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

[User]
What are some of the potential applications of quantum computing?

I thought this might be a fun question to hear what everyone has to say. Also, first post on this subreddit! :)

[Assistant] The big one right now is Shor's algorithm, which can find prime factors much faster than classical computing algorithms. This is a big deal because popular encryption schemes like RSA rely on the idea that it's basically impossible to find prime factors of large numbers.


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

[User]
[MCU] Does Tony have backups of his AIs?

After JARVIS is integrated into Vision, we never see it again, and FRIDAY takes it's place. Does Tony not have a backup of JARVIS, or even all his AIs somewhere in his computer/cloud?

Or is that not the case as we see Tony revives JARVIS only after he retrieves it's protocols in the Nexus?

[Assistant]
Jarvis was designed to be able to learn and grow and adapt. Tony wrote the basic programme, switched him on, and then stepped back and let Jarvis develop his personality from there.

Tony could in theory boot up a new Jarvis, but it wouldn't be the same. And given that he treats Jarvis almost as a friend, he probably wouldn't *want* to do that.


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

[User]
[Startrek]so where are the IT guys?

As the title says. These ships are running huge databases which will need storing/maintaining and the whole ship is ran by the computer. So who is incharge of federation IT systems?

[Assistant] Engineering. The computer is such a core part of all of the ship functions. There are some junior engineers who will deal mainly with the 'mechanical' side of things but most of the engineering department will be working on computer systems also.


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

[User] ELI5: Why do they say that you should wash your wound (or put it under a stream of water) when you cut yourself and blood is pouring? Doesn't it prevent the blood from coagulating? Which is our body's way to heal itself preventing blood to keep pouring out?

[Assistant]
In general, the biggest danger from the usual cut or scrape is the introduction of bacteria or other contaminants into your blood stream. Your skin is the first layer of defense against most foreign material; breaking it presents an immediate risk to your body. Washing the wound isn't supposed to do anything about clotting; it's just to clear the wound of any debris/contamination from whatever caused it.

Now if your wound is gushing blood (eg, opened vein/artery, limb amputated), then washing it is probably less critical than applying a tourniquet or other device to stop the flow of blood, because if you're bleeding that badly, your more immediate concern is blood loss rather than infection.


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

[User] ELI5: How does gerrymandering work?

[Assistant]
Lets say there are 30 cats and 20 dogs. We split them into 10 groups of 5. These animals must now vote for which animal is better within their groups, and the only the overall vote by the group matters.

If each group contains 3 cats and 2 dogs, the cats win in every group. 100% of the votes goes to cats, who win the election.

If you had 6 groups with 3 dogs and 2 cats, you end up with 60% of the group votes going to dogs, who win the election.

Gerrymandering can drastically alter the overall votes from the actual population, because the way you group people can eliminate votes you do not want.


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

[User]
An experienced runner and someone who is very out of shape run a mile. Do they burn the same amount of calories?

If we assume their weight and the circumstances of the run are the same, and the experienced runner runs slow enough for the inexperienced one to keep up, so the question comes down to: is there a difference in how efficient calories are used?

[Assistant]
Several factors indicate the out of shape runner will burn more calories:

* the out of shape runner will have a higher heart rate while running, which burns more calories
* he will take longer to run, which means he will be burning calories at an elevated rate longer
* if he is heavier, he will expend more energy per stride
* if he is heavier, his basal metabolic rate is increased

Two factors contribute to the fit runner burning more calories:

* being fit, he has a higher metabolism, increasing basal metabolic rate
* if he is heavier, due to increased muscle mass, he will also expend more energy per stride and his basal metabolic rate is increased

Overall, the first two unfit factor can result in large amounts of extra calories burned, while the other factors are weight dependent or only impact BSM.  So the unfit runner is going to expend more calories.


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

[User]
[Star Wars] Could you potentially use Dark Side powers by only channeling your own fear?

It's a negative emotion that spurs urgent action, right? Is there anything that differentiates it from any of the other emotions used to channel Dark Side powers? Alternatively, could you use sadness?

[Assistant] Fear and sadness are like emotional seeds, they can become constructive or destructive but aren't capable of enabling action in their raw form. They both can lead to anger hate and the dark side, but aren't inherently of the dark side.


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

[User] [ASOIAF] Of the Valyrian descended people throughout Essos, who is the most powerful?

[Assistant]
The Freehold of Volantis is the most powerful Valyrian descendant Free-City by far. At one time they were on the verge of rebuilding the old Freehold and were only stopped by a coalition of nearly all of Western Essos, Aegon the Conqueror, and the Stormlands. They have only been held back by the fact 2/3 of their Triachy has always been composed of almost pacifistic merchants of the Elephant faction who refuse to try to conquer the other Free-Cities.

Interestingly enough they are possibly the most "democratic" nation in ASOIAF as their leaders are all elected on a yearly basis by all Freeholders, which if we go by the statistics of 1/10 is a freeman then that is still a rather large number of voters. Of course they still practice widespread chattel slavery but that may change soon if the Rhllorists and Daenerys have their way.


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

[User] [Xmen] How does Cyclops miss when he shoots lasers from his eyes?

[Assistant]
Most likely, it's due to a combination of things including (but not limited to):

The direction of his eyes and the angle of his head not being the same.

The enemies having superspeed/prescience.

His head/neck muscles being unable to turn fast enough to track accurately.

Also, does anyone have any information on the speed his blasts propagate? Is it speed of light or slower?


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

[User] If chlorine is supposed to kill microbes in tap water, why is it safe to drink?

[Assistant]
Chlorination in drinking water is low enough not to cause any significant harm to humans due to our size and ability to deal with small amounts of toxic material. Given that microbes are microscopically smaller than us, the amount required to kill microbes in water is resultantly lower.

It can be likened to air in the city being 'safe' to breathe. While it won't knock you down dead, it does carry the potential for long term health risk. The benefit/cost of chlorinating water is generally believed to have an overall positive effect in that the number of deaths from waterborne disease prevented outweighs the possible increase in risk for cancers, for example.


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

[User]
[Rocky] In Rocky 3 it's established that Rocky cannot go toe to toe with Clubber Lang, because Clubber is too strong and deadly. But in Rocky 4 he goes toe to toe with Ivan Drago, who's far stronger and deadlier than Clubber. What gives?

Even after Rocky regained the eye of the tiger, Apollo's training program was focused on Rocky *not* standing toe to toe with Lang.

[Assistant] Rocky was in much better shape, stronger than ever against Drago. He also had even more motivation than in his rematch with Lang, cause Drago killed Apollo. At that point, for Rocky it was less about winning the fight cleanly and smartly than hurting the Russian and avenging his friend.


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

[User]
ELI67 Please explain like I'm 67 the difference between email, Google, Aol, a website, IE, Chrome, and the internet.

I know this kind of breaks the rules, but I think a good explanation would be whats Reddit is all about. I have always had real trouble explaining this to my older relatives and computer illiterate friends.

Edit: thanks to everyone for all of your answers.

[Assistant]
Email is like a written letter that arrives in seconds instead of days.

Google is a company that runs many websites, the biggest of which is a search engine. A search engine is a phone book for other websites.

AOL is an internet service provider, they are like a phone company but give you access to other people on the internet instead of other people with telephones.

A website is a destination on the internet, someplace to go to get information or complete a transaction much like a physical location on a street.

IE / Chrome / Firefox are your methods of transportation to get to where you need to go. They are akin to a vehicle, but thankfully do not need any gas.

The internet is like a city. It is a collection of places and people with a road that connects all these various places to each other and allow you to travel from one place to another to get what you need.


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

[User] [Star Wars] If he were paid enough, would Cad Bane or even Jango Fett have gone after Palpatine?

[Assistant] When he's Chancellor? Absolutely. "For the right price", as Cad Bane puts it. Not knowing he's, you know, Lord of All that is Evil, it's going to seem like an even easier job than retrieving a Jedi Holocron from their vault (which Bane pulled off, of course). When he's Emperor? Oof, you'd have to offer them an entire planet to each to get them onboard, they're not stupid. Naturally, they'd still end up electrocuted into oblivion.


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

[User]
ELI5 how people, who were deaf their whole life and just now began to hear, can instantly understand spoken word?

How were they able to associate words with the sounds? Like if you go on youtube and find videos "hearing for the first time" etc.

[Assistant]
Hearing and comprehending are two completely different things.  They're aware of the *concept* of speaking, so it's not surprising to them and are able to associate "dad is making sounds" with "dad is communicating," even though they have no idea what those sounds actually mean.

There may be a few out there that seem like they're comprehending, but they're still using the skills they learned to comprehend while deaf, such as lip reading -- and there could be someone off-camera signing to them.


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

[User]
[Godzilla]Why don't they shoot Godzilla in the eyes?

In all the Godzilla or Kaiju films that I've seen, the military seems to make the same mistake of trying to kill Godzilla by shooting his body, which is clearly bulletproof. Why don't they shoot at more vulnerable parts of his body, such as the eyes, which I imagine are not nearly as resistant to firearms and missiles?

[Assistant]
Note that there's not really a way to shoot something with a missile *without* hitting its eyes.

Given the number of different attacks Godzilla has been hit with to no effect, a lot of which include explosions or hails of bullets hitting his face/head, it seems his eyes are just as invulnerable as the rest of him.


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

[User] ELI5: Why is our brain able to remember seemingly random, pointless thoughts from childhood; but not specific memories we try to recall?

[Assistant] Just the way the neurons are connected and the strength of the connection. And the nature of consciousness. Its like a spotlight wandering the tapestry of memory but it cant illuminate everything at once.


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

[User]
What determines the number of segments in a citrus fruit?

Does it vary by variety (i.e., do grapefruits generally have different numbers of segments than tangerines? What determines that?)?

Why do some have odd numbers of segments? That seems kind of strange to me, but I can't put my finger on why.

[Assistant] The segments of the fruit are derived from a part of the flower called the carpels. The carpel is pretty much the female reproductive part of the flower and contains the ovules. That's why each section of fruit has seeds (assuming you didn't buy a seedless variety). The number of carpels that a a flower has is species specific but will always be a multiple of 3, 4, or 5.


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

[User]
ELI5: What specifically about puberty negatively impacts female gymnasts to the point that retirement occurs around age 20?

I've been thinking about this and am even starting to get skeptical of whether this is true or not. So I guess my question is divided into two parts: Is the retirement of female gymnasts after puberty for social or for established physical reasons? For instance, are elite female gymnasts forced to retire after their teens due to some wierd aesthetic reasons or is it due to some established medical reason such as: after __ post-pubescent age, the body becomes less compatible with gymnastics training demands? Post some real scientific studies if you can.

[Assistant]
It is a few factors but the biggest two are strength to weight ratio and the change in size of the person.

When you train things like balance, one of the biggest components of gymnastics, you are training neuromuscular connections. When you grow, those change, performance dips. With girls their highest strength to weight + height ratio happens just before puberty, during puberty they have a lot of hip growth for instance, this will add weight but also change how they can balance. That change needs to be relearned.

All sports see this dip. Runners get slower at the start of puberty then get faster again, swimmers have a dip in performance...   Pretty much any sport has this dip, gymnasts just experience it to a greater extent. The small stature of gymnasts also is good to maintain, easier to rotate a shorter person.


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

[User]
ELI5: How do antibiotics work?

How does one antibiotic kill different versions of bacterial infection? And if so, why can't it kill ALL bacterial infection? And why can't it work on a virus?

[Assistant]
They destroy or weaken various parts of how bacteria work.

For example, penicillin infiltrates the cell wall of bacteria and weakens the structure. This causes the bacteria to die.

Other antibiotics block bacterial replication or other cell functions. The key is to have one that blocks bacteria from growing while being inert to human cells.


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

[User]
[WH40k] How powerful are lasguns?

So, lets put this first, lasguns have a noticeable level of effectiveness in battle, they can put a hole clean through and ork, penetrate (I think) space marine armor at the weak spots (joints, elbows, neck etc.) and can put a hole in a tyranid as well, albeit you have to turn the said ork/tyranid into Swiss cheese before it dies. And you could just say, well, why not just get space marine and use a bolter, well, most guardsmen and civilians dont see a space marine in their lifetime, and they arent at a whole lot of battles, especially if the imperial guard is capable of winning the battle by itself, to add to this, the imperial guard is very capable of winning battle without the help of space marines (its happened many times before) so back to the question. What I want to know, is how powerful and effective will a lasgun be in efficiently killing orks and tyranids?

[Assistant]
Very effective. The lasgun is one of the greatest weapons of war in scifi history. You can reload it from anything that generates heat, leave it outside in the sun for a new clip, holds a shit ton of shots, 100% accuracy, functions in just about any environment and so simple to use a feudal farmer can wrap their heads around it.

When dealing with big bads a single lasgun wont do shit. A few hundred lasguns all firing in unison on a target will fuck up just about anything without shields.

Its a perfect anti air weapon as well. The rounds travel at the speed of light and have zero bullet drop, which is one of the reasons maintain air superiority against humans is hard. As soon as you get close to the battlefield a thousand flashlights with the stopping power of a 50 cal round are hitting you instantly from every location.

Most orks go down with a shot or two from a lasgun, once they start getting bigger you might need a handful of shots to drop an ork.

Tyranids are similar, a single round stops most grunts and focused fire can deal with just about anything smaller than titans with shields.


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

[User] [Inside Out/X-Men] What would the mind of a telepath like Xavier look like and what would be going on in there when they use their different powers on other people?

[Assistant] A mental superpower like that would probably manifest as an additional piece of machinery in Xavier's Headquarters. It would be capable of viewing other people's memories from a distance, and also casting 'memories' (not true memories, spheres of Xavier's present thoughts, but the principle's the same) to the projector areas of other people's Headquarters. It would just be another job to do in Headquarters, operated by whichever emotion is most closely related to whoever he's using his power on - Anger, Disgust, or Fear for villains, Joy for friends, and probably Sadness for Erik.


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

[User] ELI5: What does it mean when music is written in a certain key?

[Assistant] Think of the key as a starting point for a typical scale used in a piece of music. Each song will have the same basic scale in order for it to sound pleasing to the ear or, in the right key. Your basic key for music is the key of C, which employs the notes C through G and back to B again, naturally with no "sharps" or "flats." These scales can be offset starting with a different note other than C. After this is done, the pattern of sound differences must be carried over to the new notes by using sharps and flats. Using the C major and G major keys as an example, the C scale would read C,D,E,F,G,A,B, with a smaller pitch gap between E-F and B-C, called a half-step. These small gaps will change based on whether the key is major or minor. With a G major scale, you start on G and implement the half-steps into the same places they would be in the C scale. With Gmaj we see G,A,B,C,D,E,F#(sharp), keeping the half-steps where they should be (B-C, F#-G)


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

[User]
CMV: People should not be encouraged to go to university or college simply to "find themselves"

By "find themselves", I'm referring to the idea that the primary reason for attending college is to develop or experiment with your identity more, and become more mature. I'm not saying that college does not contribute to a person's maturity, but I don't think that it should be anyone's main reason for attending. These are my issues with this viewpoint:

I think the main purpose of college is to educate people who have chosen a specific subject they want to study or train students skills that correspond to a particular career path. People who are attending mainly to change as a person usually are going into college without a particular field in mind, or without career goals that they are actively pursuing. I don't see why people without a clear goal in mind should be encouraged to go to college just because they expect that experience will make them better somehow. College in north america is also incredibly expensive for most people and I don't see why anyone would need to spend that much money in order to find himself/herself. If someone's main reason for studying in college is to become a better person through education, it would make much more sense for that person to simply use the internet and/or library (which don't leave people with huge student loans) to study and explore their interests independently before committing to a degree they make not even be invested in. It honestly confuses me how so many people seem to believe that going to college will change them as a person more than any other experience in life. Again, I would agree that college can change a person for the better. I just think that the decision to attend college should not be based on the expectation that it will somehow help people to "find themselves", and instead be based on having a strong interest in a subject and/or a career in a particular field.

[Assistant]
Most graduate programs don't really care what your undergraduate major was. Most employers don't really care what your undergraduate major was. For Most college graduates - their major literally doesn't matter. The only relevant fact, was that they graduated at all.

Unless you are literally going into engineering - your major doesn't matter. You can go to Medical School with an English Degree. You can go to Law School with a Chemistry Degree. You can work for a Fortune 500 with a Philosophy Degree or Art History Degree.

>  think the main purpose of college is to educate people who have chosen a specific subject they want to study or train students skills that correspond to a particular career path.

Even if you have a particular career path - the specific subjects studied at the college level don't impact your ability to go into that career (except for engineering).

So why not do some self-exploration while you're there??


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

[User]
[Half-Life] Why does no one act surprised to see Gordon Freeman in Half-Life 2?

Apparently Gordon Freeman spends several years in stasis in between Half-Life 1 and 2. Yet when Half-Life 2 begins, no one seems shocked to see him alive or ask him where he's been.

[Assistant] Nearly everyone with the exception of Alyx and Barney was shocked when Gordon resurfaced.  Doctor Kliner declared it was a 'red letter day' upon seeing Gordon again. It's worth mentioning just about everyone is suffering from severe shell shock and from time to time had to drink from Dr. Breens private reserve as means of survival, so things are somewhat cloudy for them.


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

[User] How is it possible to treat allergies by repeatedly presenting the antigene to desentize but when you vaccinate (and booster) an antigene presentation trains the immune system to fight said antigene?

[Assistant]
A classical vaccine typically contains two things: an antigen and an adjuvant. The antigen is what you're training the immune system to recognize, and the adjuvant is a more generic substance that lets the immune system know there's something dangerous going on.

If you only give an antigen, that danger sign is absent, and the immune system instead "learns" that this antigen is not dangerous.

PS: Newer vaccine technologies sometimes don't include the actual antigen, but instead a recipe for making it (either mRNA or DNA). mRNA vaccines also don't always need the adjuvant, because encapsulated RNA itself can work as a "danger signal."


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

[User]
ELI5 why phones have the 1 in the top row and descending from there, but calculators have the 1 at the bottom and ascend?

Its never made sense to me and seems unnecessarily confusing for two very common uses of buttons with digits on them.

[Assistant]
The layout of the two devices are unrelated. Phones arrived after the calculator style keyboard.

Early cash registers and adding machines used different layouts until the standardized around the layout you are familiar with.

The lower numbers particular the zero being at the base probably made sense for prices at the time. Some even had double zero key.

The phone layout did not start out as you see it know, it was originally a round shaped ring with the highest numbers furthest away with zero being after the nine. Early phone numbers had less digits and used the lowest numbers to reduce the effort and time for dialing.

The two layout are separated by a significant amount of time. The touch time phone was introduced around 1941. Adding machines were introduced in the late 1880s.

To summarize they are different because they have different origins and purposes. Having a person who has access to both is a modern development only happening within the last 50 years when pocket calculator became commonplace.


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

[User] [LOTR] Could the Fellowship have made it through Moria safely if Pippin hadn't messed up?

[Assistant] Probably not. Moria seemed empty when the Fellowship first entered, but there were eyes and ears everywhere. The noise of nine companions, either from the clatter of weapons and armor, the noise (and smell) of cooking food, or just conversation, would have alerted a goblin sentry sooner or later.


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

[User]
How did we find out that COVID-19 was a new disease so quickly?

With the symptoms being so close to the common cold or a flu, wouldn't most doctors have simply assumed that the first patients were suffering from one of those instead?  What made us suspect it was a new virus, and not an existing one?

[Assistant]
The symptoms were nothing like the cold or flu, thousands were dying in Asia. Virus samples are frequently DNA sequenced worldwide as part of a monitoring program. A new sequence was correlated with high death rates or need for ventilators.

A better question is once we knew for certain we had a new and deadly variant of coronavirus,  why did most of the world do nothing to prevent inter-country spread until mid 2020. Protocols were developed in 2003 during the SARS outbreak, and none were followed.


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

[User]
ELI5: Why do AM and FM radio signals sound so different?

A show I listen to on FM in the afternoons replays the next morning on AM, why does the AM station sound so much different?

[Assistant]
Imagine writing out a message in your own handwriting, and later printing the same message with your printer. The letter will look wildly different. Your handwriting most likely is unclearer and more messy, but cheaper. Your printer makes everything perfectly clear and understandable, but printer ink is expensive.

.

AM and FM are separate methods of encoding and broadcasting radio signals. M works by modulating the amplitude of the signal according to the information being sent, while the frequency remains constant. This differs from FM technology in which sound is encoded by varying the frequency of the wave and the amplitude is kept constant.

.

This difference in signal type is what causes the sounds to change. AM has poorer sound quality compared with FM, but is cheaper and includes lower bandwidth making it ideal for having many stations in a small broadcast range. FM has a sharper quality at the cost of higher bandwidth, but can be blocked by physical hindrances (mountains or your wall) making it much shorter range.


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

[User]
Are there viruses that find sources of energy outside of cell synthesis (like eating) or are they created with a set amount of energy and must replicate before they "die"?

Self explanatory.

[Assistant]
Viruses have no metabolic processes. The do not consume or store energy. They never die in so far as they arent typically considered living things; more like they are bits of protein-encased exogenous genetic material thats replicated if it makes its way into a cell.

Regardless, they never die on account of running out of energy (because they dont store or use energy). They exist, until physically destroyed (if they dry out, for instance, the virion can break apart; cells and organisms can consume them; digestive juices can dissolve them, etc.).


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

[User]
ELI5: What does the phrase "needs more jpeg" mean exactly?

I was under the impression jpeg was a file format. How does it relate to degraded image quality compared with other formats?

[Assistant]
JPEG is a "lossy" compression format, meaning that the image loses information/quality every time that you save it. So, if a JPEG is saved dozens of times by different people, it tends to look pixelated and blocky from the compression algorithm.

So, "Needs more JPEG" is a sarcastic way of saying "This image looks awful from being compressed so many times".

Different file formats compress images differently. Some are "lossless", meaning that the quality does not degrade every time you save it.


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

[User]
ELI5: Why do alarms have a default snooze duration of 9 minutes?

Some alarm clocks let you change this timing, but why are most set to 9 minutes as default instead of 10 or 5 minutes?

[Assistant]
mechanical reasons. the clock looks at the last minute it's displayed for it's alarm. snooze makes it go off again the next time it hits that number. for example, if it's 8:00 and you hit snooze, the previous minute is 7:5**9**. the clock just registers the 9, and will give an alarm next time it sees a 9. if it were to look at the current time, it's a 0 at 8:00, it'd go off again right away.

it would be a lot more complicated to make a clock that can look at both final digits, and most people are fine with 9 minutes. it gives you that one more minute of being awake without quite having to get up yet. probably the most bittersweet minute of your day.


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

[User] [Harry Potter] Two supersonic nuclear missiles are launched at Hogwarts, aimed at targets 1km away on either side of that school. What alerts/stops/prevents the school from being destroyed?

[Assistant]
Potentially nothing.

Magic makes most muggle technology fizzle, but this effect was short-range the few times it appeared. And the number of wizards who understand enough muggle technology to be frightened of radioactive fallout and to develop defenses is basically zero.

The portrait on the Prime Minister's wall and other spies would likely alert the wizards before this happened.


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

[User]
ELI5: Why can't we breed with other species?

Why cant we breed with species like gorillas, when close species, like tigers and lions or horses and mules, can?

[Assistant]
The general rule of thumb for interspecies breeding is that it comes down to chromosomes, which are strands of DNA. The rest of the Great Apes (Gorillas, Chimps, Bonobos, Orangutans) have 48 chromosomes, but 2 of these chromosome have fused in Humans, leaving us with 46 chromosomes. The greater the difference in the number of chromosomes, the harder it is for species to breed. Basically, the sex cells (sperm/egg) have problems aligning and combining when the chromosome count is off.

This hasn't stopped animals with different number of chromosomes from interbreeding. Mules are the best example. Horses have 64 chromosome and donkeys have 62, so this is similar to the difference between Humans and the rest of the apes. So we can see that a different number of chromosomes is a problem, but not an impossible barrier, for making hybrids.

The other main biological problem comes down to the immune system. Your body automatically recognizes when things are "not-self." Any outside matter that enters into your system is immediately attacked by your immune system. For pregnancy, this concept is most important when it comes down to blood types. The "positive/negative" you hear about human blood types refers to a specific blood type. Basically, if a mother is "negative" and the fetus is "positive" than the mother's immune system will attack the blood of the fetus, which can lead to a miscarriage. Chimps and humans have equivalent systems that they share. So, a humanzee fetus would need to have a mother and father with matching blood subtypes.

The biggest problem to breeding humans with other apes is not biological. The simple fact is that, while it is biologically possible (if not likely), making a human-ape hybrid is a bit too mad science-y for most people. No reputable institution would fund the research, no ape center would allow their animals to take part, and the outcry from the public and scientific community would shut down any private project pretty quickly.


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

[User] [Star Wars] Who's the best pilot and who's the worst out of Han, Luke, and Anakin?

[Assistant]
Likely it goes, from best to worst Anakin, Luke, Han.
Anakin not only was able to destroy a Droid control ship at age ten, but later fought in the Clone wars, gaining more combat flying experience. He was said to be one of the best pilots in the galaxy, and was capable of using his connection with the force to aid him in battles.
Luke was close, with feats such as pulling off an impossible shot with space magic bullshittery, but he does not have the same combat experience as Anakin.
Han is the worst. Without a major connection to the force, he does not match up to the precog + reflexes of either Skywalker. He does however, have a lot of experience, so it might not be a complete stomp.

In summary, Anakin + Luke better than Han due to space magic, and Anakin>Luke due to Anakin's experience in the Clone Wars.


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

[User] [Marvel/Thor] Asgard is described as a realm where science advanced so much it became indistinguishable from magic. Why then did they revert to swords and shields?

[Assistant]
Think about e-readers.

For years, people refused to convert over to things like kindles, preferring to stick to paper books-- while the internet existed for years, which should make them used to looking at screens all day.

As the technology advanced, designers learned that making an appealing e-reader requires elements which make it mimic a book-- the pages should look like pages, and *they should turn as if it were a book.* Why on earth, realistically, do people need to swipe their pages like a book? Why not shake it? Have a verbal command? Stick with buttons, maybe put them on the sides to swipe down like a scroller?

Because it's a cultural artifact. Even as we advance technologies, we will, inevitable, keep design elements which have no logical reason for being there-- they were just culturally comforting.

Here you have the Asgardians, an ancient and powerful culture for which their technology becomes so common place that when they discuss it, they use phrases which make no sense to us and sound like magic-- but Jane Foster was able to translate, and confirm, as quantum physics. Do you know how much your average medical technician knows about radiative decay? They don't have to worry about that, they don't design the machines they just use them.

Why swords and shields? It's just a design element. Those simple shields have more tech in them than the nation of Wakanda. What will you use against such tech? Ballistic weaponry? Probably not, as Asgardians are strong enough that *their own arm-swing velocity* is ballistic level. So no-- they have ancient looking weapons, reinforced and teched up, used with super strength against other shields which are also reinforced and techned up and, on occasion, lasers, because what the hell else could kill them? And they all look like sword-and-sorcery because that is what the culture of Asgard is comfortable with.

I imagine if the US created a weapon like Mjolnir, it would look like an oversized silver Colt 6 shooter that wouldn't shoot bullets.


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

[User]
Advice needed for my TT offer vs spouse TT offer

Today my spouse got a TT offer at a public research univ in a location A near a major city. We are very excited.

I also got a TT offer today at a public research univ in a good location B near a major city. Double excitement.

However. The two locations are not close to each other at all.  We would like to try to approach both schools about the possibilities of TT spousal hires.  What approach would you recommend?  Do we mention that we are asking the other school for the same thing?  Does it help for a spousal hire to mention that the spouse has receives a TT offer from another institution?

[Assistant] Yes, tell the respective other school what the situation is. At least one of the two may come through with a spousal position. The fact that both of you have TT offers means you're competitive, and it may help with finding a position at the other place.


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

[User]
ELI5: Why do movies release on home video much quicker than they used to?

I remember from a over a decade ago that movies would take a year or more to release on VHS and DVD. Now it seems like movies release on DVD and Digital in as little as 3 months after they came out in theatres.

Why? Was VHS production holding it back or something?

[Assistant] it's takes almost nothing to release a movie digitally. and DVDs are cheaper and easier to mass produce than cassettes were. with Netflix and Amazon prime, people have so much access to movies on demand that if they were to wait so long, people would forget about it. strike while the iron is hot, so while the movie still has popularity and a following.


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

[User]
Why is skin darker around the pubic region?

I am a male and I know its not true for everybody. I also know its true for some females as well (I know my freinds have referred to it as the girl having "roast beef" downstairs). Can anyone explain it?

[Assistant] There is an increase of the melanin cells in that region for some people, it is just a genetic variant that doesnt really have a purpose that i remember learning about. Some theorize it was to help protect the more sensitive skin of the area from the effects of the sun when exposed.


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

[User]
CMV: Moral relativism is a dangerous, unwise, and practically impossible moral philosophy

So whenever I try to discuss morality on reddit, I always wind up with someone trying to persuade me that moral relativism is the best way forward. When I ask them why, they give a vague and generally meaningless answer about how it is the most reasonable approach to it, without any defending arguments. That doesnt seem very intellectually astute, so I figured Id go here, where intellectualism is at least sort of expected.

So anyways, moral relativism, from what Ive seen, either says that right and wrong is determined by each respective culture, or that it is determined by the individual. Both of these concepts are not very well thought out, and have the potential to be very dangerous. Now, Im not saying that SOME relativity in morals is bad, since some things are situational, like photographing someone. I am arguing against the people who say there is ABSOLUTELY no moral right or wrong.

First off, personal moral relativism. So if everyones moral compass is only determined by themselves, then there would be no way to justifiably accuse anyone of doing anything immoral, because, according to their moral viewpoint, it was a good thing for them. As Socrates said, no one will ever do something that they thought would be without benefit. So if someone were to, say, crash an airplane into the Twin Towers, we could not justifiably say that they were wrong, because according to their moral philosophy, they were in the right. Under this philosophy, anarchy or tyranny be the inevitable conclusion, and the world would devolve into a Hobbesian hellscape.

So if we back up from that, and say that moral relativism should apply on a cultural level, and that each culture gets to decide on what is moral or immoral and other cultures dont get a say, then you still run into roadblocks. When two cultures that interact regularly are met with clashing moral standpoints that they cannot reconcile with (slavery in America, Hitler oppressing large portions of Europe), then both groups would be forced to live under this constant pressure of pretending they were ok with the other group. This is bad for a society, and will eventually lead to either a lashing out of anger against the other, or an attempt to separate from the other (American Civil War, WWII). It would also mean that the actions of a country would be entirely justified, no matter what they did, because there would be no objective rules to govern them. War crimes, terrorism, and destruction would quickly entail without objective morality on a cultural level, and we would fall into a Machiavellian world of constant bloodshed and a might means right society.

The last thing wrong with moral subjectivism is that it is completely paradoxical. If there was someone who was morally subjective, that would mean he would not want others to enforce their morals upon him. That means he is enforcing HIS morals upon everyone else, by saying that it is wrong for people to force morals upon him. So according to him, it is objectively wrong to say something is objectively wrong, which is entirely paradoxical.

Objective morality is required of our culture to punish evil people and reward good people. When I hear people say that evil and good are just subjective and they have no meaning, i have a difficult time sympathizing with their argument because they are essentially affirming a paradoxical and completely incorrect philosophy, which doesnt seem quite accurate to me. I honestly have an easier time discussing things with a flat earther than someone who is completely morally objective, because it has become so mainstream that people assume it must be right.

I feel like Im being unnecessarily harsh against these people, but like Ive said, I have never heard a good argument for it. If you have heard one, or can make a good one that handles all the issues I presented, please, try and change my view.

[Assistant]
Moral relativism and cultural relativism are essential to disciplines like anthropology and sociology.

If you want to understand how the morals of other societies and other cultures function, you cant go in assuming that what they believe is wrong. You want to understand why they think its right, from their perspective. To do that, your own perspective will just get in the way.

And if its your own culture your studying, you dont want to go in thinking that the way your culture does things is normal, because we do it because its the right way to do things isnt a useful answer.

This isnt to say that when the sociologist or anthropologist goes home, they have still keep up neutral, amoral viewpoint! Moral relativism is a really difficult way to view the world  people feel strongly about morals! Morals are values, and whats more valuable to us that values? (We can even go post-structuralist here and ask what sort of values underlie moral relativism...)

So Im not arguing that moral relativism is the right way to see the world *always*. But sometimes its the right way, depending on what youre doing and what your goal is.


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

[User]
[MCU] Did Steve Rogers get snapped the second time?

Since he went back in time to be with Peggy, and then survived at least until the end of Endgame, we know he went through the Blip a second time. Did he get snapped that time or did both versions survive?

[Assistant]
Everything that Cap did between him hopping into the time machine with the Infinity Stones and showing up as Old Man Cap was in a different universe/timeline than the central Golden Timeline, just like the other time travel shenanigans throughout the movie.  We don't know exactly how/when Old Cap showed up, but the easy assumption is that he used his quantum watch thingy to show up on the bench instead of on the time machine platform.  Which should be possible, since they used the watch to go from NYC in 2012 to New Jersey in 1970, so we know he can pick his time and place to return.

And if we start with that, he may not actually have made it to the Snap.  Assuming that Carter's life and health are relatively similar to in the regular timeline, she'd have died somewhere around 2014, while the Snap occurred in 2018.  It's possible that Cap stuck around for all of her life, and after that point, dug his watch out of a drawer, grabbed the shield, and hopped back over to our timeline.  He may very well have missed the alternate-Snap by a few years.


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

[User]
[Dune] If the spice is needed for interstellar travel and the spice can only be found on Arrakis . . .

How did they get to Arrakis in order to find the spice? Is the story under the premise that all life started on Earth?

[Assistant]
Spice *isn't* required. A computer can make all of the necessary calculations to allow a faster-than-light jump.

But, about 10,000 years before the events of the main *Dune* books, there was something called the Butlerian Jihad, which did away with all "thinking machines," primarily computers, robots, and any artificial intelligence. Now, the prime edict of the Orange Bible is "thou shalt not make a machine in the likeness of a human mind."

This had long-lasting effects on the *Dune* universe. One, there are now people called Mentats, humans with computer-like mental capabilities who now serve the role of those former thinking machines.

Similarly, the members of the Spacing Guild use their prescience, gained from saturation in Spice, to see if a ship's planned course will end in a disaster.

The cause of the actual Butlerian Jihad, by the way, are never fully explained.


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

[User] ELI5: How do our bodies know to start puberty, where is the clock for that?

[Assistant]
The hypothalamus is the control or master gland of the body controlling all the other endocrine glands of the body, including the testes in boys and ovaries in girls.

At birth there is normally a mini puberty lasting about 6 months where the level of a hypothalamus derived hormone called GnRH (or LHRH in some countries) is very high, which causes the pituitary gland to release two hormones called LH and FSH which in turn act on the testes and ovaries.

Levels of GnRH then fall away to practically zero, as do levels of LH and FSH until the time puberty is due.

There is a gene called GPR54 and this is thought to be a puberty regulation gene as it helps to set the time of puberty by releasing a hormone called Kisspeptin which tells the hypothalamus when to release GnRH to start puberty.

The timing is set so when the body is big enough to be able to become fertile, puberty will be initiated by allowing the release of Kisspeptin. This timing can be influenced by external and genetic factors where puberty can start early or not at all (as in in Kallmann syndrome). Timing of puberty can be influenced by poor diet or excess fat in the diet which affects the levels of certain hormones or is can be influenced by excessive exercise.


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

[User]
Need Economics Joke/Pun/Reference for a Gift

Hi! Odd questions, but I'm buying a personalize oversized mug for my economist wife, and I want it to have a humorous econ reference printed on it, referring to its size. What would be a good gag?

So far all I got is "Reverse Shrinkflation" or "I Reject The Law of Diminishing Marginal Utility."

Would either of those elicit a wry smile or a sensible chuckle? Any other ideas?

[Assistant]
How many economists does it take to fill a coffee cup? None: If the coffee cup needed filling the market would have already done it.

Economist: Someone who knows everything about money but dresses like a flood victim.

After finishing all the coffee this cup, you'll be familiar with the law of diminishing marginal utility.

Economists do it in an Edgeworth box.

Five apples a day keep the doctor away. Inflation.


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

[User]
CMV: In certain forms of motorsport, the competition isn't to see who has the best driver, but to see who has the most money, best car, best pit crew and the best tuners.

These motorsports aren't very technical. Drag racing and land speed racing is go in a straight line as fast as you can. It's when motorsports start to have corners in them that the required skill to compete becomes higher. At least in drifting, autocross, rally and endurance racing, there's a big skill component that plays into the sport because of all the corners involved. Heck, even NASCAR takes a lot of skill to perform well in.

In drag racing, unless your car breaks or your driver is a COMPLETE idiot, a tube chassis drag car with a billet engine block will beat an average joe with an iron block Mustang motor 95% of the time. Horsepower costs money, and a lot of it once you get into the quadruple digits. Race gas can be 10 dollars a gallon or more, and you burn a lot of fuel going fast. Top Fuel drag cars need to rebuild their engines after every run and a bad rebuild can make or break the next race the car is in.

[Assistant]
Drag racing isn't as simple as you make it out to be. If you knew much about drag racing you'd know there are classes to keep competitors on an even playing field. If you bring out your stock mustang, you can drag race against another stock mustang.  Or you can invest to make your mustang faster, and race against faster cars.

Your top fuel dragsters are top of the heap, they generate so much power it is an engineering feat to get them down the track on one pass, and serious training is required to pilot those machines. Drivers don't get paid to drive easy cars. They get paid to drive cars that are hard to handle. If the cars are easy to drive, they are slow, and they lose.

You would be wrong to say that Mercedes passes more cars in F1. There are two reasons for this, first is they start at the front. Not many to pass. Second because they know they will start from the front, they design the cars to be optimal out in the front. This actually hinders them when they aren't in the front. You can see Lewis Hamilton cut through the field in a Mercedes, because he is one of the best out there. His teammate, although a great driver often gets stuck behind slower cars when stuck in the pack. All professional drivers have awesome car control, but not all professional drivers are of equal skill. Some are just better.

Racing is truly a team sport when you get into the professional ranks. Every aspect of the race is optimized, so having the best talent to do that increases your chances at success. Everyone who excels at what they do demand more compensation for their advanced skills. So it's just plain logic that spending more money should get you more results. But you have to balance that spend. That's what makes a great racing team.


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

[User]
Arguments against "back in the day people were tougher and smarter" and the "good times create weak men" viewpoints?

Some time ago i had a "conservative" classmate who used to talk about these types of views a lot and constantly argued that "people nowadays are dumber and weaker than people in the past" and seemed to believe the "weak men create hard times --> hard times create strong men" type view which i feel like is a huge simplification of history and is generally wrong.

What are some good arguments against and for both of these ideas?

edit: thanks for all the replies!

[Assistant]
I guess that's a more complicated question than it appears at first glance. There are several different problems to solve:

1. Were people smarter and stronger in general populace on average? Or people that were notable enough to remembered by next generations? If the latter, you must account for survivorship bias.
2. Stronger by what measure? Psychologically? Physically?
3. Smarter at solving which problems? Maybe the problems they are faced were simpler, so apparent intelligence was then higher.


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

[User]
ELI5: Why is the jugular so exposed?

Shouldn't such a central vein be more protected?

[Assistant]
well the most important jugular vein that runs to your brain actually has some pretty good coverage,  the SCM lies right over it.

as for the other jugular veins, they drain blood from places like your superficial face, head, etc.  so they're really taking blood right from the surface of your body, which makes them a bit difficult to cover up.


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

[User] [Star Wars] Does anyone ever use the Force for art?

[Assistant]
The universe is really big and full of force-sentitive beings, so probably yes.

What the Jedi would not tell you is that the good art is an expression of emotions, and the Jedi ideology is all about repressing emotions. The Sith ideology is basically about putting themself into the positive feedback loop of self-amplifying emotions to increase your power, so guess who makes the better art.


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

[User] ELI5: How do the iron sights on a gun work if they are above where the bullets are fired?

[Assistant]
Iron sights form a straight line, while the trajectory of the bullet is an arch (as the bullet falls down during flight). Usually the sights are calibrated in a way so the bullet path intersects twice with the line of sight of the iron sights. The distances where they cross (where you can get an exaxt hit) depend on the weapon and its effectice range. Nearer and farther than these two points you hit low, between them you hit high. The exact measures on how low/high you hit, againm depend on the weapon.

Adjustable scopes can be changed to (almost) always hit perfect. But you have to know the distance to your target or estimate it.


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

[User]
How does inflation work, and what are some of the ways inflation can increase?

I have a hard time understanding inflation. When I was a child, I would say the government has all the money in the world, they can just print more of it.  My father would reply by saying that would cause inflation.  What did he mean?

[Assistant]
In very basic terms, the value of money just represents all the things in the economy you can buy. So let's say you have M=money and G=goods(and services). In the short term, it's just G=M, so if M becomes a higher number, and G stays the same, more money is necessary to buy the same amount of goods. That's inflation

Another example, let's say you have 10 money and 10 goods, every good is worth 1 money. If you double the amount of money, you can still just buy 10 goods. So every good is now worth 2 money.


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

[User] eli5: How do wireless chargers work?

[Assistant]
There are two metal spirals: one in your phone and one in the wireless charger. The one in your wiresless charger spins the electricity around the spiral, which creates a strong magnetic charge because electricity and magnetism are inseparable.

Since the spiral in your phone is close enough, it causes a "sympathetic" electrical charge in your phones spiral, since the magnetic charge also makes an electrical charge.

This is why they're pretty inefficient: they need to hop between a bunch of material and the transfer of electricity this way requires way more power that a traditional charger.


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

[User] ELI5: Why do even state of the art nuclear fusion reactors use a steam turbine to generate electricity? Why isn't there a better way to turn heat into electricity?

[Assistant]
Step back and ask what you're trying to do.

You have a crap ton of heat coming off the reactor and you want to do something with it.

You can conduct that away with a solid (heat sink), a  fluid (liquid or gas coolant), or a hybrid (heat pipe). It's \*much\* easier to use fluid because you can easily move it around, the others are very fixed on the possible geometry and much harder to move long distance.

OK, so we want a fluid. Liquid or gas? Well, any thermodynamic cycle is going to need to cycle between low and high pressure and it's \*much\* easier to raise the pressure of a liquid than a gas because the compressibility of liquids is so much lower. So we want a liquid.

Now we want to get energy out of our hot fluid by using it's temperature & pressure to do work...for the same reasons that it's much easier to raise the pressure of a liquid, it's a lot easier to get a lot of energy \*out\* if it's a gas. So we want a liquid coolant that we can boil into a gas. That means our liquid should have a boiling point somewhere in a reasonable range (not too low or condensing it is a pain, not too high or all the containing hardware is too complicated/expensive). So we're down to liquids that have boiling points somewhere between where we can comfortably refrigerate (say, -40C) and temperatures we can handle without stupidly exotic materials (say several hundred C).

And we want to do all this with reasonably sized equipment, so we want a coolant that can handle a \*lot\* of energy per unit mass, which means a very high heat of vapourization.

That narrows the field down a \*lot\* and, in almost all situations, water turns out to be the best fit. Bonus points that it's stupid cheap, non-toxic, ubiquitous, and we have a gazillion person-years of technology already invested in how to handle water efficiently.

That's why we use water/steam.

But why a turbine? Well, we need to expand the gas through \*something\* to extract energy. That can be a piston, that can be a turbine, that can be a goofy water-wheel thing (Pelton turbines will work on steam if you want to). We just want whatever is the most efficient and, once we have that, most compact. For compactness you want continuous flow, not pulsed, so pistons are out. And for high efficiency you want high expansion, which means multiple stages, so water-wheel thingies are out. And you're left with...turbines.

There's no inherent physical reason there can't be a better machine out there, we just have no idea what it is. Yet.


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

[User]
What is it that makes the mechanism of a watch slow down in space travel?

Really I guess I'm looking for a layman's description of what exactly causes time to pass... Would people age differently in different parts of the Universe because of a difference of gravitational forces on their bodies? How does this affect the actual ticking mechanism of a clock or watch?

tl;dr- I watched Interstellar and used to consider myself a kind of smart person... Looking to rebound myself.

[Assistant]
Imagine for a second that your buddy Jim can throw a baseball at 60mph, but he wants to throw it faster. So he gets in the back of his buddy's pickup and has the buddy drive at 30mph while you stand off to the side. Now Jim throws the ball, how fast is it going? 90mph, right?

Well, it's only 90mph to you, because you're not in the truck. To Jim, the ball only looks like it's going 60mph because Jim is already moving at 30mph in the back of the truck. The difference in the speed is due to which frame of reference you're in, whether it's relative to being in the truck, or relative to standing there watching the truck. We call the general concept of this difference *relativity*.

Now let's say you did the same with a flashlight. It shoots out light particles, so maybe if you got in a fancy suped-up ultra fast space shuttle, you could get the light particles to go even faster. Well, not to you, because you're on the shuttle, but to your buddy Jim standing back on the ground watching you.

But it doesn't work!

The speed of light doesn't change with the frame of reference like baseballs do. Relativity doesn't work the same with light like it does with baseballs. The nature of light is so much different than the nature of a baseball, that it doesn't care what reference frame the viewer is in. It's always the same speed. This phenomenon isn't very natural sounding, but it has been shown many times to be true, and it's even part of the reason that nuclear fission works!

Well, this whole light not obeying reference frames causes all sorts of problem. Like that nothing can go faster than the speed of light! It's kind of like a boundary on how fast things can go. Pretty much only light can go the speed of light because it's massless, but most other stuff has mass so it can't even reach the speed of light.

But if "massful" stuff gets close to the speed of light, crazy things start to happen. Things called *relativistic effects*. Things like time slowing down. Except it doesn't slow down for anyone on the massful thing. It thinks time is going like normal. The clock on your shuttle ticks a normal beat just like it always did because you're on the shuttle, going the same speed as the shuttle. Time instead slows down for everyone not going the speed who's looking up at you, like your buddy Jim who's back on Earth. He's watching you zip around at maddening speeds, and when he looks at your clock on the shuttle, it seems to be going slower to him than the clock on his wristwatch. Time is passing slower on the shuttle than it is back on Earth, but only your buddy Jim and everyone else on Earth can tell.

That's what happens in *Interstellar* except the situation is switched because of the black hole. On the flip side of massless light is really massive stuff, like black holes. Their gravity is so strong, that it literally bends light which can also cause relativistic effects to happen. Matthew McConnaughey and Anne Hathaway go down to this planet that's in a place near the black hole where relativity is a bit screwy and time moves slower, while the other guy on the ship is aging waiting for them to come back. For him, it takes years for them to return, but to McConnaughey and Hathaway it was just a few hours. All because light has to be the same speed no matter who's looking at it from where.


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

[User]
Why do certain foods give you diarrhea an hour or two after consumption when it takes 8hrs to go through your entire digestive system?

Self explanatory.

[Assistant]
Well Timmy, your body needs food for energy, and they need all kinds of different food for different reasons. If your body doesn't need any more nutrients from the food, it releases it and you poop. Those are the ideal circumstances.

When the body encounters a problem, and doesn't trust the food you've given it, it speeds up the release process and waters it down so it passes more quickly. This can happen if you're sick, and the body is rejecting some foods, or if there's something wrong with the food and the body needs to get rid of it to keep you from getting sick.


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

[User] ELI5: Why do fingernails grow much faster than toenails?

[Assistant] Nails are basically protective and since our fingers are busier than our toes, they are more likely to need replacing. Also, constant exposure to sun and air may aid their growth. Feet are locked up in shoes most of the time.


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

[User]
Life outside academia

I am a graduate student, and I always thought I would like to pursue an academic career. However, throughout college, I met many phd student, post-docs and professors; I have some real doubt that I want to have the life they have, in particular because it means dedicating -almost- your whole life to it.

I would like to have some insight on how it is or not possible to conciliate an academic life with other activities, such a a family, political activity, sport activities, musical activities, etc.

Practically, I would like to know what is you position, how much time you dedicate to your academic career, and how much free time you can chose to allocate to whatever you want.

It would be really helpful to gain insight from here, cause I have the feeling people may tend to speak more freely here than the academic people I meet in real life.

Thanks!

[Assistant] Very field dependent and personality dependent too. Academics who gave their lives to the job are probably addicted to some aspects of it, either those zen 'flow' moments when doing research or getting their highs from the admiration of students. And there's never a ceiling for those since it's not a 9-5 job. You could always chase the next high and do more research, collect moar pubs. There's always some new pedagogy tricks that maybe, just maybe this time gets you a glimpse of that look in students' eyes and those small nods when they become enlightened by something you said on stage. Why would you *want* a life outside academia?


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

[User]
[Predator] Did Dutch WANT or NEED to kill the Predator? Would he have escaped without killing him if given another chance?

What I mean, was he doing it for survival only? Or did it become personal for him?

[Assistant]
I think it was both. He has no reason to believe that it would ever stop hunting him, and from what we know of the Predator, he'd be mostly right to believe it.

Avenging his team was probably an extra incentive on top of that.


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

[User] [Inception] How are the den of sleepers (In Mombassa) able to share a dream for so long without their projections turning on them?

[Assistant] They are probably not set up with a single architect designing and modifying the whole dream environment as the inception crew were.  It may be be more of a subconscious, collaborative, world building.  Something so intuitive to the dreamers would seem unlikely to disturb their projections.


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

[User]
[Marvel (any)] Could the dwarves forge an "infinity hammer" with slots for all of the gems/stones, and if so, would it be any more powerful than a regular steel hammer with slots for the gems/stones?

Basically, would the ~~Asgardian n-th metal~~ Uru help in any way in terms of power?

I guess it could allow the user to call the hammer (and thus the gems) back to him?

Wait, what if... could the hammer be forged AROUND the gems, locking them inside?  Obviously anyone holding the hammer could use the power of the gems to melt the hammer (I guess?  Do the gems work that way?  It seems like the stones do...), but ...

Speculation?

[Assistant]
Once all the gems have been collected it really doesnt matter what you mount them in, on, or anything in between. You could power a tank with the infinity stones but it would be the same as if you turned them into a walking stick or a boot.

The gauntlet adds very little to the power of the stones and once you begin to reshape reality and blink billions of things into/out of existence the fact that your power rests in a hammer or claw or danish doesnt add much.

It would be like mounting a nuke onto the end of a .22, is a .22 dangerous? Sure, but it pales in comparison to the nuke.


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

[User]
Why can't I cut a solid, and then stick the two pieces back together again?

If I take a solid iron rod, and saw it in half, what is actually happening on an atomic level?  And why I can't I stick the two solid pieces back together, unless I convert one of the pieces to liquid first?

[Assistant]
You can. In fact, it's known as cold welding and commonly used in space.

Under normal conditions, the moment you cut it, contaminants stick to the surface and the metal reacts with the atmosphere to form an oxide layer. This prevents the previous metallic bonds from reforming.

For other objects, they tend to have crystalline structures which have to be perfectly aligned to reform the bonds.


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

[User] Is the Chernobyl explosion different from a Nuclear warhead test w.r.t to the nuclear radiation it emits?

[Assistant]
The main differences between a bomb and a power reactor is that the power reactor contains much much more radioactive waste, most of it is a ground level release and doesnt go into the upper atmosphere so it has a direct/local effect, and the power reactor will continue to have airborne releases after the initial failure as the core melts.

A bomb explodes all at once, has a small amount of waste, a lot of it goes airborne, and once it explodes its done because all the material scatters or vaporizes.


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

[User] ELI5: Why does drinking water not always help with dry mouth?

[Assistant] It takes time for water to make it through your digestive tract where it can be distributed to cells via blood. Water in your mouth will *rinse* your mouth, but it won't get the water *into* the cells themselves to a significant degree.


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

[User]
We're there any ancient atheist societies?

It seems like the farther you go back in time the more religious/spiritual groups were. Were there any ancient societies that were atheist, or just never developed spiritual beliefs?

[Assistant]
Atheism is a modern conception, requiring the belief in 1. non-divine systems of explanation, and 2. acceptance of that non-divine system as a societal alternative from which to organize moral behavior.

1. is made harder by the fact that theory and divinity are hard to separate in the ancient world.  When we think of love, we think of it as an abstract non-divine concept (alternatives being material/biological conceptions).  They thought of love as both abstract (you're in a state of being) and personified (it is a divine entity that has caused your change to the state of being).  If you can't separate theory from religion (because they didn't even conceive of that separation), how can you have atheism?

2. is made more difficult by the fact that it tends to require a robust coercive alternative to moral sanction.  Usually, that requires a complex and effective legal system.  The reason why people turn to supernatural outlets for their grievances is because it is seen as more responsive than human ones.  Ancient law tended to only benefit the very powerful.  And even if it was seen as partially beneficial to the people at the bottom, there were simply not enough administrators running around at the ground level to supply everyones needs.  i.e. "where's a cop when you need one?"  A curse or a invocation to a deity is the cop everywhere, when you need it.

Some sources:

* Dickie, Matthew W. Magic and Magicians in the Greco-Roman World. New York: Routledge, 2003. Print.

* Horstmanshoff, Manfred  and Marten Stol, eds. Magic and Rationality In Ancient Near Eastern And Graeco-Roman Medicine. Leiden: Brill, 2004. 13351. Print.

* Gager, John G., ed. Curse Tablets and Binding Spells from the Ancient World. New York: Oxford University Press, 1992. Print.


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

[User]
[Batman] How come Arkham Asylum is still up and running when multiple villains keep escaping from it?

Like, wouldn't it be shut down because they cant keep people in?

[Assistant] Have you seen the people in there? Its not like any regular prision has conditions to imprison those guys to begin with... The very fact its still able to keep them is impressive in itself... And well with every escape arkham try to improve its security, but again, they are dealing with super humans, master escapists and sometimes even outside forces...


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

[User]
How do animals know that they should perform certain behaviours, even if never shown by their parents/peers?

For example, my rabbit was kept in a hutch from birth separated from the mother. And as soon as I took her home and allowed her to run in my backyard under supervision, the very first thing she did was start digging a burrow. How did she know to do that? She had never, ever been shown to do that by any other rabbit.

[Assistant]
All organisms have certain instincts or reactions built into their biology.

This is why, within reason, animals and plants will always exhibit characteristic behaviours when given the opportunity.

It's very literally in their genes. They simply learn faster and potentially more effective ways to use those instincts (for sentient creatures) if they witness another creature exhibiting the behaviour.


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

[User]
[Return of the Jedi] What happened to the Emperors guards?

Did they stay on the station or evacuate? Did they even know that the Emperor had died?

[Assistant]
Given that they were Force-sensitive, they should have felt the death of the Emperor and if they were smart enough they would have evacuated.

However, to be honest, they clearly sucked at their job.


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

[User]
ELI5: do 100% blind people see any particular color even though they are blind? If so, what do they see and why?

More so if they do see any color, how and why can/do they see that color. If they see nothing then how would you explain how that would "look"  to a person who can see?

[Assistant]
I have read an interesting article about this. You might know there are some animals that have some sort of compass in their bodies. This way they can always sense what destination they are migrating at. Asking a blind-at-birth person what they see is like a migrating bird asking a human what they sense if they can't feel where the magnetic north is.

To put this in another way. Your field of vision stops at a certain point. If theres a mosquito buzzing around your ear you can not visibly see it. Is the mosquito in an area that is black to you? Someone who is born with only one working eye misses an entire area of vision. Is this part of vision black? No, his/her vision now consists of the part that he/she can see, like all of our visions are.

Blind people don't see colour, blind people dont see black. Blind people simply can't experience "vision or colour" in the same way that you can't feel a magnetic force.


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

[User]
[Harry Potter] When did the wizarding world stop using new technology? Or alter alternatively: are they just way slower at adapting them?

The wizarding world (at least in Britain) *does* use some technology. They use the wheel they use the written word (both more than 3-4000 years old), they use glasses (ca. 13th century) and newspapers (16th century) but probably use magic instead of a printing press to produce them. They use steam trains (1800s). Their most "recent" architecture style also seems to suggest 19th century to me (e.g. in Diagon Alley).

Yes, Arthur Weasley has a flying car, but he is a Muggle artefact expert and admittedly a bit odd with regards to the average wizard.

So, the question remains: when did the wizarding world stop using new technology?

**EDIT:** sorry for the error in the title, Im typing on my phone.

[Assistant]
They didn't really stop, but slowed their development considerably, likely because of whatever drove them to keep their secrecy from muggles. Without having a common element to drive their technological/magical development in that way, and the functions of most forms of technology reproducible by magic, it slowed down. However, some stuff does occasionally filter through, from either muggle-born mages, or from wizards seeing something neat, and wanting to replicate that in a way not possible with existing technology, and magic, which is why we occasionally see anachronistic objects like Colin's camera, Sirius' motorcycle, the Knight bus, and the Weasley's car.

Development of technology might also be stymied by traditionalist wizards like Lucius Malfoy,  or Dolores Umbridge, who prefer to keep to the old ways, rather than adapting inferior muggle technology, and soiling magic with it.


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

[User]
My former P.I/Thesis Advisor went nuclear against the whole lab, me included. Advice appreciated

Tl/dr: I can't get a rec. letter from my thesis advisor because we do not see eye to eye anymore and I don't think it is my fault that this has happened.

Roughly two years ago I joined a bioinformatics lab for my Masters, my P.I. back then was an amazing mentor, she was patient, insightful and rewarded independent thinking and proactiveness. We published four papers together and went to a few conferences, so I was pretty damn sure that I would get a good recommendation letter (especially since I was also a T.A. for her class, extra-officially).

Last year we had some drama happening in the lab, a postdoc was basically just playing computer games in lab all day and leeching off the graduate students' work, the P.I. got (understandably) mad at the whole lab and fired the dude. After that she was never really the same and got progressively worse month after month, starting to verbally abuse her students in front of the whole lab and stopped relegating the good projects to us (she would just work on them herself and publish alone or with her collaborators).

During this time I was in an internship in my dream university in the US so I thought it was just a transient thing, but as soon as I got back and told her of my desires to pursue a PhD in the US she completely "disowned" me, going so far as removing me from the lab communication group since I were "already with a foot out", in her own words. This happened a few months before my thesis defense, which she went out of her way to make as complicated to schedule as possible.

I am not going to ask her for a recommendation letter, as I have no idea if she will actually write about what we accomplished or if she will sabotage me. I know this potentially looks bad for my application as she was my thesis advisor, but is there any way I can communicate her descent into spitefulness (obviously not with those words) without making it sound like excuses? I'm pretty sure she was struggling with mental health issues and a lot of stress, and that she also probably felt betrayed for trusting so much in her students and having them stab her in the back, but it seems unfair that I should get penalized for those things.

Anyway, thank you for reading thus far, have a great day.

[Assistant] You have to ask her if she is comfortable writing you an strong letter. If she isn't, perhaps a former postdoc from your lab that you have a good relationship will, and will explain the situation a bit.


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

[User] ELI5: What is the difference between civil twilight, astronomical twilight, and nautical twilight?

[Assistant]
Sunset

**Civil twilight** - sun is setting, artificial light is not needed

Sun falls below horizon

**Nautical twilight** - sun has set, but it is possible to navigate by the shape of the horizon

Horizon is no longer visible

**Astronomical twilight** - Bright stars and planets become visible

Sky is fully dark, all stars can be observed

And then in reverse in the morning.


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

[User]
[Star Wars] Has the Force ever refused to do something?

We've seen evidence that the Force is conscious in some way. Jedi talk about the "will" of the Force a lot, and the Force created Anakin seemingly out of convenience. So has there ever been a time when somebody tried to make the Force do something so against its will that it straight-up refused to do it?

[Assistant] No. The Force isn't actually conscious. When people talk about the Force having a will, they mean it in a sort of, destiny or fate kind of thing. *People* can defy fate temporarily, like Anakin did when he became Darth Vader, but he was still fated to destroy the Sith, which he did in the end over the forest moon of Endor.


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

[User]
Are numbers themselves "real"?

They are certainly real as symbols in our language of math, but if there were no sentient beings in the Universe, would "7" still exist in abstraction somehow?

Does science account for this by accepting that non-physical "things" such as numbers and mathematical truths are just as objectively "real"  as things made of matter? If so, what non-physical yet real things does it affirm exist other than mathamatical truth itself?

[Assistant]
They exist in the same way other descriptors exist.

Take brown for example. Brown doesnt exist on its own, but something can *be* brown. Even if humans didnt exist, the word brown didnt exist, the fact that an object reflects the combination of wavelengths that we call brown is still true.

Numbers exist in the same way, as quantities of things. Suppose there are two trees. Even without humans and language there is still the property of two that applies to this pair of trees.


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

[User]
[Warhammer 40K/Fantasy] Is the thing about the chaos gods not being one dimensionally evil no longer canon?

I seem to recall that Khorne was god of honor as well as blood, and Nurgle was god of pestilence but also of life and rebirth. Things like that, however when I bring this up, it's dismissed. Was this retconned?

[Assistant] They are still the gods of those things, but the negative aspects of their portfolios are far more prevalent. Khorne is still empowered by noble warriors the same as he is by senseless carnage, but there are a lot more bloodthirsty axe wielding maniacs in 40k than noble warriors. Slaanesh is empowered lovers of fine arts just like acts of depraved hedonism, but there's a lot more depraved hedonism than fine art in 40k. And so on.


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

[User] ELI5: Why do most women get their first period around age 12 when their bodies are usually not well developed enough to safely carry a baby to term?

[Assistant] Others have covered some facets of this such as puberty/menarche starting earlier now than in the past on average for various reasons, but also worth noting that the first few periods a girl has are usually anovulatory. Meaning no egg is actually released. Ovulation (egg release) requires certain hormones to reach a threshold in order to happen and while those hormones are fluctuating enough to cause bleeding (progesterone withdrawal) when a girl gets her first period, they are not high enough (LH/FSH) to release an egg. This could be the case for just one or two periods in some girls, or periods could be entirely anovulatory for up to a few years in others.


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

[User] ELI5: How do companies that make things such as drone remotes and car keys ensure that the signals wont work with other drones/cars?

[Assistant]
Much like a physical key, each remote key system uses a unique code to identify itself.  It was not always like this; in the early days of remote keys, a manufacturer would use a limited number of codes, and it was possible for a key to open a car that wasn't yours.

Today it's typically taken a step further using what is called "rolling code."  Basically, both the key and the car get a copy of the same book, and they each maintain a bookmark.  When the key gets pressed, it transmits the first sentence of the page we're on.  The car checks its copy of the book, says "yup, same as what I've got" and both turn to the next page for next time.


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

[User] ELI5:  If the flu didn't evolve, would one vaccine be enough for one's entire life?

[Assistant]
Yes.
Assuming you weren't looking for a simple yes/no answer, is your question "How do vaccines work?" If so:

People are born with a full immune system composed of cells, glands, organs, and fluids that are located throughout their bodies to fight invading bacteria and viruses. The immune system recognizes germs that enter the body as "foreign" invaders, or antigens, and produces protein substances called antibodies to fight them. A normal, healthy immune system has the ability to produce millions of these antibodies to defend against thousands of attacks every day, doing it so naturally that people are not even aware they are being attacked and defended so often. Many antibodies disappear once they have destroyed the invading antigens, but the cells involved in antibody production remain and become "memory cells." Memory cells remember the original antigen and then defend against it when the antigen attempts to re-infect a person, even after many decades. This protection is called immunity.

Vaccines contain the same antigens or parts of antigens that cause diseases, but the antigens in vaccines are either killed or greatly weakened. When they are injected into fatty tissue or muscle, vaccine antigens are not strong enough to produce the symptoms and signs of the disease but are strong enough for the immune system to produce antibodies against them. The memory cells that remain prevent re-infection when they encounter that disease in the future. Thus, through vaccination, children develop immunity without suffering from the actual diseases that vaccines prevent.


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

[User]
ELI5: How do puzzles benefit our brains?

Like, yeah I can see how it helps keep your brain active by like solving problems, but how else does it benefit the brain?

How does it improve the brain?  What specifically happens? Are there other types of puzzles we could create to better help ourselves or even overcome certain problems?

Exercises memory too I guess?

[Assistant] Puzzles mostly help your brain get better at doing those specific kinds of puzzles. Most of the train your brain using these puzzle games style services or activities tend to greatly exaggerate the expected benefits. There might be some from just generally being active, and some skills that you practice or learn in the process of doing puzzles might help with working on more general problem-solving, logic or spatial reasoning, but for the most part, its not actually doing anything special to your brain to improve it in any particular way.


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

[User]
ELI5:why do orchestras need music sheets but rock bands don't?

Don't they practice? is the conductor really necessary?

[Assistant] In addition to other answers, rock bands play the same songs over and over, most orchestras dont.  They might play the same pieces for a few performances one but then their next performances will be a different set of pieces probably by a different composer.  Looks up any major symphony orchestra schedule and youll see how many different pieces they play in just one month!  Its entirely different styles of performance basically with different goals and different needs.


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

[User]
What is happening inside your brain when you are drowsy?

Example: When you are struggling to stay awake in the car and your head starts nodding off but you try really hard to stay awake, what is happening? How is the brain able to stay awake when if feels the urge to sleep so strongly?

[Assistant]
A simplified answer: while counteracting sleep pressure (or drowsiness or sleep deprivation), parts of your brain that govern attention become more and more active as you try to sustain attention. This 'compensatory' activity in these regions also drives activity in parts of your brainstem that promote overall arousal.

These brainstem arousal centers in turn generate wakefulness in the rest of the brain, like the cortex. They also serve to inhibit inhibit sleep-promoting centers of the brain. This enables sustained attention despite sleep pressure. But eventually, with enough sleep pressure, no amount of compensatory activity will prevent lapses in attention.


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

[User]
[Marvel Zombies] How did a robot get turned into a zombie?

I'm talking about the Vision.

[Assistant]
IIRC Vision wasn't a zombie, just bashed up and hooked up to stuff by the zombies who were using his robotic systems for their own ends.  He is a prisoner of the zombies not one of them himself.

All the non-organic heroes were immune to the zombie plague.  Thats why Machine Man was the one sent to the zombie dimension.


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

[User]
ELI5:Why Does the Texture of Paper Change After It Gets Wet and Dries

Most things get wet, dry, and look similar to how they started. With paper, it ends up having a different texture after it dries. Why?

[Assistant]
Plant fibers swell when wet, and shrink when they dry, somewhat like sponges.  Among the last stages in making paper is rolling it between giant metal rollers, while it's still damp, but in the process of drying.  This pushes the fibers together, helping them interlock better so that it's stronger when it dries and shrinks down, and gives it that smooth texture.  When you get it wet again, those fibers swell back up again, and "unlock" from one another, like hair on a damp day.  When it dries back out, unless you roll it back flat while still damp, those fibers will stay unlocked and frizzy.  Paper that's gotten wet and dried again will also be less strong and easier to tear than paper straight out of the package.

There's also various chemicals that are added to the pulp to help the fibers stick together and not be quite as absorbent as it would otherwise be, and when you get it wet, some of those chemicals are diluted or washed away.

You can think of it like having naturally wavy hair, and making paper is like washing your hair, ironing it flat, and filling it full of product to keep it that way.  All it takes is a good drenching, or even just a humid day, and your hair is back to being all crazy-wavy.


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

[User]
ELI5: Are sweatshop workers better off if their factories close down?

I assume people work for sweatshops (I'm talking about adults here) because they have no better option.  Would they be better off if the sweatshops closed down?  What else would they do for money?

[Assistant]
If you're in a third world country, your other options might include:

* Farm work: You vs. the elements, back breaking work
* Mining: Sometimes in dangerous, unregulated, illegal conditions
* Waste management: Possibly dealing with dangerous waste from first-world nations such as electronics which can contain highly toxic substances
* Prostitution: STDs, possible abuse, elevated chance of being targeted for severe crime such as murder
* Crime: Well, it's illegal

Sweatshops are terrible but that's coming from a first world perspective. Many in third world countries wouldn't be able to get by that well without them.

You'd rather work in a sweatshop than in the other dangerous, even worse work conditions you could be in.