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

[User]
What happens to the spin of an electron when it leaves a nucleus?

Lets say a photon collides with an atom, causing an electron on the outer shell to be knocked from orbit.

From a classical sense, I would assume it takes some amount energy to change the spin of a particle, and that this amount of energy would depend on how far it's rotated. But, if an electron flies off of a nucleus, there could potentially be a magnetic field in ANY direction that the electron will then encounter. This means that the electrons spin could change to be oriented in any direction after it leaves the nucleus.

Now, please correct me if I am wrong, but if I am right that changing the spin takes energy based on how much it has been rotated, there is a violation of energy conservation somewhere here, as the photon would contribute a quantized amount of energy that wouldn't be able to account for the future measurement at an arbitrary angle with respect to its original orientation.

Or, am I wrong about energy and if the spin on the electron was originally up, will it just be measured as up in the magnetic field?

Thanks!

[Assistant]
The spin of an electron is always 1/2, you can never change that. However you can change its projection along some axis. If the Hamiltonian is dependent on some component of the spin vector, then the energy depends on the orientation of the spin of the particle. An example would be an electron in a magnetic field, where the magnetic dipole moment of the electron wants to align with the external magnetic field. Youll have a splitting of each possible energy energy into a doublet.

Im not sure what you mean about electrons leaving the nucleus, and magnetic fields pointing in any direction. Can you describe specifically what situation youre imagining?


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

[User] ELI5: That euphoric half-asleep feeling where you're still semi-present but your mind is also solving tangential abstract problems that you can never remember upon fully waking.

[Assistant]
One definition of a brain is that it is a "meaning making machine", it takes stimuli from your sensory organs (eyes, ears etc) and constructs a mental picture of the world.

We still have a fairly rudimentary understanding of how brains achieve this, and whilst we know that sleep is essential for survival, we don't have a solid answer on exactly what's going on, but we do know that a huge amount of (seemingly random) brain activity occurs during REM sleep.

I think the experience you describe is the product of your brain trying to make sense of the scrambled messages as bits of it wake up and other bits are still asleep.


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

[User] [General] I ask a good Genie for 1 billion dollars in cash. What do I need to tell the IRS? Are they even going to let me keep the money?

[Assistant] It would probably be treated as found money or buried treasure, which means yes you would be filing income tax on it. Nobody is going to believe you about the genie (and if they do they might try to steal it from you or kidnap and interrogate you about where it went), so you should come up with a plausible cover story about how you dug it up in your backyard or found it in your attic or something.


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

[User]
If sunscreen absorbs UV light, does that mean that sunscreen makes you warmer?

I have read that what makes sunscreen work is partly that it absorbs UV light. As everyone knows, objects in colours that absorbs visible light gets warmer in the sun (like a black t-shirt). Does that mean that you get warmer in the sun with sunscreen than without?

[Assistant] No. The UV would have been absorbed by your skin. Instead it is absorbed by the sunscreen. The same amount of energy is absorbed either way, so your temperature is unaffected. Some sunscreens increase the amount of radiation reflected, so those would actually lower your temperature.


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

[User] ELI5: How in movies when we see a character look into a mirror and see their reflection, how come we don't also see the camera?

[Assistant] They shoot from an angle. This isn't just to hide the camera; despite what you might have heard, actor's heads are not actually transparent. You can't film through the back of their head, so you can never get a straight-on view in a mirror of their face.


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

[User]
Do deep sea ecosystems follow the normal seasons?

Do ecosystems at say the bottom of ocean trenches feel the same changes as the surface or are they mostly constant being so far from the surface?

[Assistant] They are much less exposed to change. Most of the changes in ecosystems like reefs occur due to diurnal - crepuscular - nocturnal - crepuscular - diurnal shifts along with the environment being much more open to variable processess like erosion and sea forces. In deep sea areas, we dont see a lot of change due to constant pressure, light amount (not a lot) along with the conductance of water not changing at all so the temp stays at around 4 degrees permanently.


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

[User]
ELI5: Why can people live on an all or almost all junk food diet without getting really sick?

Some people don't even gain weight while living this way. Mostly or even all nutritionless and high sugar/fat/sodium etc. diet, and usually not much exercise. How come you don't see a whole bunch of college students keeling over from heart attacks after living a year on ramen noodles and cheetos?

[Assistant] You say "nutritionless", but modern processed foods are *extremely* nutritious when compared to anything but a modern balanced diet. They have vitamins and minerals and stuff dumped into them; not perfectly, but enough so that it's hard to get any nutrient deficiency.


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

[User] When animals eat other animals whole, how does the predator not get sick from any feces in the prey animal?

[Assistant] Most animals actually eat their own feces regularly, it's called coprophagia. This is a mechanism by which they can repopulate their guts with microbes. So they would be pretty resilient from feces in another animal! Plus those animals (and reptiles like snakes) likely have very acidic digestive tracts or very potent enzymes to break all that foreign material down.


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

[User] [Marvel and DC] Superpowers often create a lot of problems for the person who gets them. In direct contrast to the dour "this is my curse" outlook, which comic characters are really happy and enthusiastic about their abilities and their applications?

[Assistant]
- Phil Urich had a lot of fun when he was being the fourth Green Goblin.

- She-Hulk loves being big and green. She's a lot more repressed when she's being Jennifer Walters.

- Johnny Storm sees no downsides in being the Human Torch. Nope.


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

[User] ELI5:Why do cop cars have the small hub on the wheel instead of the entire rim or hubcab?

[Assistant]
Because when you're buying a fleet of police cars, leaving the hubcaps off can:

* save you money on the overall cost of the cars
* save you money on maintenance (replacing hubcaps)
* make maintenance easier
* keep all the cars looking standard and professional (no missing or cracked hubcaps)


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

[User]
If Bruce Wayne was revealed as Batman, would stock prices and sales skyrocket or plummet for Wayne Enterprises

I can kind of see it going both ways, but I'm not sure.

[Assistant]
Probably a better question for a finance sub, but I'd guess the increase in uncertainty would be enough to spook investors.

What happened to Stark Industries share prices after Iron Man was unmasked?


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

[User] [40k] Has the Emperor of Man ever personally encountered the Chaos Gods, Eldar Gods, Gork & Mork, or other gods? What happened?

[Assistant]
He did personally encounter at least a Shard of the Void Dragon... And promptly whupped its ass and locked it in a cave on Mars.

We also know he's had some interaction with the Chaos Gods, as they assisted him in the creation of the Primarchs.


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

[User]
ELI5: Why does giving someone a transfusion of my blood to someone not give them my immunity?

I keep up with all my vaccines and even have Hep A and B covered due to working in a hospital. But I was curious as to the reason I could not pass on my immunity to another via a blood transfusion. Is it simply because the blood cells are incapable of passing on what they have learned to the new host body?

[Assistant]
The problem here is the white blood cells, or WBCs. They have a nasty tendancy to attack everything they don't recognize. When you get a transfusion, the blood is taken from the donor and put into the recipient's body - meaning they'll start going berserk and attacking everything in sight until subdued. Riot time! It doesn't really matter in small quantities, as the recipient's WBCs will quickly overpower the donor's WBCs. But in the case that you are giving a lot of blood or the recipient has a weak immune system (aka is *immunocompromised*), the donor's WBCs will wreck havoc for a while. Not good.

To prevent this, there are a few means for getting rid of the WBCs. You can use a filter / centrifuge to physically get rid of them, or you can irradiate the blood to kill the WBCs off. This is possible because only WBCs have nuclei (DNA) that can be damaged by the irradiation. Red blood cells (RBCs) and platelets (plts) do not, and so are unaffected. Since we are generally doing transfusion for the RBCs this works out pretty well.

And of course, no WBCs means no immunity, so nothing gets transferred in the end.


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

[User]
ELI5: The difference between employees (or officers maybe, I'm not sure what to call them) of a sheriff's office and police station.

I know... I'm an idiot, but after watching another movie that had both (fighting with each other of course), I realized I didn't fully understand the difference.

[Assistant]
A sheriff is in charge of law enforcement for a county (or parish), and has deputies to assist him.  They have jurisdiction over the entire county.  A sheriff is most typically directly elected to the position, and then 'deputizes' people to use his authority.

A police department, and its officers are typically created by a municipality and have jurisdiction over just that municipality.

Then there are typically state law enforcement agencies like state troopers or highway patrol.  They are statewide, but their jurisdiction is typically what makes them different.  Highway patrols typically only have jurisdiction over the state roadways, which state troopers have jurisdiction over the entire state.

Depending on the location, there can be a lot of overlap and thus rivalry between municipal police and sheriff's deputies, which is what the movies play upon.  When the movies portray one or the other as corrupt, they both have jurisdiction within the police department's municipality, so the 'good' agency and the 'corrupt' agency are both exercising their authority.


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

[User] If I fell through a thick enough cloud, would I get wet?

[Assistant] Yup. Imagine how damp you would get running a few miles in dense fog. Effectively it would be the same as vertically through a cloud (fog = a cloud touching the ground). And if the cloud has rain droplets suspended (larger than cloud water droplets but not large enough to fall), or even if it is raining, there would be more moisture. As far as how wet you would get is dependent upon the precipitable water value within the cloud depth that you fell through.


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

[User]
ELI5: What makes a password stronger than another?

How is a password that has uppercase and lowercase letters, numbers, and special characters more secure if every character is always a possibility?

[Assistant]
Because some types of attacks will do what's called a 'dictionary attack' and try dictionary words and thing based on them (apple, Apple, APPLE, etc).  If you have to brute force a password (meaning try every possible combination) then as you add numbers, case, and specials the number of possible combinations goes through the roof (keep in mind, on average you'd have to try 50% of the possible combinations to get it right).

Having those all be possible characters in a password increases the amount of possible passwords and hence makes it hard to guess.


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

[User] ELI5: How do creatures like eels produce electricity?

[Assistant]
Top answer is specific to eels but some people seem to still be curious how cells/life can produce electricity on a chemical level.

A cell is a self-contained membrane-bound environment, like a bubble. And what goes in and out of a cell is under strict control. So, a cell can have channels in its membrane that only allow positively charged sodium ions in. After a while, the cell will then have a higher concentration of positive ions relative to its surroundings and thus, it has achieved a positive voltage potential. The cell could then discharge this  potential (through a different kind of channel perhaps) and harness the stored energy it has developed in a number of different ways.

If youd like to see a really interesting example of using cellular electric potential to do physical work, look up "atp-synthase" on youtube. This is the protein that uses a built up electrical potential to turn a molecular motor which in turn synthesizes atp: an essential stored-energy chemical. Its really cool when you see a visualization of it. And those atp-synthase motors are in the mitochondria of most living creatures, including you!


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

[User]
Are "core memories" a real thing?

Hey guys! I was recently thinking about the movie Inside Out, and more specifically "core memories". If you don't know, in the movie core memories are basically super important memories that help define your sense of self. So if you really like basketball, your first game may be a "core memory". You also only have a very small handful of them (<10).

Now I'm not expecting a Pixar movie to have 100% accurate neurology, but are there any general concepts that are analogous to "core memories" in Inside Out? Are core memories, in any real sense, an actual thing?

[Assistant]
No, not a thing. As you describe them, these "core" memories would be part of autobiographical memory (memory about oneself). But there is no limited number of particularly special autobiographical memories that define people typically. A possible exception is a highly traumatic event.

Another slightly similar concept is a "flashbulb" memory, where people remember a particular event very clearly (although not always accurately). Classic examples would be the moon landings, Challenger disaster, or 9/11/2001. There are often not autobiographical though, but they might be highly emotional.


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

[User]
CMV: Both parties would make more progress towards their goals if a greater emphasis was placed on both states rights and states responsibilities instead of trying to accomplish everything at the federal level

We currently have an issue in our political system in which the "winner takes all" and both parties are always trying to take control at the federal level in order to advance their goals. I feel we would see a lot more progress towards the goal of both sides and more compromise if there was a greater emphasis on states rights and responsibilities. Instead of waiting on the federal government to implement, for example, universal healthcare, we could allow states to implement this at the state level if this is something their voter base desires. There could even be a network of states that work together to provide and fund universal healthcare, while the states that do not wish to participate can continue operating under the current insurance based model.

California has already begun moving towards this model (not necessarily universal healthcare, just implementing a statewide service that is provided at the federal level in other countries) with their paid family leave. There are efforts in Washington and California to implement a single payer healthcare system in the state.

I feel giving greater focus to the states having the power to implement these changes without the federal government or the whole country moving with them is an ideal way to allow the more liberal leaning states to begin working towards their goals while the more conservative states that do not wish to have so many government funded social programs, can opt out. It is much easier for a US citizen to move to a different state than it is to immigrate to a different country, so if a citizen was unhappy with the direction their state was headed in, they could more easily move to a state that better served their needs and interests.

Part of this change would be a mental shift in voters to place more emphasis on local elections and local legislation and taking advantage of the existing infrastructure that allows states to provide, for example, paid family leave if they so choose. Another part of this would be scaling down the federal government and reallocating more tax dollars to local and state level governments instead of the federal government. Not sure about other states, but my state taxes are currently significantly less than my federal taxes. I think the reason everyone wants the federal government to back their goals is that they feel their states don't have the necessary budget to accomplish their big goals. If we scaled down the federal government and propped up state governments, I think more people would be happy that they could see the changes they want to see at the state level.

[Assistant]
>It is much easier for a US citizen to move to a different state than it is to immigrate to a different country

Isn't this also one of the weaknesses of this strategy?  Like universal healthcare works for the people who need extra expensive medical treatment because the people who don't are paying more than they're getting out of it.

If healthy people can leave the state easily and unhealthy people can move to the state easily, the system ends up costing more and generating less revenue.


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

[User]
If I had a 1 dollar coin, could I theoretically flatten it to the point where the coin would cover the entire Earth?

Also would the atom need to subdivide? What would happen at that point?

Edit: looking at such a large discussion about coins and atoms stemmed off from one question that I had is the weirdest feeling ever.

[Assistant]
A dollar coin has a mass of about 8.1 grams. For simplicity assume it to be all made out of copper (it's really about 90% copper). Copper has an atomic density of 63.55 grams/per mole, giving us 7.68 x 10^22 atoms in a dollar coin. The earth has a surface area of 5.1 x 10^8 km^2, so that if the coin were smashed until it was just a one atom thick layer of material (to maximize how far we can spread it) covering the entire earth, then each atom would occupy an area of about 7000 square microns. If the atoms were arranged in a square lattice, each copper atom would be at least 80 microns away from the next nearest atom. For regular bulk copper, atoms are spaced about 0.4 nm apart. So, the atoms would be about 200,000 times too far away from each other to form stable chemical bonds. Simply put, you no longer have a solid chunk of metal if you want it to cover the earth. You have a very sparse copper gas.

If you subdivide the atoms, you don't have copper anymore. But subdividing won't really help anyways. If you manage to divide each copper atom into 29 hydrogen atoms (ignoring all the messy details of nuclear reactions), then the hydrogen atoms would still be 15 microns away from each other, still several thousands times too far apart to form bonds.


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

[User] eli5: Why is Flash Player a dying/dead program, is it just obsolete?

[Assistant]
Pretty much, yeah. When Flash came out, it got popular because there was nothing like it. But Flash is not very secure, even back then. Nowadays, there are simply more, better and safer alternatives, like HTML.

EDIT: It's worth noting that this isn't a sudden kill on Flash. Websites have been slowly fasing out of Flash after being dependent on it for so many years. Like how in 2016 (IIRC), Google no longer supported Flash Player as a default feature on Chrome.


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

[User] ELI5: What is that electrical shock feeling throughout your body when you get suddenly scared (like missing a step on the stairs)?

[Assistant]
Stimulation of the sympathetic nervous system, inhibition of the vagus nerve and, soon after that, adrenaline.

The initial spike is entirely nervous, being dominated by rapid firing of the fastest signals your body sends - adrenaline takes a few seconds before it surges.


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

[User] ELI5: Where did all of Earth's water come from?

[Assistant] Scientists don't really *know* for sure where all of our water came from, but it's exceedingly likely that our water came to us in the form of icy objects like comets.  Some of it probably came from the rocky material of the Earth itself as the planet cooled and condensed.  There probably wasn't just one source.


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

[User]
[MCU] If Star Lord were to try to lift Mjolnir after the events of GOTG1, where he jumped on the power stone to save the universe, would he have been deemed worthy?

Similar to how Steve jumped on a grenade to save some of the people around him. Now I'm not sure if Star Lord in the later films would be deemed worthy but after GOTG1 with that similar noble act to Captain America, would he be able to lift it?

[Assistant] No. Noble sacrifice alone isnt enough to make you worthy. Tony Stark carried a nuke through a wormhole and Mjolnir didnt consider him worthy. Quill is still super emotional and loves to commit minor crimes.


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

[User] [Star Wars] Are thermal detonators just what Star Wars calls grenades or are they a special thing different from normal grenades?

[Assistant]
in Legends, they used to be micro thermo nuclear explosions. (yeah..)

In the current cannon, they certainly fill the same role as grenades, but they clearly have an electronic component and explode perfectly evenly, which means they don't operate like a gunpowder grenade does. There are multiple kinds of throw able explosives in star wars so people call those specific ones "thermal detonators".

You could make a normal grenade in the star wars universe, and presumably it would just be called "a grenade"


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

[User]
Can an object travel so fast that the density of its kinetic energy collapses into a black hole?

If it can, what would that look like? Would it come to a stop from the perspective of an observer?

[Assistant] No. This does not happen. No matter how fast you get a single object going, there will always be a valid reference frame in which the object is at rest, and therefor does not have enough energy to form a black hole. It makes no sense to have an object be a black hole in one reference frame and not in other reference frame, so this contradiction shows that single objects don't turn into black holes no matter how much kinetic energy they have.


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

[User]
ELI5: How does basic health insurance work?

Can someone please elaborate on what a "deductible" and "premium" are as well?

[Assistant]
The basics of health insurance (or any form of insurance for that matter) is to create a large pool of people to spread risk around. You're not sick today, but you might get sick next month. You pay into a pool every month and only pull money out when you need it. The healthy pay for the sick with the assumption that they will get benefits when they themselves become sick.

The **premium** is the price you pay every month to be part of the pool. However, when you do need health care, most insurance plans don't cover 100% of the cost. Usually the first bit of the cost has to be paid by you and the remaining gets picked up by the insurance company. That initial amount is called the **deductible**.

For example, let's say you need a surgery and it costs $10,000. Your deductible is $500. You have to pay the doctor $500 out of your own pocket and the insurance company pays $9,500.


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

[User]
Why is an asteroid ring a ring and not a sphere?

Given that there's no "up or down" in space? I'm guessing the answer has something to do with the gravity of the asteroids themselves, but I just can't visualize how that would work. Can somebody help me out? I know nothing about this sort of thing.

[Assistant]
The answer is a process called accretion. Basically if you take a cloud of dust, for example, and allow all the particles inside that cloud to have some sort of motion and interaction with each other, they will form inelastic collisions such that, each time two particles collide, their trajectories become slightly closer to each other than they were to begin with. Over a great deal of time, all of these continuing averaging-out collisions means that all of the particles start moving the same direction (if you were to add up the directional vector and energy of all the particles in the dust cloud and then subtract them from each other, there would be some net rotational spin in some direction- this is the direction of the elliptical disk that forms over time).

Particles that clump together due to gravity once they're all rotating the same direction become stars and planets and asteroids. This is the reason that most of nature forms rings or rotational planes... The solar system is (mostly) flat, the rings of Jupiter and Saturn are flat, the moons of Jupiter rotate on the same plane around it just like the planets and asteroids do around the sun, and even galaxies sometimes form disc shapes (like the Milky Way).


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

[User] [Harry Potter] How many prisoners are there in Azkaban? What is the range of committed offenses? What other prisons are there in the Wizarding World?

[Assistant] There is no reference to the number of prisoners. Apparently, murder and torture are life sentences in Azkaban, attempted murder and assault with a few years' imprisonment. There is no information on other prisons.


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

[User]
Why is my computer speaker currently picking up a radio station?

I thought I was going crazy, but my wife confirms that 93.3 is coming out of my small crappy computer speakers. This happens whether or not the jack is plugged into my computer. If I turn up the volume the static increases but the volume of the radio transmission does not. Obviously if the speakers are turned off, no sound comes out.

[Assistant]
Wires (like headphone wires or speaker wires) are often long enough to fairly efficiently pick up stray signals like radio, acting like an antenna. This signal can then be fed into something that rectifies the signal (like a diode or an integrated circuit) and be fed into an amplifier (like powered speakers) and become audible.

Under the right circumstances, a powerful radio signal can even be picked up by people's metal fillings in their teeth.


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

[User] The strong nuclear force works only for very small distances. How is this energy harnessed to make huge nuclear explosions?

[Assistant] Nuclear explosions are many exothermic nuclear reactions happening at the same time. The reactions happen when the incoming particle get close enough for the residual strong force to act between them.


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

[User] [The Last of Us] what would happen if you used a flashbang grenade on a Clicker?

[Assistant] Clickers can't see, so the flash wouldn't bother them much.  But they have exquisite hearing.  The bang might cause considerable distress, and may even damage their hearing, at least temporarily.  A flashbang might be a useful tool for evading clickers in an emergency - although it may also attract every clicker within a mile, so there is a trade-off to be had.


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

[User] ELI5 : how did people in the past ensure that a building/structure will be structurally sound?

[Assistant] They basically knew from experience in what way to build buildings for them to be sturdy. To the modern eye, the surviving ancient buildings are massively over-engineered (which is likely one factor of why they are still standing). Like, today we would build the same kind of structure using much less of the same materials. As the saying goes, anyone can build a bridge that stands, but only an engineer can build a bridge that barely stands. In this sense, all modern buildings barely stand, that is, they are as sturdy as is required plus a safety margin, but no more than that.


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

[User]
[Star Wars] Did Humans originate from one single planet and start colonizing or are they from many different planets?

With Humans, you see Humans from Tattooine, Corelia, Courscant, Naboo, etc..... but with other races they only seem to be from one place, Gungans from Naboo, Twi'lek from Ryloth, etc... Are Humans actually from multiple places or did Humans just colonize the Galaxy over the years and other races didn't?

[Assistant]
Origins of humanity are largely lost to time.

Generally it's ASSUMED that they either name Coruscant as their homeworld, or come from somewhere nearby.

> Are Humans actually from multiple places or did Humans just colonize the Galaxy over the years and other races didn't?

If we go by old canon, humanity had sent several old-timey sleeper ships to colonize distant planets way WAY back before hyperdrive times, and that's why there are so many Core worlds that have ancient human civilizations, along with multicolored near-humans from more distant worlds, similarly seeded.

Plus there were also massive forced migration during times when Infinite Empire enslaved a whole bunch of species, including humans, and relocated them at their leisure. And then there was normal colonization too, when humies got their grubby hands on Hyperdrive.

Now, apocryphal info - there were plans to make novel Alien Exodus, which would've claimed that Star Wars humans are actually humans from Earth that had some space-time shenanigans on their starship. That is not canon, despite what Supernatural Encounters might try to tell you.


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

[User]
ELI5: Semicolon: How to?

I'd like to think I paid enough attention in English class to effectively punctuate, but I am lost as to how and when I would ever use a semicolon. Examples would be great.

[Assistant]
Use it to join two closely related thoughts; each half should be able to stand alone as a sentence, but the sum is clearer when they are not fully separated.

You can also use semicolons to separate a list in which individual items contain commas. I've traveled to Bangor, Maine; Paris, Texas; and Memphis, Tennessee.


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

[User]
[General Supernatural] How far up and down does salt project it's warding power?

It's often seen in movies and stories that a line of salt in a threshold is able to stave off the attacks of supernatural beings, most commonly ghosts and vampires. My question us why don't these creatures, both of which can fly, simply fly up over the line?  Or why don't ghosts phase beneath it?  Does the salt project an infinite barrier above and below it?

[Assistant] As with most things supernatural, it depends on the intent. Salt across a doorway or window creates a barrier for that doorway or window. If there's another entrance, the creature could enter through that. If the salt forms a circle around an open area, it projects a dome (possibly a sphere going underground) of protection that intersects the ground at the salt. If the ring is smaller than human height, say just a couple feet wide around a person, or is inside a building, it would go from floor to ceiling or an equivalent height to protect whatever it encircles.


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

[User] How does a person get caught pirating music/movies?

[Assistant]
There are probably other tactics, but here's the one you hear about the most (because it's the slimiest and probably also most common):

So you download something illegally from bittorrent.  Anyone else who is downloading from that torrent can see a list of IP addresses (think mailing address, but on the internet) that are also downloading and uploading the torrent.

What the lawyers of copyright holders do is connect to torrents and see who is uploading and how much they're uploading: the more they upload the easier it is to prosecute.  They write down all of the IP addresses, make a big list of them, and sue them all as John Does.  They tell the judge "These people are stealing our content" and the judge writes a court order to the internet service provider saying that the ISP has to identify the subscriber who was using that IP address at the given time.

Now that the lawyers have a list of people, they update their lawsuits with the real names of the people and send them letters saying they can fight or settle.  A lot of people settle, so the lawyers make a major profit doing this.  It's basically some law firms' entire business model.


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

[User] When batteries are made are they already charged ?

[Assistant]
It depends on the chemistry. Lead acid batteries need to be initially formatted at the factory to determine which terminal is positive because both plates are lead sulfate. Nickle based cells are also formatted at the factory.

Many other cells are manufactured with a charge.


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

[User] ELI5: Why do kids vomit more often than adults?

[Assistant]
Baby 'vomit' is actually called positing and is to do with undeveloped and hypotonic muscle control, the stomach sphincters aren't as well controlled and there is also gas trapping which when released suddenly will bring food up with it. This is the classic immediate milk vomit after food.

Childhood vomiting occurs for all manner of reasons. Underdeveloped immune systems, greater exposure to pathogens (poor hand hygiene, eating things off floor, lots of contact with other grubby children), lower pain thresholds (they haven't experienced pain before), more cytokine release (immune response to infections that then stimulates vomiting, so things like ear infections can make them puke), less cerebral inhibition (they aren't inclined to fight the feeling), and underdeveloped language skills (can't express what/where the feeling is and thus doesn't get painkillers and soothing agents in time).


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

[User]
[Marvel] If Doctor Strange dies, who'd have claim on his soul?

So in Marvel the afterlife seems to be pretty simple; you go to the afterlife of whatever god you believe in. Sure there might be extra entry requirements, like dying in battle, but you wouldn't see a Christian in Vallhalla unless he was significantly connected to the Norse Gods in some way.

... But Doctor Strange knows about all of them. He's aware of countless pantheons and afterlives, extradimensional entities, eldritch horrors, cosmic entities and so on. It wouldn't surprise me if he's sold his soul to half of them already

So what would happen when Strange dies? I can't remember him being a particularly religious man, but he's certainly *aware* of all the mystical shit that exists out there. Do the Vishanti have an afterlife perhaps? Does every god battle over who gets to keep him?

[Assistant]
'Knows about' and 'believes in' are two different things.  All the Avengers know that Mephisto exists, but that doesn't make their souls his property.  Or Thor's, for that matter.  It's not about what religions you know of, but about what religion you *commit* to.

Strange, for his part, has the magical power and knowledge to basically choose his own afterlife.  If he wants to go to Valhalla and hang with Thor, or lurk around Tibet advising the next hundred Sorcerer Supremes, he can and will make it happen.  The only problem would be if he *did* sell his soul (and can't weasel out of it), or if whoever kills him is powerful enough to destroy or bind his soul in the process.  Both of those are known side effects of Sorcerer Supreming.


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

[User] If you pushed a balloon far enough underwater would the air inside compress to a density where the bouyant forces neutralise?

[Assistant]
Water is about 1000x the density of air, so you would need to compress air by a factor of about 1000 to make it denser than water. Water is basically incompressible - it's only a few percent denser in the Mariana Trench than on the sea surface - so you don't need to worry about water getting much denser.

Assuming an ideal gas, double the pressure means doubling the density. You get one atmosphere of pressure for every 10m of water depth, so you'd need to go down about 10km to make air denser than water. This is about the depth of the the Mariana Trench, so if air was an ideal gas this would indeed be possible, in the very deepest part of the ocean.

However, this is an *extremely* high pressure, and what really happens is that, well before this depth, the air turns into a *supercritical fluid*, which means that pressure doesn't follow the simple ideal gas law anymore. The balloon itself won't be behaving like rubber does at sea level either. You can't really make air denser than water, without changing it into something very different to normal gas-phase air.


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

[User]
What makes Venus is the most shiniest planet of the solar system?

Is it the chemical composition of Venus atmosphere or its weather phenomena what generates the shiny optics phenomena? What is the physics process of this phenomenon?

[Assistant]
I am going to assume you mean brightest rather than most reflective (but it is both)?

The brightness of a planet is determined by a few factors, and one of them is that is the most reflective (shiniest). Astronomers measure reflectivity with something called albedo, the ratio of reflected to incident light. Venus has an albedo (0.75) that is more than double the next most reflective planet - the outer planets are all around 0.3 and Mars and Mercury are around 0.15. Venus' high albedo is due to the clouds being light coloured as opposed to dark rocky surfaces of Mercury and Mars or the darker clouds of the outer planets.

The distance between Venus and the Sun is also important, the closer a planet is to the Sun the more incident radiation there is so there is obviously also more reflected radiation. Venus is almost as close to the Sun as Mercury. This follows what we call an inverse square law, a planet 3 times further away will have 9 times less incident radiation, the outer planets therefore have very low incident radiation compared to the inner planets.

The next major factor is the distance between the Earth and Venus, while Mercury is on average the closest planet to Earth, when Venus is on our side of the Sun it has the closest approach to the Earth, this will coincide with the times where Venus is exceptionally bright in the sky.  This is also an inverse square law, so if a planet is 3 times further away from us, it will be 9 times less bright.

The last factor is the size of the planet, a planet that has three times the radius will have 9 times the reflective area. The outer planets are much much larger than Venus so despite being much much further from the Sun, much much further from the Earth, and having lower albedos we can still see Saturn and Jupiter brightly throughout much of the year. Venus' relatively small size is more than made up with though by its distance to us (but only for some of its orbit, it is quite faint on the far side really).

So basically a confluence of the distance to the Sun, its size and its reflectivity and, most importantly, its distance to us all make it appear bright to us.


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

[User] ELI5: How can someone have 0% Irish in their DNA ancestry results if their biological mother shows 30% Irish ancestry?

[Assistant] Maybe think of it this way, as an analogy, not as science:  if you mother had a total of 100 genes, she would have 30 Irish and 70 non Irish.  She gives you 50. So all 50 could be non Irish. Or perhaps you were switched at birth.


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

[User] [LOTR] How good of a Leader was Denethor, before the crazy?

[Assistant]
He is described as thus:

"Denethor II was a proud man, tall, valiant, and more kingly than any man that had appeared in Gondor for man lives of men; and he was wise also, and far-signed, and learned in lore. .. \[H\]e proved a masterful lord, holding the rule of all things in his own hand."


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

[User]
Why can I see the wheel spokes on a car as it goes by if I'm not looking directly at it, but if I try to follow the wheels with my eyest hey are all blurred together ? Does the the brain only sample vision outside the center periodically so I get a strobe type affect?

Waiting at a stoplight and seeing the cars go by, if I just look at the intersection I can tell that the wheels of cars going by have spokes.  But if I look at a car's wheels themselves and follow them as they go by, the spokes are just a blur.  Does the the brain only sample vision outside the center periodically, so I get a strobe type affect?

[Assistant] The retina cells that register light and dark are more populous around your peripheral, and the retina cells that observe color are more populous toward the center.  The cells that see light vs dark are faster at processing changes than those that do color, so they can see rapid changes better than the color cells.


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

[User]
ELI5 Why isn't more antibiotics injected rather than oral?

Won't antibiotics do less harm to our beneficial gut bacteria if it is injected directly into the body rather than go through our digestive tract?

[Assistant] Not really, because if you inject something it goes into your blood, and  blood goes everywhere. But giving antibiotics orally is very much less invasive than IV. if treatments are not invasive, then patients are more likely to take them.


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

[User] ELI5: Why do models scowl while on the stage ?

[Assistant]
I remember reading somewhere a long time ago that it's supposed to be neutral expression, so as to ensure the models don't accidentally make funny faces and take the attention away from the clothes they are modelling.

I guess some of them looked like they're scowling because they're biting their cheeks to stop them from making any sort of expression?


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

[User]
[Archer] Questions about Sterling and Mallory

Going by the first episode, show made it seem like Archer and Mallory had a close relationship (Archer answering Mallory's calls whenever he was with Lana) but many episodes after made it seem like otherwise. Emotionally and physically tortured by the woman  and all. Am I missing something?

[Assistant] Sterling has some serious issues surrounding his mother and Mallory isn't any better.  They're not exactly close but they're not exactly distant either. Mallory is in intense denial about her atrocious parenting and Sterling is unable to get past the fact that deep down he wants a close maternal relationship.  In a strange way, they kind of need each other.


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

[User]
CMV: People who denounce the poor for owning "Luxuries", Just want the poor to know their place.

Luxuries to these people almost always include: Smartphones, computers, nice sneakers, jewelry. Anything that might stand out on a person as being a bit expensive. Many people, unfortunately on the conservative and neo-conservative and libertarian sides, claim that these people own these things because they are poor spenders and it is a good example of why the poor stay poor in this country.

I believe it is just the individual using whatever little resources they can to blend into society. To fool it into thinking that they are of nominal wealth, so they aren't bothered about it. So they can interact and find opportunity like any other normal-looking member of society with a smartphone and decent clothing.

Even worse, the political pundits, who make these claims are often of above-average wealth and upbringing, often with two parents supporting them in a stable home. Ben Shapiro and the Roving Millenial come to mind. Both born into affluent families. That makes me take on this view that the outrage about this is disingenious. I rarely see someone who came out of poverty taking on this view, if ever.

The Roving Millenial, who has a CRTV show now, has even gone as far to say that you do not need a refrigerator to survive, that is it a luxury. What is next? Your shoes don't have to be made of that expensive rubber, wear wood shoes? If you want these poor people to contribute and find work, why do you tell them they don't need computers and smartphones? They're affordable nowadays, but the accusers of these people always claim they have the "New" iPhone, or that they scramble to buy the newest products. They don't.

Change my view on this, do you/they geniunely care about their spending habits and the long-term effects on the country, or do you/they pick on them because you feel like they appear stupid complaining about being poor while possessing these items? Are the poor in a bad financial situation they're making the best of, or do you believe they have a "place" to inhabit and should abandon all luxuries until they are out of that situation?

[Assistant] I'd hardly call a smart phone or a computer a luxury. They're pretty much required in order to function in society these days. You need one or both for everything from applying for jobs and renewing licenses to booking flights and ordering goods online.


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

[User]
[WH40K]What would have happened to mankind if the age of strife never took place?

Feeling waves in the warp the emperor foresees the fall of the eldar and the resulting chaos. He takes control and unifies mankind under His rule.
Psykers are prosecuted wherever they are found and all focus is put on alternative FTL technologies independent of the situation in the warp. The intelligence of the men of iron is restricted so they could never develop the thought of rebellion.
When the warpstorms are beginning to set in mankind is thoroughly prepared and can continue their conquest of the galaxy unhindered under the rule of its glorious emperor.
Timeskip to M42. How is the current situation of the empire?

[Assistant]
Likely the Space Marines would not have been created, though demi-god's they were created for the "Only War" situation of the crusade, even in original it was likely Empy planned for them to all die during the crusade or sent on suicide missions. They had no place in his ideal imperium.

With alt warp travel id imagine the human empire being smaller and more concentrated, focusing on Terraforming everything they encounter. Also lots of extensive human modification, biological and mechanical. Quality of life for an avg human would be much much higher. Plasma tech is mastered everything is kept at or above archaeotech level. This all presumes his plan succeeds now though, more likely it spirals out in another way and we see a larger mechanicum cult emerging and committing their own Horus Heresy.

Chaos would look for an alternative vassal, maybe a young Tau race pre-civilization and ethereals. More likely another unknown lesser race that after 10k yrs Chaos manipulation would have some threat. During the Horus Heresy many aliens were encountered that worshiped Chaos, a united xeno-chaos empire would be likely without early intervention.

Tyranids since they are coming outside of galaxy will likely arrive exactly as before, human resistance would be strong but their smaller empire makes them vulnerable to a swarm. Probably a stalemate just like in original. Maybe Tyranids would arrive later, some say the Tyranids are attracted to the psychic imprint of mortals and its associated biomass.

Orks will zuggin and zoggin as usual but in a larger playing area. No real persecution to stomp out rampant growth but also no incentive for a WAAAAGGGHHHH!!!!!!


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

[User]
ELI5:Can someone explain washing machine cycles?

Can someone explain the differences on my washing machine cycles?  I know it seems silly to ask but I've been doing the wash since I was 15 and never really questioned what everything on the dial meant.

Specifically what does the machine do differently in the "permanent press cycle" versus Cotton?  What happens in wool? or silk?

why have a delicate cycle when you have hand wash?

Why have a dark cycle when I can just click the water temp to "cold"?

Such cycles like sports gear (cold and long), hand wash (cold, gentle) make perfect sense but how do the others differ?  Is there any material benefit?

[Assistant]
Different fabrics tolerate different levels of physical stress and water temperature. If you wash something delicate on a very vigorous or hot cycle, it's more likely to come out wrinkled or with weakened seams. If something is very bulky, a fast spin cycle will probably lead to an unbalanced load. If something is very dirty, it needs harsher treatment than something that just has a little body odor. IIRC, a permanent press cycle is gentler and shorter than a cotton cycle, and it's designed to reduce wrinkling.

Part of it is also that people will choose to purchase a machine that has more options, even if those options don't have a significant performance difference. Similar to how a bike with 18 speeds will sell better than one with only three, even though you probably only need three.

Most of your laundry can be done in cold water. Always use a cold rinse cycle; warm or hot is completely useless (your clothes should already be clean by that point) and just wears out your clothes faster.


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

[User]
If Santa Claus was real, would he cause any significant inflation?

A few assumptions:

1. The gifts are made by elves who are paid nothing.

2. The materials for the gifts are magically created, not purchased from a supplier.

3. Every child in the world 0-16 gets $400 in gifts. I know that's totally unrealistic but so is Santa.

4. The gifts cannot be returned or sold.

5. All of the gifts are delivered on December 24th.

6. The economy is "average".

7. The real toy manufacturers don't get any royalties or anything, and demand for them does go down as the supply is flooded.

That would roughly be 1.925 billion people, a total of $770,000,000,000 worldwide being created in a very short period of time. The biggest hit would probably be on the companies who Santa is screwing over, right?

And some follow-up questions:

1. Would its predictability lessen any potential impact?

2. If the gifts *could* be returned for cash value, would the (greedy) kids be creating even more money?

[Assistant] I think given the assumptions you propose santa-clause would actually cause deflation. Since the toy market would be injected with competition that is able to offer their product for free, it would likely cause a lot of downward pressure on prices overall, kind of like a technological shift in the market, where there is a significant increase in market entrents, causing the prices to go down, but this is an odd case because it's only one entrent causing the huge market shift.


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

[User]
Why doesn't an ant die when I flick it with my finger?

Flick an ant, or pretty much any other bug for that matter, and it will scurry away virtually unharmed.

Is there any reasoning behind why it doesn't get blown to smithereens?

[Assistant] Ants in particular are very durable because their exoskeleton is made of an extremely tough naturally occurring substance called chitin (also found in the exoskeletons of crabs and in the beaks of cephalopods).  In addition, ants get their incredible strength from a highly dense muscular structure that also serves to pad their internal organs.


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

[User]
ELi5: How is the Metaverse different from Second Life?

As the title says. How is it different from Second Life, or god forbid, PlayStation Home?

[Assistant]
The difference, if we're talking about what Meta and other big companies are trying to build, is monetization.

They aren't trying to build a game for gamers. They're trying to build a game for people who use Facebook and normally wouldn't call themselves gamers. So you're hearing a lot about it because they're paying news organizations to run the story, "You Could Get Married in the Metaverse and Love It" instead of, "Look at These Dorks Who Got Married in Second Life, Mock Them".

They need this because their hope is they can sell (via NFT or otherwise) licensed digital goods like virtual Louis Vuitton purses or Burberry scarves to people. People already pay hundreds of dollars and wait for hours to try and get a pair of Nike shoes online. These companies hope to regularly distribute limited edition gear and abuse both FOMO and social pressure to get people to continuously buy things that don't really exist.

It's not that Second Life isn't out to make money, but it's not out to make money *on this scale*. The point of Second Life is to fool around and have fun in a virtual world. The point of this Metaverse is to monetize every portion of your social life and recruit you as a sales rep to your friends in return for small amounts of digital currency. In Second Life you can be a lizard man skateboarding with Cloud Strife. The new Metaverse hopes you'll want to pay a $50 cover charge for access to the Liberty Mutual Limu Lounge to watch The Big Game with your buds but before dropping in spending some more money to redo your wardrobe with new time-limited 2022 Big Game content.

Ideally, they also hope to move people's work meetings into the metaverse so they can ~~spy on~~ deliver targeted marketing even while you're at your job.


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

[User]
Eli5: How do we sometimes feel tired when we havent moved or exhausted ourselves physically?

Like sitting all day at the computer doing a project or during a flight sometimes when you land you feel super tired??

[Assistant] Fatigue does not only occur due to physical exhaustion. It can come from vitamin deficiencies, dehydration, stress, or mental illnesses like depression. In case of deficiencies, your body does not have all it needs to function with vitality. If you are dehydrated, you get headaches and lower blood pressure because your body does not have enough water to make you feel vital, just enough to keep the basic stuff running, like your lungs and heart. Stress already releases hormones into your body that keep you jittery and wear you out... we should not be on constant alert to fight or flee when our greatest danger at some moment is being worried about a work meeting.


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

[User]
[Punch-Out!!] how does soda poppinsky get drunk off of soda?

so i know that the soda is meant to be a stand-in for alcohol but in-universe, its just soda. and yet poppinsky seems to have all the "symptoms" of being drunk despite only drinking soda, not alcohol.

[Assistant]
Its actually a tragic story - Poppinsky as a type 2 diabetic.  The sugar spike he gets from drinking soda causes blurry vision, disorientation, and worse, makes him even thirstier, leading to drinking *more* soda.

Yeah, little Mac is using a mans disability against him.  Pretty sad.


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

[User] ELI5: Why did the space shuttle rotate right after launch?

[Assistant] It needs to fall into an orbit in a very specific direction (not necessarily the way they were originally going) and the sooner they make the turn, the less fuel they have to use and the more the air can help turn the shuttle.


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

[User]
[W40K]If ships in the warp use gellar fields to keep out demons... then why aren't gellar field generators used when fighting demons on planets?

Need to destroy a demon ritusl summoning site to stop the mass demonic incursion? Move a mobile mobile gellar field generator in, knock the demons out of existence or squash them in place and suddenly you don't have to fight very hard to get to the place you need to go to stop the invasion.

They probably would have been a big help on Cadia?  Whatever the cost involved, and I'm sure they would be big and expensive, surely you would want to have a bunch on hand on a literal fortress planet protecting the entire galaxy.

[Assistant]
A gellar field isn't really a forcefield that blocks daemons, it blocks the warp itself. In technical terms a gellar field "emits a wave that creates a bubble of realspace in the warp".

This means a gellar field will only really work in the warp, since creating a bubble of real space in real space won't do anything.

Another potential problem is that a gellar field might need a warp drive to work, and if that's the case you really don't want to be bringing a warp drive down to a warzone on a planet, because if that warp drive gets compromised then you've got a giant warp portal right there in the middle of everything.


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

[User] Does dust contain DNA?

[Assistant]
Assuming the dust is organic in nature (i.e. dead skin cells from a once living organism), then it contains DNA. Whether or not you would be able to extract information from that DNA is variable, depending on how degraded/decomposed the sample is. DNA slowly breaks down over time after death.

Dust that is comprised of microscopic rocks/particles, other non-organic material, obviously, does not contain DNA.


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

[User]
CMV: The US should focus on its own problems and stay out of other countries internal affairs.

There is no legitimate reason I can think of, especially at this point in time, for US leaders to be meddling around in the internal affairs of other countries. With all that is happening within the US, the current priorities of US leaders seems far away from where they should be. Most, if not all, focus should be on mitigating the disastrous effects of climate change, mobilizing against the pandemic, preparing for an inevitable eviction and financial crisis etc.

Instead of dealing with issues at home, US leaders and media have decided its more important to interfere with the affairs of countries like Cuba, China, and others. Instead of using American tax dollars to aid American citizens, theyre going to bomb other countries. Instead of dealing with crumbling infrastructure, rampant poverty, and other crises prevalent in American communities, US leaders are ignore and neglect the needs of the American people in their own country in favor of expensive, imperialist foreign policy.

The constant meddling of US leaders in other countries seems to always takes priority over the needs and concerns of every day, working class American people, families, and communities. And while they love to hide their exploits behind notions of protecting our national security or fighting for democracy and human rights its much more about protecting the political and economic interests of the wealthy and powerful. It very rarely ever actually is about helping anyone.

Additionally, the problems of other countries should not be American problems. And more often than not, the US is in some way responsible for most of the worlds problems that US leaders claim they want to solve. Nearly every action the US has ever taken abroad has been detrimental to both Americans and the people of the countries destabilized by US involvement in some way. So if our leaders refuse to address the crises already afflicting Americans, they should cease meddling in the internal affairs of other countries altogether.

[Assistant]
One word Economy. The reason we care so much is because our economy dependent on other nations. The amount of international clout we have is directly responsible for the incredible wealth in this country. If we decided to become global hermits we would lose a lot of trade partners. They would join other spheres of influence which could over time even prove to be an existential threat.

People have forgotten how violent our history is. Humans are still humans. We still need to keep our foot on our enemies necks. Forgetting to do that would be very costly.


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

[User] If I was to gather firewood from an area that contained high levels of radiation, would there be a higher rate of harmful radioactive decay when I burned it, in say a bonfire?

[Assistant] Chemical processes do not affect the rate of radioactive decay. Of course, if you burn radioactive wood the smoke will be radioactive, so if you inhaled it you would have greater radiation exposure. No change in the fundamental decay processes though.


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

[User]
If you introduced a near-vacuum at, say, -20C, what would happen to an ice cube?

I know boiling points are dependent on pressure (if you put water in a vacuum bell at room temperature, you can induce boiling without changing temperature), but I'm not sure what happens to solids / melting points.

[Assistant]
Ice will sublime - go from solid phase to gaseous phase.

This is, in fact, how a lyophilizer - or freeze-dryer - works. You first freeze your sample solution until it is frozen solid. You then put it in a lyophilizer, which utilizes a very strong vacuum to keep the headspace pressure low. Your sample will then begin to sublime - and since sublimation, like boiling, is endothermic, this process keeps your sample cool. This will continue (for several hours, for a small sample) until no more water is left in your sample, and all you get is a solid powder of whatever was dissolved in the solution is left.

You may also have seen this in freeze-dried instant coffee.


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

[User] ELI5: Do people actually smoke in movies, or is it some kind of trick?

[Assistant] There are harmless blends of herbs that give off the correct look when smoked but actors who smoke in real life typically opt to smoke cigarettes. Helena Bonham Carter said her favorite movie to shoot for was Fight Club because it gave her an excuse to smoke around three packs a day.


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

[User]
Does Large Hadron Collider need re-calibration after redefinition of SI units?

How are measurements in different detectors over at LHC connected to the current values of speed of light, kilogram, etc? Would redefinition of SI units need updates in other kinds of measuring devices in science laboratories across the world?

[Assistant]
No.  The new unit is defined to be mathematically identical to the old one, and all measurement devices on the planet are still as correct today as they were last week.

We've just gone from having a very accurate experiment whose results depend on the size of the kilogram to having the kilogram depend on the results of that very accurate experiment.  Since that experiment is more reliable and repeatable than putting the old platinum cylinder kilogram on a scale, it's an improvement for the future, but it doesn't make any practical difference today.


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

[User] [Magic] In a world where magic exists, at one point does tech become more powerful than magic? At what point does tech solve more problems than magic?

[Assistant]
Technology typically has one major advantage over magic, and that is simply ease of use.

It can take a good wizard months to master the proper incantations for a proper scrying spell. It takes five minutes to train Joe to use the CCTV.

As technology advances, the uses of magic will never disappear. They will simply become more and more relegated to tasks which technology cannot properly handle. It will certainly become more specialized, more niche. But it will never go away fully.

That is of course assuming that Magitech is never properly developed and the two merge into a wondrous new field.


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

[User]
[Star Wars] Why did the Kaminoans settle on Jango Fett as a clone-donor? Could have just gotten a Wookiee and made an army of superstrong Wookiee clones

And if Dooku/Sidious/Sifo-Dyas/whoever specially requested that Jango be used... same question.

I guess it could be like Jango Fett was full of righteous anger because of how the Republic treated his people, but... like... that's not genetic. You can't clone that.

[Assistant]
A few reasons spring to mind.

First, Darth Sidious was nothing if not practical; he got as much use out of his tools as he possibly could.  If his grand plan was successful, he knew he could fill the ranks of his army with conscripts instead of clones once the New Order was formed; it would provide far more bodies at a fraction of the cost, using existing infrastructure and equipment pre-built for the most common species in the galaxy.  Long-term, a human template was the best choice.

Whats more, this army had to be trained.  Not to fight and kill other armies.  Not to fight and kill droids.  This army had to fight and kill Jedi Knights.  Unless he wanted to imbue his new legions with the Force (which had never, ever gone well) and out himself as a Sith Lord, Darth Sidious needed to find someone that could train these soldiers for that exact purpose.

In Jango Fett, the Sith had a perfect candidate.  He was human.  He was a member of the fiercest society of warriors the galaxy had ever known.  If legends surrounding him are to be believed, he slew scores of Jedi (at least one with his bare hands), and proved his worth to the Sith by doing so one more time, fighting through a horde of cultists and one of his own Mandalorian brethren to do so.

When the end goal is to kill the Jedi, the strength of Wookiees, the cunning of Devaronians, or the senses of Trandoshans wont help you.

Skill will.


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

[User]
[Rick & Morty] Upon replacing them, why did they go through the grim toil of burying their recently-deceased alternate selves, when Rick has a freakn' portal gun?

Seriously, with just a point and click that dead meat would've immediately slipped into a lawnmower reality or a fire world or any of a thousand other ways that would have conveniently destroyed all evidence of the demised. Instead he grabs some shovels and drags the bodies into the yard to spend a couple hours pitching dirt just to leave evidence of the expiration right next to his home. Rick clearly has no sentimentality when it comes to his parallel versions, so it doesn't seem like he did it for the sake of ceremony. Was there something about the bodies he wanted to keep around? Was the burial really an act of conditioning to desensitize Morty to the realities of trans-reality adventure?

[Assistant]
The effect on Morty might have been part of it - either to desensitize him, or just to punish him since the Cronenberg-ing was partly his fault.

Another possibility is he wanted to keep the bodies close because they were useful. They could be used as an emergency source of Rick and Morty DNA, or to fake their deaths. Summer gets dead Rick's portal gun from the grave later on - there's no way Rick left it there by accident. He kept it because he might need it later, just like the bodies.


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

[User]
ELI5: What exactly is an "infected website"? Can my computer really get a virus for visiting a website?

Never made much sense to me. Shouldn't I actually download & install something to truly get a virus? How would just visiting a website do my computer any harm?

[Assistant]
In a perfect world every bit of software would work perfect and getting a virus from a website would be impossible.

In the real world perfect security is the thing that is impossible and there is often exploits where something can gain the ability to download things against your will. Some bug in flash or java or whatever that allows a malicious program to get beyond it's intended bounds and alter things on your local system. More rarely but at times even things as simple as jpgs have been able to carry data that overflows some memory and gets code into some other process in your system.

Any time a flaw like this is discovered it is closed quickly. But there will always be new flaws. There will never be a time when everything is fixed forever and viruses are impossible.


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

[User]
ELI5: What does it mean that correlation does not imply causation?

I've read an example of it that left me just as confused as before. It went like this:

*If you say "Everyone who drank water in 1800 is now dead, so drinking water kills you", that's correlation without causation, because their deaths was not caused by drinking water.*

Only, their deaths weren't correlated with drinking water either, simply because humans don't last 200+ years. So, what am I missing?

[Assistant]
>Only, their deaths weren't correlated with drinking water either

They are. They are correlated because both statements about these people are true: they drank water and they did die. That's the point. The correlation doesn't mean they died *because* they drank water. As you say, they died because people don't live 200+ years. The correlation does not imply causation.

Many thing correlate while having zero impact on each other; they merely coincide.

Actual correlations:

Ice cream sales and murder.

M. Night Shyamalan box office and newspaper sales.

Use of Internet Explorer and the murder rate.

Mexican lemon imports and highway deaths.

None of these things is a direct causal relationship; they merely correlate.


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

[User]
[WH40k] Is it possible to change the chaos gods?

If humans galaxywide had a large shift in their emotions, would the chaos gods follow? If everyone took a drug that made it impossible to feel rage or hatred, would Khorne be just about honor and martial prowess then? If everyone just felt love and no sadness or fear of death, would nurgle just be about love then?

If everyone took a drug that removed feelings, Equilibirum style, would the chaos gods fade then? Would it happen quickly, or are they powerful enough to hand around for a while, just starving? I know the emperors plan was to starv the chaos gods, i just dont know how he was going to do that?

[Assistant]
Technically yes. There's actually innumerable chaos gods representing all facets of the psyche.

The big four are really just that. The biggest four chaos gods in the warp and that's mostly because they're based on such universal emotional forces.


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

[User] ELI5: If your body's cells' lives are finite and eventually replace themselves, why does scar tissue remain? Are the cells that replace the area damaged as well or forever a different type of cell?

[Assistant]
Say you have a heart attack. You heart muscle cells all die because they aren't getting enough oxygen. Heart cells can only get bigger or smaller, they can't replicate themselves. So a bunch of cells called fibroblasts show up and secrete a bunch of collagen. Collagen is a structural protein. It doesn't contract like heart muscle cells, but it adds strength to the walls and keeps the heart from bursting.

If you have a very shallow and small cut on your skin, it will recover no problem. If you have a big one, you cut out all the cells that make new skin cells. So fibroblasts lay down collagen instead. The cells still replicate and change, but now there are healthy fibroblasts instead of skin cells. You'll forever have scar tissue there.

Imagine the guards at Buckingham palace. Say they all line up shoulder to shoulder. Then a bunch in the middle die. Some new guy might show up, but instead of just standing there, instead he brings a gate to stick between the two remaining guards. The gate is strong, but it isn't alive like the guards were.


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

[User]
[general videogames] I'm a mild mannered guy, but in the last week I've killed hundreds of people and almost died several times. What sort of long term mental repercussions will this have?

Outside of the range I had never fired a gun and outside of the schoolyard I had never been in a fight.

Then all of a sudden a major life changing event happened and I've killed a lot of people.

It's all justified, they shot at me first, but even then I can't imagine this being very good for my mental health. Am I going to get PTSD?

What about my friends? The ones that lived at least (RIP Jerry) will they look at me the same way after knowing what I've done?

[Assistant]
Each kill, no matter how justified, chips a little bit more away from you. You'll get out of bed a little more slowly in the morning, and resist sleeping - resist dreaming - a little longer each night. Everything you'll do from this moment on will be viewed in the context of you, the killer. You don't just go grocery shopping, you're a killer buying cereal. You don't visit with friends, you're a killer hoping to feel human again. Without work and therapy to build new context, you risk accepting that this is who you are now. You risk traveling down that road and making choices you'd never have made before, until one day you find yourself shooting first at a poor normal guy who is in over his head. And you won't hesitate; you'll probably think you're in the right. Hell, you might even enjoy it.

Either you die a hero PC, or you live long enough to watch yourself become someone else's end boss.


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

[User]
A (probably ridiculous) question about bees posed by my six year old

I was reading The Magic School Bus book about bees tonight to 6 yr old, and got to a bit that showed when 'girl' bee-larvae get fed Royal Jelly, they become Queens, otherwise they simply become workers.

6 yr old the asked if boy bees are fed Royal Jelly, do they become Kings?

I explained that it there was no such thing as a King bee, and it probably never happened that a 'boy' bee was fed Royal Jelly, but he insisted I 'ask the internet people', so here I am.

Has anyone ever tested feeding a 'boy' larval bee Royal Jelly? If so what was the result?

[Assistant]
In honeybees, the males are haploid and have only 16 chromosomes. Their genome is entirely derived from the queen. Drones produce sperm cells that contain their entire genome, so the sperm are all genetically identical (except for mutations). The genetic makeup of the female bees is half from the mother and half from the father (male bee). Most female bees are worker bees, the ones that are to become queens are specially selected by the workers to become a Queen.

While the Magic School Bus has simplified things for ease, in actuality all larvae in the colony are fed royal jelly, regardless of sex or caste. However, those chosen to become Queens are fed copious amounts of royal jelly which triggers the development of queen morphology, including the fully developed ovaries needed to lay eggs (mostly by changing the DNA methylation patterns in the future queens).

So, to get back to the question, if a male larvae was fed the royal jelly "by accident" -- not much would happen as it wouldn't make the male diploid.  Now it may cause some methylation changes, which could interfere with behavioral responses of the male, but in general it wouldn't make him a king.


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

[User]
How do our eyes see the stars much better than a camera?

Many cameras have much larger sensors our retinas, and larger apertures than our pupils. Still, they need long exposures to capture the stars. The frame rate of the human eye is often said to be in the hundreds. So why can my eye see the stars with a 1/300 second exposure when cameras require 6 or 7 seconds before the same number of stars are visible in the image?

[Assistant]
They dont, if you could remove an eye and plug it into a printer, open the shutter for a tiny fraction of a second the picture you would get would be more or less jack.

Now take a camera, have the shutter open and close about once a second for minutes, have a powerful computer that stabilises the image, adjusts light sensitivity, and plugs in gaps by recreating complete parts out of imagination/expectation and you would probably get a much better image than our eye.

Its obviously not the hardware, its the software.


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

[User]
[BTTF] What the hell is happening in Hill Valley such that every generation of Tannen, McFly, and Strickland look like clones of the previous generation?

Biff looks just like Mad Dog and Biff Jr. Marty looks just like Shamus and his son. Mr Strickland looks just like his sheriff ancestor. Seriously what is going on in Hill Valley?

[Assistant] Morphic Resonance - a common side effect caused by the wake of time travel using first generation flux capacitors and the like. Later developments control this through flux damping and quantum filtering.


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

[User]
How low cortisol affects on your mood?

I'm currently on the process of investigating on why I have trouble producing cortisol, but due to me getting infeccted by covid-19, this had been postponed, so I wanted to know why even though I have trouble producing the stress hormone I am so stressed. I have generalized anxiety and recently I have been really angry about some stuff, not like angry enough to break material items but a standing anger, since last Friday, and before that I already was experiencing an easyness to be bothered by silly things like specific noises. Is this normal? Wasn't I supposed to be more chill due to my lack of cortisol?

[Assistant]
It would be more accurate to consider cortisol *associated* with stress rather *causing* it. In fact, it would be more accurate to say cortisol level is raised *in response to* stress. The hormone does a lot of things, but on the whole, it helps your body to deal with stress better. This include raising blood sugar level, pumping more energy to your body, and regulating the immune system and inflammation, among other things.

Thatd why, either too low or too high levels can lead to worse stress, because it means your body is handling stress inappropriately.


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

[User] When footprints of prehistoric humans or even dinosaurs are found, how does it happen that the ancient mud or sand in which they walked was fossilized and yet, in all the intervening time, the footprints were not filled in and erased by additional layers of mud that also turned to stone?

[Assistant] They are only found where some process stopped them bring filled in. Maybe a period of drought, a flood that deposited a different sediment that was more easily eroded away later, an uplift or subsidence caused by an earthquake, a river suddenly changing course, etc. It's not a common occurrence to find them.


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

[User] ELI5: What makes something truly random? Like what defines randomness?

[Assistant]
Computer person here -- there's many, many types of "random". The kind of "random" you want depends entirely on your needs.

As Steve_Jobs_Ghost mentions, a common "random" number generator is in fact entirely not random; it starts with a "seed" value and then generates new values based on the seed. However, since you generally don't know the seed, the numbers are random *to you*.

I worked at a simulation company ages ago; we let people either define what seed to start with (so they could repeat their simulation from run to run) or let the system pick one (hint: it was just the current time :-) ). This worked great: you could either get random-to-the-user values, or random-but-repeated values.

Many computers will have an "entropy pool": a set of data that they've gotten from the external world, and these are used for randomness. For example, the time between the system starting a clock, and when the user starts to type is pretty random. Until, of course, you have a bunch of VMs on a consistent cluster; then it's not as random.

Some uses of random numbers require that the number be random to an external attacker. Secure web browsing depends on this; the random numbers are picked by smart people who use the "entropy pools" in a careful and considered way. OTOH, some systems have been shipped where the "random" number used for web security was, in fact, essentially hard-wired at the factory, which isn't really random at all.

Lottery numbers fall into this category, which is why lots of lotteries use the bouncing-balls-in-a-cage approach. This is often secure, and then suddenly it isn't :-(

Some uses of random numbers in computers are to do things like a random back-off when faced with congestions. Like, if you and another person both boot your computer at the same time, you can get into a muddled state when connecting the network (technically: a race condition inside DHCP when getting an IP address). The solution is that both computers can detect this condition, and you each wait a "random" amount of time before trying again. This doesn't have to be particularly random to work.

Some random numbers are used for simulating systems like galaxies or nuclear interactions. These have to be carefully distributed with no "clumping" other than what the randomness would generate. There are elaborate tests to ensure that the number is correctly distributed. Note that these numbers don't need to be secure against crooks: there's not much to be gained by "breaking" a galaxy simulation :-)

There are sources of good random numbers. The RAND company was famous for generating a table of random numbers that they created from a carefully controlled roulette wheel (this was back in the 50s, IIRC). This is obviously only good for scientific purposes since anyone could buy a copy of the table :-)

People think that quantum effects are hard to generate; actually a common source of quantum noise is just the static you hear in stereos. This is thermal noise, and AFAICT we can prove that it's actually fully random with no "hidden variable" that we just don't understand. And thermal noise is easy to use inside a computer, and can be a great source of randomness!

OTOH, there are also known theoretical exploits: in theory, a crook could modify computers chips in the factory such that the thermal noise works until it doesn't, and after that it's in the control of the crooks. This is particularly scary because it's essentially impossible to detect :-(

The most fun random number is generated by a camera pointed at Lava Lamps. This is fun (we don't have a way to guess ahead of time how the lamps will work), but personally I'd be dubious about their statistical distribution (whether they are evenly spaced).

TL/DR: there lots of kinds of randomness, and it depends on what you need.


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

[User]
ELI5: Is it possible to sneeze while sleeping? If not why?

I know we don't remember what we do when we sleep...so I've always wondered if people sneeze while sleeping...and if not why?

[Assistant] No, at least not during REM sleep, as motor neurons aren't being stimulated and reflex signals to the brain kind of shut off. It is possible to wake up for the purpose to sneeze and fall back to sleep though, and if that happens you likely won't remember it.


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

[User]
[Batman] Why has the batcave been partially made into a museum?

He has a lot of things on display and I'm just curious why since nobody but him and his allies will ever see it. It definitely looks cool but it seems rather pointless for someone like Bruce.

[Assistant]
Even though he dedicates the VAST majority of his time and energy to his mission as Batman and all that entails, even he is smart enough to know he physically needs time to unwind now and then. He likes to think he can put those times off over and over again, but he eventually listens to Alfred or another person he trusts to find brief times to relax.

And in those brief moments when he's not furthering his goals, he likes to reflect on the good things he's done. He's got a good sense of sentimentality, (or he's just completely obsessed, it can be both with Batman) so he likes to set up and keep physical reminders.

Plus, if he ever feels overwhelmed or stuck trying to figure something out as Batman, he can look over his accomplishments and change his pattern of thinking. Even a momentary distraction administered at the right time can lead to him cracking a tough case.

There's also the reverse of all this. Bruce is someone who thinks he must take undue burdens on himself so no one else has to. It could be that he surrounds himself with keepsakes as little bits of mental self-harm. Reminding himself of his failures so he does better next time. This (to me) is why he keeps old Robin costumes on full display near him.


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

[User]
[Star Wars] In theory, could a force-user achieve nigh-omnipotence?

Or is there some sort of a limit to the force?

[Assistant] The limit is the force itself as well as the user. Most people only have so much potential in them and can't really go beyond it for too long without breaking. There's ways around this limit but the drawbacks are intense and usually fatal. The force itself has a will and is always seeking balance though it often overcorrects. Become force god and upset the balance the force will swing against you eventually and align everything from a disgruntled employee to a blind monk and everything inbetween to the exact place they need to be to bring about your downfall.


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

[User]
Will a hot drink in the fridge get colder faster if I put a metal spoon in it?

I did this one and I think it *may* have happened. I tried to figure it out with my roommates but eh.

[Assistant] Depending on how much of the spoon stuck out, it would work as a radiator somewhat. Heat would conduct up the handle and radiate out into the freezer itself. It's giving two key features: it's made of metal, which conducts heat well, and it's providing more surface area for the heat to radiate from.


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

[User] Why is causing species extinction wrong?

[Assistant]
In most cases this isn't even laboured as an ethical point; the extinction of species due to human activity has the potential to affect our environment in ways that can be detrimental to us and because of the complexity of our ecosystem its difficult to foresee the true extent of this until its too late e.g. a famous example is Mao Zedong ordering sparrows and crows to be exterminated in China because of their effect on crops, leading to a rising mosquito population which contributed to the great famine which killed millions.

I think a better form of approach is to ask whether animals qua animals have intrinsic value.


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

[User]
ELI5: Why can a refrigerator from 1943 still function perfectly but cars need their air conditioning recharged after only a few years?

I always assumed they were both simply heat pumps, so why does one run out of juice so fast?

[Assistant] Automotive refrigeration uses many rubber seals and gaskets. Whereas domestic refrigeration is all copper or aluminum with brazed connections. There are no rubber gaskets or seals. Its a hermetically sealed system.


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

[User] Why do sunburns seem to "radiate" heat?

[Assistant] It's simply a matter of 1) increased bloodflow to the area and 2) various biochemical processes involved in the healing. When your body senses the damage from sunburn, it activates the immune response, which triggers increased blood in order to deliver white blood cells needed to fight potential infection and building blocks to repair the damage. This rush of blood by itself will increase the temperature. In addition the host of chemical reactions associated with the heavy cellular construction work needed to clear debris and repair the tissue will generate additional heat.


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

[User]
Creating an an Academic CV for a PhD as a Master's student (Philosophy)

I'm applying for funding for a PhD, and this particular unviersity requires me sending an Academic CV on top of the research proposal and application questions etc.

I've looked at some guides and examples, but my problem is that I'm only a Master's student and don't yet have much to put on there - I'm worried it won't seem like enough, but how could it? I've barely even started down the academic path at this point.

Here's what I've got, which will come to under one side of A4:

1) My details

2) My qualifications (1st BA, Pending MPhil)

3) Research Interests (like 5 general areas as bullet points)

4) Publications (One forthcoming)

5) Two Referees' details.

I have a couple of questions. First, is this enough? I can't see how, at my stage, anyone would be able to add much more. Second, should I put my one forthcoming publication on there?

Any advice at all is much appreciated. Thanks :)

[Assistant] You won't really start the heavy CV building until you begin your PhD, so don't be too concerned about it not looking full. I'd rather see a CV that's short and honest instead of one that's full of fluff and unimportant information.


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

[User]
[LoTR] What happens to the Nazgul after Sauron is defeated, and they are presumably destroyed?

Seeing as they were once Men, shouldn't they go to the Halls of Mandos? It's here that I have the question. I've read that in the Halls, Men are judged for their actions in life, before going off to the unknown place that even the Valar don't know. Would the Nazgul be punished for their actions as the servants of Sauron and be banished with him and Morgoth to beyond those doors?
Or would they be judged for their actions before they were enslaved and turned into servants to evil?

[Assistant] The power of all the other rings were tied to the One, even the three Elvish ones, so once the One Ring was destroyed, their power diminished and the Nine ceased to exist. Since no one knows what if any bearing Namo's judgement has on what happens to Men after they leave Arda, no one can say if they will be judged for their actions in service of Sauron. One could say that Sauron merely harnessed the evil that already lay in them.


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

[User] ELI5: How exactly did Bill Gates become so rich?

[Assistant] He co-founded a company called Microsoft in 1975.  Their flagship product, the Microsoft Windows operating system, eventually achieved over 90% market share.  This resulted in billions of dollars of annual profits, which, as the primary shareholder, resulted in Bill becoming a very wealthy man.


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

[User]
NASA successfully nudged Dimorphos into a different orbit, but was off by a factor of 3 in predicting the change in period, apparently due to the debris ejected. Will we also need to know the composition and structure of a threatening asteroid, to reliably deflect it away from an Earth strike?

NASA's Dart strike on Dimorphos modified its orbit by 32 minutes, instead of the 10 minutes NASA anticipated.  I would have expected some uncertainty, and a bigger than predicted effect would seem like a good thing, but this seems like a big difference.  It's apparently because of the amount debris, "hurled out into space, creating a comet-like trail of dust and rubble stretching several thousand miles."  Does this discrepancy really mean that knowing its mass and trajectory aren't enough to predict what sort of strike will generate the necessary change in trajectory of an asteroid?  Will we also have to be able to predict the extent and nature of fragmentation?  Does this become a structural problem, too?

[Assistant] Because of the relatively tiny size of the target (earth) compared to the huge distance being covered by the asteroid almost any change would be enough to cause something that would hit the earth miss instead. Its also incredibly unlikely that we would accidentally knock it into a path that hits something else instead.  So for the purposes of planetary defense, no we don't need more information.  It would be useful to understand how those other variables affect the deflection if we wanted to guide it to a specific target or orbit, for example if we wanted to mine it.


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

[User]
[Wheel of Time] Through some kind of mixup, you end up as Rand at the start of Book 1. What is the fastest possible way to 'speed run' the series and end up at the Final Battle?

There are probably Tav'ren reasons why this would be impossible but if you truly knew everything that was going to happen before it did, how could you manipulate or take advantage of the events?

[Assistant] Definitely take advantage of Lanfears power when she appears as Selene. Use Callandor to take control of Ishmael ASAP and 1. Cleanse saidin, then fix the dark ones prison. Youd save a lot of lives that way.


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

[User] Why can't we have household refrigeration systems that utilise the energy transfer in useful ways (eg: to heat water)?

[Assistant]
The simple answer is that it is not worth it.

You could set up a system where water runs by your refrigerator and the refrigerator pumps some heat into the water. The  water wouldn't be hot enough (or you wouldn't have enough hot water) so then the water would then run to the hot water heater to be heated the rest of the way.

This system would require a specialized refrigerator and plumbing system. It would make maintenance more difficult on both the refrigerator, and would have only a small benefit.

Your water heater and your refrigerator don't run all the time. Each only runs when the internal temperature outside of a particular range. When your refrigerator warms up to too high a temperature it turns on. The chances of that being the same time that the water heater needs some new water are quite low. The water warmed by the refrigerator would then sit in the pipes and cool before it enters the heater.

TL;DR: You could do that and maybe we should but everything would need to be much more complicated and expensive for a small energy savings.