so few humans left that they can live in small isolated pockets that can be defended and kept clean.

By the time the population has been reduced by that much, there's no real government or military left.


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

[User] ELI5: How does adblock work and why doesn't Youtube get around it?

[Assistant]
In very simple terms, it is just a blacklist that prevents certain domains or subdomains from loading. In more complicated terms, it also parses the sites source code and looks for things like iframes etc. to unfuck the site layout after the ads have been taken out.

Also, websites rarely "notice" you having adblock and instead opt for a simpler solution: They'll just put these shaming messages in a layer under the ads so they only become visible when the ads are blocked out. It is possible to detect, but more complicated. Maybe someone with webdev experience can explain it in more detail.

As to Youtube not caring...my guess is that Google generates enough revenue from their other projects.


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

[User] [DBZ] When Goku bonked his head, did he remove Saiyan programming, or did he receive brain damage that altered his personality?

[Assistant]
A little bit of both.  Goku thoughout his life still has a couple of Saiyan personality traits that are fundamental to him - always seeking out a tough fight, a certain level of arrogance, etc.

The knock on the head did cause enough brain damage for him to forget his mission and the aggression that he'd been programmed with.  Presumably, since he was being taken care of by Grandpa Gohan, when he woke up, the old man's kindness was what imprinted on him and led to the personality that we know today.  Fundamentally innocent and human, but with an edge from his Saiyan biology.


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

[User]
ELI5: How did diarrhea kill so many people before and now its not that big of a deal?

Title really, is it just that our diet is better and decent food is much more abundant or is it just general hygiene?

[Assistant] Diarrhea causes dehydration, easy fix is to just drink more water right? Well(no pun intended) your water source may be what gave you the diarrhea bug to begin with. If you have another water source you may be able to let the bug run its course, but drinking from the same contaminated water will just keep reintroducing whats giving you the Hershey squirts so your body can never really deal with it properly. Today, we treat drinking water for that sort of thing, and have better medicine if you do catch it by drinking out of a pond or something.


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

[User] ELI5: What's the so called "deep state"?

[Assistant]
"deep state" is a term used to describe a group of government officials who wield disproportionate power over the government despite not formally being elected/in charge.

Usually, it refers to a particular group or set of groups of government employees rather than elected officials. So, for example, there might be a country where the military has a veto power over policies chosen by the civilian government, and where the intelligence community supplies secret information to discredit policies/people they don't like.

The implication is that not only does some group of government/military people have power within their own sphere---think scientists at an environmental agency arguing against some change in environmental policy---but that they are able to influence policy well outside of their actual government roles---military officials deciding that person X can't run for office, for example.

It can be used as a value neutral term---just describing states that had some trappings of democracy, but where the real control over policy was held by a smaller, less/non-democratic group.  Given most people's preferences for democracy, however, it mostly carries a negative connotation.

Like most political terms, it's precise contours are up for debate.  Most people would agree that not ever bureaucracy is a "deep state" just because it might sometimes resist/alter the policies of elected officials, but the limit is in the eye of the beholder.


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

[User]
[Harry Potter] "The moment you drink the blood of a unicorn you will have a cursed life, a half life" what were the consequences for Quirrel or Voldemort from killing & drinking unicorn blood?

Quirrel seems to have born the brunt of it, but it makes me wonder if the process changed Voldemort in some way.

[Assistant]
I imagine it's similar to the curse from Pirates of the Caribbean.

the light in your life fades away, the things that used to bring you joy no longer do so. food stops tasting so good, drink stops satisfying, company no longer fills the emptiness inside. you know something important, something that made you who you where as a bright young soul is now gone and only you remain.

for Voldy it's probably not much of a curse at all, twisted as he was, but for Quirrel it must have been terrible.


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

[User]
Why can't gravity be reconciled into quantum mechanics via Schrodinger's equation like how electromagnetism did?

I am actually a high school student with lots of interest in QM. Don't worry, i can understand the stuff behind QM, not into pseudosciences.

So the formal description of the Time Invariant Schrodinger's Equation is as follows.

E = [-^2 /2m ^2 + V]

Where ^2 refers to the Laplacian, and V refers to potential energy.

Switching from Cartesian into spherical coordinates, gives us 2 Equations, one being the Spherical harmonics and the Other being another but simpler 1 Dimensional Schrodinger's Equation that varies with R from the origin.

Defining a new function U = R*r, one gets the 1D SE as

EU = -^2 /2m ^2 U + [V + (^2 /2m)*(l(l+1)/r^2 )]U

Where [V + (^2 /2m)*(l(l+1)/r^2 )] has become the new "potential term" for distance r

So after so much math, Now comes the question. People have substituted V for the classical Coulomb potential and gotten the hydrogen wave-functions. One of the most almost earth-shattering work of century In my honest opinion.

Why hasn't there yet been any work on substituting Gravitational potential into V.

Coulomb potential = -K Ze^2 /r ; K being coulomb's constant.

Gravitational potential = -GMm /r

If we could find evidence for quantization of mass, i believe its almost trivial to just replace K everywhere in the hydrogen wavefunctions for G, and Ze^2 for Zm^2 (where m represents quantized mass) and call it a day for Quantum Gravity.

Besides the 20 orders of magnitude between K and G and therefore the impossibly small scale of quantization that man may never be able to measure.

What is actually stopping us from doing that?

Why can't gravity be reconciled into quantum mechanics via Schrodinger's equation like how electromagnetism did?

[Assistant]
This is a great question!

So the problem isn't putting in a potential into the Schrodinger equation.  When you do that, you are treating the associated field as a background which is unchanging.

The problem arises when you recognize that that external field is actually dynamical, and has equations of motion it must satisfy.  So instead of just having the Coulomb potential, you have electric and magnetic fields that are dynamical.  When you do this with electromagnetic fields, extending the classical equations for those fields to the quantum case, it turns out you can do it in a mathematically self-consistent way that also agrees with experiment.  But if you try the analogous thing with gravitational fields, you run into a problem, because the classical equations you start with for general relativity are sufficiently different from those of electromagnetism.


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

[User]
ELI5: How does a vasectomy work?

I dont quite understand the meaning of it I guess? After a vasectomy, how does a "shoot blank"?
If the tubes are tied up, does excessive semen not make them burst from pressure?
Where does the semen go, as it cant really get out of the tubes?

[Assistant] They're not tied. They literally snip and cauterize the tubes that carry the sperm from the testicles. The semen part of it comes from a different place so you still ejaculate but there's no sperm in the mix.


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

[User]
ELI5: Could some Canadian companies actually benefit from a drop in the value of the Canadian dollar?

I was shopping around for computer parts, and it looks like it could actually be cheaper for me to buy from NCIX (Canadian company) rather than a US based company.

If the Canadian dollar dropped low enough to where Americans were ordering from Canadian companies rather than US companies, would this extra business actually benefit Canadian companies despite the currency not being as valuable as before?

[Assistant] Absolutely, falling value of currency can definitely help companies which seek to do international business.  In fact some countries, like China, purposely keep their currency value low, so that their companies are more competitive.


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

[User]
When I stretch a piece of cling-wrap apart into two pieces, they seem to attract each as if electrically charged. Why is that?

I'm assuming the pieces of stretched cling-wrap become charged, since this phenomenon doesn't occur when the cling-wrap is carefully sliced. At a molecular level, what is happening to charge the plastic wrap when it is stretched apart like that?

[Assistant] The polymer chains are dragging across each other and causing friction and the build up of static electricity; much the same way it does when you rub a balloon on your head and it electrically attracts your hair.  Cling wrap is designed to stick to things by static electricity (which is why it doesn't stick to wet surfaces), it is light, thin and a poor conductor of electricity, an ideal material for static cling.


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

[User]
ELI5:How come my dog can sleep in crazy positions and not hurt her neck but if I sleep just slightly off my pillow or at an odd position my neck hurts all day.

What kind of voodoo allows my boxer to sleep upside down and contorted but I bend my neck the wrong way sleeping and I'm taking pain relievers for the rest of the day.

[Assistant]
Partially because we evolved to walk upright, that changed the way our spine works in relation to quadrupeds, and means we have a lot less flexibility in our neck than they do. The movement of our head is severely restricted, for this reason our neck muscles are a lot less powerful and developed than those of dogs. The other reason is exercise, dogs are insanely flexible and are constantly bending their bodies in crazy ways. The average modern human just walks upright or sits upright most of the day.

I have 2 labs, male is 3 years old, female is 90 days old. The big guy uses the little girl as a pillow, and she doesn't even mind. She sleeps under the weight of the head of a 60kg dog, no problems. Sometimes she sleeps with her head hanging from the couch.


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

[User]
[Star Wars] Why are sith lords cartoonishly evil?

Like, it feels like the only sith lord, hell, the only darkside user that didn't pursue the darkside for the nebulous desire for "POWAH" was Darth Vader, who at least had a tangible reason for desiring power. Not once have we really seen canon darkside users that want power in pursuit of some greater goal, again, outside of Vader. In the real world, most people due bad things or embrace darkness for tangible goals, some want to survive, some want to become renowned, some even want to change the world. Sure, some just want power, but, that's once they've already entrenched themselves in getting power to achieve their goals, not the start point for ambition. Why then, does every darkside user simply want power for its own sake, why not peace, closure, hell, even vengeance? Why is it always power for its own sake?

[Assistant] Do what you love, you know? I've yet to see anyone cackling while doing their jobs like Sidious does when fighting or electrocuting people. Dude loves his work, we could learn a thing or two from him.


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

[User]
ELI5 Why are so many flame retardants toxic?

Asbestos, PCBs, Fiberglass. All of these flame retardants are dangerous and were widely used in their time. Why are so many common flame retardants dangerous?

[Assistant]
Because the structures that give you resistance to flame are microscopic needles that can get caught in your eyes, mouth, lungs, and other important body parts.

The reason microscopic needles are flame retardant is that you're trying to maximize the amount of air in between any individual piece of material. The best would be to have an aerogel, but those are expensive, so you use the fluffiest piece of glass you can, and those often have tiny needles.


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

[User]
[DC] What if Lex Luthor hated Batman instead of Superman?

In an alternate reality, Lex Luthor never begins a one war against Superman, rationalizing that the benefits of the Kal-El's existence far outweighs Lex's concerns about him.

Instead, Lex looks towards Gotham. He's been hearing numerous rumors about a bat shaped creature terrorizing criminals and organized crime figures there.

Since Lex secretly benefits from organized crime, having come from a rough background in Metropolis himself, this sets a bad precedent, and whatever Batman is, he must be made an example of so nobody his *his* hometown gets any funny ideas.

This is towards the beginning of Batman's career, perhaps his second year.

[Assistant]
Ironically, it would be *so much worse* for Lex.
You see, Superman, for all his power, is basically a boyscout. He roughs criminals up and throw them to jail. Batman is different. He terrifies people. He gets under your skin and makes you paranoid. You know that at any given moment, he could be watching you from the shadow. And despite the fact that Superman is NOT stupid, Batman's intellect and willpower are far more scary.
There is a reason why pretty much all of Batman's enemies are in an asylum while most of Superman's enemies are in prison. One would have to be insane to antagonize the Bat.
Add to this that Bruce is not only a vigilante/superhero, he's also the boss of Wayne's Industries, and that he could fight Lex in business as well as in the streets, and things suddenly don't look very good for the ol' Baldie.


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

[User] ELI5: Why does dipping a finger into the fizz of soda make it dissipate so much faster?

[Assistant]
Most sodas are mostly water and sugar. The oil on your hands is non-polar, whereas water is polar.

ELI5: soda bubbles lose their surfactant potential when in contact with an anti-polar colloidal mixture.


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

[User]
eli5 the Difference between Asset and Property

Hi everyone,

Can someone please explain to me the difference between these two? I thought Asset would comprise Property but then I noticed property is split into tangible and intangible properties. I was thinking property was part of tangible assets but now I'm confused.

Thank you in advance!

[Assistant] A tangible asset is something you can see and feel.   Property you own is a tangible asset.  Intangible assets are something you cannot see.   An example of an intangible asset would be where you helped someone and they owe you a favour, this is sometimes referred to as goodwill.   Please note the definition of what is tangible or intangible can be different depending on circumstance, but owned property is always tangible.


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

[User]
ELI5: Why causes particles to decay? And why does it take so long for some?

Some elements for example can take millions of years to decay. Also, how can we tell their age?

[Assistant]
The stability of an atom is determined by the interaction of several different systems

1. The Strong Nuclear Force.

This holds the nucleus of an atom together by binding the constituent parts in ways that are incredibly complex, but it's very strong at super small scales.

2. The Coulomb Force.

Thus is the positive-positive repulsion that is felt by the protons in an atom. This is the force that dominates when you go a little bit further away than where the Strong Force applies.

3. The Weak Nuclear Force.

This is the cause of the actual process of decay. This force facilitates some particles changing into others. Sometimes, those particles will make the new atom unstable, and it decays immediately.

So the overall effect is that large atoms begin to exit the size for the Strong Force to apply, and some slight change due to the Weak Force causes it to go unstable, at which point, the Coulomb Force shoots out something at great speeds.

We can tell object ages with decay because while nuclear decay is a random process, it follows a strict formula that half of whatever sample you have will decay in the same period of time. This is true of any size sample. This time for half of the sample to decay is called the "half life", so if you know the sample size now, you know how much there should have been, and you know the half life, you can calculate the time to get back to the original sample.


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

[User]
How did Rutherford bombard the atom with alpha particles when discovering the nucleus in the Gold Foil Experiment?

Im confused of how Rutherford 1. isolated an alpha particle, and 2. How did he even know what an alpha particle was or even measure it?? If they hadnt discovered the nucleus yet how was it possible for him to know to shoot 2 protons and 2 neutrons at the atom? Id really appreciate if someone could explain this as I havent found anywhere that explains these details. Thanks for your help!!

[Assistant]
Rutherford's early work was on different types of radiation. Radioactivity had already been discovered several years earlier, and what Rutherford and others did is categorize it. They found that radioactive substances gave off three distinct rays that they called alpha, beta, and gamma. They understood that alpha rays were positively charged (because they could be deflected in a magnetic field), and that the rays had considerable mass relative to other forms of radiation. Because it seemed to have about four times the mass and twice charge of a hydrogen atom, he figured it was a helium ion, and later that was shown to be the case. Later he and his students and collaborators developed a way to measure how many alphas you had by relying on the fact that they would ionize a gas in a tube, and you could measure that electrical current (a Geiger counter).

The alpha particles they were using for the gold foil experiment were provided by a radium source. If you want a stream of alpha particles, you build a little metal box, put the radium source in it, and put a tiny hole in the side of it. Only alphas traveling in the direction of the hole will be released, so it acts like a little gun for alphas.

The experiment consisted of shooting alphas at a very thin gold foil. Most of the alphas went right though. But some were reflected backward at a very sharp angle. By measuring this angle and the number of alphas, he was able to conclude that these were basically bouncing off something very hard and very small. From this he then extrapolated that most of the atom's mass was in a hard nucleus, and could show (through the math) how small the nucleus had to be if it was reflecting the particles at the rate and direction that it was. It is a very elegant experiment and interpretation.

(This experiment was performed by Hans Geiger and his student Ernest Marsden, but Rutherford interpreted the results and used them to show that the nuclear model of the atom was most likely. Rutherford was in contact with Geiger and helped him plan the experiment, which was one of a series of experiments Geiger was doing on alpha particles.)

Lastly, he didn't know about neutrons yet. Those would come later. There were still many unknowns. He didn't even really know about protons  he just assumed, after finding evidence for the nucleus and understanding that different ions had different charges, that they must have positive subatomic particles in them. Rutherford's idea of the atom was one step along the way to our modern understanding of the atom; it wasn't the final step.


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

[User]
I think using only toilet paper is disgusting. CMV

The fact that people walk around after just wiping with toiler paper is actually repulsive to me. I don't see how people somehow decided that schmearing your poop with tissue paper and then pulling up your pants is hygienic. If you got poop on your hands, you would use water to remove it, not a dry tissue.

Personally, I use wipes--but I think bidets and other water based ways of cleaning are just as effective.

Please change my view so I can stop thinking my friends are poop stained neanderthals.

ALSO, I understand that there is an argument against using wipes (they clog the drains). But for the sake of my view, this is unimportant because wipes can be replaced with bidets, showers or sprays that you can put on dry toilet paper.

[Assistant]
The difference between, say, your hands and your butt is that you interact with the world using your hands. If there are some mircropoop particles around your anus, the people you meet won't be contaminated unless you get real friendly with them.

Another way to look at it is that even if you use wipes, there is still residue within your anus. Why is that not gross, but it is a few millimeters outside?


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

[User]
[Marvel]What exactly is the Watcher?

Is it ever mentioned what exactly he or she does? Are they some multiversal entity? And why are they not allowed to interfere in anything?

[Assistant]
The Watchers are a race of beings who are amongst the oldest in our multiverse. They are incredibly powerful, but have sworn an oath to not interfere, only to watch. They can perceive the entire multiverse, and have some sort of communal hive mind, yet are individuals.

Uatu was the Watcher assigned to Earth. He was bad at his job in as much that he interfered. Often. When Galactus came to eat the planet, he warned the Fantastic Four and gave them the advice needed to defeat him. He recently was murdered, no new Watcher has been assigned to Earth, though it is assumed that Uatu's newborn child will take the position when of age.

There have been precious few times that any of the Watchers have broken their vows of interference, and then all hell goes loose, for they are QUITE powerful beings.


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

[User]
ELI5: Why is there no consensus on what the optimal human diet should consist of?

Some swear on a strict vegan diet, others insist that meat is essential. Some say that so called "healthy oils" are required by the body and then there are those who don't consume them at all.

[Assistant]
For the same reason that 5+5=10 and 7+3=10. There is more than one way to skin a cat.

And other such sayings. Also, the body is incredibly complex, so if anyone says they know with great certainty what the body needs, they are lying. We can make educated guesses based on correlational and historical data, but we don't know for sure.


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

[User] If i am in a pitch black room, why do i need to close my eyes to sleep?

[Assistant] As well as keeping out light, your eyelids serve as a protective barrier, and stop foreign objects entering the eye during sleep, they also help keep the eyes lubricated stopping them from drying out.


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

[User]
ELI5: How come we call our moon "the moon," but we name so many others?

Petition to rename the moon.

[Assistant]
Because for much of human history, we were unaware that other planets had their own moons.  Ours was the only one that could be seen, so it got its own designation and was just "the moon."

In most circumstances nowadays, it's obvious that when you're talking about "the moon," you're referring to the really big, visible object in the sky, so there's no need to say anything other than "the moon" or "Earth's moon."


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

[User]
[SpongeBob] How do SpongeBob and Squidward get by with what Mr. Krabs pays them?

The boring not so fun answer is that its just a kids show dont think too much into it.

But I wonder, its very clear SpongeBob and Squidward arent paid very well by Mr. Krabs yet both of them are able to maintain living in large two story houses. Im not sure if the words rent or mortgage were ever said in the show but SpongeBob has mentioned paying bills before so I think its safe to assume that theyre also paying for their homes. Is the housing market just really good in Bikini Bottom that anybody get a house?

Also, they both regularly have groceries in their homes, Squidward also has a large art and clarinet collection and SpongeBob has an entire library in his house. How are SpongeBob and Squidward able to live their lives working for the Krusty Krab?

[Assistant]
Small town, small cost of living. While Krabs is also a tightwad, he still has to pay whatever the local minimum wage is. In some areas that can be enough to get by one, especially given that with only 2 employees Squidward and SpongeBob likely get alot of overtime.

Their houses also appear to be constricted of flotsam so they're likely the equivalent to mobile homes, which are frankly quite affordable, if commonly shitty. They're rarely shown eating out, or paying for entertainment so frugal spending may be assisting. If the minimum wage is low enough they may be living off government subsidies as well.


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

[User]
[Star Wars: The Clone Wars] how are Plo Koon and his clones able to survive in space?

I understand that Plo is able to withstand the pressure of space for a short time (I assume it's a thing his species can do), but are the clones protected by their armor? And how do they breathe? I was under the impression their helmets acted as respirators at best

Also a semi related question, what is the purpose of Plo's goggles/eye shields? I know he has his mask because his planet has low oxygen or something like that, and it helps him cope in the rest of the galaxy, but do the eyes serve a similar purpose?

[Assistant]
Plo's species are very hardy and can survive the hard vacuum of space for a short while. The goggles and masks his people wear keep them from being suffocated and blinded by what would be an otherwise toxic gas mixture that most species breath normally.
As for the clone armor similar to stormtrooper armor it has a built in air supply allowing for short jaunts in space or underwater without additional air tanks. Once the system detects unbreathable air or lack of it seals the external filters and begins recycling its internal air supply. It lasts only a few minutes but is enough that with proper breathing and decisive action can make all the difference.


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

[User]
Is there anything you can add to water that would raise it's freezing temperature?

There's lots of stuff to lower the freezing temperature, from salt to antifreeze, but is there anything that raises it?

[Assistant]
Technically no. This is because solutions have lower enthalpy than pure water. This is one of the rare colligative properties of solutions, and happens regardless of the solute.

Practically, you can add gelling agents like gelatin and agarose to induce gel formation at above-freezing temperature. However, water molecules will still remain in the liquid state, so this is not really "raising" its freezing temperature.


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

[User]
How much is the "lag" in the real world?

When playing multiplayer video games, we often experience lag. I think it can be defined as the length of time since the information is sent from the server until it is received by the computer being played on. The player then experiences the game a few milliseconds after it actually happens.

I was wondering how much lag is there in the real world? How much time does it take, for example, for the eyes to receive information send it to the brain and for the brain to "experience" what's happening?

[Assistant]
We can actually measure how long certain signals take to propagate through the nervous system using a technique called evoked potentials. Using a set of electrodes on the scalp surface, you measure the response of the brain to a long set of stimuli and average them to get rid of all the random, moment-to-moment signals. Then you get a reproducible waveform.

For instance, there's a peak called N20 (sometimes N19) which corresponds to the arrival of sensory information from the wrist to the primary sensory cortex. This takes about 20 milliseconds. Arrival at the primary sensory cortex is just the very first step of sensory processing, but that means a sensory "lag" from your wrist is at least 20 ms long. From the foot it's more like 45 ms.

In the visual system, there are multiple identified responses and no clear agreement about what they mean. The N75 response is thought by some to represent the first arrival of visual signals to the occipital cortex, where visual processing begins. This would give a minimal visual "lag" of 75 ms; however, the P100 wave is associated with actual perception of visual stimuli, meaning the lag might be as much as 100 ms.

There are a lot of evoked potentials that have been described. There's a P300 that, to simplify, represents the recognition of a meaningful (as opposed to arbitrary or meaningless) visual stimulus. That's as much as 500 ms after the stimulus.

The idea of "lag" however is complicated by the fact that there is some sort of processing going on through the entire process. Even before visual signals arrive at the occipital cortex, basic processing in the retinal ganglion cells have started to define color opposition and contrast. That's within the first 10 ms. So the fact that it takes 50 or 75 or 100 ms to make it to the visual part of the brain doesn't make it a lag in the same way a server lag is a lag.


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

[User] [star wars] billions of years after the original trilogy, if the technology in the star wars universe went far enough does the milky way exist in star wars, and could someone travel to it?

[Assistant]
Well for starters the Milky Way DOES exist, its just far, far away from the GFFA.

Now as for your question, it is technically theoretically possible to travel from the GFFA to the Milky Way. In fact, there is limited extra galactic travel already in the world of Star Wars. The Rishi Maze is an irregular dwarf galaxy locked to the main galaxy. It is where Kamino was located and can be seen in the ending of ESB.

Now as for traveling to other major galaxies, like mentioned, it is theoretically possible but there are some caveats.

Galaxies are orders of magnitude further apart than stars, and while Hyperspace "shortens" the distance it would still take a massive amount of time and energy. A ship would have to be able to carry enough supplies, especially enough Coaxium, to keep the Hyperdrives working. It would be a very difficult and expensive endeavor, but again, technically possible.

The second, and more salient point is that a Hyperspace route would need to have been plotted ahead of time. You can't just aim a ship at a direction and jump into Hyperspace,  well you can, but as Han so elegantly pointed out, that is how you crash into something and die. A route with jump points and coordination with obstacles and disturbances, all which are in motion, needs to exist to travel safely. In the past, this was done by explorers who made micro jumps, recorded data, compiled them, and essentially made maps. A very time consuming, expensive, and dangerous endeavor.

It could theoretically be done between galaxies, but the thing is no one knows just what is in between. There are ribbons of dark matter, energy, and who knows what else. All of that would have to be mapped, and it would take eons upon eons of time. Again, theoretically possible but crazy difficult and expensive to do. It wouldn't be the work of a generation, entire civilizations would rise, fall, others rise in their place, only to rise and fall themselves in a countless series before the work could be done, making it very hard to fund such an endeavor.

There is also one final point. Legend has it that there is a Hyperspace disturbance that surrounds the galaxy, maybe all galaxies, making it nearly impossible to cross the threshold. The Rishi Maze is essentially a satellite of the GFFA that the disturbances have all but disappated between the two, but who knows with any other galaxy. If one is even able to leave the GFFA, there is no guarantee that one could find their way into another.


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

[User]
ELI5: Why does CO2 make a drink like Coke feel 'fizzy' while nitrogen gas makes a drink like beer/ale feel smother?

Is it to do with the slight difference in charge between the C and Os or something about the kinds of receptors that are stimulated?

[Assistant]
Bubble size.  imagine bubble wrap for mailing packages - it comes in different sizes, some with lots of little bubbles and then some with fewer but bigger bubbles.

In beer, N2 makes lots of little bubbles while CO2 makes fewer big bubbles.  And just like how fine silt feels smoother than rough sand in your fingers,  finer bubbles feel smoother in your mouth.


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

[User]
ELI5: How does Google Maps calculate my route so fast? What sort of logic do the algorithms use to find the fastest route?

Additionally, how does it calculate the ETA with the current traffic conditions?

[Assistant]
Google knows the speed limit of most roads, you can add them yourself on Google Map Maker. They also know where many stop lights and stop signs are.

Since they know these things, they know a route which has a 10 mile road with a 60mph speed limit is faster than an 8 mile road with a 45mph speed limit. They also consider a route with the least amount of stop lights/signs is better.

As for traffic, every phone that uses Google Maps for navigation has location services turned on, meaning they know how many cars are on the road, and how fast they are moving. Apple Maps does this also, but because Google Maps is cross platform, their traffic data is more precise and abundant.

Google takes all of these factors in determine ETA.


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

[User] Why does metal feel colder than the ambient temperature?

[Assistant] Metals are better at conducting heat. The heat from your hand flows quickly into the metal, cooling your hand and your nerves detect that. Air is a much poorer heat conductor, which is why you can safely put your hands in a 250C oven, as long as you don't touch the dish.


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

[User] ELI5: Why are pay pal and ebay splitting ? what does this mean for me as a seller and buyer?

[Assistant]
Up until now, PayPal has basically just been a division operating under eBay, but it has the potential to grow much larger than that but in some ways is hindered by the fact it's part of eBay and, for example, cannot make deals with other companies that may have competing interests.

PayPal is now going to split and form its own company that is an entirely separate entity. This allows eBay to explore the possibility of accepting and integrating with other payment services and allows PayPal to negotiate business deals with other companies that may directly or indirectly compete with eBay.

There will almost certainly be a one year (or longer) transition period where basically nothing changes for the buyer or seller on eBay. After that, other payment options may be added... but from what I've read, eBay and PayPal will continue to work together to handle payments on eBay for ~6 years at which point the companies will re-evaluate whether to continue working together (and it's at that point Paypal potentially may no longer be a payment option on eBay).

The agreement between the two companies also prevents eBay from making their own competing payment service and further prevents PayPal from making an eBay like marketplace.


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

[User]
[Batman Arkham] There's a man, code name Enigma, and he seems to want me to solve puzzles

He lacks social skills and from the looks of it, money, means, and ability. He makes some neat puzzles, but what if I just don't engage at all? He's got a safehouse, so I'll just... ignore him? Ignore his puzzles he for some reason calls 'riddles', ignore all of that, and just go about my business? He seems childish, and the best way to tame a brat is to ignore them. Not to feed any attention.

[Assistant]
Ignoring a bratty child works pretty well because children are quick to change their behavior to find a way to earn attention. This process, over time, enforces more socially acceptable behavior, as their brains learn to associate bratty behavior with undesirable outcomes.

That is not the context of your relationship with The Riddler. The Riddler may have an inflated ego, but his puzzles demonstrate a technical proficiency that he could clearly be a danger to other people (even if he doesn't pose much threat to you). His ability to plan and place his riddles in ways that get your attention specifically demonstrates a nuanced understanding of social behavior. His impressive productivity in producing puzzles for you demonstrates a level of obsession that is closer to that of a stalker than a fan.

When you ignore stalkers, they don't perceive it as a cause to abandon their obsessive behaviors, they see it as a reason to escalate. Someone who is obsessed with getting your attention will take a lack of attention as a sign that they need to do something bigger or more noticeable. Are you sure you're comfortable encouraging an obsessive ego-driven engineer to escalate his attempts to get your attention? As long as his puzzles aren't hurting people, and as long as they remain simple enough to solve without much effort on your behalf, it may simply be better to contain this threat by playing along. Meanwhile, each puzzle gives you a bit more insight into what the Riddler is capable of and what he's interested in. Taking a few minutes to solve them here and there could be a good way of preparing for a scenario where the Riddler turns more towards evil or chaos.

But let's be honest, all that justification above is to feed your hero ego. We both know you well enough by now to understand that you won't let any schmuck run around telling people he's outsmarted you. The only thing that will stop you from solving his puzzles is when you escalate to solving the puzzle of the Riddler himself. Until then, letting the rest of Gotham see that the Bat matches wits with a supposed mastermind goes a long way to convincing thugs not to try to outwit you.


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

[User]
[Warhammer 40,000] What was our glorious Emperor doing during the Dark Age of Technology?

I was poring over the ancient chronicles of the Unification Wars, relishing in the Emperor's godlike exploits, when I was struck with a question:  Why did our God-Emperor not reveal himself when mankind was at its height?  Surely if he'd emerged then, humanity would have reigned over all, and the xenos would kneel before our might.  So why did he not emerge?

[Assistant] The Emperor chooses his role depending on the circumstances.  Before the cataclysm, the Emperor worked in secret to bring mankind to the height of it's power.  And make no mistake, mankind before the fall was the greatest race in the galaxy.  The orcs were comfortably contained and of no threat except to the poorest and most isolated of worlds, and the decadent Eldar were a mere shadow of their former selves, and they never had the kind of power that mankind did at its height, no matter their vain protestations to the contrary.  After the opening of the eye of terror and the destruction wrought by the Iron Men, mankind was in a precarious situation.  The Emperor was unwilling to let 40000 years of guidance and careful shepherding go to waste, so he revealed himself and took a more active role in the affairs of mankind.


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

[User]
[Star Wars] Why can't R2 send the plans to the Death Star wirelessly to the Rebel Base at the beginning of A New Hope?

Also why can't all of the hacking into  buildings (such as during the Battle of Endor during ROTJ) be done wirelessly instead of making R2 Trek through a battlefield?

[Assistant]
Well, let's see where he was.

On the *Tantive IV*, it's being boarded by Imperial troops. No doubt they've jammed the communications array.

On board the Death Star, they're on a high security military station. No doubt all external communications are watched very closely.

On Cloud City, the place was under Imperial lockdown. Wireless access to doors was doubtlessly locked.

On Endor, the door they needed to get access to was an entrance to a high security facility providing defense to an orbital station that was still under construction. They had it locked down, too, as Vader knew Luke was on the shuttle heading down there and no doubt would have warned the officers of that base.

You know what the easiest way to "hack" into a system is? Have physical access to it.

What you really should be asking is: *why* an astromech has the tools and capabilities to hack into secure systems?

[It was also the late 70s/early 80s. Wireless communications for computer systems were basically nonexistent outside of television and radio, neither of which are really good mediums for transmitting large amounts of data - like, say, the blue-prints for a massive battle station.]


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

[User] ELI5: Why do objects, like my couch or a coin, feel bigger than they look if my eyes are closed?

[Assistant]
Your hands are not 'tricked' by distance, like your eyes.
On top of that, your field of view tricks your mind into processing an object within an entire scene - a couch is viewed in the living room -  which is larger.


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

[User]
ELI5: What exactly is angular momentum and how does it work?

Everything I have read explains angular momentum with lots of physics jargon way above my head.  Anyone have a simple explanation out there?

[Assistant]
Momentum is a measure of how hard it is to stop something that is moving. A tennis ball is easier to stop than a basketball. A spoon thrown at you is easier to stop than a bullet. Momentum depends on two things, the weight (actually mass) of the thing and the speed (actually velocity) with which it is moving. A moving bus has more momentum than a bicycle for instance.

All of these examples have one thing in common though. They are all objects moving in a line - the corresponding momentum is called linear momentum. There is another type of momentum, angular or rotational momentum, that is possessed by objects that are turning. A spinning coin is easier to stop than a massive carousel. Again, it is a measure of how hard it is to stop something spinning, and again depends on the mass of the object and the speed with which it is rotating (angular velocity).


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

[User]
I don't see why we should prevent pandas from going extinct. CMV.

From what I understand they subside almost exclusively on one food source (bamboo), have few mechanisms of self defence, don't particularly contribute anything amazing to the ecosystem, and furthermore have a very low rate of reproduction (panda viagara is still in development, clearly). If evolution itself is impeding them don't see why we should try to keep a sinking ship afloat.

[Assistant]
I just replied to a similar CMV about this a few days ago. Pandas are a poster animal for the WWF and many other animal rights groups on the planet. We need the panda species to survive to inspire other humans to care about other things in life such as global pollution, and other potentially endangered animals. If the panda were to go extinct, people will look at the event and say that if groups such as the WWF(who we have given an ENORMOUS amount of money to) why should we waste money on other similarly futile efforts for other animals and for the climate and other issues.

Animals such as the Dodo and the White Rhino have gone extinct in the past, but society has mostly forgotten them because they were never widely publicized. Pandas on the other hand, are EVERY WHERE. If they were to fail as a species, the repercussions would be devastating for these wildlife groups. Even if some people were motivated 'not to let it happen again', most people would feel that it was a lost cause and decide to let nature take its course, just as you are implying it should. Even if a small, temporary spike in donations to these groups was seen in the wake, it could never balance the vast amount of money already invested into pandas as a species, all of which would then be lost.

Additionally, allowing pandas to die out would wreck havok on the ecosystem they're native to. They are the primary form of reproduction for the bamboo plant(by digesting, and relocating seeds), which is, in and of itself, home to many insect/bird populations. The panda is the key to making that entire ecosystem flourish. They don't have self defense mechanisms because they never needed them. They were established, evolutionary, as essential to the ecosystem they lived in, and never had any serious competitors or predators until humans came along.

The reason the Panda species is struggling is NOT evolution. Humans, as with many species lately, have extensively hunted pandas in the past for their pelts, and deforested much of the bamboo habitat they used to live in for the strong, unique wood it contains. Pandas on their own flourished as an essential member of their ecosystem, and their evolutionary lack of a defense mechanism is proof of that. It wasn't until human involvement that panda's existence was threatened. It is correcting this human error that will make it possible for us to find the courage to correct other, more threatening human errors such as pollution. If we can't save the pandas from ourselves, how are we going to save us from ourselves?


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

[User] eli5 Why do school buses stop and open the door at railroad tracks?

[Assistant]
During a whiteout blizzard in December 1st, 1938, a school bus driver Slim Silcox was driving 39 students in the town of Sandy, Utah.

Silcox decided to drive over a railroad crossing that has never had any train traffic during his normal school pickup hours. However, because of the weather conditions, he did not see or hear a train that was driving on the tracks because the train was delayed from it's normal schedule. The train T-boned the bus and killed 24 students instantly including Silcox. 3 students died later from their injuries.

Because of this incident, buses are required to stop before rail crossings and look and hear for any oncoming trains. Since then, there have not been ~~any~~ many severe collisions. Many regulations are written in blood.

Edit: People have mentioned other bus/train collisions since this one.


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

[User] ELI5: Why eating salty food makes you retain liquids, but drinking ocean water would kill you from dehydration?

[Assistant]
When you consume a lot of salt, your kidneys need extra water to process it.  It gets that water by making you feel thirsty and drink more water, and holding that water in reserve for your kidneys.

Your body actually handles both saltwater and salty food in the same way.  You are only in danger of dehydration if you don't have access to regular water after.  If you drank seawater followed by regular water, you'd retain water and be fine, if you ate a bunch of salty food without drinking after, you'd risk dehydration.


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

[User]
[Avatar] Did the other Avatars have to deal with any issues with Fire Bender when Sozin's Comet appeared?

Kyoshi lived through the appearance of the comet at least twice, and Yangchen probably also saw it. So did either of them had to deal with issues caused by the buffed Fire Benders? I know Kyoshi fought a lightning bender in her youth, and there would have been some big problems if that guy got buffed by the comet.

[Assistant]
Likely yes. The comets existence was documented well before Sozin's time and, while it's never stated outright, it's implied that its effect were known as well.

It was probably treated the same way as the effects a full moon had on Waterbenders.

There undoubtedly were firebenders that took advantage of the comets passing but few really had the vision or drive that Sozin had.


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

[User]
On a cellular level, where does lotion go when you rub it in?

I wasn't able to find a lot of info on this. Best answer I could find is the lotion molecules move in between the skin cells. It didn't tell me how far they penetrate though or if our skin would just absorb lotion if it was left alone on our skin.

[Assistant] Most lotions are just emulsions of oil and water, and the skin the water and oil molecules do not actually penetrate very far, unless of course the skin is broken. The lotion will just saturate the stratum corneum  which is the topmost layer of the skin made of casts of dead keratinocytes. The reason why lotion can make skin look less "ashy" is because by saturating and hydrating the stratum corneum, it makes it more transparent.


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

[User] Eli5: Why when you yawn your hearing goes down?

[Assistant]
The dampening of the eardrum occurs during a yawn because a muscle, tensor tympani, contracts somewhat
immobilizing the eardrum. This muscle is a safety feature which helps prevent damage from loud sounds and
contracts involuntarily although some ppl can cause it to tense on purpose. Speech therapist.


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

[User] [ELI5] Why is it lawmakers can tie unrelated issues into bills they are hoping to pass?

[Assistant]
This is known as a "rider", and is allowed in some legislations but not in others. And since what is "unrelated" is to some degree a matter of interpretation, it can be hard to make up rules that definitely prevent it.

The only legitimate reason to allow it seems to be that **it can reduce veto powers** as a part of the "checks and balances" that support the separation of powers.

This is what's happening in the USA: the Republicans have the majority in both the Senate and the House of Representatives, so they can pass pretty much any bill they like. The Democrat president, however, can *veto* any bill he doesn't like. Adding a rider to a budget bill (which the president kinda *needs* to pass) is a way for Congress to get around this veto power, or at least make the president think *really* hard about how important the issue is for him.


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

[User] ELI5:If illegal immigrants in the United States have constitutional rights, can they also bear arms?

[Assistant] When you're reading the constitution, if it says citizen, then you have to be a citizen to have that right.  If it says person, then any human within the jurisdiction of the US has that right whether here legally or not.  So, like the 5th and 14th amendments specify person, so they apply.


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

[User] ELI5: Why does cold brew tea have half the caffeine than hot tea, but cold brew coffee has more caffeine than hot coffee?

[Assistant]
Almost certainly it's the brew time. the solubility of caffeine is not great at low temperatures (thus takes longer to extract), so the tea was probably not brewed for very long.

another thing to consider for coffee is that hot water likely doesn't contact the coffee for very long, where tea often is seeped for longer.


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

[User]
[Star Trek] What are the odds I get a Klingon woman?

24th century human here! I've been doing runs here and there around the Alpha Quadrants and run into a lot of attractive species but let me tell you something-those Klingon women are *incredible!* What do you think my odds are as a... cargo transporter/security escort of getting a Klingon bride? I understand they do not play nice in the bedroom, will I need an EMH program standing by on my honeymoon?

[Assistant]
Forget about trying to act like a Klingon or capitulating to "Klingon ways." You couldn't ever compete with actual Klingon males.

Bank your hopes on finding a Klingon woman that has a human fetish. It's a big galaxy and, odds are, they have to be out there.

As the Vulcans say: Infinite Diversity in Infinite Combinations.


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

[User] ELI5: How does philosophy progress, as a field, if the theories can't be empirically tested?

[Assistant]
Philosophy is about the questions, not the answers. You could theorize an answer for a previous question and ask new questions with that premise.
Edit: philosophy was not always that way. It is the root of all sciences, like math, phisics, biology, etc. Different philosophers used to specialize in different fields. It was all philosophy. So there are answers to some of the questions. But it became more and more abstract over the years. But the same happen to math. Advanced math is very very abstract.


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

[User]
Does the bioavailability of certain foods changes when eaten with other foods?

When I saw "studies on the bioavailability of zinc in man: II absorption of zinc from organic and inorganic sources", I was intrigued. Are there such things as anti-nutrients, i.e. are there some things which impair the absorption of nutrients, vitamins and minerals?

[Assistant] Depends. IIRC absorbtion of iron can depend a lot on what its eaten with. Vitamin C, acidic foods, proteins etc. making it easier to digest and grains, calcium, spinach, coffee etc. making it harder to digest. Iron is just one very spesific example of course.


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

[User]
ELI5: How it possible that using the same energy as walking, we can travel much faster with a bicycle ? Is there a limit to building other machines that make us travel faster using human energy ?

Because when I'm on my bike, I sometimes think it's a miracle that I travel so fast whereas I'm not even pushing at all.

[Assistant]
Bicycles are one of the most efficient forms of transportation humans have come up with. The only thing that is more efficient are recumbents, which are just a derivative of bicycles where you lay down and are more efficient due to less air resistance, and "velomobiles", which are recumbents with a drag-reducing body.

There's a few reasons why it's more efficient than walking, but primarily, it's the fact that we raise and lower our body with every step we take forward while supporting our entire weight. It's not much, but that inch or two your entire body mass moves up and down every 2 feet (one step) you move forward really adds up over thousands of steps. On a bike, your body is fixed, and your legs are used to just move you forward-no vertical movement, no supporting your whole body weight. Far less energy is needed since the bicycle is "doing the work" of holding you up while making each "step", or pedal, move you further.

The limit to building machines that make us travel faster using human energy is air resistance and friction (but mainly air resistance since our friction reducing technology is very good these days). To put it in perspective, the world record for paced (car in front to reduce air resistance) on a bike is 167mph, but only 83mph un-paced.


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

[User]
I just had a friend tell me that the same equation used to find the escape velocity of Earth is the same equation used to find the velocity an electron needs to break out of an orbital. Does this mean the force holding an electron in an orbital is similar to the force of gravity on Earth?

If the same equation is used for both problems, then i imaginne something has to be the same or similar for that to work. The only thing I could think of is the forces being the same or similar. Is my assumption correct?

[Assistant] Yeah classical physics does not correctly represent the behaviour of an electron, but both gravitational and electrical forces decrease with the square of the distance. That's why the two calculations have the same form.


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

[User] Eli5 When a company headhunts an employee from another company, how do they know how well that person is performing and how much of their companies success can be attributed to them?

[Assistant]
They often don't because they can't ask that company directly. That's highly indiscrete and would really tick off the hiree, unless he or she had made it known that they were intending on leaving and gave their permission for the contact.

Generally recruiters rely on other ways of measuring that person. These include assessing the person's resume and educational history and industry certifications, results from testing and interviews, checking references from previous companies that the target might have worked for, contacts with prior knowledge of that individual that have either worked directly for them or were their customer or business partner, and online searches on sites like LinkedIn.


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

[User]
Eli5: how were they able to pinpoint the exact cause of a rocket failure

I'm assuming now engine use real time monitoring systems and sensors. But how were early rocket designers able to determine what caused a rocket to explode like a raptured fuel line or something? Did they just guess?

[Assistant] Even early rockets had some form of telemetry that that transmitted live readings on the status of certain systems. You could use that data along with visuals (film and still photos) coupled with examining the wreckage, and you could usually get a pretty good idea of at least what major system was the problem. For example, if shortly before a rocket broke up, there was a voltage spike in the guidance computer and the rocket veered off course, you could reasonably trace that error to the circuit in the electrical system that provided power to the guidance computer.


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

[User] ELI5: when youre showering and the water suddenly turns icy cold or scalding hot for a few seconds before returning to its previous temperature, whats happening?

[Assistant]
Water temperature in the shower is determined by the mixing of cold water + hot water from the two different pipes in your house.

If the water pressure suddenly changes, like for say someone flushes the toilet, the cold water pressure in the shower drops and the temperature increases.

Most showers these days have valves designed to minimize this effect. Because suddenly having nothing but scalding water can be dangerous.

The valve mechanically senses the drop in pressure and adjusts the pressure of the other pipe to compensate, but there's still a fluctuation in pressure and temperature change. It just isn't as bad as without the valve.

Your valve might also be worn out.


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

[User]
Is there any literature on the metaphysics of how does the 'self' change in intimate relationships?

I think relationships can have an influence on 'self', I was wondering if there is any material on how does that influence manifest itself in the short run vs long run? A sample material would define what is influence, what is intimacy, not just dictionary or psychological definitions but rather how they arrived at that definition of it as a phenomenon.

For example: I'd say influence is a phenomenon of domination, a moment of psychological defeat, where one gives away or shares the agency over a fraction of the territory of 'self' to the influencer. This way the influencer gains more intimacy and power over the one he is influencing. A relationship is a shared ground and the one who is more influential would have more say in other person's life. The more influential a person is to one, the more *their* thoughts the person starts to accept as his own which in turn replaces their original notion of their own 'self' and influences their self-image, identity etc.

My notion is pretty vague but pretty much that's the kind of stuff I'm looking for to read in depth. Thanks.

[Assistant]
Yes! Although interestingly enough in your post you've already started using some of the technical vocabulary in the field.

Levinas was a really important philosopher, known mostly for his 'phenomenology of the other' which he developed across several major works. A phenomenology of the other considers how the other (especially for Levinas, another human being) appears to us in consciousness. In this, he describes the difference between the 'sites' or 'territories' of the Self and the Other as being in constant exchange during the face-to-face encounter.

He devotes a lot of time in *Totality and Infinity* to reflecting on how the 'face' of the Other reconfigures when it is presented as love. He views love as being something of a surrender of the Self's site to the Other - for this he uses the phrase 'to cease apology'. We can only imagine that by this he means 'apology' as *Apologia*, the Greek word for 'defence' (specifically against accusations e.g. in a legal case). That love is the cessation of apology seems to mean: in love, we no longer fortify the site of Self and defend it against the approach of the Other; we open up ourselves to them and allow them to totalize the site of the Self (generating an experience he calls 'diachrony').

He also speaks of love as an 'incestuous' relation. It seems like by this he means that love begins when the Self recognizes a 'belonging' in the Other, such that they are from the Same. That is, despite the radical Otherness of the Other, we detect ourselves in them. There are some ways of reading just what's going on here in his phenomenology: it could be that he means something like 'the relation of love occurs only when the Self sees it-self in the Other *without looking for it*', so that it's a natural belonging. This reading is of course debatable, but it's good as an introduction to his phenomenology.

Hope this helps!


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

[User] ELI5: Do people with fully prosthetic legs have the ability to run for longer periods of time due to them not having muscle exhaustion in their legs?

[Assistant] No, in fact they would get tired faster. The amount of energy it takes to run is still approximately the same because the person still weighs approximately the same. But, now they have fewer muscles to provide that energy. That requires the remaining muscles to work harder.


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

[User]
[Star Wars] Best CIS Droid Ground Warfare Tactics

The Banking Guild has put me in charge of a small mining and agricultural world. We recently have begun mining and refining an ore vital to the war effort. Its only a matter of time before the Republic clones and jedi show up to ruin my career.

I have a lot of standard issue CIS equipment, some in orbit but mostly ground forces. Lots of battledroids mostly. What can I do? The Guild would not approve any large investments, but I can confiscate what is on planet. I could give droids farm tools if I thought it would help.

My thoughts are:

Try to have any battle be on open ground to leverage my superior numbers.

Introduce some form of Volley Fire to compensate for droid inaccuracy

Confiscate any noxious chemicals to use against the fleshie clones.

Anything else? What can I do to hold this world for the CIS and save my career?

[Assistant]
Try and see if you can get some recon to find out the incoming GAR troop numbers. Try to make your presence seemingly minimal, so as to try to fool the Jedi and clones into thinking there are fewer battle droids.

Then surprise the Force out of them by pinching them with your army of droids.

Open ground battles are a detriment to both sides. Try to get the battle to be somewhere more obscure, like a mining district, or somewhere where you'll get a lot of cover and tactical advantages for your droids.


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

[User]
ELI5: Why is the trade-off of the American soldier so controversial?

I am just seeing there is a lot of controversy.  Why? What is so confusing about this trade? Am I missing the bigger picture?

Edit: I tried to provide a summary of what the debate was bring out.  Apparently, it comes across as a smear campaign against Obama.  It appears the real controversy is not about the American soldier, but our political system and how the branches interact with each other and the media - a common concern for Americans.

[Assistant]
We have two policies and a law that put the President in a bind:

1) The United States does not negotiate with terrorists. Been a policy for several decades now and we obviously did here. In fact, this is the first time we've ever negotiated directly with Taliban/Al-Qaida to exchange anything.

2) The United States military leaves no man behind. Dead, alive, captured...if there is something to recover and bring back home, we will go out of our way and risk many men to do so. He was a POW for 5 years and had no idea where to get him with special or conventional operations. Deserter or not, we don't leave a man behind.

3) Congress must, by law, receive 30 days notice of what the president intended to do. Even the Bin Ladin raid, certain members of Congress with the security clearance knew the raid was happening, when, where and how. It's being debated if Obama actually notified members of Congress in the timeframe required by law, but it seems as if he didn't.

It brings up many questions for all Americans and what is the cost of a life. Is an American worth five lives? Six? Ten? How much are all the current Americans being held hostage around the world worth to us? This deal broadcast to the world what we *might* do and have done to negotiate for lives. They have become bargaining chips now with a set price and have an estimated retail value. That's food for thought.

Other issues include that the five prisoners were battled hardened and high ranking members of Al-Qaida who have reportedly killed thousands. Now they want nothing more than to see the US burn for locking them in a hole for so many years. It's no doubt they will take their vengeance seriously.


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

[User] [Marvel/DC] Are there any super powered individuals who just choose to live relatively normal lives?

[Assistant] In Marvel and DC the overwhelming majority of superhumans live normal lives. There were over 30 million mutants in 616 Marvel at one point and less than 1% were actually doing anything noteworthy with their powers. Most people dont want to fight crime, rob banks or rule the world.


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

[User]
Some questions about getting into and working in academia

I am currently a Junior in high school.

I really love math and computer science. My dream is to be a researcher in some area of theoretical computer science, but I have a few questions that make me doubt the practicality of my dream:

1. Most people who make notable contributions seem to have prestigious awards (like field medals for math) and come from prestigious universities even for their undergrad. Is this a wrong perception of mine? If I am unable to get into such a school, does this somehow decrease my ability to do anything "significant?"
2. What are some downsides of working in academia?
3. Is there a significant difference between joining a private company (organizations like Microsoft Research, DeepMind, Google Brain, FAIR, etc.) and doing research at a university as a professor?
4. What is the general path to becoming a researcher? I understand the whole Undergrad -> PhD/Grad School sequence, but what comes after this?
5. Elaborating on (1) and potentially answering (2), it seems to me like academia can be a relatively stressful and "toxic" field, with a large amount of importance given to prestige, research output, etc. Is this true? If so, how bad is it?

Thanks. Any advice would be greatly appreciated.

Edit: One thing I should add is I am neither interested in nor skilled at teaching. I would think this is a good reason to stay away from professorship, but do correct me if I am wrong. I am aware that my opinion on teaching may change over the years.

[Assistant]
Me:
Reads I am currently a Junior in high school. Rolls eyes.

Also me:
Reads whole post. Wildly impressed by OPs maturity, self-awareness, and thoughtful, well-researched questions. Sends digital high five. OP is going to do just fine.


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

[User] [Star Wars] Are the humans in Star Wars different than Earth humans? If so, how?

[Assistant] Only in very subtle ways, nothing you'd notice at a casual glance. Their gut bacteria, for example,  would likely be different from ours, and given that some species of alien (like twi'leks) can interbreed with humans, you'll probably find snippets of alien DNA in a few. Depending on the planet they developed on, there might be certain physiological differences,  but they'd be minor.


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

[User]
[Harry Potter] Could muggle ingenuity eventually defeat the wizarding population?

I remember reading a book and took interest in its description of the ingenuity of humanity and the evolution of technology, the book proposed concepts such as global point clouds, which could render a 3D space of the entire earth in real time, supercomputers that could process the enormous amounts of data received from said point clouds, firearms that can identity the location of a target through said point clouds and AI that can operate thousands of machines simultaneously. How would wizards fare against a muggle society that has achieved this level of ingenuity?

[Assistant]
It's already happened. Muggles rule the world, and the wizarding world lives in the cracks and fringes.

Of course, they don't mind that because there's no need for conflict or for one society to "defeat" the other. Peaceful coexisting is working out just fine, even if most of one side doesn't know the other exists.


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

[User]
[Rick and Morty] How come a bunch of high school kids don't freak out going to a party with aliens, robots, a genetic clone of Adolf Hitler and Abraham Lincoln?

In Ricksy Business Summer and Rick's parties merge and not one kid seems surprised by the guests at the party.

[Assistant]
You've clearly been attending the wrong parties, if this is surprising.

Though actually, a lot of the whole high school mentality for groups of kids like this is about fitting in. Nobody wants to be the one saying 'what is all this crazy shit!?', and since the other guests seem to apparently be cool, and there isn't something immediately awful going on, the party don't stop.


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

[User] ELI5: Why do brands sell chips for 3 or 4 or 5 dollars in normal stores, but in dollar/value shops, they are sold for a dollar for the same brand and size bag?

[Assistant]
It is not the brands that decide the price. It's the store owners. Supermarkets and value stores have different business strategies, and the margin they try to make on a product is different.

First, what is margin. Margin is the amount of profit a retailer (like a supermarket) wants to make on a product. Retailers have contracts with suppliers to sell their items. They will buy the item at a certain price from the manufacturer, then sell it to customers at a higher price. The difference between the price they paid and the price you paid is the margin and that is where the retailers make their money.

So basically what happens is Chips Manufacturer will sell their chips to both supermarkets and value stores at, say, 50 cents per bag. A value store that sells that bag of chips for one dollar makes 50 cents worth of profit on each bag; a supermarket that sells that bag of chips for two dollars makes 1.50 worth of profit on each bag.

What sort of margin stores decide with often differs from product to product, but in general is determined by their business strategy.

A dollar store basically makes their profit from selling large quantities. They go for a low margin on each product, and they only make a bit of profit, but they try and make up for that by selling a lot. They also try to keep their costs low by doing things like keeping their shop layout very simple, not having a lot of staff, not offering speciality items, offering a lot of no-brand items.

Supermarkets often go with a different strategy. Compared to dollar stores, they aren't trying to be the cheapest, they are trying to offer a better overall shopping experience. This can be because of ease of shopping, helpful staff, the assortment they offer. But hey, all those things need to be paid for as well. So they charge a higher margin on products.


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

[User] CMV: Jefferson Davis Statue on my campus should stay.

[Assistant]
J. Davis was the leader of the rebels who wanted to break up /dissolve our country; so what's so illogical about not wanting his likeness around?

And to top it off, he committed treason to protect his right to own blacks. It wasn't to save innocent children from mass genocide or something like that; it was to defend slavery. That's a concept 99.9% of Americans are against today.

It's not surprising at all to me people want the statue to go away, lol.


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

[User] ELI5: Why does the top post on the front page seem to appear out of nowhere when all the other posts on the front page stay in roughly the same position?

[Assistant]
Due to the time aspect of the algorithm, a post reaches 1, then slowly will move down (if it follows a similar ratio of up/down votes (likely), as opposed to dropping out of sight if there was a backlash of downvotes on it)

But a new post would be upvoted at its own ratio which will often be higher than other posts on the front page, and therefore quickly reach the top position since it is newer and has higher upvote ratio than everything else currently on the front page (due to previous high upvote ratio posts are likely ranked lower due to age by this time)


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

[User]
How can you feel when people are looking at you? (If you actually can and it isn't paranoia or something)

Can people sense when people are looking at them, have there being any studies to prove it? If people can how do they do it?

[Assistant]
There have been studies, iirc.  Some googling might help.

But, people cannot feel it.

Most oft-cited example is sitting in a classroom and you feel someone looking at you, so you turn around, and someone is looking at you.  Well, it was the act of turning around that caused them to shift their gaze to your movement...


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

[User] ELI5: Why is calculus important in the medical field?

[Assistant]
When you take any medication, someone has to have calculated how long the drug lasts at each dosage level. They have determined the correct dose for each body weight. They know how that medication is affected by other drugs, including how the duration or decay rate changes.

To do these types of calculations, scientists and pharmacists use computers... But they used to use calculus.


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

[User] Non-economist social scientists - What part of your discipline is not understood well among economists? How might an economist benefit from further study in your discipline?

[Assistant]
sociology could perhaps inform economists relating to the workings of capitalism in general, and it's conception of "free"-market, specifically:
- the relations of political power influenced by/influencing the economic sphere, and it's consequences towards effective and real citizenship;
- the role varied social inequalities play in a so-called meritocracy;
- the understanding of globalization as an arena where different global versions compete, rather than an inevitable process or state that has been achieved;
- the role of the State (as economic regulator) in different geographical areas of the world-system - central, semi-peripheral or peripheral - and it's consequences over time;
- the social conditioning of taste, and it's implications in the definition and reproduction of class;
- or the irrational aspects of individual decision in the supposed all-rational marketplace.