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

[User]
Software Package?

To describe the situation, I am a very recently graduated PhD student who will be entering a faculty position in the fall. My field is biostatistics. I have recently published a paper detailing some (in my humble opinion) cool new methods that is garnering some attention, and several groups have contacted me about implementation of my methods via an R package that I published. Great! I'm excited and humbled that people have found my work useful.

Here's the problem: my R package sucks. Frankly, it sucks ass. I'm not a programmer and I did not approach package development holistically; instead of evolving the package alongside my work as I wrote the paper, I chucked a bunch of disparate functions in the package after I had hardcoded my methods repeatedly (with tweaks) throughout my research. Broadly put, my methods integrate multiple sources of data that have very nuanced and confusing formatting (think genetic and genomic stuff). Trying to provide a full suite of functionality for this application feels daunting, bordering on impossible. There's lots of fine tuned QC that it feels like my package should implement, but doesn't. There's some QC and alignment my package performs, but there isn't a coherent pipeline, and many reasonable things you would want to do are not easy to implement.

What's the solution here? Is there one besides 'do better'? I'm not a software developer, I find it boring as hell and I'm not good at it. Do I dedicate a couple of weeks + (that tbh I don't have) to really upgrading the package and retesting it in all of its use cases? Is the responsibility on other researchers to understand my shitty code? Should I just keep answering questions over and over and try to gently guide researchers along so they don't give up on my method? Curious as to how others handle this.

[Assistant]
Im not lucky enough to be an owner of a popular package (congrats!), but one thing you could try is to make the package source code accessible to the public and let other people help you out.

I dont know where is your package hosted (CRAN?) but if you also host it on Github and describe that optimalization is needed in the readme, someone who finds your method useful could help improve your code.


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

[User]
ELI5: If the universe is constantly expanding at all points, how can earth (and other planets) maintain a cyclic orbit around the Sun?

Wouldn't the distance between the sun and planets slowly increase which would cause them to eventually lose orbit?

[Assistant] The other answer is wrong. The distance between the earth and the sun is not increasing due to the expansion of space. The gravitational well that is created by our galaxy forbids it. In other words, the gravitational force generated by our entire galaxy counteracts the effects of the expanding universe, and *within* the galaxy (where we live), space is not expanding.


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

[User]
[Spoilers][No Way Home] Exactly how powerful is...

The Green Goblin? He took Tom Holland to the wood shed physically and was able to withstand a Spiderman probably not pulling his punches. And Spiderman has been shown to be able to stop a punch from Winter Soldiers metal arm with ease. Does this mean Green Goblin is on par with or stronger than a super soldier?

[Assistant]
Green Goblin is far stronger than an MCU supersoldier. The Goblin Serum from the Raimi-verse is more powerful than the Super Soldier Serum from the MCU.

Peter Parker is probably the strongest human in the MCU that weve seen other than Captain Marvel and the Hulk (if he counts as human). He held up that walkway at the airport fight and throws around cars with ease. Norman is in his physical tier. We dont know if Norman is stronger or weaker but we know its not much different either way.

Norman is probably physically much stronger than Captain America.


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

[User]
[Dnd 5e] I'll a human with 18 in all stats who wants to live forever, what's the best way to do It?

I know some people going on a quest soon and I could join them, I heard about liches but it seems lots of people want to kill them and it's hard to enjoy. What's the best method to live forever and be able to enjoy it. I would like to get powerful to if possible.

[Assistant]
With an 18 CON you're going to get a good bit of the way there just with clean living and staying out of trouble.  But with an 18 INT, you knew that already.
Outside of that, become an 15th level Wizard or better, or get to know one willing to cast for you, and the *Clone* spell should do it for you.
You'd have to get it recast any time you actually die, but there's no real reason you can't keep the chain going in perpetuity.


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

[User]
ELI5: Why do the photos I take not match exactly what I'm seeing?

For example: It's a gorgeous sunrise. The sunlight is shining through tree branches and illuminating streaks of light through the morning fog. I snap a picture to capture it, and end up with a photo of... a nondescript tree with some light behind it. Why doesn't the camera capture the image like I'm seeing it?

[Assistant]
A camera lens and processor (or film) aren't exact analogs for your eyes and brain.

There are a lot of things that control what an image looks like - the ammount of light coming in, the focus, the color pallet, etc. Your brain manages all these things automatically. Cameras let you adjust these settings manually, or try to approximate a "best fit" automatically, but they're inevitably going to be a bit different than what your brain interprets, and the resulting photo looks different.

Getting the camera to take the picture you *want* exactly the way you want is why photography is still considered an art and a profession - computers just can't get there on their own most of the time.


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

[User]
How long after publishing a paper is it still ok to present it at a conference?

Lets say you haven't published anything new for X months and you have no new results to present since that last paper. Would you still present the results of that paper if X=6? X=9? What about after a year? When would people start to get irritated?

Obviously this question is relevant for a field where people primarily publish in journals and just give talks at conferences, not for fields where conference proceedings are written.

[Assistant] In the biological sciences, its generally considered inappropriate to present posters or talks of your already published work unless it was purposefully invited. Conference talks/posters are for new thingsit can be an extension of the previously published stuff, it just cant literally be the content of your last published paper.


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

[User]
[The Purge]How does America maintain a modern economy when skilled workers are certainly being killed at a higher rate than normal and even accidental fires would surely consume cities during The Purge? to say nothing of the countless businesses which would be destroyed by disgruntled employees.

The last one I think is the biggest problem. After the arson, obviously. Even if people did not intend to burn everything down, uncontrolled fires from The Purge would consume entire cities. After that, is there any reason to imagine that disgruntled employees would not destroy their places of work or kill their employers?  There is a pretty big gap between billionaires with private fortresses and small business owners and managers across the country.  Low-level managers would probably be killed in the tens or hundreds of thousands, resulting in massive production problems in every industry.  Low-level to medium level managers are not going to be able to afford armed guards.

[Assistant] America is on its last leg.  The Purge has so thoroughly damaged the fabric of society that it won't be long til complete collapse.  Pretty soon it will break apart into petty fiefdoms and armed fortresses.  Primary means of production will be guarded with large swaths of lawless wasteland in between.


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

[User] ELI5: Why is cold water so effective at getting rid of suds?

[Assistant]
Suds, or bubbles, in water are a result of decreased surface tension.

As the Surface Tension increases, the Surface Area is caused to decrease. Bubbles on the surface are a surfeit of surface area, compared to the flat surface of your non-soapy filled sink, so they exist at a much reduced tension.

It turns out, as water heats up, it's surface tension goes down. If you floated the largest sewing needle you could, on top of water in a pot, and heated it, it would fall in before the water boils. You could use a thermometer and over several attempts, the temperature when it falls in should be pretty close to the same every time.

Conversely, the cold water has higher surface tension and is better at pulling back the bubbles.


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

[User]
CMV: Confidence does not comes from within. It comes from external validation and success.

First; just logically it makes no sense that confidence is a choice. If it was as easy saying, Ok Im going to be confident there would be no self doubt, self esteem issues, or insecurities.

Looking more at this, confidence is a result of factors such as self esteem. Self esteem is internal but often it is shaped by outside experiences. A person who has for the last 15 years of his life been told hes ugly is not going to have a good view of himself. Even if hes able to accept being ugly, its still highly likely that he wont have that self esteem.

Now lets say someone is physically attractive from childhood. This person gets attention from the preferred sex even as a child and this continues into high school and college. Do you think this persons confidence in say dating would be a result his inner thoughts or the validation he received all his life.

Another example would be a job. A person who has worked on their craft for years and had multiple accolades is going to be confident. But what about a person whos work constantly has errors And they are constantly reprimanded. Not as confident.

When youre given praise or attention for something you will feel more confident in it. Confidence come from outside in, not inside out.

[Assistant]
Confidence is the result of a process - of having the courage to do something you've never done before or are not good at doing, but are willing to practice at until you get better. The reward for this process is what we typically refer to as confidence.

No one is born a naturally amazing public speaker, or pole vaulter, or comedian.

When people say confidence is a choice, they really mean the choice to give it a try, knowing you might fail or do badly, but that the outcome is that next time you'll do it a little better.

People who are so scared of failure that they don't even try generally view confidence as a commodity that some people have and some people don't, rather than for what it is - the end result of making a choice.


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

[User] ELI5: why do plants get root rot from overwatering, yet you put cuttings in just water to grow new roots? And also just like whats the difference between that and hydroponic gardening in general?

[Assistant]
So, plants grown in hydroponic systems can still get root rot however... Properly installed hydroponic systems should contain air pumps that help to supply O2 to the plant, as well as a drainage system (ebb & flow system). Root rot occurs in waterlogged soil where O2 is mostly inaccessible.

It might be more helpful to view root rot as the plant's problem. It's not that there's anything wrong necessarily with being in water; it's that the plant is diseased.


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

[User]
ELI5:how would I calculate the rain flow into a water tank off a given corrugated iron roof structure? Say I had a four square metre roof and the given average rain fall (say it was 1000 mm annually)?

I'm building a water tank system for an off the grid property- just for occasional use, so a 1000 litre tank. I want to get the optimum results without massive wastage or shortfall so some ideas would help. Thanks in advance.

[Assistant]
Even if you can say you'll get a consistent 1000mm per year, your figures will only be vague and will vary. Rain doesn't often fall vertically, and your roof may or may not be flat. If your local winds tend to blow rain towards the east, and you're collecting rain off a roof that slopes away from that direction, you won't collect much rain.

If we simplify it by looking at a completely flat roof with vertical rain falling on it, we can just treat it as a volume, that is we just multiply the area by the depth of water we get - so 4m^2 * 1000mm = 4m^3, which is 4000 litres over a year.


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

[User] ELI5: Why are people more comfortable sleeping with a blanket over them even in warm climates?

[Assistant]
There's a couple reasons.

One reason that has already been stated is that it's a psychological thing. Maybe in school you studied psychology and learned about Maslow's hierarchy of needs. Basically this is a principle that states that in order to achieve higher levels of comfort such as self-content, one must have the most basic levels of comfort such as shelter and security. A blanket provides a type of security that makes it easier for your animal brain to calm down at night and fall asleep.

The second reason is air movement. Even in a 75 room, if there is a ceiling fan going and you are laying there with your shirt off, you will feel chilly. Throwing a blanket on gives you your own comfy little microclimate.


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

[User]
[Spider-Man: Far From Home] Spoilers: Mysterio

Did anyone at SHIELD bother to run Beck's fingerprints, DNA, and/or facial recognition profile to discover that he was actually a former Stark Industries employee?

They kind of took him at his word that he was a superhero from an alternate Earth.

[Assistant]
Talos isn't a very good Nick Fury.

He never doubted Beck enough to check the disguise. Even if he did, he might have been easily convinced by "Your Earth's Beck worked for Stark? What a coincidence!"


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

[User] [Videogames] When jumping/falling, how do videogame characters change the direction of their trajectory?

[Assistant]
Atmosphere is not a vacuum. Propulsion and changes in direction come from providing a "push" against a medium.

With enough force against the air, you could jump on it, walk through it, swim through it etc.

They simply push hard enough to "double jump"


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

[User]
[Star Wars] What was the functional purpose of the Death Star's Meridian Trench (aka; the trench Luke flew through to fire the torpedo).

Looking at pictures of the Death Star and with exception to the disk, the entire Death Star's surface is dense metal structure...

except for the trench.

What would be the functional purpose of having a trench like that running the length of the entire equator?

[Assistant]
The trench is one of 18 across the surface of the Deathstar, which offer access to maintenance points, docking bays, hangers etc. It also allows a place for things like thermal exhaust ports to come out somewhere that they are unlikely to be damaged by any kind of attack on the surface, which could be harmful to the core.

It was never expected that the Death Star would be attacked by single fighters/bombers, the whole thing was pretty much designed to be invulnerable to other huge ships which might be sent against it. Even then they had heavy turbolasters to stop anything which might pass into the trench and it worked pretty damn well against the fighters that *did* attack it.

A trench is a great idea to have a sheltered space for all these hangers, maintenance points etc to be located, safe from anything that might be near the surface. it's one of many, *many* good* design ideas in the Deathstar.

Although it turned out that there was a "vulnerability" in that there was a thermal exhaust port that could be fired down, it was almost impossible to do. It needed a lucky Jedi farmboy, guided by the force to get the shot on target, without that there is practically no way it is *ever* having anything bad happen to it.

\* Good at the time.


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

[User]
How do you tell the difference between a prehistorical tool's usage date and material date?

Carbon dating and other chemical dating shows us the age of the material but how exactly do we know when something was used or altered?

EDIT: Comments basically say that organic material acts differently to inorganic material and therefore can be chemically dated more accurately. And it is often the more about the surrounding materials that we knew about prior to finding the tool like food debris. Though often largely educated guesses.

EDIT: It seems we use far more than just carbon dating to find the creation and usage date. Usage of organic material is usually changed in some way, like burnt wood turning to charcoal, which gives more evidence of dating. Other materials like spear/arrow heads can gives clues based on other known sites.

[Assistant] Also, depending on how the tool was found, it can be dated by what layer of sediment it's under. If it's buried at the same depth in the same area as bones that can be dated,  then usually the tool will be assumed to be from the same period. Obviously,  not as accurate as carbon dating,  but at least it gives a general idea.


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

[User]
Do imaginary components of equations ever play a physical role?  Are there deep reasons to ignore them, or is it all empirical?

I understand from Euler's equation how imaginary components fall out from periodic systems, but I have always been bothered by the fact that real world solutions only take the real component.  Are there cases where the imaginary component plays a role in reality?

Any insight would be greatly appreciated, thank you.

**Eureka Edit:**

These responses have been excellent, and I thank you all.  I particularly appreciate the effort made by duetosymmetry, RobotRollCall, and others in clarifying my misconceptions about the of complex numbers in general.

Should anyone be monitoring this post further, I would like to present what I learned here and see if I'm on the right track.

Imaginary numbers are a series of numbers orthogonal to the real number line.  A complex number, therefore defines a number plane.  This additional dimension always (almost?) contains meaningful information about a system, but it is not always relevant for the questions you want to ask.  Also, some systems can be fully described using real numbers, so why complicate things...

When dealing with periodic systems, the "imaginary" component represents information that is not explicitly stated in a trig function, but is there nonetheless, such as phase.

Again I thank you all, and if I didn't reply specifically to your comment please don't take it personally.

[Assistant] As platypuskeeper mentioned, it comes up when looking at the impedance of an AC circuit. For instance, a resistor and an inductor in a circuit might have an impedance of 50+30I Ohms. The reason the imaginary part goes away in quantum mechanics is because pretty much any measureable quantity involves multiplying the wavefunction by its conjugate.


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

[User]
[Avatar The Last Airbender] what would've happened to the avatar reincarnation cycle if there were no more airbenders?

What would've happened to the reincarnation cycle if the fire nation had successfully killed Aang, thereby exterminating all airbenders?

Would it simply skip air after a firebender avatar? Would that be the last of the avatars?

[Assistant]
There had to have been at least some level of intermarriage between the bending tribes. It doesn't usually come up because even a child of two benders would only inherit one or the other at most.

In this case it would. An airbender avatar child would be born to someone with airbender ancestry, even if they were a nonbender or lived in a different environment.


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

[User]
ELI5 Why is finding water on other planets one of the most important things for us to look for in the case that there is life there?

I get why it could be important but nothing else seems to matter when looking for life.

[Assistant]
So life needs chemistry to take place to exist.

For chemistry to take place chemicals have to come into contact with each other.  A chemical sitting on one rock and another on another rock won't react with each other.

So they need to mix in something.

This best place for chemicals to mix is in a liquid.

Of all liquids water is the best for this to happen in since water can dissolve more chemicals in it than any other liquid.

Hence, they look for water.


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

[User]
ELI5: How are dice fair?

Shouldn't 6 appear more often because it has the most amount of holes and has a lighter weight than all the other sides?

[Assistant]
Casino dice have the holes filled in with a contrasting color so no weight difference.  They're also clear/translucent so the players can see no weights inside the dice.

The stamped dice you're referring to are going to be "close enough."  Technically head/tails are likely a little different too but it won't be enough to matter.  As far as the physics behind the stamped dice, the 1 will have the least amount of material removed and would therefore be the heaviest which would put it the least common roll.


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

[User]
[Wreck-It Ralph] How can video game characters can be in two games at once?

For example, the arcade has Street Fighter and Marvel Vs. Capcom, Ryu participates in both games.

Is there duplicated characters? Does Ryu has to transfer from one fighting game to another as quickly as possible?

[Assistant]
They're different Ryus. The Ryu from Street Fighter certainly has a lot in common with the MvC one, but they aren't the same.

What gets *really* complicated is when you hook up multiple copies of the *exact* same game in an arcade.


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

[User]
Why do we use gold instead of silver?

Today I found out that silver conducts electricity better than gold (wikipedia).

Since gold is also so much more expensive as silver, Why do we use gold in almost all our electronics instead of the apparently superior silver?

[Assistant]
Gold doesn't tarnish, for one thing. For another, it is much more ductile than silver. That means it's easier to draw into wires. Gold can also be hammered out so thin as to be a single atom thick, without losing its conductive properties! That's one reason it's also used as a coating in the visor of astronaut helmets.

Silver, on the other hand, is much more brittle, and does tarnish. Devices with silver wiring would require much more maintenance to ensure that tarnish didn't interfere with the conductivity.

I hope all that made sense!


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

[User]
ELI5: why are you constantly thirsty when having Diabetes Type I?

Before getting treatment obviously. So I understand it's because you pee more often because the sugar makes you pee more often, but what about the details of how it leads to that?

[Assistant]
Glucose is an osmotic, which means it pulls water out of your tissue and puts it into your circulation, which increases your urine output. So increased glucose in your blood causes more water to be pulled into your blood which causes more water loss (and glucose) in your toilet bowl. This increase in water loss will ultimately trigger your thirst drive to balance things out again.

So diabetes makes you pee, which makes you thirs..ty.


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

[User] How does regenerative braking recharge the battery in an electric car or motorcycle?

[Assistant] A generator and an electric motor are identical. A motor takes electricity and turns it into motion. A generator takes motion and turns it into electricity. When it comes time to stop your vehicle you can switch the function of the motors to harvest the kinetic energy of your vehicle and rapidly slow you down at the same time.


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

[User] [General] What human societies have a reliable mechanism for producing a continuous chain of skilled benevolent dictators?

[Assistant]
The islandnation of Tropico always seem to have the best el presidente.

I personally believe that this is because of a number of factors like it being an island (not a lot of contact with the rest of the world, so people will think they have a great life. It is not like they have anything to compare it with) and of course the great assistant of el presidente: panoptimal.


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

[User]
[God of War 2018] We know there are Greek and Norse pantheons - Kratos has met them. Each have their own methods of creating the world which we know to be literally true. How is this possible?

Kratos has seen the Titans who created the earth. He has been to Niflheim and Muspelheim which mingled to make the steam of creation. We have literal evidence of 2 different methods of the creation of reality. How is this possible? The world was only created once. Who did it? Something here is screwy.

[Assistant]
They're gods, why wouldn't it be possible?

The Greek pantheon created the world for the Greeks, while the Norse pantheon created the world for the Norse. Both of those worlds just happen to be on the same planet.


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

[User] ELI5: What is a conductor in an orchestra actually doing? How much control does (s)he have?

[Assistant]
Conductors have a much larger role to play in rehearsal than at a performance.  Conductors tell the musicians how to play in regard to style, speed, and volume.  The conductor's interpretation of the piece and how they choose to direct the musicans can drastically change how the piece is played.

However, once a group of musicians has played through a piece +150 times in the exact same style, the conductor could drop dead on stage and the musicians could finish the piece without batting an eye.


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

[User]
When light travels through empty space, is that space still empty?

What I mean is, you can't see light if it's not reflecting off something, so does filling the void in cosmic space with invisible travelling light mean that the space is still empty?

[Assistant] Empty space is just a mental construct, a model. In reality no portion of space is actually empty, even on a tiny scale. It's full of neutrinos, dark matter, dark energy, photons, sometimes atoms, and always fields (electromagnetic, gravitational, etc.)


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

[User] ELI5: Why can I take out dead batteries, flip them around and then they suddenly become usable again?

[Assistant]
Most cells (technically, most "batteries" are actually just one power cell, not a battery of cells, but never mind that) are strips of metal with a chemical paste between them, rolled up into the familiar shape.

The electrical capability of the battery depends on the chemical reaction between the paste and those metals. The small amount of energy you add into that reaction from the heat and motion (which latter is a bit like shaking up a soda) can allow the battery to release more of its stored energy -- sometimes *just* enough more to be over the threshold of what your device needs to work.


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

[User]
ELI5: How did game manufacturers of tabletop games ensure that at the opening of the game, theres equal probability of every player winning ?

the most prominent example is chess which has had the same rules (including quirky rules like en passent) for more than a century. And those rules stand the test of time in that even the best computer engine evaluates most starting moves to be about equal. I also played a game called splendor which has multiple winning tactics but it seems like each tactic has equal pros and cons. I am speculating that now there are brute force methods devised so that a computer plays the game over and over again and changes certain modifiers and stats until the game is equal for each player. The game would then be released with those modifiers. But I wonder; how did game making tacticians of the past who did not have access to such complex computer programs, ensure that in a game that has a million possible moves, there is equal probability of any player winning with the best play ?

[Assistant]
Short answer: they don't.  For most games, it's *not* known that there's equal probability of winning with perfect play.  For some popular games, actual *perfect* play guarantees that one player or the other will win - Connect 4 is simpler than chess, but a prominent example of a game where perfect play *always* allows the first player to force a win.  Yet we're collectively still willing to play it, because most people don't know how to play perfectly, and of those who do a reasonable proportion might still make a mistake.

However, game-makers generally have a reasonably good idea that within the bounds of human play, each player has a decent chance of winning, simply because they've playtested the game and had others do the same for several iterations prior to release, and taken the time to patch any obvious discrepancies that may have arisen.  They'll have taken a variety of test-players and tweaked the rules until they got roughly even outcomes.  They can, and do, still miss things, but these things tend to be relatively buried in the rules.

For games like chess, it's a similar situation, only there was no single "game-maker" and no "release", so the rules were adjusted by the players "on the fly" to keep the game even enough to be interesting.  Before the establishment of governing bodies for some of these games, the rules might have differed depending where you played.


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

[User]
[DC/General Superheroes] Are there any cults that worship superheroes?

A key factor in the formation of cults is gullible members believing in what the leader says or is capable of. But in the case of heroes of Superman, we know what he can do, he's a titan among men. Considering that he can protect earth from  darkseid, an insanely powerful god of new genesis, no doubt some think of him as a messianic figure.

Have there existed groups of people who formed twisted religions around people with superhuman abilities? Have any heroes or villains ever interacted/fought with a cult that followed them?

[Assistant]
There are. Superheroes have provoked various religious reactions.

There's been a group that worshipped Superman as a god. That provoked some religious people to view Superman as the anti-christ, luring people away from their true religion.

The idea of Superman has also been brought into existing religions with some viewing him as an angel of their god.

Superman finds it all uncomfortable & always makes sure to argue against any worship. He's just a helpful alien not a god, demon or angel.


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

[User] ELI5: Why standing up quickly sometimes causes me to black out for a few seconds, and standing up and stretching is even worse.

[Assistant]
I had this problem a lot as a teenager, and had to see a neurologist and cardiologist about it.  Here's the basic idea:

When you're lying or sitting down, your heart is in a "rested" state.  Your pulse slows down and your muscles relax, and your brain needs less blood to function as your nerves and body become calmer and calmer.

When you suddenly stand up, your muscles and heart start to quickly "wake up" and work harder, and your brain all of a sudden needs a lot more blood to send messages throughout your nervous system.

You black out briefly because your brain isn't getting enough blood from your heart in the short period of time in which it needs it.  This is usually because the message isn't getting to your heart fast enough via your nervous system, and conversely, the blood isn't reaching your brain by the time you're on your feet.

Eat more salt, drink more water, or Gatorade.  Electrolytes help your nerves work more efficiently.


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

[User] [Marvel] Are the X-men open to training young people who develop powers they cant control that arent mutants?

[Assistant]
Yes, but associating with the X-Men is opening yourself up to a world of hate, so most such young people either go to the Avengers Academy or just strike out on their own.

A lot of their non-mutant students are from offplanet (such as Broo, Kid Gladiator, Warlock, and Longshot), and wouldn't be able to fit into the mainstream population.


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

[User]
ELI5: Why do flies often find their way into people's houses, but not butterflies?

I live in Ireland, if that is of any use.

[Assistant] There are way more flies than butterflies,  for one.   Butterflies drink nectar from flowers and lay eggs on leaves,  both of those things are difficult to find indoors.   On the other hand,  flies thrive in trash and they are everywhere,  so they get inside often.


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

[User] ELI5: does running on treadmills have the same benefits as regular running?

[Assistant] Similar but not the same because when outside your body is also dealing with surface, terrain and weather conditions. Because of these differences your body has to work at balance more, work at changes in breathing more often (heat, hills, wind and such) and also you have to get home so you can't stop just any time.


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

[User]
[Lotr] What did Sauron do as the necromancer?

Did he raise any dead? I know that you cant bring back the souls of the dead, as they have left the world, but you can controll souls that are stuck in middle earth. Did he just controll them, or did he raise any soulless zombies, just corpses? Or was it just a name he picked to scare people?

[Assistant] Dead, no.  He's the necromancer because he bends (but doesn't break) Middle Earth's rules of mortality.  Even the ringwraiths aren't technically undead, since they never actually died; they simply had their lifespans stretched far beyond natural limits.


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

[User]
Why is diffuse reflection a hazard of working with lasers?

Moreover, how can surfaces that appear shiny be diffuse reflectors of UV wavelengths? Also, how can surfaces that appear dull be specular reflectors of IR wavelengths? What is about those wavelengths that allow them to act differently on those types of materials?

[Assistant] A surface consisting of microscopic features may work like a mirror for wavelengths larger than these features. So actually IR and UV are not special, they react the same way to surfaces structured relative to their respective wavelengths.


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

[User] ELI5: How does the body become heavier when you exercise for the first time in a while when you should be losing weight?

[Assistant] It's pretty much a collection of some water weight that then gets shed. You still will lose weight as you lose fat content, but for the process of muscle usage to occur, water is needed for those chemical processes. Glycogen fuels the body during exercise, and needs water to bind with and generate energy for muscle use.


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

[User]
Just starting to read Meditations, and starting to learn about different philosophies in general, but a common theme I am seeing is the value of a simple life, free of the unnecessary, returning to nature, etc. and I have a question...

Marcus Aurelius in particular emphasizes that we are fleeting, and to realize that before long we return to the elements we originated from. To focus not on the excess or unnecessary.

My question is, if life is fleeting, should we not indulge in it, and enjoy what it has to offer? Not to a point of obscene wealth, but to ensure that in the time we have, that we find comfort, entertainment, prosperity, and joy in the things around us as well?

There is definitely more value in personal connection with oneself and with others, to be one with nature and to live harmoniously and kindly. Is it not ok to also indulge in seemingly frivolous things that give us a sense of enjoyment in our short lives? Can we not also appreciate the beauty and craftsmanship in a piece of art, or a finely woven dress, or a car that is a pleasure to drive, without succumbing to worshipping them? Am I being vein, or am I missing a point somewhere?

[Assistant] It is quite simple. Marcus Aurelius does not see frivolous things as real enjoyments. Living life to the fullest, to him, is not getting expensive foods, driving a nice car (well, obviously since he did not know what a car is, but you get the idea), etc.


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

[User]
How much energy is lost from reflection on solar panels, on average?

How much light that could potentially be turned to electricity is reflected by solar panels?

[Assistant]
Some good information here, some bad information.

There two major sources of reflection off a solar cell. The first is off the top surface metals - both the two thick bus bars and the thin fingers that cover the top surface. All incident light off of those is reflected, so the coverage is the amount lost - usually something like 4%.

The second is related to the index mismatch. Any time light passes through an interface with two different index materials there is a reflection. A good example is the reflection you see off of a glass or water surface. Silicon (the most common solar material) has a very high index - around 4 - so the amount of reflection is quite high. This is reduced by an anti-reflective (AR) coating with intermediate index. You can also use thin film interference to improve the AR coating even more. This is why solar cells appear blue - it is the same reason that a thin film of oil on water causes colors to appear. In this case, green light, which there is a lot of, is absorbed very strongly, and blue less so.

So the question is "How much light that could potentially be turned to electricity is reflected by solar panels?" - how much of this is inherent loss and how much of it is avoidable?

1. Metalization loss can be completely eliminated through various schemes. Some all back contact cells are currently in production (by an american company called Sun Power) which have no metal in the front. Standard cells can be improved by improving either the conductivity of the metal on the front or the aspect ratio - making it more tall than it is wide. Other possible schemes are nano structured metals which will conduct electricity but not reflect light.

2. Most commercial cells use a single layer AR coating of silicon nitride. Significantly less reflection can be obtained with a dual layer AR coating (and this is used for top performing research cells), but this is both more expensive, and less effective once the cell is encapsulated in glass. Something like a 2.5% efficiency gain should be possible here.

Finally, the texturing also effects the reflection of the surface. This is also a question of economics. Most commercial cells use base etched surfaces, which create random pyramids. However, the record cell used patterned inverted pyramids which provide less reflection, but is a much more expensive process.


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

[User] ELI5 hows does my brain recognise fake computer graphics which are intentionally designed to not fall within the uncanny valley? Im watching a movie action scene which I know is unreal yet its perfectly real at the same time?

[Assistant] Generally the difference is light. If the light is hitting objects at different angles, or if its not passing through partially transparent objects like skin, your mind will see that something is wrong.


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

[User]
If zombies primary instinct is to eat, why do they often stop eating to attack new victim?

If you have nice, warm, freshly catched pizza in front of you, and saw another pizza with same fillings on the other table, would you stop eating  just to get bite of the other?

Plus question, are zombies always hungry, do they ever come full and not want to eat people for a while?

[Assistant]
Their primary instinct isn't to eat, it's to eat uninfected flesh. Soon after biting someone, they are no longer uninfected, and other targets become more appealing.

This explains why zombies don't eat each other, why they don't completely devour the people they bite (thus creating more zombies), and why zombies are usually mutilated, but not completely destroyed. They start eating someone, but at some point that person becomes a zombie, so other sombies stop eating them, and the new zombie remains half eaten.


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

[User]
When riding my bicycle, I can stop pedalling, make a 180-degree turn, and the bike still continues moving (though at much lower speed) in the opposite direction. Why?

Momentum is directional and as far as I can see there is no other input energy being applied to the bike (or me), so how can it move in the opposite direction?

[Assistant]
When you turn the front wheel by turning the steering bar, the front wheel is turned to be out of line with the direction of motion. Yet the momentum of the bike keeps pushing it forward. This causes the front wheel (and by extension, the bike) to exert a force on the ground (perpendicular to the direction of the wheel).

Due to Newton's Third Law, this force on the ground is met by an equal and opposite force from the ground working on the bike. It is this force that alters the momentum of the bike, rotating it in the direction that you're steering.

For this process to work, the wheel must be able to exert a force on the ground. Therefore, it must have grip. Trying to turn on a very slippery surface (e.g. ice) will have very different effects.

edit: The force exerted by the bike also slightly alters the momentum of the Earth. The total momentum of the combined Earth+bike system is still conserved. But due to the non-trivial difference in mass between the Earth and the bike with its rider, the effect on the Earth is completely negligible.


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

[User] [ELI5] What exactly is a mushroom? How do they differ from plants or animals? And what makes some safe for human consumption?

[Assistant]
A mushroom is the fruiting body of some types of fungus. The reason the fungus living in the soil underground or in a rotting log grows them is to distribute spores which are like mushroom versions of seeds.

Fungus are an entirely separate branch of life from plants and animals.

Some of them develop a poison which can kill people who eat them. Some don't.  Producing a poison takes extra energy, so ones that don't probably developed in areas where there were less animals likely to eat them.


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

[User] Whocd are some philosophers other than Plato who argued that being a immoral person was not in that persons self interest?

[Assistant]
You can find something like this argument in Frederick Douglass's writings. He makes the point over and again that slavery hurts both the slave and the enslaver. In his autobiography, he illustrates this idea with reference to a woman who tried to teach him to read. Her husband (the slave-holder) flipped out about it and forbid her to teach him more. After that, she became really cruel to the young child Douglass. Douglass draws the conclusion that her own native morality was corrupted by her being the position of slave holder.

He's not the only 19th-Century anti-slavery thinker who made this point, but he's probably the most acclaimed.


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

[User]
ELI5: Why do phones have a limit of how much expandable storage they have?

As in, say there's a phone that has 32 gig and can be expanded up to 64 with an external SD card. Why wouldn't it be able to go up to 128 or something with a bigger card? What's limiting that?

[Assistant]
Different standards.

There are three different types of SD formats, these also apply to MicroSD.

SD: Up to 2 GB

SDHC: Up to 32 GB

SDXC: Up to 2 TB, although cards of that size don't exist yet. People have only been able to make 256 GB MicroSD cards, and those are still very expensive.

So when a phone manufacturer says it can take MicroSD cards up to 128 GB, it means it can take SDXC cards, but they don't want to be misleading so they say 128 GB instead of 2 TB.


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

[User]
Say that I weigh myself just before bed: 150lbs. I weigh myself immediately after waking: 148lbs. What processes happen while I sleep that cause this overall loss of mass overnight?

Assuming no expulsion of waste between measurements.

Measurements taken either naked or wearing the same clothes.

[Assistant] The weight loss would be due to breathing, mainly in the form of expelled carbon dioxide with some water vapor as well.  You intake oxygen, but expel carbon dioxide (basically just an oxygen molecule plus a carbon atom), with that extra carbon coming from the food you ate.  All the carbon adds up.  You also lose some water vapor out of your cells into your lungs, and from there into the air.


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

[User]
[W40K] Why didnt the Emperor (big E) store away an STC

He has a degree of prescience but even without prescience, having an STC, a source of knowledge of all humanity, is something that would have let his crusade be way easier across the galaxy to reconquer splintered humanity and the galaxy itself.

An STC seems so goddamn useful. Something so useful that as a perpetual superhuman Emperor you would keep one stored away... somewhere on Terra, in safe keeping, hell it seems so useful as to store multiples with multiple back up contingencies. And its not like they were in short supply, pretty much every colony ship could just get one and they were shat out across the galaxy.

[Assistant]
* STCs were mainly designed for colonial & exploration efforts. Terra itself would have far more sophisticated production facilities and knowledge spread across innumerable databanks across the planet and Mars.

* STCs weren't the end-all and be-all of knowledge back then, so Big E might not have prioritized saving them over other, now-unknown attempts he might have made to preserve knowledge.

* STCs weren't exactly line items in Future!Amazon and since E-Money was operating in the shadows, he likely deemed his covert efforts be better spent elsewhere.

* The devastation caused by the AI uprising and wars against the Men of Iron could have theoretically led to the destruction of most of the STCs, with only a handful surviving because they were too far from the fighting, deliberately hidden, or outright lost as the Warpstorms grew.


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

[User] ELI5: why flat bed tow trucks use beds with a little bit of an arch to them - instead of being truly flat.

[Assistant] The built-in arch compensates for the sagging due to heavy loads on the bed. So when the load is applied, the bed of the truck wants to be flat, instead of sagging down. This is more important for large trucks than it is for pickup trucks, say, because of the length of the bed.


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

[User]
CMV: There should be a separation between State and Private Corporations

Just as in the past, and specifically in this country to ensure religious freedoms, there was a clear and distinct separation between church and state, now there needs to be an updated view on this to ensure separation between state and private, corporate interests.

It's no conspiracy to state that vast amounts of money from private entities goes into lobbying against issues that often have the public's best interests. For instance, the big tobacco companies lobbying against additional health risk labels on packaging, lobbying doctors to minimize disclosure of health risks, etc. As we've also seen recently in the 2016 elections, vast amount of money is also spent by both internal and foreign private agencies (Cambridge Analytica for example) in polarizing the masses and pushing their own divisive propaganda. Most politicians are flat out bought and controlled by private money because they need the cash for their campaigns, and in return, they push whatever policies their benefactors want while pretending to be serving the people.

There needs to be very strict control and regulations against this. If someone wants to run for politics, it should be 100% publicly and transparently funded. While it's a "free market capitalism system", there should be prohibitions on what private entities do with their money, like no lobbying, no donating to PACs or political campaigns, etc. Actually enforcing this is another story, and it's not like this will be the end to all corruption, but I think having a clear separation between these two bodies of power is necessary to ensure a true "democracy". Currently, private corporate interests are arguably much more powerful than state entities, and I would go so far as to say that the State is just the Corporation in State's clothing.

Edits:

\- Assume Im talking about the USA

\- By private entities or private interests I clarify this to mean privately owned corporations with the financial capacity to influence politics in a way where it is primarily focused on benefiting the main/largest stakeholder of said corporation.

[Assistant]
>there should be prohibitions on what private entities do with their money, like no lobbying, no donating to PACs or political campaigns, etc.

Lobbying itself is just advocacy for public policy. Why would you ban that ability of anyone to advocate for public policy? Everyone is a private entity. This would violate the 1st Amendment and basically preclude anyone from speaking to the representatives about any issue ever. That sort of invalidates the entire point of a representative government. How can they be representative if we can't tell them how to represent us?


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

[User] ELI5: How does the human body know when it's 37C if its only reference point (the outside world) doesn't have a stable temperature?

[Assistant] Your hypothalamus knows it wants a certain temperature. If it's too hot or too cold, it adjusts the rest of your body to lose or conserve heat. It doesn't know what that temperature is. It just knows it wants it at a certain temperature. This is because humans have evolved to favor that temperature. The advanced mammals who set their thermostat lower ended up getting more fungal infections and dying. The ones who set it higher burned a lot more energy and ended up starving. The one's who set it in the middle did the best. Then years later when doctors measured it, it turned out the temperature was 37 degrees C.


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

[User]
Why haven't we completely discovered ocean's deep creatures yet?

I have heard so many times that most deep water creatures are yet to discovered, why is that so? We have discovered so many things in space through telescopes and space programs and yet our own ocean's depth is unknown. How hard is it to create a device that can scan or image deep oceans?

[Assistant]
It is perfectly justified that we yet have to describe an enormous amount of species from the oceanic deeps.

Compare with Earths surface: we have been categorizing and describing species there for millenia. And yet we still are not done, as we find new species every year.

In comparison, the ocans are three times as large as the continents, and far less accessible. Benthic areas outside the continental shelves have only begun to be looked at within the last 75 years or so (beeing generous). Even today they are barely accessible at all, despite the increased use of ROVs and minisubs. You can't caracterise species through bulk large scale long distance viewing (that would be akin to trying to define the species of a rainforest from high-altitude fly-bys - you are going to miss out on most and won't get enough detail for the rest): you have got to get there and see/sample the critters first hand.


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

[User]
CMV: Geoengineering is the only short-term solution to climate change that has a chance of success

I am convinced at this stage that any solution that would require most people to change their behaviour is doomed. For instance, the gun debate in the US is completely stalled, even though gun owners are a minority. Now imagine replacing them with meat eaters or car owners who are the majority. The current price squeeze illustrates this really well - despite higher prices, people don't want to switch to non-petrol solutions for cars and heating because those are even more expensive. In short, making such big changes requires big cuts to standard of living for many.

In other words, for reasons of cost, pleasure, standard of living or simply pure selfishness, most people wouldn't make the change. Suddenly trading off the future of one's grandkids for one's immediate prosperity, albeit cynical, seems quite attractive for most (or at least a large chunk of) people. The governments could try to force behavioural change, but in democracies a strong and vocal reaction is inevitable.

Carbon free generation doesn't seem like a particularly good option either. Renewables have very expensive reliability until viable energy storage is a thing. As for nuclear, the fuel is now very expensive too, and installations take just way too long to build.

Therefore in my opinion the only viable options are (relatively cheap) geoengineering projects, to which most people would be indifferent (with good PR) because they don't touch them directly, and government efforts should concentrate on these. Good examples are space silicon bubbles to increase Earth's albedo and carbon capture using controlled algal blooms (by fertilising the ocean). The success of these is not guaranteed, but at least they have a chance at it. This will buy us time to develop better energy sources such as fusion or good energy storage to move away from carbon for good, which should be the second focus area.

[Assistant]
A better option is weaponizing selfishness. Find a way to make it cheaper to not spew carbon and live in safer places than it is to do so. That's what's already going on: beachfront properties are being bought up and turned into parks or anything like that.

 Alternatively, incentivise carbon capture. If a good, cheap use can be found for its byproducts, then soon we'll have a global cooling issue.


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

[User]
[General] What is your favorite spaceship design?

I'm an aerospace engineer and I was invited to teach a class on aerospace design to graphic designers in the video game and film industry.

One of the things they want me to go over are case studies on why a certain ship design can or cannot be feasible. For example, the TIE fighter from Star Wars actually has a very plausible design.

Now I'm a Star Wars fan so I have most of those ship designs covered, but I was wondering if you guys could help me with some of the other spaceships out there from other sci-fi film/video game universes to get a bit of 'diversification' rather than just "so onto our next case study, another Star Wars vessel..."

ADDENDUM: RIP my inbox. thanks for the replies guys!

[Assistant]
Personally a fan of the design of UNSC ships from Halo. Big boxy square things, yet sleek and modern at the same time.

I also quite like any of the Imperium of Man's ships from WH40k, but that's just because they're fucking cathedrals in space.


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

[User]
[musicals] I started singing randomly the other day, what is going on?

I'm a banana vendor in New York City. The other day some girl came down the street singing about love lost, or missing her honey at the big dance or some crap like that. Suddenly I had the overwhelming urge to sing along with her, or more like be here backing singer. I swear I even heard an orchestra. Am I going crazy? Was she some sort if witch ?

[Assistant]
There's a demon named Sweet in your town.  If you're lucky the Slayer will deal with it.  If you're not, you'll eventually take part in increasing number of musical incidents and will finally dance until you burst into flames.

Good luck!


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

[User] ELI5: Why can Eric Clapton say cocaine on the radio but Wiz Khalifa can't even say joint/doobie?

[Assistant] I think you are referring to the song Cocaine, covered by Eric Clapton. 2 reasons why he gets away with this: 1) the song is (purportedly) anti-drug, and 2) it was done in 1977 before censoring everything became the agenda of those in power... so it's probably considered classic music, as opposed to modern rap which glorifies drug use and therefore gets censored.


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

[User]
How do you calculate velocity in space?

Do you use Earth or the Sun as a frame of reference? Is there some way to find out how fast they are moving through the universe?

How does the speed of our solar system affect time? If you found a way to come to a stop (with respect to all of existence), would the traveler age faster than everyone else on earth? Would the earth appear to move away slower?

Disclaimer: I am not really educated in any of this, barely have any knowledge of relativity, just curious.

Edit: Would it matter which direction you started moving? For example: moving away from Earth in the direction of the expansion of the universe would increase your true(?) velocity, while moving toward the center would decrease it.

[Assistant]
You can use any reference frame you like, there is no absolute frame of motion in the Universe.  If we measure the orbit of the planets, then the speed is in relation to the Sun - but if we measure the orbit of the moon, then the orbital speed is in relation to the Earth. The speed we measure Voyager travelling at, is in relation to the Earth, which is why on sites such as NASA the velocity report of the Voyager crafts change in relation to where Earth is in it's orbit - in reality the Voyager crafts are travelling at a constant velocity.

We wouldn't know if we had truely "stopped" in the Universe, as there is no outside, or known centre to measure our Velocity - we would just know what our velocity/motion is in relation to xyz coordinates of whatever we decide to measure our velocity against.


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

[User]
Why does adding simply floating numbers in Javascript result in extra long return values?

For example, when I add \`0.4 + 0.2\` I end up with \`0.6000000000000001\`.

Another example, \`0.1 + 0.7\` results in \` 0.7999999999999999 \`.

Can anyone explain what's going on here? Why don't these result in simply \`0.6\` or \`0.8\`, respectively?

[Assistant]
0.4 and 0.2 cannot be represented precisely as binary floating-point values. The closest representable values are actually:

    0.40000000000000002220446049250313080847263336181640625
    0.200000000000000011102230246251565404236316680908203125

When these are added together, the result _should_ be:

    0.600000000000000033306690738754696212708950042724609375

but again, this cannot be represented precisely as a binary floating-point value. Instead, the closest representable value is:

    0.600000000000000088817841970012523233890533447265625

The next question is "how should this value be rendered to the user"? You have decided (perhaps implicitly) to display this value using 16 decimal places. Formatting this value as a 16-decimal-place string yields:

    "0.6000000000000001"

A similar thing occurred when you added 0.1 and 0.7, except that the closest representable value to 0.7 is just _under_ 0.7.


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

[User]
[Avatar: The Last Airbender] Are Earth-Benders creating matter?

They regularly throw up great pillars of rock into the air. Are they displacing existing rock, creating fresh rock, or something else?

[Assistant]
They do not create rock otherwise they would not need the rocks as a source.

They move it around. The great big pillars come from the fact that Earth tends to go pretty deep so they have a lot to play with.


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

[User] [Captain America] I work as a guard at a secret Hydra lab/lair. I'm pretty sure Captain America is gonna raid us someday. When he does I plan to aim for his knees and not his shield; any flaws in my plan?

[Assistant]
First, you need to be able to hit a moving target that has the speed of a cheetah and agility of a housefly, moving in unpredictable zig zag pattern, and who is always going from cover to cover in most optimal and tactical way possible.

Then you need to either completely surprise him or shot fast enough before his reflex kick in and move his shield few inch lower to block your bullet.

So yea, unless you also had the super soldier serum or some other super power, it probably wouldn't be happening anytime soon.


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

[User] With most animals that perform mating rituals, the male has to impress the female. Are there any species where it's the other way around?

[Assistant]
Yes.  Probably the classic example is Jacanas.  Females are bigger, brightly colored, and defend a territory containing several males.  The dull-colored males build nests and guard eggs laid in them by the female.   This is usually called a sex role reversal mating system.

There are also any number of pair-bonding species where males and females must both impress each other...blue footed boobies, for example.  Males and females tend to look similar in these systems and need to work together to successfully reproduce.


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

[User]
ELI5: Why can't an orbiting spacecraft match the speed of the Earth and decend into the atmosphere to reduce the friction of reentry?

It seems logical to be able to safely drop into the atmosphere in this manner without the reentry burn.

[Assistant] Because friction slows you down for free, but reversing a low-earth orbit requires an absurd amount of fuel. It takes a gigantic rocket to lift a few hundred pounds into orbit. In order to slow the spacecraft down you'd need to carry the rockets and fuel required to do so into space, which would require a much, much larger rocket.


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

[User]
[Spider-Man 2] Even acknowledging that Spider-Man is pulling his punches like he usually does, how is Otto Octavius able to withstand so many of Spider-Mans attacks?

Hes a middle aged scientist who gets the ability to control four metal arms with his mind and no other superpowers. So even with Spider-Man pulling his punches and not hitting him with his full strength, how is he able to withstand so many hits? Hes still just a human being. Lets assume this will also carry over to No Way Home where hell withstand THREE Spider-Men hitting him.

[Assistant] In some versions,  the arms protect him automatically, so it wouldn't be out of the question for the arms to  move Otto so that he rolls with the punches and  dampens the blow. When the arms can't directly get in the way, that is.


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

[User]
[SPIDER-MAN] does peter HAVE to stick out his pointer finger, pinky finger, and thumb to shoot web?

I mean could he just curl his hand into a fist to do it? Also how does he punch bad guys and not activate his webshooters?

[Assistant] In the Raimi version, yes, that's just how it's triggered. The same is true for other versions, but in most other cases it's a mechanical trigger, so he could have it operate differently if he wanted. It's just convenient in that it's a gesture that's not likely to happen accidentally.


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

[User]
[ATLA/Star Wars] If an Avatar is teleported to the world of Star Wars, how long can he or she pretend to be force sensitive and use earth/metal/blood bending to act like they're using the force?

Let's assume that this Avatar can do all sorts of bending, for how long can they pretend they're some extremely strong force user? Can a Jedi or Sith figure out easily that the Avatar is not really using the force? how does one even prove the difference between someone being a force user and using some telekinetic chi force?

[Assistant]
I think trained Jedi and Sith can often sense the Force in others, so they may be able to tell whether the Avatar is doing so. We have seen that some can hide their Force abilities (Palpatine was very good at this) so maybe nobody could be certain about it and would be convinced for a long time.

Also it's possible that Bending does actually use the Force and the Avatar is just a powerful Force-user.


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

[User] ELI5: Why are so many types of toothpaste advertised as whitening toothpastes? Shouldnt every type of toothpaste be cleaning and whitening your teeth regardless of the type?

[Assistant] "Whitening' toothpastes typically contain stronger abrasives and substances with the specific aim of attacking hard-to-break-down stains and changing color through chemical action. This is in addition to the contents of usual tooth paste, which is mostly concerned with breaking down plaque, minimizing decay, and freshening breath. This can certainly lead to an improvement of appearance, but not necessarily to the same scale if you've got significant coloring.


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

[User] ELI5: If most Muslims disagree with the actions of violent fundamentalist extremists, why isn't there a stronger reaction against it?

[Assistant] Many Muslim leaders in the Middle East have spoken out against these extremists, even from the huge Islamic university in Cairo (the name escapes me at the moment). They have even said that those like ISIS can no longer even be considered Muslims. It's just not publicized much in the West.


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

[User] ELI5: How do hostile takeovers work? Is there anything stopping Jeff Bezos from just buying everything?

[Assistant] Normally, when one company wants to buy another, management approaches the target and they begin discussions. If the target does not want to sell for whatever reason, they can tell the acquirer to go pound sand. If the acquirer really wants to, they can do a hostile takeover if the target is publicly traded and get the financial backing in place and go to the public markets and just start buying large blocks of stock. Once they own enough, they can get a board seat and influence the target or just keep buying and force them to give in.


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

[User] How does the body build a tolerance against substances?

[Assistant]
It can be a very complex process and is different for every chemical, but we can describe the general trend of whats going on when a body develops tolerance.

Firstly, the body developing tolerance is different from the brain developing tolerance, but they are still closely dependent on each other. The body being tolerant is physical tolerance. This happens because your body can metabolize the chemical more quickly. A body might be able to drink lots of alcohol because it has alcohol tolerance. It has more liver enzymes to metabolize the alcohol before it can even get in the blood stream, so less alcohol can go to the brain. The body can develop some degree of physical tolerance to most drugs, psychoactive or not.

Then there's psychological tolerance. Once the chemical passes into the blood stream, and only if it is the correct size/shape, it can pass the blood brain barrier. In the brain it causes psychoactive effects by bumping into and activating a variety of different neurotransmitter receptors, or by binding to allosteric modulation sites, or by preventing reuptake of a neurotransmitter, or by causing the nerve to dump all of its neurotransmitters into the synapse, etc... Very complex chemical cascades ensue. Repeated exposure will cause the brain to adapt by producing more/less neurotransmitters, producing more/less receptors, pulling receptors in/out of the cell membrane, turning receptors on/off, and of course growing new (and possibly unwanted if the drug is addictive) interconnections between neurons. This makes the brain "better" at doing brain things while its surrounded by the drug, which makes its worse at doing brain things when no drug is present. Only psychoactive drugs produce psychological tolerance because only they can pass the blood-brain barrier and act on the nervous system.

Both of these tolerance processes are really specific cases of the body maintaining homeostasis. Anytime a body takes in any exogenous substance, it responds by trying to 1.) metabolize the chemical, absorbing whatever it can in quantities that are favorable to 2.) restore normal functioning business-as-usual as soon as is necessary. This is homeostasis. It happens when you take in any chemical. Not just drugs, even food, and (to a much smaller degree) water and oxygen/CO2. Our bodies develop tolerance because they are always trying to restore business-as-usual. If business-as-usual involves a foreign chemical in your blood stream, the body needs to adapt to tolerate this chemical imbalance. Tolerance is proof of your body maintaining homeostasis as best it can.


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

[User]
ELI5: Why did Latin die

Why is Latin completely dead? For instance, in Italy, why was the language revamped, if Latin was native to that country. I know that Latin combined with regional dialects around Europe to form the languages we have now, but why in Italy specifically was it changed? Didnt the Catholic Church push hard to keep it?

[Assistant]
The language wasn't revamped. First and foremost, language changes naturally overtime. The way that words are pronounced just shifts. That's the primary difference between Middle English and modern English. So the Latin spoken by Julius Caesar probably didn't sound the same as the Latin spoken by Constantine, which sounds different from Church Latin. Italian was the product of Latin naturally changing overtime and mixing with not only neighboring languages, but the Gothic, Greek, Arabic, and other languages that invaded modern Italy over the years.

Second, the church did work to preserve the language, but only within the Church. They didn't really care outside of that. They made Latin the only language that you could use religiously or academically by the High Middle Ages, but didn't care how regular people spoke.


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

[User]
CMV: US media companies want a controversial president because they can make more money

My theory: Media companies make money from their stories. More controversial/shocking the stories = more readers = more money.

Thus,  media companies "indirectly" like Trump because everything he does is  (seemingly) intentionally controversial. This means that media companies  make more money when someone like him is in office.

This  could go for any president though... I bet that whoever wins the 2020  election will be just as controversial as Trump (or actually Trump  himself) because the media will be reporting on the most controversial  figures.

Hopefully  I did an okay job at explaining my theory. If you have a question, I  will respond to you first and then update my description box so that  other people will not get confused. :)

[Assistant]
CNN viewership is down 26% from 2018: reported by the Washington Examiner. Forbes citing similar numbers as well.

They arent making money off of Trumps presidency, even though they are arguably against him the most.


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

[User] Can light waves interfere with sound waves? (or vice versa)

[Assistant]
Yes. For example, a sound wave can cause a spatial variation in the refractive index of a material, which will cause light to change its path. This is called the acousto-optic effect. You can use a laser to heat things up so fast that they emit sound, and this is called the photo-acoustic effect.

A basic interference pattern of sound waves and light waves won't exist in normal circumstances though.


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

[User] ELI5: Why do our bodies build up tolerances for things we may not want a tolerance to?

[Assistant]
Your body is always trying to maintain homeostasis.

If you start pumping a bunch of testosterone, for example, into your body, it achieves homeostasis by reducing natural testosterone production to compensate.

If you ingest caffeine all the time, thereby blocking adenosine receptors, your body compensates by developing even more adenosine receptors.


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

[User]
ELI5:How do filming companies shut down major cities for making movies? Like Las Vegas or New york

To be a bit clearer, I just got done watching the hangover part III, and when they're driving down the strip or on top of a hotel (obviously not green-screened) how do they get all those thousands of people to stop what they're doing for the day, or hope everyone will behave when they're recording?

[Assistant]
They only shut down a block at a time. What you see as "shutting down" the whole city is just editing. And it gets super annoying when you work on Park Avenue South, because christ they love filming there. Jerks.

Also, anyone on film is a paid extra. These aren't just thousands of regular people walking around that they asked to be on film.


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

[User]
ELI5: Why is it a bad idea to pay off one loan with another loan?

I know there has to be a catch somewhere but when I looked it up I could find none. You can't just Dodge interest to a bank like that right?

[Assistant]
You pay interest every month on a loan.

If the second loan is much shorter and/or at a lower interest rate this can be a good idea to save money overall.  That's called "refinancing" and it happens all the time.

If the new loan isn't really different than the previous one then you're just wasting the loan origination fees.  Banks don't extend new loans for free.


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

[User] If I want my summer beverage to stay cold longer, should I wipe off the condensation or leave it alone?

[Assistant]
Leave it. Condensation on a glass has the same effect as sweat on our bodies. At it evaporates, it draws heat from the underlying material, slightly cooling it down. This effect is of course not present when you wipe it off.

Additionally, when condensation forms, the warm condensed water will transfer it heat to the glass and the beverage to come into thermal equillibrium. If you wipe the condensation off, you make room for new condensation to form. After all, the humidity in the air remains unchanged in this process. So when you wipe off the condensation that just transfered its heat to the beverage, you allow this process to start over again, letting more heat be transferred from the water in the air to the beverage.


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

[User]
Why do children's films always paint every conflict as black and white, with an obvious good and bad side?

Any Disney or Pixar movie in the past always has a good character which struggles against some foe by mustering help along the way, which in the end they are victorious from. Why have almost of all of them only presented one side, and if they do show the other side of the story, it is always some trivial wrong which evil-doer obviously is in the wrong for justifying an evil deed which is way out of proportion? Do filmmakers just think their target audience is incapable of dealing with gray areas?

[Assistant]
I can't remember the citation, but I've seen research suggesting that very young children (preschoolers?) have a very hard time dealing, cognitively, with complex moral situations. They learn lessons about morality through simplified situations, and black-and-white scenarios with clear moral lessons seem to be the best tool to teach morality.

Perhaps moviemakers just don't adjust their method for older children...?


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

[User]
Why isn't forced copulation the norm in the Animal Kingdom?

Wikipedia has a brief section on it, citing several examples of forced copulation but it appears from there that it is not the norm across the Animal kingdom. This seems puzzling to me since it would seem to carry a massive evolutionary benefit to those males who could copulate with females regardless of cooperation.

I would speculate that the reason is because females have generally evolved methods for preventing it (I believe this is true in ducks, with the shape of the vagina). But is this true in other species?

Edit: Thinking some more, I woud imagine that if 'rape prevention' in females has evolved, then sexual attractiveness from a male standpoint, should include this ability. Has this been established?

[Assistant] Females evolving methods to prevent forced copulation is part of the story - there is strong selection on males to mate with as many females as possible (whether or not the female wants to cooperate), but there is also strong selection on females to be picky. Another part of the story is cryptic female choice, in which females in many groups have control over whether to fertilize their eggs with a male's sperm after mating with him. This means that even if a male was successful in forcing a copulation, he may not end up producing any offspring, and selection would thus favour the male who can convince females to willingly use his sperm.


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

[User] ELI5: Why are AK47s such a common and popular weapon?

[Assistant] The fact that an AK-47 can be manufactured for as little as $150 is a main cause of this. Not only that, AK-47's are extremely potent at various distances and low maintenance, meaning that you could basically stuff it with mud, pull the mud out, and it would still fire.


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

[User] ELI5: How are steep and difficult mountains like K2, Annapurna, Jannu climbed for the first time without ropes, ladders and harnesses from above for support?

[Assistant] The first climber is climbing above their gear, setting new anchors and hooking into them. The last climber in the team removes the anchors. If anyone falls they will be caught by the other team members through the anchors along the route.


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

[User]
[MCU] How would the Major problems involving law and finance be solved after The Blip ?

Half the population disappeared for five years. Homes would be cleared out and sold to someone else so theyd be homeless and they wouldnt have any money because after money is left in a bank for so long its seized by the government. And what if someone had a warrant on them for arrest before they were snapped ? Are they just forget about it and act like their innocent ?

[Assistant]
>Homes would be cleared out and sold to someone else

Who? Half the would-be buyers are gone and the others have bigger problems in the short term than real estate speculation.

>and they wouldnt have any money because after money is left in a bank for so long its seized by the government.

Money exists by fiat, the amount of it that exists is the amount the government says exists.


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

[User]
ELI5: How do museums keep dust off their artifacts?

Wouldn't feather dusters or blowing them damage them over time?

[Assistant]
It depends on the artifact.

The truly valuable or delicate are kept in special cases - climate controlled to ensure perfect humidity, temperature and lighting, and creating a clean and sterile environment.

A lot of things are just kept behind glass - they may accumulate a little dust over time, but since the cases are closed it takes a long time to accumulate and only infrequent cleaning is actually needed.

Other things we don't really worry about - a duster or other suitable cleaning implements isn't realistically going to cause much harm to most everyday objects, so they just clean as necessary.


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

[User] Is there any culture (current or past) that doesn't honor their dead?

[Assistant] It doesn't answer your question as you're looking for exceptions, but ceremonial burial has been found as far back as Neanderthals nearly 300,000 years ago. The difficulty with your question is that it's much easier to find bodies that were buried in a particular way or with some sort of ceremony or meaning because those civilizations or pre-civilizations that *didn't* perform some sort of special funerary rites would have left very little evidence that they *didn't* do anything special with their dead.


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

[User]
[MCU Infinity War] Why could Xandar, Loki, or the Collector not stop Thanos?

When Thanos destroys Xandar and takes the power stone, he has none of infinity stones in his possession. So it was just his army versus the HQ of a galactic empire. How is it that they so easy fall to him? Or how does Xandar not figure out how to use the stone and stop him, or at least ship it off so it doesnt fall into his hands?

Thanos then attacks the Asgardian ship housing Loki and the tesseract. This should have been the power stone vs the space stone, why did Loki not even attempt to use it upon seeing Thanos wielding his own stone? Youd think the space stone + Thor + Hulk + Heimdall could do anything to slow down Thanos. They literally just defeated Hela in the events of Ragnarok, so theyve shown they can stand up to a universe-wrecking villain.

Then, when he travels to Knowhere, it is the power stone and space stone vs the reality stone. The Collector knew of the power of the reality stone, why was he unable to put up any sort of fight to stop him?

Even when Thanos sends his children to get the time and mind stones, how is it that they can overpower competent wielders of stones? by this time Strange has had plenty of time to study and master how to use the time stone, but barely puts up a fight. Vision is literally the embodiment of a stone and doesnt throw a single punch.

Is Thanos just the only one capable of intentionally using the stones to the fullest of their powers? It just seems like it should have been harder for him to be stopped at the beginning of Infinity War instead of instantly being able to acquire stones to instantly get three of them in thirty minutes. Not only that, but two opposing stones got taken out on earth by two people each! How is this supposed to make sense?

[Assistant]
Out of all of your examples, the only competent user of an infinity stone was Dr Strange. Even without any stones, Thanos and his army are incredibly powerful. Thanos on his own took down Thor, Cap with mjolnir, and Iron Man. Thanos' army also seemed to be doing considerable damage against the combined forces at the end of End Game. Ignoring the stones, if not for Scarlet Witch or Captain Marvel (Dr Strange was out of the fight), Thanos would have probably defeated everyone else.

It isn't too crazy to think that Thanos could either assault Xandar, or have his powerful assassins sneak in and grab it.

As for Loki, he knew he couldn't beat Thanos, even with the space stone. His best bet was to lie about it and hope Thanos leaves them to go check the ruins of Asguard. Loki only revealed it when his brother's life was on the line.

Thanos and his forces are just THAT strong, and Thanos has a gauntlet specifically designed to allow him to use the stones.


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

[User] Eli5 Why can our bodies heal/repair broken bones, cuts, etc. but not repair the effects of aging?

[Assistant]
I think most of the comments are dodging the deeper question of why cells are unable to divide and reproduce endlessly. While it's true that we evolved to include cell death, and evolved to die, there is an underlying biology that causes cell senescence.

The problem is damage to your cells' DNA. In order to repair any damage, your cells have to be able to produce the necessary proteins. Imagine keeping a 3D printer working by 3D printing the parts you need to repair it. As a bearing or nozzle begins to wear down, you can just print a new one and install it. In fact, if your 3D printer falls apart entirely, you can use your other 3D printer to print an entirely new printer.

However, in order to do that you have to have the files that the printer uses in order to print the parts you need. If those files get corrupted in one of the printers, it won't be able to correctly make the part that it needs. If the file is only a little damaged, the printer may be able to sort of make a new part that *mostly* works, but it isn't perfect. As you replace parts, even between different printers, the new parts will be made from corrupted files so the parts will be less and less able to work properly.

Why can't your cells repair their DNA? Your cells *do* repair DNA, a *lot*. However, their methods for detecting damage aren't perfect. Some damage inevitably manages to sneak through. It may *appear* to not be damaged by the proteins built to find damage. Or, the damage may occur on the parts of the DNA needed to *make* those proteins, so that cell can't detect the damage at all. Or, the genes you need to build the repair proteins may themselves get damaged and broken. Eventually, inevitably, damage accrues and your cells' ability to detect or repair the damage wanes, until the damage *cannot* be repaired and your cells have to make do with faulty proteins.

The damage comes mainly from three broad sources. The first is mutations caused by carcinogens and radiation. These things directly damage your DNA. As stated, your cells have a lot of ways to detect this damage and fix it, or to cause the cell to self-destruct so that it can't pass that damage on to a new line of cells. That can always fail, though. The catastrophic version of that failure is malignant cancer, but even if the cells don't become cancerous they may not be able to do their job effectively.

Another source is errors that occur during DNA replication. DNA is a *big* complicated molecule and the proteins that copy your DNA strands don't always work the way they should. You guessed it: your cells have tools to avoid that happening and tools to fix it when it does happen, but again, sometimes those tools fail and an error occurs. That error might insert, delete, move around, or change the base pairs as they get copied. One or both of the new daughter cells will take that error with it, and if that error damages a vital gene, the cell can't build that protein and may not be able to do its job.

The last source is a bit more complicated and has to do with how cells copy DNA. There is an enzyme that your cells build that "unzips" your DNA, and then another enzyme (actually two, it's complicated) comes along and grabs onto the end of it and "zips" it back up, using new base pairs for one side so that one side of the new strand is old base pairs and the other side is new base pairs. The enzyme that "zips" the DNA back up needs a bit of DNA to grab onto. It can't start at the *very* end. It's kind of like an actual zipper, that you need the little tab at the end to pull the zipper on.

That little end tab does *not* get copied by the enzyme. That means some of your DNA gets left behind and doesn't get copied. Your DNA has bits of DNA stuck to the ends called *telomeres* that exist solely to be grabbed by that enzyme and get left behind without getting copied to the new DNA. Since the telomeres don't code for anything, it doesn't matter that your new cells lose it. Your cells start with a *bunch* of telomeres and lose them over time. Eventually, cells that reproduce very quickly (like skin cells) run out of telomeres and start losing important DNA as it gets copied. When your cells are first dividing as an embryo, they produce an enzyme that builds those telomeres so you don't run out too early. At a very young age, though, the gene to make that enzyme turns off, the enzyme goes away, and you stop making telomeres. Why? Because, as stated by others, death is built into our evolution. There's no point in building endless telomeres as your risk of dying to disease, predators, or cancer increases with age. You have also evolved to die so that you don't continue to take resources from your offspring, which would decrease their chances of surviving and spreading your/their genes further.

TL;DR: Your cells need DNA instructions to build the things needed to repair themselves and everything else in your body. Your DNA gets damaged as you age until your cells don't have the instructions they need to build the things they need to repair damage.


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

[User]
My advisor hasn't read my paper draft I sent him 2+ months ago. Should I be more forceful in my request or keep waiting?

At the beginning of December, I sent my advisor a draft of a paper I want to submit which he'll be a coauthor on. I need held deciding *where* to submit, and putting some finishing touches on it. As far as I can tell, all he needs to do is read the paper and say, "This is good, submit to the Journal of Really Cool Findings", or say "If you do XX and YY, you'll be able to submit to the Journal of Really Cool Findings."  It's frustrating because this paper is just about done, but I'm awaiting his final approval. I really want to submit before I forget the details of the work I did.

I think this is taking so long because he's unusually busy this semester. He's normally very busy, but this semesters he's developing a class from scratch in addition to his standard research load. I do not want to keep asking my advisor to help me push out this paper; he is always respectful of my schedule and never forces me to work at a pace I feel uncomfortable with. I would like to extend the same courtesy to him. At the same time, I want to get this done, and I think relatively little work is required from him to do that.

What is the best way to handle this? Should I wait until my advisor helps me through the submission processor on his own time (maybe with occasional gentle reminders), or should I be more forceful with my requests? I lean towards the former, but I wanted more input.

[Assistant]
Maybe you could send him an email suggesting two journals where you think you could submit the paper, and ask if he has any preference among the two options.

Then you can politely ask if he had time to read the paper, or, if he is busy, when does he expects to be able to do it.


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

[User]
ELI5: Why do games have press any button to continue before they start?

I mean specifically before the main menu of a game even loads. Such as fifa, rocket league, battlefield, etc...

[Assistant]
Its an old leftover requirement.

Basically it sets which controller or input method the game will pay attention to. So for example if your system has 2 controllers whatever one you press becomes player one.

It is still a requirement for games to pass certification and ship on consoles, thus you see it everywhere.


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

[User] [Star Trek DS9] Garak's mannerisms and way to speak seems to differ from other Cardassians. Is he considered to be the equivalent of stereotypically gay/flamboyant by Cardassian standards?

[Assistant]
Garak suggests that folks like him tend to tailor their outward personas to match their surroundings. Being a rare case of a Cardassian chiefly living among non-Cardassians and outside the conventional power structure, and his mannerisms and speech are optimised for dealing with that, to the best of his abilities as a trained espionage agent.

Also, potentially significant spoiler >!he's also spending pretty much all day on the technological equivalent of a fistful of uppers. The Obsidian Order implanted a device in his brain that lets him stimulate the pleasure centers on command. While this was originally intended as an anti-torture device, he got in the habit of just leaving it on to help him power through the crippling ennui and depression of his fall from grace and exile.!<


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

[User]
Why are fires around Chernobyl increasing radiation levels?

I've seen several articles talking about increased radiation levels near Chernobyl due to grass/forest fires, but none of them say *why* a fire would cause increased radiation in a previously affected area.

My initial guess was that the plant life has "absorbed" latent radiation, but now that it's on fire, it's being spread through ashes. I know this is wrong because radiation is energy, so it isn't just sitting in the plants.

Could someone fill in the gaps of my knowledge?

Thanks!

[Assistant]
Radiation is energy, but it is emitted by matter - and the matter in this case are the little bits of radioactive materials that were dispersed out of the reactor when it exploded and burned.

The forests around Chernobyl contain a lot of radioactive particles that initially landed on the ground and over time worked their way into the soil and water, and were taken up by plant growth.

When those trees and plans burn, all the radioactive particles inside them (which dont burn) get dispersed and lifted into the air as part of the smoke, and spread around again, and all along theyre emitting radiation.


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

[User]
[Star Wars: TFA] Why did Poe tell FN2187 that BB8 had the map to Luke Skywalker?

They've literally just met, a rebel general tells a stormtrooper the contents of a highly classified piece of intel.

[Assistant] I think by the time he's killed his battle brothers, defied the will of his superiors (including the most powerful person in his faction), and escaped in a stolen military spacecraft, there's no going back for FN.