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

[User] [Jaws] So, did the mayor get reelected?

[Assistant]
In the book, no; he comes to Brody's house to tell him he's leaving town.

He was being pressured by the Mafia to keep the beaches open because they had invested a lot in Amity's real estate so he probably went into hiding.


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

[User] ELI5: How come it smells so much worse when someone else goes to the bathroom?

[Assistant]
The real reason:

You are adapted to not find the smell of your own shit repellent, because you must be motivated to do it and find it relieving to do so. That means your own shit smell is fine to you as you are doing it. If you shit, leave it alone, and come back to it a few minutes later, all those associations are gone and you'll treat it like anyone elses shit.

Gross, but that's really how it works.

edit-

Y'all motherf-ers need Jesus.


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

[User] [DC Universe] Would Catwoman have a compulsion to chase laser pointers like real cats do?

[Assistant]
No.

Contrary to what some would have you believe, Catwoman is not compelled to act like a cat in any meaningful way. She's just someone who likes cats, wears a catsuit, and is a "catburglar" who sometimes steals cat-themed statues.

Her behavior doesn't really resemble that of real cats in any significant way.


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

[User]
ELI5: What is Olber's Paradox?

One of the books I was reading (on astrophysics) used this term and I wasn't quite sure I understood I properly. So, I thought I'd look to the learned men and women of Reddit to help me understand this. ELI5 guys!

[Assistant]
It suggests that the universe is dynamic and changing. In the past people thought the universe was basically static: it always existed, will always exist, and doesn't really change much.

But if the universe had always been here and always been in this state, that means the light from all stars everywhere would have reached earth by now. The entire sky would be filled with stars. The gaps between the oriignal stars would be filled in when the light from them reached us.

Which means that if the universe was always there, the light would have reached us by now. So it would never be night. The sky would always be blue, because of the light always passing through it.

Since there is a night, it suggests that the universe is dynamic and expanding, and that the light from stars far enough away has not reached us, and never will.


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

[User]
ELI5: Freezing Warts

I was at the doctors office today to have a wart checked out and when I asked,  the doctor explained that by freezing a wart, our immune system kicks in and begins to fight it off. What I don't understand is how by freezing a wart our immune system decides to begin fighting off the infection. Why wasn't it fighting it off before? What does freezing the wart actually do?

[Assistant]
Freezing the wart irritates the area, causing a small amount of swelling, redness, and sometimes pain at the wart site.

The area is injured by the freezing, and in that inflamed, injured area the immune system responds by increasing its presence in and around the swollen areas. Like a city adding more cops to a area with a spike in crime. The hope is that the increased immune surveillance, one of the immune cells will find on of your skin cells infected with the wart causing virus (HPV) and sound the alarm to your immune system to begin fighting HPV infected cells.

Why doesn't your immune system do this already? One, your outer skin, like most areas with little circulation, gets little immune surveillance. Your immune cells, like cops, need roads to get to the site of a crime/infection. You can increase the surveillance by causing a small amount of damage. The other reason it may take a few treatments, is that HPV is very good at hiding inside your outer skin cells, so your immune system may not pick up on it on the first pass.


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

[User]
Why are plants green and not black?

Plants use light energy in photosynthesis, and reflect green/some yellow (mostly) wavelengths of light. Why would plants not be black in colour, in order to absorb all the (coloured) wavelengths of light and increase their energy input, which in turn would (hypothetically) increase photosynthesis? There must be a reason why, or plants would have evolved away from this colour choice by now. Is it because 'green' light does not supply optimal light energy conditions for the plant?

[Assistant] Actually, black objects DO reflect 'light' - they reflect parts of the electromagnetic spectrum that we can't see. Anyways, you're running on the assumption that evolution creates the most optimal possible solution to a problem, when what it really does is simply allow the most optimal existing solution to grow while other, less optimal solutions die out. Maybe some day, plants will be black. That requires that mutation to show up and thrive first :)


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

[User]
[General] Immortal individuals tend to become apathetic, cruel etc, as time goes by, especially if they were born mortal. What are some examples of immortals who benefited from their immortality?

By benefited I mean became more empathetic and appreciative of life  the small and big things. Those who did not become jaded but instead aimed to better themselves and the world(s) around them.

[Assistant]
Hob Gadling from the Sandman. Wouldn't say he didn't become jaded, at certain points, but he always snapped out of it after a few decades-centuries. Even after living for hundreds upon hundreds of years, losing family and friends, including [](#s "his best friend,") he still wanted to live life, as much as he could.

Never really truly gained wisdom or a grander understanding of life - he just lived it a day at a time.


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

[User]
ELI5: Why doesn't a vacuum have the temperature of "Absolute Zero"?

I understand what they call "Absolute Zero" is the complete absence of all thermal energy, meaning that there is no movement at the atomic level whatsoever (probably not a 100% accurate explanation, I know, but rough idea), so why is it that a complete vacuum isn't at the level of absolute zero even though there is no thermal energy within it (as in, why don't we get instantaneous frost bite from touching something such as a thermos, or storm windows that contain a vacuum within, and why is it so difficult for scientists to actually attain that level (or lack) of thermal energy, and just get extremely close to it?

[Assistant]
A vacuum doesn't have a temperature. Temperature is the kinetic energy of particles.

You don't get cold by touching a vacuum because there is nowhere for your heat to go. when you touch a cold object, like ice, you get cold because your molecules knock into the object's molecules, transfering energy,  heat, to them. In a vacuum, your molecules have nothing to transfer their energy to.


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

[User] Is it possible to catch a second strain of the "Common Cold" while still suffering from a first?

[Assistant]
Of course. The "common cold" is a collective name for ~200 viruses. A co-infection involving more than one virus is not uncommon.

For some viruses this actually plays an important part in their evolution. For instance RNA viruses can exchange genetic material in a process called recombination.


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

[User]
Will sterilisation with gamma rays not make the product radioactive or destroy the product?

I was told yesterday that sometimes drugs are sterilised using gamma rays because some drugs can't handle being heated. Then he added that it's also used for food!?

Is there not a risk of the drug, food or packaging becoming radioactive? Or will the rays not alter the drug or the food?

I am also wondering if this done in very controlled facilities? But he said it was very common, but I thought it would be too expensive!?

[Assistant]
Gamma rays will not make the material radioactive, unless they are of just the right frequency to excite nuclei in the material. But even then, that will just cause a small fraction of the nuclei in the material to gamma decay back to the ground state, and that usually happens very quickly.

If the gamma rays don't have exactly the right frequency to excite any nucleus in the material being irradiated, then it won't activate the material at all.

Activation is mostly just a worry with neutron radiation rather than gamma rays.


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

[User]
[LOTR] why are the Dead Marshes cursed?

I haven't read the books in forever, but is there a reason why the marshes outside Mordor are cursed by ghosts?

[Assistant]
The main battle of the War of the Last Alliance was fought there, before the Black Gate. It lasted months, but in the end the armies of Gil-Galad and Elendil broke the armies of Sauron, enabling them to enter Mordor and beseige Barad-dur.

The ghosts are the spirits of the many thousands slain.


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

[User] Do insects sleep, or do they just stay up forever?

[Assistant] Insects do sleep, at least kind of. They enter a state of rest called torpor. When in this state they remain very still and do not respond much to stimuli. Some types of insects, such as fruit flies show similar signs of sleep depravation as we do; they get grumpy and have problems coordinating properly if they haven't had enough sleep.


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

[User]
[LOTR] Isildur and Elrond accidentally slip and fall into the pits of Mount Doom after defeating Sauron. How does the life of everyone involved in LOTR change?

They bring the ring with them.

[Assistant]
Most of them wouldn't exist.

The Shire won't be founded as the Hobbit's would have had no reason to leave the Anduin.

The history of Gondor and Arnor would be different so no Aragorn, Boromir, Faramir, etc.

It's likely Rohan would not be founded.

Without the Three the elves would have left sooner. Lorien, Rivendel, etc are abandoned.

Gandalf and the wizards have no reason to come to Middle-earth. Without Gandalf Smaug would still be in Erebor (unless he never showed up).

Basically the last 3000 years of history would be completed different.


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

[User] [The Truman Show] What would have happened if the show had been cancelled before Truman discovered the truth?

[Assistant]
I believe the contingency plan for this was for the news to be broken to Truman very, very carefully. He would then be housed in a safe and secure environment with regular psychiatric evaluation with the aim of eventually integrating him into the world. The evaluation would have a second purpose though: **to convince Truman to keep making TV shows.**

The fact is, Truman is too big of a cash cow to let go. He can never really be free. That's why the next show would be pitched: *Truman in New York*. You'll laugh, you'll cry, you'll be rooting for him all the way, as Truman attempts to lead a normal life in the big city! Then there would be the spinoffs:

* *Truman at the office*. Watch out for his craaaaazy boss, Mr Goldstein!
* *Tru Love*. Follow Truman's love life as he searches for the one.
* *Tru-man and Wife*. Watch Truman and his bride-to-be plan their wedding! You saw it on the Truman Show, now watch it happen for real!

and finally:

* *Truman Jr.* Where everything starts again.

Truman might leave the dome, but if everything went to plan, he'd never really leave The Truman Show.


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

[User]
ELI5: What actually happens inside us during the stomach drop moment?

Ive been thinking about this a lot ever since I almost dropped a boiling bowl of soup over myself as I was carrying it.

That was definitely the most intense its felt but Im intrigued as to what actually happens inside. It literally felt like my stomach dropped and my heart was racing.

[Assistant] I think your body shifts the blood away from your stomach into your muscles to prepare you to act to the stressful event you are witnessing. It's the fight or flight response, your nervous system pushes adrenaline into your system and it triggers all of that fun stuff.


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

[User]
How do we calculate current world population? Also, how accurate is that count?

Burning question on my mind for awhile now. How do scientists calculate the current number of people on the planet? Is it some massive database, clever *guesstimation*, or something else?

[Assistant]
Censuses, surveys and estimation. Most (all?) countries have some sort of census, literally asking everyone in them how many people are there. This can be validated by taking smaller populations and checking the numbers (like census data says 100 people live in this district, lets go door to door and physically count them and see how much the census was off). Sometimes people from outside (like another international organization) will do these checks.

Then other people might do their own independent estimates, find X buildings in a city, Y apartments per building, and Z people per apartment. Multiply it out and see what you get. And then extrapolate those numbers to similar areas.

There are also records for stuff like new housing, death records and birth records, it gives you an idea of where people are moving and how the population is growing. Current numbers are estimated with the best known numbers plus estimated growth rates.

This is generally done from the lower level up, and each country gets their own population count, and experts figure out how accurate it is and get that best estimate. Add up all countries and you get a very good estimate of population.


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

[User] ELI5: Why is it that North Americans/Western Europeans who move to another country are referred to as "expats", whereas others who do so are referred to as immigrants/migrants?

[Assistant]
An immigrant is someone who moves to your country.

An emigrant is someone who moves away from your country.

A migrant is someone who moves often (sometimes to the point of being semi nomadic) primarily in search of temporary work such as harvesting crops. They may be immigrants or they may be native born citizens.

An expat is technically someone who has emigrated to a different country but have not given up citizenship to their native country. It however is often used in place of emigrant as "emigrant" is a cognate of "immigrant" and it often causes confusion when talking about things.


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

[User]
How can a photon have a mass of zero without violating the mass - energy equivalence?

Photons are particles without mass. But whenever a system emits one, it loses a small fraction of its energy, and therefore its mass. However, the photon lacks mass and only transports energy, so conservation of energy is given, while conservation of mass is violated. If the photon is added to another system, the other system gains (although very little) mass.
So is a photon transporting mass without actually having any? I'm really confused right now, and might be I just miss something simple here.

Thanks in advance for any answers!

EDIT: Thank you all for taking the time to write these answers down. They did indeed clarify a lot, concerning my question and giving a lot of further, interesting information!

[Assistant]
Yes, everything you've said is correct (for a particular choice of "system" versus "surroundings"). It's because mass is not exactly what you think it is. Mass isn't simply "the amount of stuff" in the system like you might've learned in introductory science classes.

Mass is just energy **not** due to the overall motion of your system as a whole. Since a photon has no mass, all of its energy is energy of motion (you could call it kinetic energy).

The mass of a system of particles is not simply the sum of the masses of the particles. So while photons have no mass, adding or removing photons from your system can change the total mass of the system.


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

[User]
[Bioshock] If most of Rapture thought Sander Cohen was a psycho and a hack, why did Ryan keep holding him up as Raptures best artist?

I dont think I found one audio diary praising Cohen in the game.

[Assistant] Cohen was manipulating Ryan, playing into his ego. He knew how to illicit reactions from the leader of Rapture which he used to label his rivals as dissidents and have them declared criminals and killed.


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

[User] ELI5 - Why do we have fiscal years, and what is the reason for their time period?

[Assistant]
Calendar year doesn't always work best. Companies don't want to have to deal with end of the year reporting, etc. around the holidays, or their business is tied into the holiday season -- a retailer wants to end their year after the entire holiday season (gift buying, and returns/exchanges) has occurred. Other businesses might end their fiscal year whenever they pass their peak season, or in a slower part of the year.

Also, it may be as simple as when the business started -- if it was founded in August, then they keep running 1 year cycles that begin in August, ending their fiscal year in July.


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

[User] ELI5: Why is it often times easy to give advice to someone in a tough situation, but when youre in their shoes, its hard to make up your mind?

[Assistant] Along with answers people have given, it is also a matter of perspective. We can see the bigger picture when we are seeing someone elses situation. But when we are experiencing it, we are lost in the details.


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

[User] Why don't we have green or blue or other color people?

[Assistant] This answer may be simpler than you are looking for, but humans' skin color comes from melanin. The amount and placement  of melanin in the skin is determined by genetics, this is why some people are darker than others when they don't get as much sunlight or why some people freckle note than they tan or vise versa. Melanin is dark brown in color while all skin without melanin is a semi translucent white thats a bit pink over a body,so the only possible color range is from white-pink to very dark brown.


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

[User]
ELI5: Why are community colleges able to provide classes for such a low cost while university tuition is sky-high?

From my experience, I've received *better* education sometimes at community college than I have at university. The CC seems to be doing well in terms of funding and keeping faculty/staff/students happy, and I loved being able to pay for school out of pocket.

Transferring to a university was a real wake up call. It was well over $1,000 per class. At CC I could take four or five classes sometimes for less than a grand. What is so different that makes the costs of the two so polarized?

[Assistant]
I think it has to do with the efficency between community colleges and state universities. Since community colleges don't provide some of the luxuries that a university offers such as research, luxury spas, study abroad programs, these institutions can focus more on instructing students at competitive rates. In addition, community colleges do not compete as agressively as universities when it comes to faculty.

Also, universities are known for having more higher education administrators, which adds to the cost of a university education.


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

[User] ELI5: Why is it thought that if travelled faster than light, we would go back in time?

[Assistant]
Because the speed of light is the speed of 'causality'. Its the fastest that something can affect something else somewhere else (Yes that sentence is correct).

So think of shooting a laser beam from point A to point B. You turn on the laser beam, and then it hits point B, and that's the order of things. If you could travel faster than the speed of light, than you could be standing at point A and then beat the beam of light to point B. But since we agree that things can't happen faster than the speed of light ('causality'), you'd be at point B *before* the laser was turned on at A, even though you were previously at point A right as it was turned on. So you went backwards in time.


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

[User]
[Marvel] Bruce Banner is building a machine that will instantly pulverise him when he turns it on. Would the Hulk prevent him from completing it?

Let's say Banner wants to kill himself once and for all, without being angry or anxious about anything. He sets up a machine which can instantly pulverise himself when turned on. He knows he can't shoot or drown himself because that will just alert the Hulk to save him, so he builds the machine slowly over a period of weeks. He maintains his heart rate and blood pressure.

You can basically boil this down to if Hulk can sense Banner actively working against him without undergoing emotional stress that increases his heart rate or blood pressure, or putting his life in immediate danger.

[Assistant]
Upon suffering fatal damage, the Hulk takes over and regenerates the body wholy. He's regenerated from bits of flesh on a skeleton in the comics, and survived a bullet to the roof of his mouth in the MCU, as well as a fall from a helicopter where he clearly didn't transform until after impact.

The Hulk doesn't need to stop Banner. Unless the damage was literally instant, the Hulk would emerge as Banner was killed and stop it. Likely super pissed that Banner tried to kill himself, and by extension The Hulk.


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

[User]
What causes the circles under your eyes when you're tired and what causes them to go away when you sleep?

My troll brain is keeping me awake wondering this.

[Assistant]
Adenosine. It is an endogenous (originating within the body) neurochemical that has many and diverse effects including vascular dilation and muscle relaxation. It also gives you that sleepy feeling and induces the stereotypical behavior of preparation for sleep: retiring to a quiet and dark place and lying still.

Adenosine, overall, inhibits the release of excitatory neurotransmitter chemicals including norepinephrine. Norepinephrine causes the layer of muscle surrounding blood vessels to contract. Adenosine-caused inhibition of norepinephrine release allows blood vessels to dilate. Thus the dark color under the eyes. The shortage of norepinephrine also allows the muscles around and behind the eyes to relax, allowing the eyeballs to sink into the skull.

As the day progresses the concentraion of adenosine in your bloodstream gradually increases, until there's enough to give you that sleepy feeling. As you sleep the concentration of adenosine gradually decreases, until you awake.

Anything that increases adenosine concentration will tend to make you feel lethargic, sleepy, or tired. For example: trauma (tissue damage) releases large amounts of adenosine from ruptured cells. That's why a wound or injury can make you feel tired. In extreme cases enough adenosine is released to cause the condition called shock.


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

[User] Do other mammals get sunburnt?

[Assistant]
It Depends.

If an animal has thick fur, it takes way longer, because hair is pretty good at protecting the skin from radiation. (The reason why most people never get a sunburn on top of their head)

Reptiles and birds actually never get sunburnt, because unlike skin cells, scales and feathers are dead material, so DNA-damage can't happen and they cover the skin fully, thus providing excellent protection.
(A plucked bird would get sunburnt very quick)

Now for "naked", fur-, feather- and scaleless animals, which humans belong to, there is a possibility to get sunburnt, however animals like elephants and rhinos have a very high melanine content in their skin, so the risk of a sunburn is very low.

A naked mole-rat, however, would be at pretty serious risk of sunburn due to its skin's extremely low melanine content.


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

[User]
[Lord of The Rings] What was Smaug doing up north before he came down to conquer Lonely Mountain?

Did he have a hoard up there? Why was he there?

[Assistant]
> Did he have a hoard up there?

Most likely. When the Dwarves migrated to the Grey Mountains, the Dragons weren't too happy with that and fought them for years. Eventually, the Dwarves admitted defeat and most of them left the Grey Mountains. You can assume they left behind numerous treasures and abandoned multiple holds which some of the Dragons would've taken possession of. Considering Smaug was the last of the great Dragons, it's highly likely that he was alive back then as well.

> Why was he there?

Because that's where most of the Dragons lived following Morgoth's defeat. There was a large valley in the Grey Mountains called the Withered Heath, which was basically a breeding ground for Dragons.  One could assume that Smaug was born up there, hence why he lived up there.


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

[User] [MARVEL] Why doesnt Iron man put multiple arc reactors in his suit to avoid low power level issues?

[Assistant]
Optimization requires making tough choices.  If you want to have the flak and chaff guns, the flares, the tank busters, lasers and repulsors, missile barrages, air current detectors, internal fire suppression system, and a cutting edge AI that's smarter than most humans, you've gotta cut out a few extra "nice-to-haves".

How often does he run out of power anyway?  Usually it's only after a prolonged engagement for the fate of the world.  Day to day it's fine.


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

[User]
How long is the process of a supernova?

How long does the initial explosion take? One second? One minute? One hour? Several years? Also, how long does it take for a supernova to become a neutron star/black hole.

[Assistant] Once the nickel/iron core of the star exceeds the Chandrasekhar limit (~1.4 solar masses) electron degeneracy can no longer support it against gravity: it becomes energetically favourable for electrons and protons to undergo inverse beta decay to form neutrons (and neutrinos), leading to a cataclysmic implosion of the core.  The implosion and initial formation of a neutron star takes roughly of 1/4 second.


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

[User]
Could solar power be used to cool the Earth?

Probably a dumb question from a tired brain, but is there a certain (astronomical) number of solar power panels that could convert the Sun's heat energy to electrical energy enough to reduce the planet's rising temperature?

EDIT: Thanks for the responses! For clarification I know the Second Law makes it impossible to use converted electrical energy for cooling without increasing total entropic heat in the atmosphere, just wondering about the hypothetical effects behind *storing* that electrical energy and not using it.

[Assistant]
There's a lot of different physics bundled into this question. The technical physics answer to your question is 'no,' but the real answer from a practical perspective is 'yes.'

First, the amount of energy arriving from the sun every second is absolutely ginormous, about 10^17 Watts of power. If you could collect all of this energy (like by covering the world in solar panels and batteries) you'd only need about an hour of sunlight to power civilization at current usage for a year. So all solar panels we currently have only collect a tiny fraction of a percent of incoming solar flux.

But there's an important thing here- collecting sunlight to use will generally heat the planet more than it will cool it. Yes, that energy does temporarily end up in batteries, but that energy is still on the earth and using it will eventually convert it to heat. That's just the laws of thermodynamics, used energy ends up dissipated as heat (it's why your laptop gets hot, especially so when it's using a lot of energy like when you're playing a video game).

Really, if you wanted to cool the planet you'd want to reflect sunlight back to space so that it never gets absorbed. This is what climatologists mean when they talk about the 'albedo' of different things. It's like a measure of the 'whiteness,' or how much light a thing reflects. Clouds are great at reflecting sunlight back to space, and so are the ice caps. Concrete, farmland, and especially solar panels are very bad at reflecting sunlight. In principle, if you build solar panels on a surface that has a worse albedo then you'll be effectively cooling the planet. The surface will reflect more light, and will also generate electricity sparing us fossil fuel burning.

And that's the final point- fossil fuels. Ultimately, if you want to cool the planet, you'll want to remove CO2 from the atmosphere. These gasses increase the atmosphere's opacity to infrared light, trapping more heat from the sun and raising the surface temperature like a blanket. That's really the primary thing driving the heating. So in the most relevant sense, solar panels are good for cooling the planet because they replace traditional fossil fuel burning energy sources.


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

[User] ELI5: From a legal standpoint, how much does diplomatic immunity actually allow a person to get away with?

[Assistant] Absolutely anything, theoretically. In practice, it completely depends on the relationship between the two governments. Libya has gotten away with shooting a British cop dead in London on the grounds the person doing the shooting was inside the embassy at the time, and the British cops had no right to search the place or interview anyone. On the other hand a Russian diplomat here in Canada killed someone while driving drunk some years ago. We couldn't prosecute him, but the Russian government recalled the guy and charged him under Russian law. I'd be willing to bet it would have been much more pleasant for him to have waived immunity, but so it goes.


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

[User]
[Batman] This Matches Malone guy... why do people trust him?

Every small-time legitimate businessman in Gotham City seems to have heard of Matches Malone, and most of them seem to be of the opinion that he's a stand-up guy. But where do they get that from? What line of business is Malone in? What gangs is he associated with? What jobs has he done?

Why should I, a hard-working businessman, trust Malone with the hypothetical details of my alleged and unproven felonious activities, the sort of information which I obviously would not share with just any potential snitch?

[Assistant] Matches was a an independent crook that had a well known reputation. He was dependable and got the job done and by criminal standards he was pretty ethical. He ended up dying and Batman decided to hide his death and use the Matches persona to his advantage. He maintains that reputation so that he can use it for undercover work.


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

[User]
CMV: The abundance of charisma-casters in 5th edition Dungeons & Dragons is a design mistake

D&D is represented by three major pillars which are used to approach the world and the characters in it - exploration, social interaction, and combat. Each class plays into one of these aspects more than the others, allowing players to choose what type of game they want to play. For example barbarians are great at combat at the expense of being much less powerful in exploration (no useful abilities other than braun) and socials (since strength and constitution trump all else). However apart from bards whose lore makes sense for them to be social butterflies (since they channeled their performing arts into magic), warlocks and sorcerers kinda stick out like a sore thumb. Indeed, their prevalence means that investing in social skills for any other class becomes a waste of time since the cha casters get both social skills AND combat power from investing in it. When was the last time the fighter was the party face out of a party of 4 or more people? Pretty much never.

I think that this design decision interferes with RP, and for the rest of the party to ignore this design decision means significantly compromising their combat power for what is ultimately not an awful lot of gain. In my opinion, both sorcerers and warlocks should be int casters. This might run afoul of making them tread on the toes of the humble wizard, but if this is truly a problem then their designs should be diversified even further.

[Assistant]
Maybe it helps to rethink the meaning of charisma in Dnd.

It has less to do with social prowess and more to do with force of personality. Its the reason why intimation is considered a charisma trait, and why charisma spell saving throws exist (youre saving against losing your own state of self)

Warlocks are defined by their relationship to their patron, no intelligence required to signed a contract with a devil but it may require a great amount of charisma to get what you want from such a deal

Sorcs may have little to do with persuasion but they can shape magic by sheer willpower. Their magic is not a learned ability so it cant be intelligence, but it makes much more sense if it was an aspect of their inner character, their personality.

Dnd 5 has moved drastically away from the old era of dnd. Combat and Exploration are frankly not so important anymore, at most you may get one or two combats per session and most exploration is more abstract and loose than the multilevel mass dungeons of yore.

Many players now-a-days are more interested by social encounters, and its unfair that for only one or two party members to have all the charisma power in their hands while others are forced to wait until they feel useful again. Therefore charisma is given a great boost and is more spread out amongst party members so everyone can feel included in the story.

Theres also a reason why wizards are sole-intelligence classes, its because theyre frankly one of the most powerful and could be very prone to abuse with mulitclassing min-maxing. The game designers perhaps found it easier to simply keep wizards the only true intelligent full casters.


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

[User]
How to do a literature review if there is no literature published on the area?

 I am a geology student and I am trying to do a literature review. The problem is that the study area is very small and there is no literature published on it. My master's guide is the first person to work on this previously unexplored area. His earlier masters' students have worked in this area but I think I can't use their thesis as a reference in my paper. Can someone please help me out here? If someone has published a paper on a novel work can you link it here? It might help me. Thank you in advance!

[Assistant]
Your literature review should explain the gap in the existing field that your project will fill. Is there literature in surrounding areas that you can discuss? You need to set the scene for the reader and explain why they should care about your project.

For example, you might be doing a project on a new technique for basket weaving that saves hundreds of hours. Your lit review should talk about basket weaving in general, then narrow down to the various techniques of basket weaving (i.e. what's been done before). You can then talk about the fact that no-one has done research on your specific technique yet, and then explain your project.


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

[User]
Eli5 Why cant cancers just be removed?

When certain cancers present themselves like tumors, what prevents surgeons from removing all affected tissue and being done with it? Say you have a lump in breast tissue causing problems. Does removing it completely render cancerous cells from forming after its removal? At what point does metastasis set in making it impossible to do anything?

[Assistant] Some cancers can be, but the surgeon has to balance getting all of the cancer and none of it breaking off and not damaging the rest of the organ where the cancer is which may be keeping the person alive.


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

[User]
[Green Lantern] When Green Lantern makes a megaphone to project his voice, does he have to imagine the circuitry or does imagining the shape of a megaphone help him will a louder voice?

This question could be extended to any sort of tool that he creates.

[Assistant]
The form of the megaphone is irrelevant.  The Rings are devices which directly translate *will* into *effect*.  The symbol of the megaphone is simply a conduit for the Lantern to focus his/her/its will.  Some Lanterns use such symbols to focus, but it isn't strictly necessary.  With sufficient focus, the Lantern could simply will his/her/its voice to be louder.  But for Lanterns of races that tend to focus on physical objects as symbols, it is often a helpful tool, like a mnemonic device.

This is why some Lanterns create projectile weapons to fire blasts, while others just fire the blasts directly; or why some create vehicles to fly, and others simply fly.  Beyond this, there is also a certain amount of personalized style in these creations; while too much of this is discouraged, a reasonable amount can serve to increase confidence and thus willpower.


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

[User] Would a lightsaber cut through Captain America's shield or bounce off?

[Assistant]
Lightsabers are basically plasma blades.

Captain America's shield has withstood the heat of a nuclear blast, heat vision hotter than the sun, lightning hurled by the gods themselves, and years of plasma bursts.

The lightsaber blade would stop dead once it hit the shield, and you could leave it there for days and it wouldn't damage the thing.


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

[User]
[WH40k] Your Warhammer 40k army models just got Indian in the Cupboard'd

Your grandmother just died and bequeathed you her cupboard. Unaware it's magical and turns plastic toys into real life boyz, you put your entire professionally-painted, $5,000 Warhammer army inside the day before the big tournament. That's when things get weird. But how weird?

How would a WH40k army deal with a much bigger and much less grimdark 21st century Earth?

[Assistant]
So while the original ~~SCP~~ Cupboard brings figures to life, it doesn't seem to have any additional anomalous properties that would allow for warp-related activity.

So it kinda depends on how that plays out.  There is no warp in this universe, or if there is it's much calmer.  You'd see a lot of fireworks, but unless your collection included things like cyclonic torpedos, it's containable.  They're small.

If the Cupboard somehow does allow for 40k-style warp capabilities in 21st century Earth, then fuck, better hope the Space Marines win.  However then you could also use the cupboard to animate some Jedi/Wizards/Gods that might help calm the threat.


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

[User]
[Spider-Man PS4] Putting aside the fact that it's a fictional work, how does Peter build his suit being that he barely scrapes by money-wise, and where does he find the equipment for his suit parts and how is he so damned good at making the suit look good, how is he so good at sewing.

Genuinely how does he make a suit like that on a small budget and how is he so good at sewing and (I assume) screenprinting. And is there anyone i can look up who made a replica of the advanced suit with actual materials for the white part similar to the in game materials and not just spandex patterns?

[Assistant] I believe it's assumed that he uses OctoLab workshop, like when he made his Advanced Suit in the beginning of the game, and with puzzles in there he develops advanced materials for the suits himself (which sorta bites him in the ass, when Octavius uses the results for his own transformation)


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

[User]
ELI5: What does Kafkaesque actually mean and how is it supposed to be used?

We are all probably familiar with this term, but I still have no idea what does it really mean. I've read two books by the author Franz Kafka, the guy who was the origin of this very term. I tried looking online, searching for definitions and stuff, but I still have no idea what was that all about, nobody explained it clearly. I wanted to find a simple definiton with an example, but I found pile of text. Maybe they need all that "extra" stuff to explain it because it is not very simple, I guess. Can it be explained in a few words, if so please do it and if not, I will go through the long version, too. Thank you.

Edit: Thank you, I went through your comments, they were really helpful.

[Assistant]
It's used as an adjective to describe something/a situation "having a nightmarishly complex, bizarre, or illogical quality" to the point of being oppressive, like the overall atmosphere of his books.

We often use it to speak against bureaucracy and administrative procedure that make no sense, but it applies to a lot of things.

TLDR: Something that makes no sense, in a bad way.


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

[User]
[Aquaman] How is the villain a threat when this is a world in which Superman is active?

So iirc the Ocean Master wants to unite the Atlanteans so that they can attack humanity on the surface for all the damage theyve done to the ocean. Hence Aquaman needs to stop him.

My question is why it even matters? Because even if Aquaman had lost or failed somewhere during his adventure the moment the Atlanteans would have attacked the surface theyd have been absolutely bodied by Superman. Unless theres some sort of reason that wouldnt have happened.

[Assistant]
He'd still have potentially caused more destruction than superman could stop at once, especially with a multi-pronged attack on the surface.

And what's more, the fact that Atlantians would be killed by Supes if they attacked, and seen as an enemy of the surface countries, may be all fine and dandy for the surface world but the point of the story is that Aquaman is saving both the surface world *and* Atlantis.


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

[User]
Is there some "quick and dirty" supposed counterexample to virtue ethics, as there is to deontology or utilitarianism?

What I mean, for utilitarianism and deontology, there are a bunch of well-known examples that are at the very least meant to strongly challenge your intuitions surrounding those moral frameworks, and demand some kind of explanation. Usually something like the deontologists would have to say that lying to an evil person for the greater good is still immoral, and the utilitarian would have to agree that doing harm to a very small group of people for the enjoyment of a much larger group is permissible. The murderer at the door and brutal gladiator-esque games in Rome are common examples.

**PLEASE do not comment on whether or not these examples are ultimately convincing**, I called them quick and dirty for a reason and I don't care. I also don't care how well it ultimately works against virtue ethics. I just want to know whether some example like this exists, that seems to contradict the core tenets of virtue ethics.

[Assistant]
The main objections involve showing (1) the virtues offer too little action guidance or (2) the virtues are culturally relative.  Sometimes this can be showing by creating a dilemma and showing that the virtue ethicist cant clearly choose.

Like in the lying murderer case - it seems like lying to the murderer is dishonest but telling the truth is disloyal to your friend. Both seem bad, if were using the virtue words correctly.


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

[User] Say I were to wake up in the Mesozoic Era, would the air still be breathable for humans?

[Assistant]
Yes, the composition of the atmosphere would be similar enough to today.  Carbon dioxide levels would generally be much higher than today (present day carbon dioxide levels are just about the lowest they've been in the earth's history) but still well below 1% which is perfectly livable.  Oxygen levels are a bit more variable, but for the Jurassic and Cretaceous they are generally above present day levels, so no problems there either.  In the Triassic oxygen starts off fairly low compared to today's levels, about 2/3 the amount, and rises throughout.  That'd be about equivalent to 3 miles altitude (5km) at sea level.

So if you were transported immediately from today to the early Triassic, you'd probably be easily winded until your body could adapt.  But absent any medical conditions (and assuming you weren't transported to the top of a Triassic mountain) you should be able to stick around long enough for something to eat you.


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

[User]
[General] What (Super) Villain has actually understandable and agreeable plan?

Thanos for example, many people agreed with wiping half universe for the greater good of everyone that survives.

[Assistant]
Thanos was violently wrong. With the power of the infinity gauntlet, he could have solved resource shortages in any number of ways, from opening up dead planets to get at the metals inside, to accelerating star birth from nebulas, to simply conjuring a wildly efficient food source, to taking over the universe and rationing and distributing everything himself, or, likely, some combination of the above. Instead he goes for the snap, which leaves every society we see affected by it devastated, *at best* where they were before, and often far worse.

Rant aside, Mister Freeze. Dude just wanted to figure out a cure for his wife.


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

[User]
Strange pointer behavior in C [ Segmentation fault(core dumped) ]

I made a program that lets you choose a minimum and a maximum number as limits to generate a random number, which then is used to create a matrix of those rows and columns, then you do the same thing for the elements of the matrix and in the end it prints the sum of the elements.
It works with small numbers, but the problem is that if I input numbers such as min:5 and max:10 the pointer to the matrix gets a value which then changes when it goes in the sum function (I printed its value three times to track it along the execution) giving a "Segmentation fault (core dumped)".
Why does this happen, obviously the pointer tries to access a "cell" that it can't use, but why does it change value and how can I solve this?

Sorry for the long code:

    #include <stdio.h>
    #include <stdlib.h>
    #include <time.h>

    void generate_m(int dim_tot, int col, int *n);

    int sum(int dim_tot, int *n);

    int main()
    {
    	srand(time(NULL));

    	int min_r_m, max_r_m, min_c_m, max_c_m;
    	//rows
    	printf("Insert the minimum of rows: ");
    	scanf("%d", &min_r_m);
    	while (min_r_m <= 0)
    	{
    		printf("Insert a number greater than 0: ");
    		scanf("%d", &min_r_m);
    	}
    	printf("Insert the maximum of rows: ");
    	scanf("%d", &max_r_m);
    	while (max_r_m <= min_r_m)
    	{
    		printf("Insert a maximum number greater than the minimum: ");
    		scanf("%d", &max_r_m);
    	}
    	//columns
    	printf("Insert the minimum of columns: ");
    	scanf("%d", &min_c_m);
    	while (min_c_m <= 0)
    	{
    		printf("Insert a number greater than 0: ");
    		scanf("%d", &min_c_m);
    	}
    	printf("Insert the maximum of columns: ");
    	scanf("%d", &max_c_m);
    	while (max_c_m <= min_c_m)
    	{
    		printf("Insert a maximum number greater than the minimum: ");
    		scanf("%d", &max_c_m);
    	}

    	const int DIM1=(rand() % (max_r_m-min_r_m+1)) + min_r_m;
    	const int DIM2=(rand() % (max_c_m-min_c_m+1)) + min_c_m;
    	const int DIM_TOT = DIM1*DIM2;
    	printf("\nrows: %d columns: %d area: %d \n", DIM1, DIM2, DIM_TOT);
    	int m[DIM1][DIM2];
    	int tot;
    	int *p_m = &m[DIM1][DIM2];

    	generate_m(DIM_TOT, DIM2, p_m);

    	tot=sum(DIM_TOT, p_m);
    	printf("\nThe sum of the elements in the matrix is: %d", tot);

    	return 0;
    }

    void generate_m(int dim_tot, int col, int *n)
    {
    	int i;
    	int max_n, min_n;
        printf("\npointer: %d\n", n);
    	printf("Insert the minimum number: ");
    	scanf("%d", &min_n);
    	printf("Insert the maximum number: ");
    	scanf("%d", &max_n);
    	while (max_n <= min_n)
    	{
    		printf("Insert a maximum number greater than the minimum: ");
    		scanf("%d", &max_n);
    	}

    	for (i=0; i < dim_tot; i++)
    	{
    		*(n+i) = (rand() % (max_n-min_n+1)) + min_n;
    		printf("%d ", *(n+i));
    		if((i+1)%col == 0 && i != 0)
    			printf("\n");
    	}
    	printf("\npointer: %d\n", n);

    }

    int sum(int dim_tot, int *n)
    {
    	int i;
    	int tot=0;
    	printf("\npointer: %d\n", n);

    	for (i=0; i < dim_tot; i++)
    		tot += *(n+i);
        printf("\npointer: %d\n", n);

    	return tot;
    }

Thank you for your time.

[Assistant]
int *p_m = &m[DIM1][DIM2];

You're getting a pointer to the last elments of the array here, rather than the starting elements. This causes your other functions to read/write out of bounds of the array, messing up all kinds of other stuff.

Instead, you probably want:

    int *p_m = &m[0][0];

...to get the address of the start of the array.


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

[User]
[SCP Foundation] Has the Global Occult Coalition ever thought about toning down their homicidal tendencies?

After events like SCP-2002, in which the GOC possibly doomed humanity to extinction through their overeagerness to blow stuff up, has the agency ever seriously considered taking a more lenient stance on anomalies?

[Assistant]
The GOC has parallels to the American Military- it's a militant world police force that rose to power in the aftermath of World War 2 because there were no occult powers left that could stop them. Crucially, it doesn't exist in a vacuum- there are literal anomalous cities and governments providing it with backing, it's part of a larger hidden society.

The GOC's ranks are already filled to the brim with anomalous entities and people who know how to leverage the anomalous. If they've gotten involved at all, it's because they already did the legwork to decide whether this is the friendly sort of anomaly that'll pay taxes to the Mayor of Three Portlands once they get past the language barrier, or the sort of anomaly that went on a genocidal rampage against the fairy city of Hy-Brasil in the 80s, against which they had to break out mecha and helicarrier gunships.

The issue, of course, is that they often fuck up and break something they shouldn't have, because when all you have is a hammer everything looks like a nail. But it's helpful to think of those fuck-ups in the context of the Ameriacan drone strikes that took out a wedding; a huge fuck-up, but a distant one committed outside the immediate "in-group," so no one in a position to provide civilian oversight really cares.


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

[User] [HP]Is having sex using love potions considered rape in the wizard community?

[Assistant]
Probably but then again is it rape if you wipe their memory? And Im not kidding, there must be a rape epidemic in the HP universe considering the over the counter availability of rape drugs that would make Bill Cosby drool combined with almost every single person able to manipulate memories with a little practice.

Dont worry about the legality of anything the justice system is so broken it barely even matters.


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

[User]
ELI5:why are we trying to get colonies on Mars and not the moon?

It seems like it would make more sense to use the moon as a launch point for further space expansion.  Is there a particular reason why there's so much talk of Martian colonies over Lunar ones?

[Assistant]
Mars is better than the Moon in every way except for its surface gravity and distance from Earth.

Advantages of Mars over the Moon:

--24 hour day.

--an atmosphere that mitigates temperature swings, unlike the Moon that goes from about -250 degrees fahrenheit to +250 degrees fahrenheit over 14 days.

--an atmosphere that enables easy production of things like rocket fuel or plastic or possibly fertilizer (depending on how easy it really is to condense out Mars's trace nitrogen), unlike the Moon that has volcanic rock and nothing else.

--geology that may have, through the action of water and more recent vulcanism than on the Moon, created concentrated ores of certain metals, unlike the Moon whose metals are roughly evenly distributed across its surface.

--an atmosphere that could allow you to save on rocket fuel by using it to slow down and land.

--the dust on Mars isn't as fine and damaging as lunar regolith is.

The advantages of the Moon over Mars:

--low gravity, so you can build an electromagnetic launching system.

--proximity to Earth--it might not take less fuel to get there, but it's faster.

--sunlight is higher-intensity at the Moon than at Mars.

As Mars advocate Robert Zubrin once put it, "the Moon is to Mars as Greenland is to North America."


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

[User]
ELI5: If I am/my kids are vaccinated why should I be afraid of those who are not vaccinated?

Vaccination should prevent people from getting sick, so why are people so freaked out that some of these diseases are back?  Maybe I just don't understand how vaccinations work.

[Assistant]
It's about something called 'herd immunity'. Basically the principle is that if you have 95% of a population vaccinated against something, then effectively the disease cannot penetrate that population because it won't have enough people to spread to.

In the short term, if you're vaccinated then no, you don't need to be worried about catching the virus - but what happens if that virus manages to penetrate the population because not enough people were vaccinated against it for herd immunity to work? Still, you're safe because you're vaccinated. Problem is, the virus has now penetrated the population and can evolve and mutate in such a way to bypass your vaccine, and since vaccines take a long time to develop there probably won't be a new vaccine for the new strain before you become infected yourself.


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

[User]
ELI5:Why can't the government create a program similar to the WPA during the Great Depression to provide thousands of jobs while getting long-needed construction projects done?

EDIT: thank you for all of your comments. A lot of you had fantastic explanations.

[Assistant] We totally could!  It would just require raising taxes (to pay for all those salaries) and increasing the size of government (adding all those new government jobs).  Those are both toxic political ideas right now.


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

[User]
When an electron quantum tunnels, does it physically move through a barrier or does it "teleport"?

Is there even a actual physical barrier or do people just use it as a way to explain tunneling?
Any details about this subject would be welcomed.

I have a very rudimentary understanding of quantum tunneling, so please excuse my terminology.

[Assistant]
The electron doesnt have a well-defined position at any given time. It has a spatial wavefunction, which is nonzero in both sides (and inside) the potential barrier.

If you were to make perfect position measurements of a bunch of identically-prepared systems, youd be sampling from the probability density function given by the squared modulus of the wavefunction. Sometimes youd find the electron on one side of the barrier, and sometimes on the other.


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

[User]
CMV: It is no surprise the world overall is becoming less religious in the 21st century

Many consequences of the sexual revolution including greater acceptance of unusual gender identities and sexual preferences, greater access to birth control and abortion are things that most religions find abhorrent and sinful. Many people choose to pursue those sexual paths rather than conform to a religion that says what they are tempted to do in the bedroom is a sin.

Because of the hyper individualism merged with capitalism that comes from catered Netflix lists, Facebook feeds and Spotify playlists, more and more people want the world to conform to them and not vice versa. So, they often expect the same thing from religion, which has led to some churches turning into Christian rock concerts with very different doctrinal interpretations than what they professes a couple decades ago. In trying to appeal more to people who don't like religion as much, they lose their parishioners who were their core base to begin with.

However, there are many religions which decide to stick to their doctrine and thus lose activity or membership because they don't support gay marriage.

Add moral relativism, shortened attention spans and a growing population of people who would rather pursue their own pleasure on a holy day when the higher power they can't appreciate because they view a relationship with it as very transactional, and you have a world that values religion less. If they do have a religion, they want it to lull them into a sense of false security telling then that they're good people, not to tell them that they might be sinning and can have eternal consequences for it, mich like the drugs and alcohol they use on the regular.

"If God didn't prevent my dad from dying of cancer, whats the point of worshipping him anyway if he doesn't give me what I need when I want it?"

[Assistant]
You missed the most obvious explanation: easy access to information contradicting the religious teachings.

Religion conforming to personal beliefs has been a thing since the beginning of religion. That's why both slaveowners and abolitionists firmly believed the same religion supported their completely opposite stances.


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

[User] ELI5: There are tons of stories about companies using loopholes to not pay taxes in countries they do business in (Facebook in England, Ikea in Australia). My question: Why don't countries go after these companies more? Don't they WANT the taxes they've lost out on?

[Assistant]
The whole point of a loophole is that it's legal, so there is nothing to "go after them" for, on the face of it. The companies aren't breaking the rules of the game, they're just using the rules  in ways the referees didn't expect.

Governments can try to pass new tax laws (or repeal previous ones) to close the loopholes, but lobbyists will do their best to stop or at least influence this process. New laws will likely have their own loopholes as well, inserted by those who have been lobbied, as simple oversights, or unrealized interactions with other laws or treaties.


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

[User]
Do I need to go to a top college to be successful in computer science?

I'm currently a freshman in college majoring in computer science. The college I am going to is a smaller, local college that definitely is not prestigious or world renown. I was wondering how much influence the college I went to will have on my future attempts at getting a job. I have a passion for tech and coding and learning and I want to do very well in this field. Also, I just landed my first internship which is exciting. But, will my degree from this little college cause me any trouble later? Or am I just overthinking this?

[Assistant]
There might be a starting height cap and a starting wage cap difference but ultimately you will not want for jobs if you are doing software engineering at all, many companies hire on the spot for passing a basic programming test and will put you in at some pretty great wages.

Note a Bachelor's degree opens a whole lot more doors than an Associates Degree. You will see your starting wages pretty much double in some regions for the difference.


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

[User] [Harry Potter] I realllly want to become a ghost when I die. How can I change my odds to ensure this?

[Assistant]
Be so afraid of death that you will subconsciously "refuse" to move on to the afterlife. Your consciousness will remain here forever.

It comes at a cost -- you've semi-cheated death, so now you get to semi-live. Forever, bound to the most traumatic place, where you died and you retain that memory and all that comes after. It's not a fate you would want. That's why almost everyone who died chose to move on.


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

[User] ELI5:If Snapchat owns all the photos taken with the app, why isn't the owner being charged with possession of child pornography?

[Assistant]
Snapchat doesn't own the photos taken with the app. You can read their Terms of Use:

> You retain all ownership rights in your User Content. However, by submitting User Content to Snapchat, you hereby grant us an irrevocable, nonexclusive, worldwide, perpetual, royalty-free, sublicensable, and transferable license to use, reproduce, modify, adapt, edit, publish, create derivative works from, distribute, perform, promote, exhibit, and display such User Content in any and all media or distribution methods, now known or later developed (the "User Content License"), subject to any privacy settings you have set to control who can see your User Content.


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

[User]
ELI5: Why do US based airlines lag behind in service and quality, especially in their premium cabins?

Anything from ground service, to in flight food, how can an economic powerhouse like the US have such universally poor quality airlines? (Certainly I'm not talking about safety.)

I don't see any US-based carriers on this list of top airlines:

ANA All Nippon Airways

Asiana Airlines

Cathay Pacific Airways

Emirates

Etihad Airways

EVA Air

Garuda Indonesia

Hainan Airlines

Japan Airlines

Korean Air

Lufthansa

Qantas Airways

Qatar Airways

Singapore Airlines

Swiss

Thai Airways

Turkish Airlines

EDIT: I wanted to add 2 cents from Gary Leff:

"What I desperately wish I could remember is which of these books it was where I read extensively on United Airlines President Pat Patterson. Patterson had been the Wells Fargo loan officer who authorized funding for Pacific Air Transport, later acquired by Boeing Air Transport, which was ultimate merged in with other carriers to become United Air Lines. Patterson moved over to Boeing and then to United, becoming General Manager and ultimately President of the airline.

While hes perhaps best known for approving the hiring of in-flight nurses which morphed into onboard flight attendants, hes also more than any other, the man who brought union control into the operation of the airline business. The version of the story I recall is that he believed that the unions were closer to their workers, and better understood their needs, than management was. It wasnt just a matter of collective bargaining, but deeply held belief, that the workers would be better off (and that this would benefit the airline) if unions and union procedures handled scheduling.

Im not a scholar in this area by any means, but the shift from company control over its employees to union control  and from management evaluation of employees to roles and responsibilities determined by seniority  has consequences which reverberate across the industry today.

Great flight attendants provide great service because theyre proud to do so, because theyre driven to do so, internally. In some ways the exceptional US flight attendant deserves much more praise because they are doing it on their own, when there is little if any benefit to them to do so. They arent going to lose their job as a result of occasionally grumpy and often lackluster service. They arent going to get paid more for going above and beyond for a customer. They do it because theyre internally driven and believe its the right thing to do. I truly thank them and honor them.

But as long as scheduling is done by seniority, and pay is doled out by route, and as long as commendations and criticisms are only ancillary to performance evaluations, pay, and perks, airlines arent going to be able to align the incentives of their frontline workforce to deliver outstanding service.

It isnt all institutions, and it isnt all culture, but the two of them combine so that superior companies drawing on service cultures and fostering those cultures can provide a superior experience. Mediocre companies drawing on a service culture will offer good and bad, just as companies here in the US without strong service institutions will occasionally offer flashes of brilliance (but often good enough). And in most cases I dont expect either the cultures or the institutions to change very much."

[Assistant] A good number (but not all) of those airlines are subsidised by their government for political/ prestige/ strategic reasons, so a $100 ticket buys you $150 of product. Emirates/ Eithad/ Qatar especially don't have business models that would survive without outside money.


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

[User]
[Star Wars] When Vader tells the officer "We'll have to destroy them ship to ship. Get the crews to their fighters," was he undermining Tarkin's authority?

Seems like Vader made the call on his own.

[Assistant] Kind of, but not really. Vader operated outside the formal Imperial military hierarchy. He deferred to Tarkin because they respected each other and Tarkin was favored by the Emperor, but the rules that apply to other Imperial officers didnt apply to him and everyone knew it. He was technically defying Tarkins orders by taking his fighter group out, but he wasnt doing anything to impede the Death Stars mission. As far as Tarkin and the other Imperials were concerned, Vader was just being restless and bloodthirsty. If Tarkin had ordered Vader back to the Death Star after  Vader launched and Vader ignored him, that would have been more serious.


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

[User] [Naruto] How did the feudal lords keep the shinobi from taking over, both before and after the villages were founded?

[Assistant] Well before the villages were founded things were bad. Ninjas primarily traveled with their clan and were nomadic. They were in constant warefare and ended up creating a lot of grudges. This combined with the fact that they had no home and no outside clan support meant that they could only rely on themselves if they wanted to take over from the feudal lords. The feudal lords themeselves were not defensesless. They usually have loyal samurai and ninja to them guarding them. And if this didn't work they could hire the blood enemies of the attacking clan to fight for them. After the founding of the villages things were different. You would be correct in assuming that if a village did want to take over then it would well be in their power to do so. The reason they don't is more of an honor thing. When the first villages started popping up they needed outside support to get going. This support came from the feudal lords who saw the opportunity of having a reliable source of trained ninja in their borders. The villages didn't become self sufficient at first either and the lords had to eat a loss for a while. Now at this point they are self sufficient and have the power to take the country, but this is the same country that gave them a home. The same country that allowed a safe place for their families to grow. The country that provided for them all those years. The kindness shown to them is not forgotten even in the newer generations.


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

[User] [MCU] Since Ego is a Celestial, why does he appear so different from the other members of his species?

[Assistant]
Theres a really interesting theory related to this that involves the purpose of a group of Eternals as SPOILERS PAST THIS POINT

*spoiler*
Shepherds for the gestation and creation of new Eternals.

Essentially, whatever planet Egos initial seed was planted in had its sentient life (meant to power him and create his body) wiped out by Deviants or some form of cosmic disaster, leaving behind just his brain and no perceivable signs of life to other Celestials, and so they left him for dead. His rage and a galactic-sized inferiority complex related to his people, as well as the presence of Eternals on Earth (a place where he put his own seed) implies that he still operates in a similar manner to other Celestials, but is basically attempting to usurp them by creating more like himself from his own seeds and doing so on worlds where fully grown Celestials plant their own.


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

[User]
Is a light-year a fixed distance?

I know that the speed of light is a constant speed (186,000 mi/s) and that it travels roughly 6 trillion miles in one year.  But when light travels for billions of years, doesn't the expansion of the universe affect how long (in distance) a light-year really is?

[Assistant] Yes, a light year is 9.4605284  1015 meters as defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year (A Julian year is a unit of measurement of time defined as exactly 365.25 days of 86,400 SI seconds each).


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

[User] ELI5 - is dying of a broken heart real? Is there a scientific explanation?

[Assistant] As a matter of fact, yes, it is. In the early 90's, Japanese cardiologists first described a phenomenon they named "Takotsubo Cardiomypopathy" which roughly translates to Octopus Pot in Japanese. It is characterized by a sudden weakening of the cardiac muscle fiber and can be brought on by strong emotional stressors such as the loss of a loved one. The name comes from the shape the heart takes on as viewed via a CXR, or, more likely an echocardiogram which strongly resembles the type of pot that traditionally would be used to catch octopi in Japan. The actual presentation mimics an anterior wall MI (heart attack) but there is no blockage and thus no infarct-only temporary (and many times reversible) weakening of the heart tissue.


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

[User] [Marvel]If Iron Fist jumped out of a passenger plane without a parachute, does he possess any abilities which would let him survive or is he going to become an Iron Pancake?

[Assistant]
He's the immortal Iron Fist.  He would first get mad and cry a little.  Then he'd smack himself around a bit (to get in the mood), calm down, summon his chi (there would have been a previous bit where he told himself to do this), and IRON FIST THE MUTHAFUCKIN GROUND right at impact.

A Krakatoa crater would result, layers of sod and earth and rock peeled away like a Bloomin' Onion from Outback Steakhouse, and as the camera dramatically panned away, in circles all around him (as he gazes dramatically backwards over his left shoulder), we'd see that beneath the ground peeled away by his Iron Fist were large structures emblazoned with strange glyphs, which he would recognize as being related to K'un-Lun.

Roll credits.


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

[User]
If planes are pressurized why do we have our ears popping?

I mean, there is supposed to be a constant pressure in the plane and the pressure is supposed to be independant of the outside pressure, so why do we have our ears popping when the plane is gaining altitude?

[Assistant]
Aircraft *dont* maintain constant ground level pressure in their cabins. Theyre required by law to maintain a *minimum* pressure, which is equivalent to the pressure at an altitude of 8,000 feet. So when a plane takes off, the pressure in the cabin falls until it reaches the minimum required by law, and then remains at that level for the duration of the flight. When it lands, the pressure increases until it matches ground level. So your ears may pop on take-off and landing.

The reason is cost. A pressurized cabin must hold in high pressure air at cruising altitude, and the greater the pressure differential between the inside and outside, the stronger the cabin must be. Strength requires more material, adding weight and reducing fuel efficiency. At sea level, the pressure is 14.7 psi, while at 8,000 feet the pressure is 10.9 psi, for a difference of 3.8 psi. So if the cabin maintained sea level pressure, it would need to withstand an extra 3.8 pounds for every square inch of surface area, making it heavier.

The FAA determined that 8,000 feet is a good compromise that the vast majority of people find comfortable. Even if youre sick, it wont kill you unless you have something like pneumothorax, in which case you shouldnt be flying anyway. So they settled on that number. But the majority of aircraft manufacturers do better. The Boeing 767 maintains at least 6,900 feet of pressure, the Airbus A380 averages around 6,100 feet, while the Boeing 747-400 wont let it drop below 5,200 feet. So your subjective impression of ear popping may vary based on which plane youre in. Itll also vary depending on where you take off or land. If youre taking off from sea level, the drop from zero to 8,000 feet is substantial, and youre going to feel it. If you take off from Denver, youre already at 5,200 feet, so you may feel no change at all, or a very small change.

There are business jets that can maintain sea level pressure all the way, like the Emivest SJ30. They dont care as much about per-seat passenger costs, so theyre willing to spend a little extra on reinforcing the cabin for passenger comfort. But big commercial airliners are designed with compromises between comfort and cost, and not having sea level pressure is one of those compromises.


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

[User] ELI5: What happens to your brain when you "blackout"?

[Assistant]
Your short term memories are not being converted into long term memories.

You can be somewhat coherent at the time of a blackout, you just won't have an recollection of it.

It is similar to how you can be driving and suddenly realize you don't remember the last 20 miles.  Driving in boring and routine, and if nothing noteworthy occurs, those short term memories won't stick.  You are aware and alert the whole time, you just don't remember.


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

[User]
[James Bond] Apart from it being an iconic name and action in the film, why would a well trained spy like bond always give out his real name, essentially blowing any cover he has?

I mean, he could get away with it the first and second time but really! By now, if there is a criminal/Evil mastermind grapevine in the James Bond universe, they could already have spread around his name and photo so he can't even go undercover anymore. I doubt real spies or any of the 00 agents do it.

[Assistant]
He only gives out his name to bystanders or the girls his flirting with, the villains either already know him or only learn it after he's already breached their defenses.

It's also an intimation tactic, imagine knowing that Britains top Spy is on your toe.


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

[User]
When you delete something off a phone or computer, where does it actually go?

How can you put some data into a hardrive, then you can magically make it disappear for more room for data?

[Assistant]
Data is merely a series of bits (1s and 0s) and bytes (8 bits..more efficient in a lot of ways).

So...you have this device which stores that information. Well, you also have to store **where** you stored that information.  Let's say that you want to store a 2MB song on an 8GB device. There are somewhere near 4,000 places it could be put. How can you tell where it is? The same way you tell where a book in a library is. You create an index.

So..what you do is you store the data then you tell the device where the data is.

When you "delete" the file, you are just removing the references that that space is used: the index. Whatever was written is still there until something writes over it.


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

[User]
[Star Wars] Did Order 66 make the clonetroopers permanently aggressive?

Even after killing off the Jedi, the clones seemingly go completely insane, they go full fascist outright worshipping the Emperor, they start subjugating local populations, oppressing the civilians of the former Republic, it's as though all pretense was dropped immediately, like all the clones had always been evil almost, did Order 66 overwrite their entire personalities?

[Assistant]
Somewhat Out Of Universe, but there's 2 explanations from both the Old Expanded Universe ("Legends") and the "Disney Canon":

Legends - All Jango Fett Clones had various "Orders" ingrained in their minds during training, to prepare them for various situations they'd encounter on the battlefield. They were also conditioned for (mostly) blind loyalty to the *Supreme Chancellor* himself. So when he gives the Clones the command to "Execute Order 66", both their conditioning as well as fervent loyalty played into most of the Jedi being killed. The Clones were *thinking* soldiers, not *questioning* ones.

Disney Canon - The Clones had "inhibitor chips" that upon activation would subvert their free will and guarantee their compliance with any orders given. After Order 66 was executed, same as Legends.


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

[User] [North American History] How did relations between Canada and the US evolve after the War of 1812?

[Assistant]
Canada was not it's own dominion until 1867. The successive and successful repulsions of American invaders help foster budding Canadian nationalism as well as a sense of security. [Spoiler] The burning of the White House by British forces helped instill confidence in the British citizens of what would later become Canada.

The US reacted like a clumsy cat. While still licking its wounds, it pretends that everything was intentional.  The US "renovated" the White House and has glossed over the successful invasion and sacking of the nations' capital since.

While the war had little impact on British citizens living outside of north America, Future-Canadians were bolstered by this successful defense and symbolic retaliation. No efforts were made to invade the US because Future-Canada didn't have the military power to invade and occupy. The message that Future-Canada could defend her borders nicely was received.

The US did not try to invade Future-Canada again and has striven for friendly relations ever since. This is in part because US geography education is lacking and while it is very obvious that Canada is aware of the location of the US capital the reverse may not be true for most Americans.

The real losers are the native americans who allied themselves with the US. They are probably the only group of people to lose land in this war.


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

[User]
[vampires]How does the whole 'you need an invitation to come in' work with apartment complexes?

So apparently vampires can only enter houses if they are invited in by someone who lives there. I live in an apartment complex that has around 1000 people living in it. Does a vampire just need to be invited in to the lobby by someone or each individual apartment? Is it only the owner that can invite vampires in or can renters invite them in too? Sundown is about 9 hours away here so I have some time, but not much.

[Assistant] It's not a "house" that a vampire needs an invitation to, but a "home".  It's a subtle but important difference.  A vampire can enter most buildings as he likes, but needs to be invited into where you live.


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

[User] ELI5: Why does it feel like we only sleep for like 5 minutes when in reality it's more like 8 hours?

[Assistant] I think this is because parts of the brain involved in short-term memory and consciousness are inactive.  When you sleep you sort of forget that you exist.  If you are not conscious then you are unable to sense the passage of time.


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

[User]
ELI5: How effective is blocking in real life martial arts?

I often see in games/shows/etc with lots of fighting people blocking with their arms or legs. Does this have any basis in real life, and if so how do they not get hurt blocking with their extremities?

[Assistant] It is effective. The trick here is that while it does hurt to block a punch with your arms or legs, it hurts less than if they just hit you directly. You redirect the motion, rather than absorb the blow. While it is exaggerated in movies and games, blocking punches and kicks is better than being hit in the head.


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

[User] ELI5: If the Scandinavian languages (Danish, Norwegian & Swedish) are mutually intelligible, why are they considered distinct languages instead of different dialects of the same language?

[Assistant]
Its kind of a semantic argument, you could make the same point for Italian, Spanish, and Portuguese.

while it is a partially political distinction the many thing is that mutually intelligible is really hard to prove as a set concept. The main theory being that just because you can understand a few words doesn't mean you can hold a conversation. and there is a fuzzy line in there somewhere that splits dialects and languages.

I wish there was a better answer but there is no golden rule.


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

[User]
ELI5: Why Doesn't Germany simply withdraw from the EU?

Germany is often seen as the potential savior of the EU right now, with bailouts flying about and member countries sinking deeper and deeper into debt. Germany has been holding strong, has a strong economy, and is oft described as the backbone of the common currency system. So why isn't it in their best interest to revert to their own currency and write the Euro off as a failed experiment? Please note I'm American, and economics isn't my strong suit so be gentle lol.

[Assistant] Germany has a vested interest in keeping the European economy alive and relatively strong. If German left the EU and the entire European economy took a dive, that would come back to bite Germany in the ass in the form of reduced trade and probably "migrant" workers (people who live in other EU countries who go to Germany to try to get jobs). This would end up damaging Germany's economy as well, so the end result would be everyone in a depression/recession. It's in Germany's best interests to keep its trading partners and geographical neighbors economically strong as a means of protecting its own economy from a possible downturn.


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

[User]
eli5: Why does there have to be water in a toilet all the time?

Urinals have proven that there doesnt need to be water all the time for number 1. So for number 2, couldnt there only be water when the toilet flushes?

[Assistant] The water forms a seal that prevents gasses from the sewer from coming back into the house.  Its the same reason there is a P-shaped bend in the pipe under your sink.  Water collects there and forms a seal.


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

[User] eli5 why does a manual car have a clutch but pedal bikes dont?

[Assistant]
Because, while even the most elite cyclists might push their pedals at 110 revolutions per minute, with a maximum gear ratio of 2.33 to 1, for a top gear speed of 260 RPM, a normal car will idle at 600 RPM, and most will change gears at around 2000 rpm. Plus the actual components being driven are much, much **MUCH** heavier.

So, the simple, bottom-line answer is that changing gears on a car is simply beyond human strength and speed, without the benefit of a clutch.


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

[User] ELI5: the rule in English that makes 'enough' pronounced like 'enuff' but 'though' is pronounced 'tho'

[Assistant]
Congratulations, you've just figured out by yourself the first lesson of Linguistics 101: Orthography (writing system) has absolutely nothing to do with language.

Language is part of the human experience. Every human being has language and learns it without being taught. Orthography is something that we have invented, and you have to go to school to learn it.

Have some more:

uf- enough, rough, tough
af- cough, trough
au- bough, drought, plough
ou- dough, though
aa- bought, sought, thought
oo- brougham, slough, through
uh- thorough, borough (in some dialects, esp. British)
up- hiccough
ok- hough (spelling reformed to "hock" in the 20th century)
okh- lough (irish spelling of "loch")

If you're curious, how this happened is that these all used to be pronounced the same: the "lough" one. The "kh" (ipa: /x/) phoneme left the English language, and people found new ways to pronounce words that used to have it.


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

[User]
What is the evolutionary advantage of primates losing endogenous Vitamin C production? And are there nowadays humans who are able to produce their own Vitamin C?

I am wondering because it seems plausible to me that due to illnesses spreading more rapidly in human societies as opposed to hunter gatherers, it could be that the immune system advantage of producing Vitamin C could outperform whatever advantage the loss of Vitamin C production had.

[Assistant]
Evolution does not necessarily have to be an advantage, it can be enough that it is not a disadvantage.

If food supplements the Vitamin C intake, there are no negative consequences of no longer producing it.

If those with the gene variation that no longer produces Vitamin C do not have any disadvantages because of it, the gene can spread. Which is likely what happened.


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

[User] What did paleolithic humans eat?

[Assistant] specific answers to this question will depend a lot on what part of the planet you're talking about and also what season of the year, the only good way to summarize it would be "whatever they could get their hands on that wasn't poisonous, and sometimes even then"


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

[User]
ELI5: Why is salt mined when there's a bunch of it available in the ocean?

I'm sure its harder than mining, but how and why?

[Assistant]
Sea salt takes a lot of space and time to produce.
You have to be able to flood huge fields and then you have to wait for evaporation to remove the water and leave the salt behind.

So basically you need a hot, dry country, a coastal area that can be turned into salt fields and quite a lot of time and effort.

Mining is a lot quicker, takes up less space, and can be done in countries with colder, damper climates.

Obviously there are pros and cons to both which is why we see so many different kinds of salt production.


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

[User]
CMV: I think these confederate statues should be torn down.

Keeping the statues up because you want to preserve history is not a good argument. We don't have statues of Osama Bin Laden up to remember 9/11. Therefore we should not have statues of people who fought to preserve slavery.

Although George Washington and Thomas Jefferson owned slaves, their statues should not be torn down because they are not famous for owning slaves and did other things that gave them good legacies. Robert E Lee on the other hand did nothing good for America.

Also, the Civil War was almost entirely about slavery. The Lost Cause narrative is not true. If it were, I would be more than happy to keep these statues up.

[Assistant]
> Although George Washington and Thomas Jefferson owned slaves, their statues should not be torn down because they are not famous for owning slaves and did other things that gave them good legacies. Robert E Lee on the other hand did nothing good for America.

Robert E. Lee obviously served the US in wars before the civil war and defended the country.

The only reason the founding fathers aren't famous for it is _because_ people like to erase history and try to keep it from people as to not tarnish their reputation. Like it or not but one of the reasons for the war of independence was that England was working to eliminate slavery.


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

[User] [Shadowrun] After the Goblinization, did lonely orks and trolls continue trying to chat up humans, or did the Awakening make them feel attraction for their own race?

[Assistant]
Hey chummer, what are you trying to say? You one of them humanis pricks? we are *all* metahumanity, and genetic studies show our DNA is no different, its just the magic that changed us. That's why a dwarf can lay down with an orc and have an elf baby.

so its no different to having a preference for, say, blonde girls or dad bods. Just that us trolls fall exclusively in the dad bod category.


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

[User]
[Invincible (Show)] Why didn't Martian Man tell the world the truth about Omni-Man?

The Martians are shown to know who the Viltrumites are and what their goal is.

[Assistant] They claimed to know what viltrumites are, but it really seemed like the king just didn't want to come across as ignorant. Regardless, the king also said that he was privy to the information specifically because of his position of power, so it's possible that viltrumites aren't known to civilians.


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

[User]
ELI5:CTRL-ALT-DEL to login?

Windows computers can be configured to require entry of the key combination before it will prompt you for login credentials... Why? What does this do to enhance digital security?

If it does somehow give a big security boost, why isn't it used for other password services (email, online bank)?

[Assistant] It's a key combination which no program can intercept, because originally it was used to reboot the system. If you type ctrl-alt-del and something happens, you know it's Windows itself that responded to the key press, not some evil program designed to look like the login screen to trick you into giving it your password.


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

[User] Can someone explain me the chemistry behind stains and why some stains cannot be removed?

[Assistant]
**TL;DR - Some stains are held in place by weak chemical bonds but others are held by strong covalent chemical bonds that won't be broken by traditional solvents or surfactants (soaps).**

In principle a stain is a bond between the surface of the original material and the molecules of the stain agent. That bond strength can vary greatly depending on the original surface and the stain agent. Some surfaces have very little microscopic surface area (e.g. a laminate countertop) whereas others like a cotton thread (hundreds of individual fibers) have a lot of area. Some materials are also porous (e.g. wood) and that adds extra surface area.

The stain agent reacts with the available surface area in some way. An example of a weak interaction might be a solvent that dries up and leaves a film of stain on surface, like most colored liquids dried on metal. If you add solvent the stain will move from the surface back into the liquid. If the surface is porous or has a lot of area, then it might take a lot of time for the stain to all dissolve, because the solvent has to get into the pore and the stain has to then get out of the pore.

Some stain materials will form stronger bonds with the original surface and won't just dissolve into their original solvent. In those cases people add a surfactant (e.g. soap) or cosolvent to help increase the solubility of the stain in the cleaning solution vs the adsorption of the stain to the surface.

Sometimes the reaction is so strong that most normal solvents won't break the bond between the stain and the surface. This is the case with most dyes which are engineered to covalently bond to fabrics and not dissolve into a solvent poured onto the fabric. If the bond is strong enough it may not be possible to break the surface-dye bond without also damaging the material that makes the surface. An example of this would be bleach which is good at destroying dye molecules, but also eats away at the underlying material - although at a much slower rate.


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

[User] [Foundation] During the early days of the Foundation it is revealed that the four barbarian Kingdoms have lost their atomic technology and reverted back to chemical energy. How does these Kingdoms maintain their star-fleets and interstellar trade?

[Assistant] A big theme is that things that used to work still work to a certain extent, so a spaceship that was build 500 years ago still can take atomic fuel and function, but if a key component of that ship burns out, nobody is able to fix it. They know how to operate old machines but not exactly how they operate. Knowledge breaks down until everything is insanely specialized. So they could mine uranium with old machines, make atomic fuel from uranium with old machines, and use hyperdrive with old machines, but if any of that breaks, as things do, they couldn't repair anything. It's a very slow degeneration. And power plants for the public use would probably be first to go cuz there's no military benefit and those kingoms were at war and would prioritize military over domestic.


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

[User]
What would happen if two gas giants (say Jupiter and Saturn) would collide?

Lets say you place Jupiter at one end of a run way, and on the otehr end you place Saturn. You trigger something to where both planets are in line and will directly hit each other. Since they are the most massive planets, would any gas be able to escape due to gravitation? How would a gas giant collision look like? Would they just mesh up and form one giant gas planet, or would the gas just escape into space?

[Assistant]
On planetary scales, aggregation does not matter. Whether the planet is made of solids, liquids, or gas, makes very little difference. Gravity trumps everything else.

Collisions of such large planetary bodies would release a tremendous amount of heat, partly due to kinetic energy (the speed of one planet bumping into the other), partly from gravity. The merged body would be quite hot initially.

Depending on the collision speed, angle, whether it's frontal collision or just "grazing", etc., the planets may merge more or less into a single ~~bigger~~ heavier planet, or would shatter and spew out pieces of material all over the place. The pieces would tend to either fall back down, or remain in orbit around the merged body and coalesce into one or several moons.

It is not impossible that some fragments would end up ejected at high speeds and keep moving forever away from the collision, although that's probably not very typical.

---

EDIT: Do not imagine that planets are either solid, or liquid, or gas. Think of them as giant loose piles of little billiard balls, kept together only by gravity, and that will give you a much better understanding of what happens during a collision.