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

[User] ELI5: If all fossil fuels come from dead plants and animals of the past, was all the carbon trapped in them present in the atmosphere as CO2 at some point? If we dug out all the fossil fuels in the world and burned them all today, would the atmosphere be comparable to what it was like before life?

[Assistant]
No, it wouldn't be comparable to what it was like before life. If nothing else, the oxygen in Earth's atmosphere was made by, and is maintained by, living things. In fact, life is responsible for major changes in Earth's geology; more than half the minerals found on Earth require the oxygen in our atmosphere to form.

But to a lesser extent: yes, by burning fossil fuels we're returning carbon that has been buried and kept out of the atmosphere for eons, and returning the Earth to a state of higher carbon dioxide in the atmosphere. Before the formation of those deposits, Earth was much hotter - there were palm trees at the poles - and in the most extreme climate change scenarios that's basically what we go back to. (Realistically, not all fossil fuels are economical, and that shift will take a very long time. So we won't see that in our lifetimes even in the worst cases.)


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

[User]
[DC] Do Metahumans have any sort of solidarity or kinship the way that Mutants do in Marvel?

It seems that metahumans rarely, if ever, consider themselves distinct in any way from the aliens, robots, magicians or what have you that they work alongside, and usually align more along good and evil. Is there ever any point wherein Metahumans consider themselves a distinct group, separate from other humans? Or does no-one care how you got your powers, and what matters is what you do with them?

[Assistant]
In marvel, mutants are a discriminated minority. That tends to create a sense of identity among a group- they have those shared experiences and common enemies. In essence, in marvel, "mutant" is something like the queer community (if trans people could shoot lasers), and have that solidarity against a world that, as the tagline goes, hates and fears them.

In DC, there is no discrimination, and thus no reason for, say, the flash to specifically bond with other metahumans any more then with other blondes. In DC, "metahuman" is something like a hair colour. How much kinship do you feel with people who have the same color hair as you? Exactly.


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

[User] ELI5: On Cops, you always hear the officers talk about the offender leaving a well known "Drug House". If a house is that well known why hasn't an attempt already been made to obtain a warrant and shut the operation down?

[Assistant] if you shut down the house quick, you haven't caught the supplier feeding the drug house.  if you monitor it, you can figure out who is delivering to it, follow him, and find out what place is supplying this house and other houses.  work your way up the chain and bust the production house eventually.  Basically, cut the head off the serpent and the rest of it dies too.


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

[User]
[DC] When does Batman ask for help?

Batman is known for his intellect, detective skills and technological prowess when it comes to fighting crime, but when does he throw in the towel and ask for help?

[Assistant]
As early and often as possible. Batman would simply not be able to function if he wasnt getting help, whether its from Alfred, Gordon, one of the Robins, or any other member of the Batfamily.

The idea that Batman refuses to ask for help mainly comes from the Arkham games, but even then hes still constantly receiving information and advice from Alfred and/or Oracle.


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

[User]
ELI5: why can bitumen laid on a road be driven on almost instantly , however in carparks etc must not be driven on for up to 2 weeks?

We just had bitumen laid in our carpark at work and have been advised not to drive on it for 2 weeks to let it cure , however when they lay it on a road you can drive on it straight away ?

[Assistant]
Was the product hot when applied? Asphalt paving is usually applied hot and then rolled to compact it. As soon as it is cool to the touch it is OK to drive on it with light traffic. However, there is a similar product often called cold patch, normally used to fix potholes. This is not heated and typically not compacted as firmly and as a result can be displaced by the weight of traffic or parked cars.

Then there is the possibility that the existing asphalt was simply sealed with a petroleum based sealant which takes time to cure and is virtually never used on public infrastructure.


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

[User]
ELI5: Why do our eyes often suddenly perceive spinning movements as slower than their actual speed once a certain speed threshold is reached?

This refers to the effect often seen in strobe discs used for turntables, zoetropes for incredibly old films, and even things as basic as car wheels, in which at when objects spin fast enough our eyes suddenly view them as spinning slowly. Is this linked to saccades?

[Assistant]
Common misconception: Your eyes operate in a certain frames per second. The issue with this is that our eyes don't operate in 'frames.' It's much more complex.

However, the frames per second method is the easiest way to explain it. So, imagine a camera is recording a helicopter. The camera is recording in a smooth 60 fps, and the helicopter's blades are spinning at 60 RPS (3,600 RPM- way higher than an actual helicopter, but this makes for easy math). So, each time the helicopter makes one complete rotation, the camera records a frame. It is in the same position as the previous frame, and as the next frame. This creates the illusion that it is in the same location.

However, math doesn't always work out, so often, things will actually be just above or below this perfect threshold that allows us to see it in the same place. This creates the illusion that it's slightly spinning forwards or backwards. It might be different for different people- it's really based on how fast the brain can organize the information your eyes are giving you, however, there's always a limit. Your brain often simplifies the information it receives instead of completely ignoring it, resulting in motion blur.


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

[User]
[MCU] In order to obtain the soul stone, "you must lose that which you love". What's the minimum amount of love required?

As an example, I would be relatively upset if Richard Dean Anderson (MacGyver/Jack O'Neill) were to be tossed into the void, or my boss, or any number of people I interact with daily. Normal people continue to live their lives even when the most precious person in the world is taken from them, so where's the cutoff?

[Assistant] I suppose it must be subjective.  Gamora feels no love from Thanos, but killing her nevertheless fulfills the criteria.  The love seems to be something felt by the sacrificer.  And as far as we know, it's just binary: you either love someone or you don't.  So, as long as the person obtaining the stone loves the person who is lost, the price is paid.


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

[User]
ELI5: 360 Videos

Recently I've seen videos pop up on Facebook that allow me to rotate the direction I'm looking in the video. How is this possible?

[Assistant] Those videos are created by using a specialized device that captures footage through numerous cameras simultaneously, and then are stitched together to create the illusion of a seamless recording. YouTube has had support for this kind of video, but as you can imagine, very few videos on the service utilize it.


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

[User]
Is there a reason why solar flares resemble magnetic lines of force?

I've seen pictures of solar flares and they almost always remind me of the iron filings rearranging themselves in the magnetic force lines shape. Is there a reason to this?

[Assistant] Yes. Because the sun is made of plasma, and because plasma is essentially dissociated (divided into nuclei and electrons) atoms that are electrically charged. Essentially the plasma actually follows those magnetic force lines.


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

[User]
Do gravitational waves weaken over distance?

And, in case they do, what are they interacting with that weakens them?

[Assistant]
Far away from the source they weaken with an inverse distance square law for their power and an inverse distance law for their amplitude, just like all other waves - as the wave spreads out over a larger volume the intensity goes down.

There is a non-zero interaction with matter that can reduce their intensity in theory but that is completely negligible.


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

[User]
[Star Trek]Why don't vessels travel at maximum warp all the time and do they have or need any protection when they travel at warp speeds?

It was probably asked before but I think we need a break from Star Wars questions as they seem to make out 90% of this sub now.

So I started watching ST:TNG again because I haven't seen it since I was a kid and every time they need to go from point A to point B it's at different warp speeds.

Now I know it might be because they have time and the crew needs to rest but is there any other reason to do so? Energy preservation, strain on the ship or the warp core maybe?

Also, do they have any radiation protection like Serenity has and is it possible that something from Event Horizon or Warhammer 40k might happen while they travel at those speeds?

[Assistant]
Higher Warp levels put more strain on the drive systems in addition to using up more anti-matter (fuel).

Spoilers for an episode of TNG:  As we see (you'll see) in TNG, some areas of space can actually be damaged by frequent high warp field levels as well.


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

[User] [It's a Wonderful Life] Every time a bell rings an angel gets his wings." Could I just set up a machine that rings bells multiple times a minute to aid angels in their search for wings?

[Assistant]
I think the underlying premise of your question is flawed; footage seems to suggest that an angel receiving his wings *causes a random bell to ring*, rather than the other way around.  Mary, George, and Zuzu are standing around when they hear ringing from a tiny ornamental bell on a nearby Christmas tree - nobody is actively ringing the bell (although maybe the crowd is jostling the tree).

I propose an experiment, similar to the Sudbury Neutrino Observatory - we set up a spherical chamber, and line the interior with bells.  As angels continue earn their wings, we can use the Angel-Wing Array to triangulate the position of heaven.  Once we know where Heaven is, the possibilities are endless.  Peaceful contact?  Trade?  Conquest?  Certainly, proof of an afterlife, at least.


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

[User] [Star Wars] When Vader struck down Obi Wan and he disappeared, what did he think happened to his body?

[Assistant]
He was probably confused as hell. But being the stoic killer he is he didn't show it because it would imply he wasn't the all knowing monster his men and enemies see him as.

Perhaps he never fully understood what happened that day, the Sith do not have any such abilities and even Palpatine likely wasn't aware of such power existing.


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

[User]
[Elden Ring] Some corpses, mine included, disappear. Some don't. Why?

Edit: I'm specifically looking for why some corpses diseappear and *some do not*. What's that about?

[Assistant] When you die, your essence returns to the Erdtree so you can be reincarnated. Your body is carried to the foot of the Erdtree by the living jars. By the time you are "alive" again, more than 12 hours have passed (in-game time). That's why your body is gone when you return to the site of your previous demise.


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

[User]
ELI5: Why does the force from a magnetic field on an object act perpendicularly to the direction of the field?

My friends and I in physics tried to look it up but we still just don't understand it.

[Assistant]
I assume you're talking about the Lorentz force? To be perfectly accurate, your question should have been "why is it perpendicular to the field and the direction of motion".

I won't try to answer this in its entirety since it's too much. But let's take a look at a simple example - two parallel wires with currents flowing in them.

I've always found magnetic forces easiest to understand from the standpoint of general relativity. Specifically, length contraction.

Let's say you're in space accelerating towards a planet. As you approach the speed of light, you will see the planet appear to get sucked towards you. The length between yourself and the planet is contracted. Actually, all the lengths along your axis of motion are contracted (including stuff behind you).

Now let's say you have two parallel wires, with currents moving in opposite directions. Imagine yourself as an electron in one of those wires. Now look over to the opposite wire, what do you see? You see electrons moving along your axis of motion. That length is now contracted. Because it's contracted, the density of electrons in the other wire appears to be higher. The wire now has a net charge! There's a net negative charge in the other wire, and you're an electron, so you get pushed away. The wires repel.

Now imagine wires with currents going in the same direction. You're an electron looking over at the opposite wire. You see positive charges moving relative to you! The other wire now appears to be positively charged, so you get sucked towards it! The wires are attracted together.

This is why electric and magnetic fields are two aspects of the same thing - they really ARE the same, just in different reference frames. The parallel wires show the truth - magnetic fields are just relativistic electric fields. Notice that the Lorentz force is always either attractive or repulsive towards the sources, just as an electric field should be.

I hope this helps.


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

[User]
ELI5: Why do most hallucinations instigate fear to the person suffering from it?

For example (sorry if the example is poor, but hopefully someone can get my point): most Schizophrenics see things that look threatening or hear voices that tell them to hurt themselves or just say horrible things that scare them.

[Assistant] Believe it or not it's actually influenced by the culture you are in. The eastern world, Asia, India etc...voices and hallucinations are nice and kind and encouraging for the most part, here in America they are harsh and mean. It's an environmental thing.


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

[User] ELI5:Do criminals who get movies made about them while they are still in prison (Whitey Bulger, George Jung, etc) receive any sort of compensation?

[Assistant] Several states have passed laws saying that convicted criminals cannot make money off their life of crime. So no money from book deals, movies, TV shows and the like. Sometimes the money goes into a fund for victims and their families. But all of that would depend on the state where the criminal is in prison.


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

[User] [Cosmic Horror] What's the science behind going insane after staring at an Eldritch being ?

[Assistant]
So, firstly, a lot of people who see eldritch horrors don't actually go crazy. If you're ranting about how you can't leave the circular room because a time-travelling eldritch dog can attack from any corner, you're going to come off as crazy even if you're completely right. If you look at a lot of "insane cosmic horror characters", they're actually perfectly coherently putting across the facts of the situation. It's just that putting across the situation coherently sounds insane.

As for why people go crazy? Simple mundane trauma, like any other horrifying experience.

People are confused by the eldritch beings, but forget these encounters are painful, terrifying and deadly on both a visceral level, and on learning things like "the earth is doomed" level . They "cause madness" because they're traumatic events to go through, especially as no-one else will believe it. They seem more so because of A. the isolation and B. the fact you sound crazier, but most people would have been given just as much madness had they been attacked by a pack of wolves as Ithaqua.

Basically, the idea that there's some Aura of Madness is a misunderstanding. It's simply mundane trauma, combined with the fact you're now (completely accurately) screaming at people about the octopus men who lives in the pacific. None of Lovecraft's protagonists had anything more then mundane PTSD from a deeply traumatic, if bizarre, experience.


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

[User]
How does the protein p21 "know" to bind to G1-S Cdk preventing its uptake of cyclin, when DNA is found to be damaged?

Also how does the cell know to produce this protein? I guess "know" isn't the correct term but i just can't fathom how the cells chemistry regulates all of this, is there a constant system checking the DNA for damages?

[Assistant]
When DNA is damaged, the cell automatically tries to fix it by performing one of several repair mechanisms (base excision repair, mismatch repair, nucleotide excision repair). During these repair processes, single stranded DNA is exposed. Sensor proteins, such as the ATR kinase, recognizes these abnormal single-stranded DNA stretches, becomes activated, and phosphorylates the N-terminal domain of p53, preventing its usual degradation. When p53 is phosphorylated, it in turn is activated and can go to the nucleus to stimulate the expression of several genes, one of which is p21. When p21 is expressed, it is free to bind to CDK1/CDK2 to stop the cell cycle. So in short, p21 "knows" when to bind to CDK because it is selectively up-regulated in the presence of DNA damage.

So from that, you can imagine that in cases where p53 is mutated (like in cancers) it no longer has the ability to drive the expression of regulatory genes such as p21. This therefore abolishes any protective cell-cycle checkpoints and allow cancers to grow and accumulate more and more DNA mutations.


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

[User]
Chinese Room Argument Applied To Human Brains

Why doesn't the chinese room argument apply to biological brains, in particular human brains?

The obvious rejoinder is that human brains are not symbolic, but I don't think that works.  If you have a human brain, it is 'just' made up of neurons performing computational tasks (aside:  we know that the computations are way more complicated than McCulloch-Pitts models, but assume that it's not some Penrosian quantuum calculation).  Does that mean that an analog brain consisting of neuron-like units would 'understand'?

Alternately, if you replace the neurons, one-by-one, in a human brain with synthetic units, does it stop 'understanding'? (immediately?  at some point?  when all neurons are replaced?)

And if the synthetic units themselves use symbolic computation internally, would that affect it?   (Or if the neuron replacement was actually a person computing the in-out relationship?)

Finally, if you replaced a cluster of neurons (a microcolumn, for example) with a single larger computational unit, would the human-machine hybrid still 'understand'?

It seems to me that the Chinese room argument is vulnerable to an argument from the other side, that if the CR does not 'understand', then people don't either.

I can only assume that this argument has been made better by real philosophers, but I can't find a discussion.  Can someone point me to it?

[Assistant] Searle's Chinese Room is not presented as an argument against thinking machines. As Searle likes to say: human brains are machines that think. So we KNOW machines can think. It's an argument that syntax (symbol) manipulation alone does not get you semantics (understanding/meaning). Today's computers are algorithmic. All they do is manipulate symbols. The CRA shows that a machine that works solely by manipulating symbols can't get you semantics. Since we know that the brain gets us semantics, we can infer that it does not work solely through algorithmic manipulation of syntax.


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

[User]
Why is earth's orbit elliptical and not round like that of a revolving ball attached to a string?

I know the Kepler's law of planetary motion but still whats the reason its not perfectly circular orbit?

[Assistant]
No real-life orbit is *perfectly* circular. Circular orbits are a special case of elliptical orbits where the two foci of the orbit coincide.

There are many ways to make an unstable orbit, and there are many ways to make a stable but elliptical orbit. There's only one way to make a perfectly circular orbit, and that's by setting up the initial conditions such that the orbit velocity always balances the force due to gravity (or by adjusting an elliptical orbit to be circular, which is just as hard). This means you need to start your orbit at *exactly* the right speed -- if you're a single meter per second away from that number you'll end up in a stable but elliptical orbit.


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

[User]
ELI5: Why do you get extremely hot right before freezing to death?

Apparently you feel so hot immediately before you freeze to death that many victims take off all of their clothes. Can someone ELI5?

[Assistant] When you are cold, the blood vessels near the surface of your body constrict, reducing the amount of warm blood exposed to the cold and limiting heat loss.  Your body can only keep that up for so long, and when it finally gives up, the warm blood comes rushing back to the skin, giving the illusion of being too hot.


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

[User] What would happen if two black holes that are equal in every way were right next to each other?

[Assistant] Outside the event horizon, the gravitational effects of a black hole are the same as those of a regular object of the same mass so if their event horizons don't overlap, they attract each other like any other two objects with mass. As for what happens when they are close enough to overlap....I'll let someone more knowledgeable answer that.


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

[User]
ELI5: Why is the slippery slope argument not considered a valid argument?

This has always bothered me, because I can think of instance where bad behaviors can definetly lead to worst behaviors. The classic, if you smoke pot you'll use harder drugs, is clearly not true in itself. Weed doesn't cause you to want to do harder drugs, but since weed is illegal in a lot of places, it could expose you to hard drugs and you could become a user. I understand that this is not always the case, but I'd like to better understand why this is considered a fallacy when it could be true sometimes.

[Assistant]
Fundamentally, A argument (legit ones) require proof and logical deduction.

Slippery slopes USUALLY rely on assumption.

While doing weed = illegal = more likely to commit other illegal act seems legit at first glance, IT IS BASING it's legitmacy on 1 single prospect, and then making more assumptions. You simply don't do this. Just like how you don't see a person being late once and conclude he have trouble keeping time and thus is a unreliable person.

A Slippery slope requires multiple stages and multiple assumptions, where A->B and B->C and C->D thus A->D. We know A =/= D, there is 0 correlation or causation but because you look at the flow of thought thinking "huh it has a point" thus you believe in this false statement. This is why fallacy are so powerful, not just because they are wrong, but because they can seem legit.


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

[User]
How famous was Plato in his own time?

Reading Plato, I often wonder how many people got to know his magnificent philosophy during his own life time and the generations right after. Were his books 'published' and available outside his academy? If Plato was well known, would his fame reach beyond Athens and Attica?

[Assistant] We know that most of Plato's work (unlike Aristotle's lecture notes) was written ("published") for an audience of educated Athenians, and that his works were probably read by by contemporary members of different schools in Athens and then within the Roman Empire.(Cicero, Seneca, Epictetus show acquaintance with his work, whether from complete copies or digests is a moot point). Given his immense influence in philosophic thought in the Classical world, one must assume that some or at least portions of his writings were widely available, even though he failed to rise to the "best sellers" list.


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

[User]
ELI5: What is frame pacing in video games, and how does it change the gameplay?

I've been reading about how games like Destiny at launch, and Bloodborne have had "frame pacing" problems, but I can't seem to get a solid answer of what it is.

[Assistant]
Johnny and Amanda take 60 steps over a minute to cross the length of a hallway.

Johnny takes one step per second. Every step would not look much different from one another so his motion is very smooth.

Amanda hops every other step. All the even steps take 1.5 seconds while all the odd steps take 0.5 seconds.

Both Johnny and Amanda are making the same number of steps per minute (frames per second), but the timing per step (frame pacing) differs. Johnny's steps would look very smooth but Amanda's are much more erratic, making the action feel less smooth and jittery.


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

[User]
[GTA V] So what happened in the immediate aftermath of "Meltdown"?

Did Michael really just hastily bury all of the bodies of the Merryweather personnel and dispose of their weapons and vehicles before anyone especially the police showed up?

Based on a Bleeter post by Michael's neighbour, Hayden Dubose silencers were not being used and thus everyone heard this gun battle going on in a high-end neighbourhood.

[Assistant]
> Did Michael really just hastily bury all of the bodies of the Merryweather personnel and dispose of their weapons and vehicles before anyone especially the police showed up?

Apparently yes.

We know that the attack on Michael's house did not make the news.  The news reports after that night focused on the premiere of Meltdown, with no mention of a gunfight in Vinewood Hills, aside from the Bleeter post you mentioned.  So either the authorities did not know about this event, or it was covered up somehow.

Now, granted, there might be some incentive for the government or for Merryweather to cover up this incident because it's not okay for Merryweather to be attacking a private citizen at his house, and it's also very embarrassing for Merryweather to have failed so spectacularly at their mission, which comes after quite a few setbacks for Merryweather. But ultimately a coverup is very unlikely because Michael is very wary of his true identity being discovered, so it's not plausible that he would cooperate with the authorities or with Merryweather to accomplish any coverup.

So how did Michael hide the evidence of this attack?  Well, after he repelled the Merryweather mercs, he told his family that he's going to make a call.  The most likely recipient of this phone call would be Lester, who's got all kinds of connections with the underworld and thus would likely be able to mobilize the manpower needed to dispose of the bodies and clean up the crime scene.  Sure, it's a stretch that this could be accomplished before the police showed up, but then again Lester's pulled off other miracles before, such as being able to immediately locate people throughout San Andreas no matter where they are, and identifying Michael's payments to Dave Norton despite Michael now using a fake identity and transferring the money through multiple proxies.  So if anyone's going to help Michael pull off something like this, it'd probably be Lester.


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

[User] ELI5: Why I can send/be sent a text message that won't appear until hours later?

[Assistant]
Text messages are "store and forward" - they don't go directly from your phone to the other phone.  And although they're not guaranteed delivery (they can and sometimes do just get lost), they do get retried when they fail.  Sometimes the phone the message is going to happens to be unreachable the first time, so the message gets retried a little bit later, and so on.

Now add in the fact that text messages are kind of fit into the little unused spaces in the data network in between more important activity (like phone calls).  So they usually have to wait at least a little bit before there's a space to forward the to the next spot on the network, and on towards the phone they're being sent to.  Delays are common.


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

[User] [General Superhero] Are there examples of high tier heroes or villains who are all powerful in most areas but can't do the easiest thing a normal person can easily do?

[Assistant] I mean if you look at the X-Men heavy hitters like Rogue can't shake someone's hand, also Legion who is extremely powerful struggles in everyday life due to the personalities in his brain and schizophrenia.


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

[User]
ELI5: In the United States, who/what determines if a minor gets charged as an adult?

Yesterday's stabbing suspect is a minor but will be charged as an adult.  Not finding an official explanation. It seems the public just goes along with it in many cases.

Update: So I'm not really getting a concrete answer that makes sense. The time is 1:16 PM CST.

[Assistant] The law in that jurisdiction will lay out who can get charged as an adult, and who must be charged as a minor. Often, there will be overlap in the age ranges. In that case, it's going to be the discretion of the prosecutors whether to file charges as an adult or not.


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

[User]
Could it be considered unethical for an author to make a character suffer?

Here's my reasoning. At least when it comes to their main characters, authors will usually have a very specific idea of who their character is, what kind of person they are, etc, to the point where if given a situation, they can easily know how the character would react.

To me that seems similar to having a detailed simulation of a sentient being on a computer (the computer being the author's brain).

So what I'm wondering is: are there enough differences between that simulation and a real sentient being so that making them suffer in a story isn't unethical? If so, what are those differences?

[Assistant] There seems to be very significant gaps here, namely between someone you are imagining in your head and a complicated simulation model, and between a complicated simulation model and an actual person. The obvious gap between someone you've imagined and a complicated simulation model is that is does not process any information in any way, the reaction to whatever stimuli you think up in the case of the imaginary is purely just something you come up with, while in the case of a  complicated simulation model it will process the new information you have given it, and based on how its been set up, will react in whatever way.


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

[User] ELI5: Difference between low weight-high rep/high-weight low rep and use in relevant techniques or combinations.

[Assistant]
In a very basic sense, the body adapts to the sort of activity that it thinks it will need to do in the future, based upon past experiences. For example if you are exposed to greater amounts of sunlight then your body will react by increasing the production of melanin which will result in a tan.

If you use relatively lower weight with a high amount of reps then you body will adapt to sustained output, increasing your stamina.

If you use high weight and lower reps (by necessity) then your body will build larger muscles in order to achieve the higher peak output.


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

[User]
Is it possible to have a planet and a moon in close enough proximity that their atmospheres mix?

I'm thinking of planets something like Pluto and Charon (yes, I know, Pluto's not a planet) where you have 2 large objects spinning around each other in fairly close proximity.  Assuming that these 2 objects both have an atmosphere, would it be possible for these atmospheres to mingle?  Or would an orbit that close together be unstable (due to atmospheric drag perhaps?).

I'm writing a science fiction story where it may be possible to travel from the planet to the moon while remaining in atmosphere (albeit, a very thin atmosphere).

EDIT:

What about if I introduce a third body?  A planet, a moon with a very elliptic orbit and a second much further out moon.  The closer moon's elliptic orbit would usually carry it close to the planet at perigee, but not close enough for their atmospheres to touch/mingle.  But once every thousand orbits or so the second moon would influence the other's orbit enough to make it dip closer to the planet (lets say a couple of thousand KM of the planets surface, for argument's sake this is a large planet with a deep atmosphere), then on the next orbit it would "straighten it back out again".

Could this be stable?  Would tidal forces rip the moon apart?  Would the constant drag in those once-in-a-thousand close passes be enough to destabilize the moon's orbit and send it crashing into the planet (or slingshot it out to space)?

For the sake of the story this has to be a stable arrangement that has existed for untold millions of years.  Also the close passes would have to be within living memory (a couple of thousand years apart would work, maybe as far apart as 10,000 years).

As a side note, I suppose I'll have to write in that at perigee whether or not the atmospheres mingle the moon's gravitational influence would cause massive tides, increases in volcanism, and just general doomsday scenarios.  Actually, this would work out very well in the story.

[Assistant]
This is not possible in the long term, at least not for planets. Let's consider that the atmosphere always remains aerodynamically flyable by a suitable craft, which is around 100 km on Earth (depends on the design of the craft really, but air density has a big say in it). It's less on Mars and more on Titan.

So let's put Titan in orbit around Earth and have their atmospheres touch. Interesting things happen here, as we've really caused both objects to overflow their Roche lobes. Do the math, and you find that the surface of Titan is 500-900 km from the surface of Earth. That's very low!

Things get really exciting really quickly. Earth, being more massive, strips atmosphere from Titan. It's a slow process, but eventually Titan would have no appreciable atmosphere left. It won't get this far, though. It'd need around half a million to a million years, and we don't have  that time.

The most exciting thing is the tidal effect. Being in a prograde orbit at 3,400 km (Titan's radius is 2,500 km), it orbits once every 115 minutes, rising in the west and setting in the east, really whipping around Earth. It raises, depending on location, 1 km to 5 km water tides and a 100-200 metre land tide. This causes cataclysmic earthquakes and complete volcanic resurfacing of both bodies, but more fun is still to come.

As Earth rotates much more slowly than Titan is orbiting, it sweeps the tides back a little, causing slight concentrations of mass just behind where Titan is in its orbit. This pulls Titan back ever so slightly, speeds up Earth's day a little, and lowers Titan's orbit. After around 50,000 years, Titan has experienced so much tidal drag that it gives Earth a nice big hug. The disintegrating Titan will smear itself around Earth's equator, leaving a trail of 10 to 100 km deep, 800 km wide gouges down to the upper mantle, boiling the atmosphere and leaving behind fractured, smashed terrain. It's not so much an impact crater as a complete obliteration of Earth's entire surface.

So in short, yes you can do this, but you don't want to be anywhere near either of them if you do.


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

[User] eli5 What does it mean when a court "temporary blocks" a law, an agenda, etc. and what's the purpose of it?

[Assistant] The legal process can take a while to play out. Both sides have to prepare their cases, then court proceedings, then the judge has to issue a ruling, etc. But what happens while the processis ongoing? This is where one side will petition the court to block a law temporarily while the legal process plays out. The judge will basically ask the question "how much harm will be made if the law is enacted and then struck down?" to determine what it's status will be in the interim.


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

[User] ELI5: Something with a 1/100 chance happening 100 times doesnt mean it's 100/100. How can I find the more accurate chances?

[Assistant]
You mean the chance of it happening at least once after 100 tries?

At each try it has a 99/100 chance of not happening. For it to not happen 100 times, you can multiply the 100 99/100 probabilities together. You can do that easily on a calculator with the ^ (power) operator.

(99/100)\^100=0.37, so the chance of it happening is this subtracted from 1. 1-0.37=**0.63, or 63%**


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

[User]
[Ready Player One] Why did James Halliday make it so expensive that poor people couldn't make it off the spawn planet?

If you couldn't afford the ability to teleport, you could not leave. Why not make make it so you can teleport to at least some or just ONE other planet for free? Why not allow users who create their own planets the option of turning on free teleporting or something.

[Assistant] Because the entire point of a P2W economy is that not everyone can or will pay. If you pay a hundred bucks for the golden helm of ass-kicking, then go out and see a dozen such helms, you're not getting ahead by spending money, you're catching up.


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

[User] ELI5 How does charcoal filter out stuff from water?

[Assistant] Besides normal old filtering by catching big stuff like a net, activated charcoal has tiny pores in it. The tiny holes grab up stuff in the water and entrap it. Eventually the holes get filled up and it doesn't work so well so you need a new filter.  One gram of the stuff can have a surface area of 3,000 square  meters according to wikipedia. That's nearly half a football field. Lot's of little holes for stuff to get caught in.


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

[User]
ELI5: Why does food that is nutritionally bad for you taste so good?

Fast food, candy, pizza, etc. Not saying that healthy food tastes bad, but something about unhealthy foods make them addictive to eat.

[Assistant] Our taste buds evolved under vastly different conditions than we live in today. Calories, fats, sugars are essential for survival in a harsh environment, but most of us don't live in a harsh environment anymore so we need less of that stuff. Our taste buds don't know that though.


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

[User]
ELI5: Why did my wet towel dry in the freezer after it was frozen?

I've been freezing a wet towel to make smoking outside more bearable. And after it was frozen solid I left it in the freezer for a few days and it dried. Umm how? Where did the ice go?

[Assistant] It sublimed! Many freezers are kept at a slight vacuum to make them easier to keep cold. But that vacuum is lower than the vapor pressure of water, so ice can turn directly into vapor. There is still no where for the water to actually go though. So if you look around you'll find it attached to the freezer walls or ceiling as ice again.


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

[User]
What is the most amazing astronomical event to take place in the near future?

After reading about the upcoming "once in a lifetime" transiting of Venus across the Suns disc, It got me to wondering what other amazing astronomical events I can look forward to in my lifetime.

I've missed out on quite a few eclipses and comet passings due to being too young or naive, so I'd love to know what to look forward to and prepare for in the next, let's say, 50 years.

Which will look the most impressive? Which is the most rare? Which is the most scientifically significant?

[Assistant]
That will have to be the supernova of Beetleguice.

The star is set to go into supernova (within the next 100,000 years which is near future in astronomical terms) It could very well happen next week.

anyway the explosion will be so bright that it will be seen for weeks on end during night and day.


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

[User]
ELI5: Why are warm blankets cozy, but rooms of the same temperature are stifling?

EDIT: I mean blankets that have been exposed to an artificial heat source (such as a dryer), guys! Not a regular blanket I've been sitting under.

I'm not that big of an idiot.

[Assistant]
Warm blankets are cozy because your body generates warmth which is transferred into the blanket and air trapped under the blanket. This warmth slowly dissipates out the outer side of the blanket into the cooler room and you don't over heat, allowing your body to relax as it is not working to raise or lower your internal temperature.

In a room of the same temperature your body is still creating warmth but it has no where to dissipate to. This makes your internal temperature rise and you feel sweaty and uncomfortable as your body tries to cool down.


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

[User]
In Radiation Sickness, how does the latent stage - when patient looks and feels generally healthy even though the body is dying - work?

Why does that happen? Their body is dying, so what's the deal with suddenly feeling better. Is it similar to how your body goes into shock to keep you from feeling pain?

[Assistant]
Cells use their DNA as templates (via RNA) to make enzymes and other proteins. Acute radiation poisoning smashes the DNA to such an extent that it is not functional. Transcription can't happen, as not enough DNA remains intact for it to do so.

During the "dead man walking" phase of radiation poisoning, the cells are able to use the existing proteins, but they can't make anything new. As old proteins degrade, they aren't being replaced. This causes a breakdown in homeostasis. Meanwhile, however, the longer-term tissues of the body continue to work as normal, they don't need to do much transcription. This includes the brain and muscles (including the heart), the liver, the kidneys and the pancreas.

Cells can't divide (they can't even try, the DNA to do so is bust) so epithelial cells in the skin and  alimentary  canal cannot maintain their tissues. This is a longer term problem, and one our patient won't live long enough to worry about.

The epithelial domain includes the entire gut, so sufferers have extremely acute GI issues. It also includes the skin, so it tends to "slough off" as it isn't being replaced as normal but the processes pushing cells outwards don't cease.

This opens the possibility of using artificial means to keep a person alive.  Hisashi Ouchi was kept alive for 83 days after an extremely intense radiation exposure which would have otherwise killed him in a few days. It's best not to research him very much: Nerves remain entirely functional, and he'd have been in unimaginable agony throughout.


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

[User]
[Warhammer 40k] What is the human population in the galaxy?

Some sources like the Warhammer 40k wikia say that the current human population is in the tens of trillions, but then a lot of fans and random people say that the number is easily in the quadrillions. So what is the right answer?

[Assistant]
There are easily a few quadrillion humans within the galaxy, the number of Hive Worlds (roughly 32,000) multiplied by their lowest possible population to be considered as such (100-200 *billion*) is at least a quadrillion, then there are the ~968,000 worlds with varying populations ranging anywhere from as large as double digit billion to a few thousand.

This is not including those heretics and traitors that have fallen from the Emperor's grace and thrown themselves in with the filthy Tau xenos.

In fact the size of the Astra Militarum is so large, and death and recruitment happen in such large numbers that it is literally impossible for the Adminstratum to estimate the active number of soldiers within the Imperium, add on the fact that not even every Imperial citizen joins the AM (one must first be in their PDF for a single Tour before being allowed to join, unless from certain worlds.)


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

[User]
CMV: There is no plausible ending for the "Song of Ice and Fire" series that isn't Daenerys on the Iron Throne.

First things first: I don't dislike Daenerys. I think that throughout the course of the series, she has grown as a leader and is coming into her own as a potential ruler for Westeros. Does that make her deserving of it, per se? That's a matter of opinion and it's not one that I necessarily prescribe to.

However, I do think that regardless of whether or not anyone else is deserving of the throne, be it Jon, Asha, or Arianne, there will be no one else who takes it because of the giant fucking deus ex we've watched grow through the span of the series.

I'm talking, of course, about the dragons.

At the end of the day, if Dany has dragons, does it really matter how many men Jon has loyal to House Stark? If Dany has dragons, does it make a damn bit of difference what Cersei schemes and connives into existence? Of course it doesn't. Short of Jon going Azor Ahai on Dany's Nissa Nissa, she's the biggest OP that ever lived. You simply cannot defeat dragons in the War of the Five Kings.

Now, I know that there is at least one historical incidence of dragons being defeated. Aegon's Conquest indiciates that the defeat of the dragons, Meraxes' slaying in particular, is plausible, but within the context of the War of the Five Kings, it's just not going to happen.

Dany will take the Iron Throne with fire and blood. The Song of Ice and Fire is, of course, about Jon and Dany, but at the end of the day, fire will always come out on top. Does that mean that she'll be a good ruler? Probably not, especially if she has to burn Moscow to get to the throne. I do, however, truly believe it is the only reasonable endgame. CMV.

[Assistant]
Daenerys will rule Westeros, but not from the Iron Throne. This is the only reasonable endgame.

The lore of A Song of Ice and Fire is full of epic wars and kings and queens and conquerors of destiny. But it's implicit in the fact that *this* story is the one being told (as well as in its details) that this story is the "big one" - the one that will truly shape the fate of the world. Daenerys, or anybody else, simply ending up on top when it's all over and resuming business as usual from the Iron Throne doesn't mesh with that fact. The outcome of the saga needs to be bigger than that. It has to be both climactic and cathartic. It can't be merely a return to normal, it has to be a significant transformation.

The Iron Throne represents the cyclical evil of Westeros - it's *the* Throne in the Game of Thrones. It's the status quo. Daenerys (and Jon Snow) represent the opposite of that. They can't just win the game, that's not big enough - they have to transcend it.

They have to destroy the Throne, figuratively and literally.


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

[User]
What is the difference between VM based languages and those without VM?

Why are some languages VM based and some are not?

How do language designer decide if they want their languages to have VM or not?

If Java did not have JVM, what would happen?

If C has VM, what would happen?

[Assistant]
Not much from the user perspective. Its possible that a VM language is more similar to a native language over another VM language.

Pro:

VM code is supposed to be more portable.

Con:

VM code is slower

That's about it. Everyone's gonna get mad and say JVM is optimized and just as fast as C++ blah blah blah; for the most part though, VM's are slower.


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

[User]
Do bad role-models and stereotypes in media really cause bad behaviour and low self esteem in individuals?

It gets brought up in discussions from time to time, movies have bad stereotypes. Girls get low self esteem because they look at super models in fashion magazines. Men think they're worthless because of the dumb husband super wife trope in series. Video games get criticized because of sexualisation.

But is there actual evidence that these bad role models and stereotypes actually cause bad behaviour or low self esteem? Isn't a persons direct surroundings (friends and family) a more important factor in behaviour?

[Assistant] There is the famous doll test by Kenneth and Mamie Clark from 1940. In it, groups of black children were asked to choose between two dolls, one black and one white, but otherwise identical. The majority chose to play with the white doll. When asked why, the children said the white doll looked 'pretty' and the black doll looked 'ugly'. The experiment was repeated in 2009 with similar results.


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

[User]
If you willingly choose to forgo health insurance and end up in the emergency room, you should have to bear the entire cost of your stay, with no assistance from taxpayers. CMV.

With the Affordable Care Act continuing to face political troubles, many young people - the so-called "young invincibles" - are choosing to pay a penalty, rather than purchase health insurance, whether to make a political statement or because they do not expect to find themselves in a hospital anytime soon.

However, accidents and freak medical events can strike anyone, anytime, which was part of the impetus to include an individual mandate in the ACA. It used to be that if an uninsured person was in a car accident and ended up in the emergency room, and said individual could not pay, the rest of us ate the costs in higher premiums. The mandate to purchase insurance hopes to do away with this practice.

Regardless of whether you have a moral problem with government mandates, I believe that if you *willingly* choose to forgo insurance - sans those who were granted exceptions in the law (the poor not covered by Medicaid, Native Americans, etc.) -  you should not expect a dime of support from the rest of us if you ever end up in the hospital.

If anyone has a better way to mitigate the practice of taxpayer-subsidized emergency room visits by the uninsured (who now have no excuse to remain that way), I would love to have a discussion about it.

Edit:
1) There have been some totally legitimate points made about the extraordinarily high costs of health care provided at hospitals, and I think it certainly makes sense to add that as part of the health care reform equation.

2) I should probably clarify that this post is mostly directed at those individuals refusing to obtain health care simply to be stubborn, or to "stick it to the government." For those who cannot afford it on their own, they could either qualify for Medicaid or a subsidy on the exchanges, or they might be granted an exception under the law.

3) I personally would have loved to have seen a single-payer system implemented in the United States, because I truly believe in caring for those most destitute among us. But we have to work with what we have been given, and my view stems from the fact that many "Young Invincibles" are expecting the rest of us to pick up their tab (by incurring higher premiums) if something happens to them, because they chose not to participate in the first place.

[Assistant] This is already the case. An uninsured person goes to the hospital, they get stuck with a huge bill, they go bankrupt and don't pay, and the cost gets diffused to everyone else. The rest of us aren't literally paying their bill, it just works out that way.


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

[User]
[X-Men] Can I be an Omega Level mutant and NOT join X-Men or Brotherhood of Mutants of any other group?

Say if I was an Omega mutant, will I always have people keepings tabs on me and/or trying to persuade me to join some cause?

What can I do to just be left alone? What if I just want to live a normal life and not be dragged into some war?

[Assistant]
You'll probably always have at least SHIELD keeping tabs on you and the Brotherhood and X-Men, and maybe the Avengers, knocking on your door asking you to join.  If you move and change your name, they'll just find you again.  Joining a secret organization would give you cover, but that means giving up on a normal life.  Using your powers to make them fuck off would classify you as a threat and SHIELD or the Avengers would intervene.

One option would be to sue SHIELD and the Xavier Institute for harassment if they won't take the hint, but there's a chance that some footnote in the Sokovia Accords would cause you to lose.  And the Brotherhood are already criminals, they won't care.

Another option is to move to NYC and make friends with Spider-Man, who is absolutely willing to stand by your right to be left the fuck alone.  He's made the X-Men and the Avengers to back off before and he will do it again.  Though you'll still have to sit through the "great power" speech.


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

[User]
ELI5: why are some hormones such as melatonin available for sale OTC, while dopamine, serotonin, etc. isn't?

I know nootropics may help increase these levels, but dopamine is both a neurotransmitter and a hormone, so why do I have to rely on Reddit to get it?

[Assistant] Dopamine and serotonin don't cross the blood brain barrier, so ingesting them won't do anything. They do things outside of the brain though, and it turns out those things are pretty much always bad if no carefully and properly dosed. It's the same reason why you can't buy many other drugs OTC. Melatonin on the other hand is pretty benign. It's pretty much impossible to overdose. If you take too much, you'll just be excessively tired, irritable, and have a headache.


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

[User]
What happens to the food/drinks that "go down the wrong pipe" and aren't coughed back up?

As many of us know, humans are bad at eating and drinking. Our epiglottises (?) occasionally fail at their ONE job and let small bits of food or drinks into our windpipe. Often, when this happens, we cough up whatever "went down the wrong way" and it's fine. If it doesn't happen, there are potentially really serious effects, including pneumonia. I get all of that.

What I don't know (and am having surprising trouble Googling) is what happens if something *doesn't* get coughed up and *doesn't* create a significant-enough problem that it requires medical intervention. Lungs (obviously) don't have stomach acid or muscles designed to break down the thing, so does it just stay there, like the thin layer of crumbs under the couch cushions? Does liquid eventually get absorbed into Gatorade-fueled pleural fluid? What actually happens?

[Assistant]
The upper branches of bronchi to your trachea are lined with ciliated epithelium, little brush-like projections, that beat rhythmically to help get smaller dust and liquid particles mixing with mucous back up to your pharynx, where you hack a bit and swallow them or spit them out.

Anything too big or too far down gets slowly diluted by mucous producing cells and absorbed (liquids), or potentially walled off and slowly degraded by immune cells like macrophages (solids).


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

[User]
My father passed away during the last year of my PhD abroad, how to keep my motivation up and make it through to the end?

The title says it all, really. I admittedly came here to vent a little bit, but mainly to look for some advice, either from anyone who has gone through something similar or from those with general advice for getting through really rough times during a PhD.

A little bit more about me and my situation:

I am doing a PhD abroad, several thousands of kilometers from home, and my deadline to defend my thesis is in less than six months from now. My father passed away a few months ago and, though he had been ill for some time, it was rather unexpected. I quickly flew home and stayed for a few weeks before coming back to work. Since I've been back at work, I've been a complete mess and my motivation has just been hanging by a thread. I am constantly homesick and still grieving a lot. I can become very emotional at unpredictable times. It's very hard to concentrate. Additionally, I'm feeling more isolated than ever, as many friends have moved away recently and I don't speak my host country's language very well.

While I would like to take a break (technically possible for up to one year, I believe), it would be complicated. For one, it would involve a visa extension, which would be tricky and expensive. I'm on a tight budget, especially after flying home on a moment's notice those few months ago, so I can't really spend a lot in general, let alone visa fees or extra airfare right now. Lastly, my mum is strongly encouraging me to stay and finish since I am so close to the end. She wants to see me finish my dream and she's worried that something could get in the way of me finishing if I were to take a break. I agree with her and finishing on time is probably my best option.

Overall I've been very content with how my PhD has gone and I'm not behind schedule, even after taking almost a whole month away from work. Before my father passed away, I was already feeling a bit of the normal stress and pressure of a PhD student in their final year, but I was extremely motivated and I could handle virtually anything that came at me. But now I just feel so different... like I am suffocating. Dreading the next day, the next task, the next meeting, etc. Each day I feel the motivation draining away more and more and the growing feeling that an inevitable burnout is coming.

How can I survive or maybe even try to thrive during these last months? How can I find my motivation again? What are some ways to handle the grief and intense homesickness at the same time as the PhD? For anyone who has faced similar circumstances to any of the above, what helped you the most?

Thanks for any and all advice :)

[Assistant] Try talking to someone before making a decision. You don't have to fight the emotion in order to push through your degree - the degree is tough enough on its own. Your university must have grief counselors and therapists as part of their health services. Talk to them, or someone you are close to. It will likely take multiple sessions but it is worth it. They will help with what is causing the dread. All the best; you can get through this :)


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

[User]
[40K] Other than scale, is there any difference between chaos gods and daemons?

What I've found on the subject seems to imply that they're all warp-born entities made of the same warp-stuff as echoes of things in the material world, but the chaos gods are much, much more powerful than any daemon, and are capable of some special feats like making daemons themselves. Is this the case? Are there any examples demonstrating otherwise?

[Assistant]
Daemons are not separate from the Chaos Gods. It is inaccurate to point out differences between daemons and the gods, and it is simply wrong to imply that any of the Four are actually really big daemons.

Daemons are created on the whim of a Chaos God out of his own essence, given any form of independence on a whim, and on a whim they cease to exist. To compare the gods to their daemons is like comparing a human to his own fingernails.


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

[User] ELI5 how does a brain store information better when theres an interest rather than when there isnt?

[Assistant]
Picture a sandbox on a breezy day. Emotions have an impact like drawing deeply.

Deep lines in the sandbox make it easier to see even if some sand blows in. Also, every time you think of the same thing you redraw it even deeper.

Repetition is really what makes things stick, so the initial impact (omg! This is so cool!) makes a good solid picture, and something youre interested in will also be repeated in your mind redrawing those lines even deeper.


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

[User] ELI5: Why do so many species enjoy being rubbed or scratched?

[Assistant] This has to do with sociality. In humans and other primates grooming is an important part of social bonding. In dogs and cats it may be more to do with having co-evolved with humans. If the dog likes to be petted then it will be friendlier and will be selectively bred. Cats have a natural urge to rub their heads on their friends. We see this in pretty much all cats. Some of that behavior comes from cats having scent glands in front of their ears, so they are rubbing their scent on their friends. So it's basically a way for a social animals to strengthen and reinforce bonds among their group-mates.


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

[User]
[The Expanse] Where the fuck is all the water going?

Ceres is said to have had enough water for a 1000 generations, the Earth and Mars took it all. I mean, okay, I Mars took all the ice as part of a terraforming project I can see that. Removing it on mass from a central easy to get to point. Maybe Earth was using it to refill it's ships and for Luna maybe. Even still that doesn't account for, what has to be dozens of other massive asteroids and comets accost the system.

All that history aside, the thing that bothers me the most is the seeming lack of advancement in critical recycling systems aboard ships and stations! Even today aboard the ISS there extreme little "waste water". How can it be that in the 23rd century in places where water and air are so precious that there are not extreme measures put in place to recapture all water? I just seems like ships just dump there waste directly into space.

They clearly have fusion power plants, which means... I'd assume, power is relatively cheap. They should have more than enough to collect black and gray water, sift and treat the water, then boil and re-condense it. Especially on Earth where sea levels have risen by 50ft, to the point where they are drowning in sea water!

[Assistant]
The recycling equipment that they have the Expanse is insane compared to today. No way in hell could we keep several stations of large populations self-sufficient with our current engineering (although there are possible solutions but nobody can try them out). It's like the difference between looking at a Roman city's sewage system compared to ours.

As for where all the water is going, it's all going to the Earth (massive lifespan + overpopulation = nightmare logistics) and the Mars terraforming, which Mars needs a HUGE amount of water for. In the end, they don't give a shit about the Belters, so they aren't willing to share any more water than they have to.

Think of it in today's terms. We 'buy' quite a few resources from Africa, where people are truly poor, and yes there are people who care about poor African countries (Somalia, Nigeria) but most people don't care, or only pretend to care (like the UN in The Expanse), because they have their own problems. The only people who benefit in Africa are the corrupt dictators who get all that Western money while people starve. The same dynamic is repeated in the Belters (poor) and the Governers (of the stations). Notice how the Governers had that massive garden? They aren't dying from lack of water.


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

[User] Is your skin and hair able to absorb and utilise vitamins and minerals from creams, lotions and shampoo?

[Assistant] Absorption through the skin depends on quite a number of factors. The concentration, molecular weight, solubility and duration of contact all play a role, as well as where the skin is located (the skin on the scrotum absorbs things very quickly, while the skin on the bottom of your foot absorbs things very slowly). Molecules pass through the layers of the skin via passive diffusion. The stratum corneum (outer layer of the skin) is the main rate limiting barrier in skin absorption, and lipid soluble molecules can pass through it much quicker; however, nearly all molecules can pass through the stratum corneum to some degree.


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

[User]
ELI5: How does a touchscreen work?

And how does it know if you're using a finger or not?

[Assistant]
There are several different types of touchscreens. The two that you're probably most familiar with are resistive and capacitive.

Resistive touchscreens, which are used in Nintendo's products and pre-iPhone PDAs and smartphones have flexible plastic screens. When you push on the screen, you squeeze multiple layers together and this completes an electric circuit.

Most modern smartphones use capacitive touchscreens. These touchscreens are made of glass. When you touch the screen with your hand, you distort the electric field in the screen and it can measure where that change took place. Insulators, like plastic or most fibers, won't distort the field so the screen won't recognize them. "Smartphone gloves" have metal fibers woven into the fingertips to make the screen notice them.


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

[User] ELI5: Why do some foods have an after taste - And what causes the after taste?

[Assistant]
There are two things you need to know; how taste buds work, and how saliva works

Saliva is the first part of digestion, believe it or not. The food is actually being broken down at a molecular level before you even swallow it!

Taste buds are sort of similar to the nerves you have on your skin. Your hands are really good at understanding the texture of what it touches, whereas your shoulder for example, is pretty bad at it. You can think of taste buds in the same way. Taste buds are just very very specialized nerves (sort of), that can understand what different things taste like.

The regular flavor of something is just how the taste buds process that food. The *aftertaste* comes when your taste buds start tasting the food *after* it's been broken down. The few particles of food left in your mouth after you swallow are still being broken down, and your taste buds do their job by "tasting" these leftover compounds.


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

[User] How can nuclear naval reactors produce almost as much power as nuclear power plants, yet are many times smaller?

[Assistant] They don't, even the largest Naval Reactors don't have as much MW potential as a full size civilian reactor. What they do have is higher levels of enrichment, allowing for longer usage times before refueling and to allow the Navy to reduce the overall size of the Reactor system. So make your fuel "Stronger" to allow for you to use a small system to harness the energy it outputs. The Civilian ones are larger, and are able to harness the output of a "Weaker", reactor because they are able to create a more complex system in order to increase efficiency.


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

[User]
[Dragon Ball] Do female saiyans get zenkai boost from child birth?

I'm no doctor, but from what I've heard, giving birth can be an extremely traumatic experience for the body, so much so that women have to spend time physically recovering after doing it. So in theory wouldn't it be like pushing their bodies to the limit while training or fighting?

[Assistant]
They dont have Childbirth the human way. You see the babies grow up in artificial incubators so that the women are free to fight if needed.

What i guess is the embryo is taken out right after conception and put in the incubator.


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

[User] How do we know it rains diamonds on saturn?

[Assistant]
Technically we don't "know"

We know

1) The chemical composition of the atmosphere contains a good chunk of methane based on light reflection analysis.

2) We know the mass/volume/density of saturn based on lots of other math and observations.

We put those together and realize that in certain areas of saturn there is enough pressure/temperature to form diamonds.  These would form for a bit *sorta* like rain/drops and hail do in our atmosphere and then "rain"


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

[User] [The Ring] Since the girl climbs out of the screen the movie is played on, why not play it on a really old smartphone and isolate yourself from any other screen?

[Assistant]
Sadako is a supernatural entity, and you're trying to apply logic to her.

She may emerge from the screen all tiny, but she'll kill you anyway.

She may emerge small, then grow to full size before killing you.

She may make your screen grow before emerging and killing you.

She may emerge from another screen before killing you.

She may suck you into the phone through the screen, killing you.

She may telepathically possess your body, forcing you to kill yourself.


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

[User]
Can light orbit an object?

To clarify, is it possible for light to approach an object in space in such a way that it will enter a stable orbit and not eventually pass an event horizon, such as in the case of a black hole, instead it will continue forever in a circular orbit.

[Assistant] Light can orbit a black hole at a distance of 1.5 times its event horizon radius; this is called the photon sphere. For rotating black holes the shape is more complicated. However, these orbits are unstable: a small perturbation to the orbit sends them off to infinity or into the black hole.


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

[User] CMV: The politically correct understanding of the differences in human genetics might be in our best interest socially, but isn't necessarily the truth.

[Assistant]
1. There is no such thing as a "superior" gene or trait because it all depends on what the environment is. It's like saying that the ace of spades is the best card. It is in some card games, but it's the worst card in others.

2. Even genes that seem really horrible often have some really good qualities too. For example, the gene that causes sickle cell anemia is the same one that protects carriers from malaria. On the flip side, some supposedly good genes have bad qualities too. The gene that causes strong testosterone output in men also causes baldness.

2. Genes aren't everything. The environment that a person grows up in plays an equal or larger role in how a person turns out. A person might have a gene that predisposes them to heart disease, but with proper exercise and nutrition, they might never know.

4. With technology, genes matter a whole lot less. Say a person is genetically disposed to be thin, which is bad for cold winters because they can't retain as much heat. Now they can just put on a jacket or live in a heated home. On the flip side, a pale-skinned person is much more likely to get skin cancer in sunny environments. Now they can just put on sunscreen or a hat.

Genes are much more complicated than you'd expect. It is really hard to pinpoint down what genes are good or bad. Plus, by the time we finally do learn how they work, it's likely that we will have developed gene therapy that will allow us to tweak our genes as necessary to best match our environment.


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

[User]
[X-Men] My teenage kids are both mutants with cool powers, I'm not, Magneto keeps sniffing around my back porch, how can I get him to leave?

My son and daughter are twins in their late teens with fire and ice powers respectively, that asshole Magneto keeps showing up and giving grandiose speeches during friday backyard grill night. Anyway what is the best way to embarrass Magneto as a middle aged suburban dad? Like obviously he can't grill for shit, but should I call him out on that or make him mow my lawn and then say he didn't do it right? I don't want my daughter and son joining his stupid gang, they can make a million bucks each working for Sam's Club powering the carts the fatties ride around in, they don't need the Brotherhood.

[Assistant]
Throw your aluminum cans at him, they're not Magnetic so he can't throw them back at you.

Keep a loaded super soaker so you can spray him when he's floating.

Buy a non metallic speaker and blast "it's raining tacos" every time he tries to launch into a speech.

He won't hurt you or destroy your house as long as he's trying to win over your kids.


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

[User] Eli5: How do so many countries commit war crimes, and yet there seems to be little action against it?

[Assistant]
There is no world court that can go around arresting people for committing war crimes.  The closest thing you have to that is the International Court of Justice.  But the ICJ is more of a Western European political tool than anything else.  It would never prosecute a Western European leader, and cannot operate in countries that are not militarily controlled by a Western European country.

But there is also a problem with your question, which is the assumption that the commission of war crimes is widespread.  There is reason for that because the media in general, and people on the internet in particular, like calling every action by countries they deem to be their enemy a war crime.

In order for a civilian killing to be a legal war crime, the killing needs to be done intentionally, with knowledge of the civilian's status, and there cannot be a military purpose behind the killing.

That means that if a bomb misses its intended target and strikes a civilian that is not a war crime, because there was no intention to kill civilians.

That means that if a building is reasonably believed to be housing solely combatants, but it turns out to be a civilian building instead that is not a war crime because there was no intention to kill civilians.

That means that if combatants are hiding amongst a group of civilians, the killing of those civilians is not a war crime because the killing had a military purpose.

In the modern world, the overwhelming majority of civilians that are killed by a military are killed because their government intentionally deceives it's opponent into thinking that civilian buildings are in fact military buildings or because militants attempt to use civilians as human shields.  When civilians are killed under those circumstances it does not give rise to the commission of a war crime.


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

[User]
ELI5: Why is the face so important in determining how attractive someone is?

Why does the position of someone's eyes, nose and mouth make them a more desirable sexual partner?

[Assistant]
It's a sign of genetic health and societal standing.

First there's symmetry. A general sign of health is a relatively symmetric face, with two eyes that sort of look like each other, a straight nose, and so on. Yes there absolutely are exceptions - we are also attracted to the novelty of someone with different coloured eyes, and Harrison Ford's crooked schnozz kind of adds to his roguish tough-guy charm. But in general, symmetric faces mean a greater chance of cute kids, which means a better breeding partner.

Then there's smoothness of skin, not too much or not too little hair that's in the right places, lack of redness in the eyes, even white teeth, cleanliness which means you're not just back from shoveling fertilizer, and so on. All of these things have been conditioned by what society thinks is attractive both from an appearance perspective and from a financial support-your-kids perspective, on top of our genetic basis for attraction. And that's why people with these features show up on Vogue and Maxim and GQ and so on.

Why the face? We wear clothes that usually cover our bodies, and we face people when we talk to them. This makes the face the most obvious and concentrated set of signals that might help assess attractiveness, and so it's there that we quite often assess someone as attractive or not.


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

[User] If all the polar ice caps melted, would the ocean become less salty?

[Assistant]
Physical oceanographer here.
There was an article published in Science 7  years ago answering this exact  a question using Paleo oceanographic  evidence from the last deglaciation (Synchronous deglacial overturning and water mass source changes by Natalie Roberts and others).

Deglaciation does, by simple math make the world's oceans less salty but not in the way you think it would. It takes gargantuan amounts of energy to mix water masses with different properties, so instead of the entire ocean reducing its spicyness (salt concentrations), you'd see certain currents take the biggest hits while others remain pretty much unchanged.

Now, the ocean currents that have been shown to be most affected by current and past deglaciation are those feeding deep, cold water to the world's oceans (water can only sink to the bottom of the ocean near Antarctica and Greenland). In case of a total deglaciation, this supply would stop, meaning that:

 **The rates at which deep water resurfaces and that at which surface water sinks to abyssal levels would reduce drastically. Freshwater, the article finds, would remain in the upper ocean and drive overturning there.**

In short, a deglaciation partially stops the exchange of energy, salt, and heat between the deep and upper ocean, leaving only topography-driven and tidally-aided sources for turbulence to cause 'communication' between these two layers. This is pretty much how lakes work (no tides though, but being smaller, lakes can have their bottom layers accelerated by wind under some special conditions), so oceans would become much more similar to them. This is by no means that currents would stop (wind and tides would remain stirring everything up), but it is only the deep/upper water exchange that would pretty much disappear.


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

[User] ELI5: Why on the peak of Mount Everest is snow, when the clouds are underneath?

[Assistant] So you know how you can get drops of water forming on your window because of the cold? Well that happens up there too exept that it is so cold that the droplets freeze and the air so thin that they are very small.


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

[User] How is it possible to brute force a password when most computers/websites lock a user out after a low number of incorrect tries?

[Assistant]
To check if someone typed in the correct password, the computer (server or local computer) calculates a hash of the typed in password and compares it to the stored hash of the correct password. If both are identical, the user knows the correct password.

Hashing a text produces another text, the hash. This hash can't be reversely computed into the original password, therefor you can't tell the password by looking at the hash.

For brute forcing, you need the hash. For a local computer, you can just read it from the drive (if the drive isn't encrypted). For a web service, you may get the hashes from a security leak of the service, which are often uploaded after a breach. When you have the hash of a user, you can begin to try out passwords, hashing them and then see if the resulting hash is the same as the one you are brute forcing. If they match, the correct password is the one that produced the identical result. Because everything is local now, you can try as often and fast as you like.


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

[User] ELI5: If our muscles become stronger after repeated use, why does our neck always get sore after looking down at our phone for too long?

[Assistant] Because you're not using your neck muscles when you stare down at a phone, you're keeping them static and stretched for long periods of time. Muscles benefit from repeated contraction, while static prolonged stretching weakens them over time.


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

[User]
CMV: The most efficient way to end police brutality is to make cops criminally liable for their actions on the job and stop funding their legal defense with public money.

I think this is the fastest way to reduce incidents of police brutality. Simply make them accountable the same as everyone else for their choices.

If violent cops had to pay their own legal fees and were held to a higher standard of conduct there would be very few violent cops left on the street in six months.

The system is designed to insulate them against criminal and civil action to prevent frivolous lawsuits from causing decay to civil order, but this has led to an even worse problem, with an even bigger impact on civil order.

If police unions want to foot the bill, let them, but stop taking taxpayer money to defend violent cops accused of injuring/killing taxpayers. It's a broken system that needs to change.

[Assistant]
The problem is that lawsuits against only the officer don't really happen. The city is included (and usually the main defendant) in the lawsuit.

I think requiring the cops to carry insurance to cover legal fees would work better. It doesn't immediately cripple someone's finances if they are sued, and begins to force them out of the job as soon as questionable behaviour starts, as opposed to just going on admin leave the first few times. Treat it like car insurance where premiums go up very quickly even with relatively small infractions and have incentives for time without incident.

Better yet, have the insurance pooled between each precinct, or even each city, so that one guy being a shithead will cost all the other officers more money in insurance premiums. It would make people think twice about hiding smaller infractions since they show a propensity for worse behaviour. You just have to make sure that the premiums don't go up for the group if the bad officer is fired and that cover ups have huge premium increases, otherwise there is more incentive to hide bad behaviour.


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

[User]
ELI5: Why aren't things in orbit constantly accelerating?

Objects in orbit are constantly in free fall correct? So shouldn't they be accelerating from gravity, I know that gravity's effect greatly lessens as you get further from the surface, but still it's a force that should be accelerating, so why isn't the moon and the ISS constantly orbiting faster and faster?

[Assistant]
They are constantly accelerating.  But it's important to know that, in physics, "accelerating" doesn't mean "getting faster".  Rather, it means "changing velocity".  And velocity is a vector, meaning that it has both a direction and a magnitude.

We tend to think of the magnitude portion of velocity as the "speed" of the object, and acceleration as increasing that speed.  But changing the *direction* of the velocity vector is also acceleration.  So the acceleration of objects in orbit manifests as the constantly changing direction of their velocities.


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

[User]
ELI5: Why haven't we all been sucked into a black hole by now?

Shouldn't black holes get more and more dense with every thing they suck in?  Shouldn't this lead to more gravity and thus more things being sucked in which would lead to more gravity and....

edit: Maybe I should clarify, it seems like the effect would be exponential growth, and over billions of years it seems like there should be some black holes that have collected entire galaxies by now.  Also, maybe explain it to me like I'm 10.

[Assistant]
Imagine you have a star. Now imagine there's an imaginary sphere around the star that's the size of the star. When the star collapses into a black hole, imagine that imaginary sphere is still there (representing the star's original size). Even though there's a black hole at the center, outside of that imaginary sphere it will not exert any more gravity than the original star did.

**tl;dr: A black hole won't "pull" any more than the original star did, unless you pass within the space the star used to occupy.**


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

[User]
ELI5: why do extremely profitable companies still engage in shady practices?

For example, Boeing and Pfizer are two I can come up with in recent times. Boeing with its quality issues with the 787 and Pfizer with false marketing. And yet these companies still make billions of dollars every year. Why don't they just spend the extra time and money to ensure quality and not deceive their customers? It seems like it would be better in the long term for the company's reputation and the costs of fixing their mistakes and dealing with the government surely offset some of the profits they made by taking shortcuts. Are companies just inherently that greedy?

[Assistant] When doing something illegal and paying a fine is more profitable than doing something legal, it's just the cost of doing business. Businesses are rarely required to admit any wrongdoing, and there are no real repercussions.


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

[User]
[DC] What is the most depressing version of Justice League?

I know the flaspoint paradox and all but are there any more fucked up versions / paralel universes besides this one ? (Maybe Dark Night: Metal too )

[Assistant]
The League of Gods and Monsters could be fairly summed up as: What if the Justice League were dysfunctional jerks?

* Superman is the son of General Zod, sent to Earth so he could carry on Kryptons legacy of conquest and imperialism. He was found by a loving but desperate illegal immigrant family who took him in, and his upbringing was a harsh struggle and he grew cynical and embittered.

* Batman was once brilliant but frail scientist Kirk Langstrom until he used experimental nanotechnology to fix a genetic blood disorder. The side effects left him with superhuman abilities but a hunger for human blood. Horrified at what hed become, lived on the streets feeding on petty criminals until Superman found him and took him in.

* Wonder Woman was once Bekka of the New Gods, pledged to marry the son of Darkseid to secure an alliance. Against all odds, she found that she was in love with her betrothed, Orion, who was a really nice guy under the rough exterior. To her horror, her family treacherously slaughtered him, Darkseid, and most of the guests at the wedding. Emotionally adrift, she ran away to Earth.

Today they work for the US government (who can barely keep them under control and are constantly scheming to find ways to replace and dispose of them) and have absolutely zero limitation against killing.


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

[User]
[Star Wars] What if Palpatine was forced to execute Order 66 earlier than he originally planned to?

Lets say Arc Trooper Fives was able to reveal Order 66 to the jedi before getting killed. Then Palpatine is forced to execute the order early before the jedi could take action against him. How would this play out with the Clone Wars still going?

[Assistant]
Even at the height of the Clone Wars, Palpatine had the majority of the hearts and minds of the Republic on his side. Granted, it wasn't until his kidnapping and subsequent assassination attempt by the Jedi that he fully secured his position, but he was close. Palpatine would have been able to spin it as something like "I was reliably informed by people loyal to this Republic that a militant extremist arm of the Jedi had begun plans to weaken our great nation from within." We saw hints of this sort of stuff going on already as the Jedi buckled under the pressure of the Clone Wars. Barriss going rogue being the prime example of this.

People are frightened of the unknown more than anything. And the Jedi with their secluded practices, weird magic powers, deadly energy blades, and the ability to control minds, make a great deal of people very nervous. They would have bought just about anything Palpatine sold to them if he told a convincing enough lie about them going rogue. His trap to destroy the Jedi and secure Sith domination was too intricate, and too well executed for it to fail in this particular series of events. It just wouldn't have been as flawless.

However, this probably would have resulted in fewer Jedi deaths since the news would have gotten out before Palpatine could squash it. And definitely greater resistance from senators like Bail Organa and Mon Mothma, who would have seen right through the bullshit just like they did in the real version of events. It's possible the Galactic Civil war could have been a slightly shorter affair if more people aligned against the Emperor. Or it might have ended before it began if Palpatine were made aware of his enemies sooner, since he would have had no problem with killing them.


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

[User]
ELI5: When you lose weight, where does it go?

I mean, Law of Conservation of Mass. Do the fat cells just leave via your poop? Do they come out as sweat? Okay, I'm pretty sure it's not that. But where does it go?

Yea, I've taken Physics and Chemistry and Meteorology and other stuff, but not Biology (at least not since high school).

[Assistant]
The fat cells actually never leave, until or unless that cell dies off naturally, as all cells eventually do.

When you lose weight, you burn off the energy that the cell contains. This is like drinking the water out of a glass -- the glass is still there, but the content is less.

This is why it's very easy for a formerly fat person to re-gain the weight. The cells are already there, and are already used to storing excess fat.


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

[User]
[ATLA] Would it be considered dying in the avatar state if Katara hadn't healed Aang at the end of season 2?

Aang goes into the avatar state at the end of season 2, and Azula shoots him with lightning. He nearly dies from this until Katara saves him with the magic water.

If Katara hadn't saved him, would this be considered a perma-death in the avatar state, or would he need to have died quicker for that?

[Assistant]
I believe so, yes.

Aang didn't just nearly die. He actually died. Until Katara healed him with the spirit water, he was clinically dead.

Ironically, dying in the Avatar State probably saved him. If he hadn't, he would have reincarnated, and nothing could have brought him back.


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

[User]
How does government agencies know whether a death is vaccine related or not?

I have read a few articles about deaths shortly after the Covid vaccine, and in all of them there were the reassurance that the death was not related to the vaccination, but there hasn't been any explanation why.

What is the technique used to determine whether a death was related to a vaccine or not and why is it not provided so the public can be put at ease with scientific data?

[Assistant]
Here's the dealio: we don't know for sure but we have a lot of science saying it doesnt.

Each day you have various opportunities to die randomly. Heart attack, stroke, aneurysm for instance. When someone does die under strange circumstances we do an autopsy and find out why.

All of the history we have on how many people die of what cause gives us a rate. For instance x number of people die each day from y disease.

This rate gives us a baseline and we monitor it to see if there is an increase.

So far the number of people who have died after taking a covid vaccine has not show any baseline increases. Since the numbers remain at their expected levels, we can safely say the covid vaccine isn't causing death in people.


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

[User]
ELI5: Some members of US congress have notoriously low attendance ratings and this seems to get brought up a lot before elections (for example, John Kerry in 2004 and currently Ted Cruz). Not trying to exonerate anyone, but what are some possible reasons for a low attendance rate?

Not trying to make a case for anybody. I'm just wondering why. Sorry if this has been asked before-- I couldn't find it if it has.

[Assistant]
Most of the time, everyone knows the result of a vote before it is taken, and it is more of a matter of putting your position on record.  Bills almost never fail to pass because someone didn't show up...in fact, Congress has an informal courtesy system, where if someone wants to be out of town during a vote, they pair up with someone who is going to vote the opposite way, and they both miss the vote.

So low attendance isn't always as bad as it seems.  If you are travelling the country trying to drum up support for a bill, that can be more important than actually voting for it.