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

[User]
ELI5: Why is cancer research so expensive?

Where is all the money from fundraisers and charities going?

[Assistant]
Cancer is not one disease, it is a huge variety of different diseases.  People who study cancer and develop treatments are doctors (MD and PhD) who require a lot of expensive education.  They are assisted by technicians that also have expensive educations.  The lab equipment they use is very expensive.  Tests of new treatments and drugs take a long time and require extensive oversight and documentation.  FDA approval of new treatments takes a long time.  Equipment to synthesize and manufacture new drugs is expensive.

On top of that, millions may be spent pursuing new treatments that are ultimately determined to be failures, requiring researchers to abandon them and start over.

On top of that, many charities may not actually devote much of their earnings to research.  Use charitynavigator.com to research charities to see how they spend their money.


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

[User] Eli5: Why is a hard drive so much bigger in comparison to a SD Cards or USB stick, even though the storage space is the same?

[Assistant]
Because a mechanical hard drive needs to fit its spinning platters, optical reader assembly, and controller circuitry into its chassis.

Flash memory devices like USB sticks and SD cards have no moving parts, storing their data directly on a chip. Therefore, they can be much smaller.


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

[User]
[The Flash] generally speaking all Speedsters can do the same tricks even gruesome ones though heroes don't what unique tricks could different ones have?

Trying to figure out some "trademarks" for two different villain Speedsters and heroes all with the speed force not slowing down others type of power.

[Assistant]
As we see in CW's The Flash, when you're dealing with the same powers (superspeed), different abilities are a result of different levels of experience, different ethics and differences in creativity.

That said you can further distinguish two speedsters by giving them weapons; give on a sword made of an unbreakable material and he's cutting things up in the blink of an eye; give one a firearm and maybe he uses his superspeed to ensure he never misses.


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

[User]
[Matrix] Are the physical bodies of the humans better than our own? Can they physically do any of the martial arts and athletic feats in the real world that they can in the Matrix?

Surely they *know* the techniques because they've been uploaded with the info directly into their brains, but are their physical bodies capable of replicating any of the movements that they've learned in the real world?

I'm imagining something like what happened with Jamie Madrox in Marvel.  He sends out a duplicate and he learns a martial art (for example).  When they reintegrate, Jamie now knows the martial art, but he doesn't have the muscle memory in his body, but he still might know everything perfectly, so it would be a matter of training his body to get the physical side of the mental knowledge that he has.  Would it be anything like this?

[Assistant]
Their real bodies are weaker than their digital ones for lack of exercise and, on top of that, they can't break the laws of physics.

On the muscle memory front, it's very likely that the uploaded martial arts data doesn't include accurate muscle memory for either their real or digital bodies but that it doesn't matter to the digital world since their confidence that they're doing it right would be enough to make it happen.


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

[User]
[Star Wars] Why didnt the CIS genetically engineer a virus or bacteria specifically tailored to clone trooper DNA?

Seems like a pretty easy way to wipe out the clone army while avoiding civilian casualties.

[Assistant]
Because Palpatine was in charge of both the Republic and the CIS, and always intended to have the Republic and its clones win.

Plus, with a bioweapon, you need an effective delivery system. Given that the clones rarely remove their armor and helmets and their suits are completely sealed to the point that they can operate in space with just an oxygen tank and jetpack, the possibility that they'd be affected is low.

The CIS did use bioweapons several times throughout the war, but most never made it out of early testing phases - see the Blue Shadow Virus, for example.


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

[User]
CMV Even if irrefutable proof of widespread corruption in the US government came to light, the American people would be unwilling and unable to effectively respond.

I post this more as a panicked cry for reassurance rather than a bout of playful combativeness. In other words, I'm assuming a grim future which I feel I should spell out:

'By the people, for the people' has become a bad joke as elected officials take bribes with impunity from private entities that either harm the community and the world at large with their products and actions or otherwise would not have been successful if not for the actions of powerful government officials. Vote rigging is rampant so that politicians can continue serving interests that are not the public's. The armed forces are kept well funded and loyal at the expense of social programs. As unrest amongst the rank and file surges, civil society becomes fractured and quarrelsome.

I've tried to paint a picture of a society that requires a revolution against the higher class, political or otherwise. My point is not that we as a country are headed in that direction, but that if and when we get there, the American people will not respond. The most powerful military in the world ensures that physical resistance would be futile. Anecdotally, I've seen a lot of people refusing to acknowledge sketchy political goings-on (especially this election cycle), and I believe that head-in-the-sand attitude will only get worse due to our 'addiction to the status quo.' Our entire modern life, from entertainment to the food we eat, relies on the actions of massive corporations with government subsidies. Ultimately, if those entities are shown to be working in concert against the American people, what recourse do we have?

[Assistant]
No one expected the Russian Revolution.  No one expected the sudden end of Ceausescu's regime in Romania.  Surely a band of peasants in Vietnam could never defeat a world empire?

The people don't know their own power.  Yes, things are grim, and the future is uncertain.  There has, however, been a massive social shift.  Workers are slowly but surely regaining their class consciousness.

The winds of change are blowing.


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

[User]
[Marvel] Why haven't the Asgardians declared Eminent domain on the infinity stones?

Surely a bunch of fecking humans can't be the best ones to keep it?

MCU.

[Assistant]
As was previously said, having more than one Infinity Stone in a given place isn't especially smart.

First, Asgardians aren't invincible and Asgard isn't impregnable.  On the off chance they *did* fail to protect their home, any enemy that conquers them would still only have a single Infinity Stone to their name.  Further, Odin kept an Infinity Stone on Earth for one of two reasons; either humans were entirely too stupid and weak that nobody would honestly think that he'd seriously keep a Stone there (lending to security by trickery) or that humans had the potential to be some of the baddest motherfuckers in the galaxy (lending to security by humanity).  Either way, the Tesseract is secure.

What's more, Odin may well be aware that perhaps Asgard isn't *the* safest place in the universe.  Were it not for the Convergence and some truly shit luck, the Aether would never have been recovered, for example.


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

[User] ELI5 why water is slippy in some situations (wet road for example) and grippy in others (licking the top of your fingers to turn the page of a book for example) ?

[Assistant]
Its all about relative friction. Friction will decrease slightly when you have a wet road on rubber tires vs dry road on rubber tires. Your fingers normally have oil on the surface, so water on your fingers on paper will have more friction than oil on fingers on paper.

If you had rubber fingers (or rubber gloves on), water will make them more slippery.


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

[User] ELI5: Why is my money worth different amounts in different places?

[Assistant]
You could be talking about 2 things here; the exchange rate or the purchasing power parity.

If you are talking about the exchange rate, the difference in worth has to do with political and economic history. The Indian Rupee (INR) was pegged to the dollar ($1=1INR) in the 1940. What that means the reserve bank on india controls the amount of money in circulation in the economy such that even with all the currency trading and trade going on the value remains fixed. But soon enough the government started running out of money. So they started printing money to meet expenses. So, now the currency started depreciating - because there was a lot of INR in the market and not enough demand for it. This was the pattern till 1991. In '91 India liberalized its economy. Now, a lot of foreign investors wanted to buy INR with dollar, so they could invest in India. So INR stablized to a certain degree (the government was still printing money, mind you).

During the financial crisis INR appreciated a great deal too. This was mostly because lower demand for the dollar. Now the trend has reversed and the INR is going down again. Currently it is at around 55INR to 1$.

Similarly after WW2, the Japanese economy was weakened a great deal. So the currency fell. After japan started rebuilding and exporting again, the currency steadily rose against the dollar;  But it still in the 80:1 range. It is considered strong because of its trend of gaining in value against the dollar.

Purchasing power parity is the difference in actual cost of a commodity or labor in a different country. This depends on the availability of that commodity in the country. In India there are lots of people. Hence labor is cheap. Indians cannot freely travel to a country were the wage is higher. So if an Indian wants to buy an Ipod made in China, he has to make something of value for the Chinese inside India and export it to them. If he was free to travel to china, he could have gone to china, worked there and eared enough to buy an ipod.


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

[User]
[Neko Atsume] Where are these cats getting all these gold and silver fish?

Also, why are they giving them to me instead of eating them, I thought cats liked fish?

Most importantly though, they tell me I can buy cat toys with them? Who wants to be paid in fish? Barter economies aren't that common these days.

[Assistant]
What you have to realise is that while these are cats, they aren't exactly normal cats. Look at the rare cats. Guy Furry can cook. Bob's using a walking stick to get around. Xerxes is royalty. Some - like Guy Furry, Sassy Fran, or Kathmandu - are capable of walking around on their hind legs.

These cats are *smart*. Really smart. And this doesn't just apply to the rare cats, either. Even the normal ones like Snowball or Pickles have more smarts then you'd give them credit for.

The point is, those aren't actual fish. They look like fish, and they're called fish, but they aren't edible. They're a valid form of currency, used by the cat population of this area. And you're a vendor, providing entertainment and food in return for tips or occasional gifts. The cats pay you, and then you spend the money you get on upkeep.

I mean, you can convert your local currency into gold fish in the game. You just went to your local travel shop and exchanged currency.


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

[User]
CMV: The tip system in the United States for delivery drivers and servers blatantly punishes empathy. For this reason, it should be abolished.

I would also agree that practically any system that punishes empathy should be abolished.

Servers and delivery drivers should be paid just like other professions. The wage should be around what an average server would make now, with the option for adjustment based on performance and higher wages at restaurants with higher expectations. Here is why:

I understand the money has to come from somewhere,  and it would basically be just added on to food prices. This is fine. This just means everyone is actually paying equally for the service they are equally recieving.

In the current system,  many do not tip at all,  and others who feel empathy end up covering for it out of respect for the person serving you. This is unfair. You may argue that I should just tip what's reasonable and not worry about that,  but then that's not fair to the server. The system highlighted above helps make it fair to anyone and punishes selfishness and greed instead of empathy. CMV.

[Assistant]
>In the current system, many do not tip at all, and others who feel empathy end up covering for it out of respect for the person serving you.

Do you have statistics for the amount of people who do not tip? It seems as though your entire argument hinges on the idea that most people do not tip, so that burden falls on the 'regular tippers'


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

[User]
[General Fantasy Dungeon Crawl Video Games] Why are there so many freaking dungeons? Why are they so sprawling and labyrinthine? Why are they all seemingly abandoned?

*Watsonian aside for context: I play a lot of idle dungeon crawl RPG games. Examples include Clickpocalypse 2, Idle Sword 2, Dunidle, Soda Dungeon, and others. They're games where you select your players, buy gear, upgrade gear, and sometimes deploy things like spell scrolls. What separates them from other dungeon crawl games is that combat, healing, etc. occur automatically. You upgrade stuff, go do some work, come back an hour later, and buy upgrades. Your guys basically progress through an endless series of dungeons.*

\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~\~

Okay, so it is my understanding that traditionally, a dungeon is a semi-finished area underneath a castle, a monastery, a cathedral, or another large structure in a world inspired primarily by medieval European folklore and history.

Traditionally, these areas are generally used for holding prisoners. These could be outlaws who hunted illegally on the king's land or something, they could be prisoners of war, whatever. Sometimes there are torture chambers and such, sometimes not.

**Why are there so many unexpectedly, impractically large and sprawling dungeons, which are by all accounts completely and utterly abandoned, and consequently infested with various monsters?**

Much of the time, they don't even seem affiliated with any castle or monastery. When they are, the building itself also appears abandoned. There are no prisoners or guards or anything. In fact, there aren't even any rooms that look like they were ever designed to be holding cells at all.

Who built these and why? Why did they abandon the dungeons, and/or the structures above said dungeons? Why are they incredibly massive and sprawling, often dwarfing the castle they're attached to?

Why did whoever abandoned them neglect to collect their gold and treasure before doing so?

Why are there so many abandoned? I mean, abandoned structures, sure. But why so many of them? Was there some kind of apocalypse or something?

[Assistant]
The dungeons were created by many different cultures and species throughout the millennia.

In a few cases they were literal dungeons - underground areas designed to house criminals and political prisoners.  They were created to be labyrinthine and extensive to foster a sense of hopelessness in its occupants and to prevent escapes.

Sometimes they were created to house dangerous monsters - creatures sacred to a specific religion, unholy abominations made by magical experimentation, exotic beasts obtained in faraway lands.  They may have been kept as sacrifices or to sacrifice to, maybe they couldn't be killed for political/social reasons, maybe they were literally unkillable.

Once there were structures above these on the surface.  They have since rotted, crumbled, and/or burned to the ground.

Other "dungeons" were built by races who live under the surface, like dwarves, goblins, dark elves, etc.  These were their cities, homes, outposts, and trade enclaves.  Powerful wizards and other eccentrics likewise might make strongholds for themselves underground.

They are all called dungeons because that's a generic term for a constructed underground structure, distinct from natural tunnels like caves and volcanic pipes.


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

[User]
[Tarzan] Why doesn't Tarzan have back problems?

He's always hunched over and walking on his hands, wouldn't this destroy your musculoskeletal system?

[Assistant] A lifetime of active living and constant stretching for that next vine or branch has endowed Tarzan with the sort of flexibility that would be the envy of a veteran contortionist... he walks hunched on his hands because he feels comfortable doing so, but he could bend backwards and touch his toes with his elbows, if he so wanted.


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

[User]
[Star Wars] How far back does the Republic know of its own history?

I'm going through Knights of the Old Republic again and it made me wonder, does the Republic have any records of these events? What about the Mandalorian Wars or the formation of the Republic? What is the earliest event that the Republic still has records of?

[Assistant]
Pre-Purge, the records reached back thousands of years, roughly 25 000 BBY, to the formation of the Old Republic.

Though, there are some sources that have records stretching back almost 40 000 BBY, such as the Temple of the Ancients on Lehon, which was home to the Rakata of the Infinite Empire, who are responsible for most of what we see as "natural" on certain planets (extreme tree growth on Kashyyk, Tatooine being a desert instead of it's natural forests, etc)


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

[User]
ELI5:Butler's Gender Performativity

I am trying to fully understand Judith Butler's theory of gender performativity and I would like some help.

[Assistant]
The basic (and simplified) idea is that gender--what we think of as masculine and/or feminine--is performed in the ways we act, speak, dress, move, etc. and doesn't really exist outside of that performance. We learn how to perform this way from dominant culture and conventions--what someone might  (incorrectly) call "normal male" or "normal female" behavior. But these "normal" qualities (and genders themselves) don't actually exist--rather, we are all repeatedly mimicking them and are rewarded for doing so (or punished for not doing so). We merely impersonate the qualities we've been taught match the gender we've been told we possess (like females being demure or males being aggressive) until those impersonations (and gender itself) become belief and seen as something natural and assumed.

She so talks about drag and subversive gender performance, but that gets a bit more complicated. Is there a specific point you're stuck on?


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

[User]
[Star Wars] The Death Star is absolutely massive, but does it have a health club and gym?

Looking for work and I'm curious about their benefits.

[Assistant]
Confirmed? No.

Probably? Yes.

The Death Star had over two million personnel and was designed as a mobile city of sorts. It contained recreation areas, cantinas, bars and other expensive luxuries. It'd almost certainly have a gym- or whatever qualified as a gym in the Star Wars universe.


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

[User] ELI5 why gold is referred to when we are speaking of wealth, even though platinum is rarer, less reactive and more expensive?

[Assistant]
Gold, as a metal independent of other metals, has been known since the dawn of history, named and readily identifiable. It has a melting point when pure of about 1000C  which is pretty high for a metal. It occurs unalloyed in nature fairly often.

Platinum was unknown as an independent metal in Western society until the 1500's  and then solely because *conquistadores* discovered (stole) Native Central American artifacts made from it. It is often alloyed naturally with other silver-white metals, and often mistaken for other silver-white metals. It melts at about 1700C, higher than what most refineries operated at until they understood what platinum is.

Gold is rare, but readily identifiable  of all the metals, it and copper are the only ones that are not naturally some sort of silvery-white in their unoxidised states. So until fairly recently, platinum was unknown or unidentified or mistaken for silver.

There are any number of other rare  and therefore precious  silver-white metals; platinum today is fairly valuable specifically because it is useful, as a rapid catalyst of a number of chemical reactions. That is generally why it is more expensive  there's a high utility demand for it. Gold is so expensive today primarily because there is a high utility demand for it  in electronics.


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

[User] ELI5: Sometimes if you drink enough water you can feel it slosh around in your stomach. Why do we feel it under certain circumstances even though there are always contents in your stomach, like stomach acid?

[Assistant]
If you haven't consumed anything in a long time, your stomach will be mostly empty. Because it's empty, it's being sqished together tightly by the rest of your body. There isn't even a lot of acid in there or anything.

If you fill it, the walls of the stomach stretch, and more gastric juices are added. If you eat or drink quickly, a lot of air will also enter the stomach. That's usually where the loud sloshing comes from - the waves you create on the ocean of your stomach. A very stretched out stomach full of liquid, might wobble around a bit, due to the momentum of the water etc.

Pretty much like a water bed.


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

[User]
How does the wait time paradox work?

I've read a lot of it on the internet and I found this. If a bus comes every 10 minutes (certain) then you'll on average wait 5 minutes. But if a bus comes on average every 10 minutes (uncertain) then you'll wait on average 10 minutes. How did they calculate the 10 minutes? I tried google scholar but couldnt really find something.
Really interested in this because I'm following a statistics class this semester.

[Assistant]
The waiting time paradox is a good example to show why some naive thinking and calculation can be very wrong. (Also, there is a missing part to this since strictly speaking you do *not* know that the average wait time in the uncertain case is 10 minutes, unless you have additional assumptions.)

For these two problems, let *W* = our waiting time and let *M* = the time between successive bus arrivals. Then *W* and *M* are random variables, and we want to calculate the expectation *E*(*W*).

 1. ***Case 1:*** *M* is constant. In other words, a bus arrives every *M* minutes, on the dot, no matter what. To calculate *W*, we reason that we arrive at the bus stop at some random time between 0 and *M* minutes after the last bus arrived. So *W* is uniformly distributed on the interval [0, M]. Hence its expectation is *E*(*W*) = *M*/2. So if the buses arrive every 10 minutes guaranteed, then our average waiting time is 5 minutes.

 2. ***Case 2:*** *M* is not constant. In other words, *M* is, in principle some random variable supported on the interval [0, ). So some buses arrive very soon after the previous bus. Some buses arrive very later after the previous bus. All we know is the value *E*(*M*), i.e., the average time between successive buses. This doesn't really tell you much. If buses alternatingly arrived 5 minutes and 15 minutes after the previous bus, then *E*(*M*) = 10. Our wait time is clearly between 5 and 15 minutes. It is also clearly greater than 5 minutes since there is a positive probability the next bus arrives more than 5 minutes later than the previous one. So already we see that our expected waiting time is not the same as in Case 1. (In this example, *E*(*W*) = 6.25, which is slightly larger than 5.)

The problem in thinking that *E*(*W*) = *E*(*M*)/2 is that the formula *E*(*W*) = *M*/2 for Case 1 was derived under the assumption that *W* was uniform. If *M* is not constant, then we have no reason to believe that *W* is uniform. All we really know is that if the maximum value of *M* is *M**_max_*, then *W* has support on the interval [0, *M**_max_*]. The distribution need not be uniform, c.f., the example in Case 2 above.

Now the missing part... often when people refer to this paradox they give an unqualified statement of "if the bus arrivals are uncertain but 10 minutes on average, then the average waiting time is 10 minutes". That's wrong as stated. Period.

However, there is a specific distribution of *M* that people usually have in mind. Random discrete arrivals with a known mean are often modeled stochastically by a Poisson process. So the arrival time (*M*) between any two buses has an exponential distribution f(m) = Te^(-Tm) where *T* is the known mean arrival time, i.e., *E*(*M*) = *T*. (This assumption is a common approximation.) Since the exponential distribution is memoryless, it follows that any point in time is a point between two successive bus arrivals, the interval between which is again described by the same exponential distribution. So in this case, *E*(*W*) = *E*(*M*) = *T*.

In reality, the distribution of *M* is neither a point mass (as it would be if all the buses arrived every *M* minutes on the dot with *M* constant) nor exponential. For buses that tend to arrive on schedule most often, the distribution of *M* would have a very tall spike at the average *E*(*M*) and decay very quickly beyond that value. (For instance, if the average successive arrival time is 10 minutes, *M* might be approximately normally distributed with mean 10 and standard deviation 1.) In cases where the buses are almost always on schedule, the average wait time is very close to the average successive arrival time. That's why you don't usually feel like you're waiting more than half of the successive arrival time.


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

[User]
[Star Wars] How much wealth does the Jedi Order possess at the time of Episode 1?

I feel like they should be extremely wealthy.  They own the main temple on Coruscant, and maintain others across the galaxy.  They've been around for thousands of years, more than enough time for even the worst interest rates to make them insanely wealthy.  They have the funds to buy spaceships and in the past they've fought wars against the Sith.  Are the Jedi incredibly wealthy, or does all their money go elsewhere?  Do they subsist on donations or are they self-funded or are galactic taxpayers paying their salaries?

[Assistant]
Their wealth isn't as huge as you'd think.

* They don't own any capital class ships, all of their travel is either done on Republic-owned vessels (see Episode I), public travel options (Episode II) or in starfighters.

* They only really maintain the Coruscant Temple, and while there are indeed others, they are mostly left alone except for pilgrimages, and the one on Coruscant is the only one we know of that has any real technology being used, so they're not paying huge amounts for power. And for that matter, these buildings are ancient; the Jedi Temple on Coruscant is over 5000 years old.

* They do own a fleet of droids, but those are relatively inexpensive.

* The last time they fought the Sith was with the backing of the Republic, so it's not like they were paying for the war out of pocket - it was two galactic scale governments going head to head.

* They have the Archives, which are among the most complete libraries in the galaxy. Jocasta Nu noted (somewhat arrogantly, but also deservedly) that if something is not in their archives, it does not exist. These archives can likely be used by non-Jedi scholars and professors, should they ask.

* The Jedi do not have salaries. They get mission stipends for basic necessities, but they're not paid beyond that.


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

[User]
[LOTR] I'm a mortal who lucked out and was given a trip to the Undying Lands. What awaits me there?

Assume I'm, idk, a hobbit who has born the One Ring. Or maybe I'm just a dwarf who was best buds with a Silvan prince during my lifetime in Middle Earth, and manages to hitch a ride to Valinor. What awaits me there? Do I enjoy any kind of immortality, or am I destined to just live out the rest of my mortal days in a really, really nice retirement village with lots of pointy-eared nature fanatics?

[Assistant]
Your status as a mortal is not changed upon going to the Undying lands. If you are mortal, you will still pass away eventually.

It is the only place in the world (mostly) free from the corruption of Morgoth. So the scenery is going to be as pleasant as any you might find in Middle Earth, and probably very primitive compared to the industrial advancements of Men.

If you have any interest in any subject matter, you'll be able to indulge that into your hearts content (assuming it isn't something vile) as for just about any area of endeavor there is a Vala or Maiar who is basically the embodiment of that. Enjoy gardening? They've got an ~~app~~ Vala for that.

It certainly helps to be fascinated or at least tolerable of elves and their way of life, as that is going to be the dominant culture there. But elves are not a monolith and you can probably find a subset that is suitable to your liking. Enjoy poetry and generally admiring the Vala? Hang out with the Vanyar. Enjoy crafts? The Noldor are your people. Like the sea? Check out the Teleri.


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

[User] What is at the bottom of deep fresh water lakes like the Great Lakes?

[Assistant]
That depends on the lake.

Usually, the very bottom is bedrock, like granite or limestone or so. However, over years, this gets smoothed down by currents to form sand, which is mixed with materials that have sunk, like leaves, wood, dead animals, and human garbage, as well as various soils and sands that have washed downstream.

Low spots tend to fill in more, like drifting snow, so you end up with flat areas filled with silt, with high areas of exposed rock.


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

[User]
If each atom has its own spectral lines, how does blackbody radiation cover all possible frecuencies?

I mean,a copper filament emits according to the temperature, but shouldn't it emit only in the "copper spectrum"?

[Assistant]
The natural lines are broadened and shifted by different effects. There is Doppler broadening, which refers to the Doppler effect shifting the emission wavelength, because the emitter is moving. Since the particles have a random distribution of speeds, this converts a single spectral line into a Gaussian distribution. Similarly there are interaction effects (like pressure broadening), a particle temporarily shifts its energy levels (and thus its emission light), while close by another particle. These effects average out the narrow spectral lines and you end up with the black body spectrum.

But no object is a true black body radiator. E.g. if you put copper dust into a flame it will look more greenish than an ideal black body. Or look at fireworks, depending on their ingredient they glow in different colors.

TL/TD: It is a statistical effect, averaging out the emission from many particles being in random states.


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

[User] [Harry Potter] Why couldn't Harry have used Hermione's Time Turner to go back and stop Voldemort and his parents dying? Thus stopping years of tragedy?

[Assistant] Time travel in Harry Potter doesn't work that way. Rather, it works in causality loops. Harry can't save his parents in the past because they're already dead in the future. This is how the Patronus works in the third book - he knows he can cast one because he already casts one in the past/future.


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

[User]
How does a hypothetical Alcubierre drive solve any problems with relativity at all?

It seems to me that the "Alcubierre drive" doesn't actually solve any problems that it attempts to.  It's supposed to allow faster than light travel because the spaceship using it isn't actually moving with respect to the space around it, but why does that matter?   The space inside the bubble including the ship, would still be moving relativistically with respect to everything else in the universe, and would still be limited by c.  Isn't that the only thing that matters?

The contraction of space that an Alcubierre drive creates is kinda like Lorentz contraction, in that it would allow something to traverse more space in less time. Which is how muons created in the upper atmosphere make it to Earth's surface before they decay.   However, Lorentz contraction still has an upper limit at the speed of light, and it still requires exponentially more energy the more contraction you want.

I don't get why this was even a popular idea in the first place?

[Assistant]
It can still be used to communicate back in time as part of a "tachyonic anti-telephone." If two things outside each others' light cones can communicate (it doesn't matter how, or what tricks are used), then with the right choice of reference frames they can communicate back in time.

It also violates the energy conditions of the universe, requires negative-energy-density material, and a host of other issues.

Alcubierre did not conceive of this because he thought it could be made. He did it because it was an amusing trick to do with the mathematics of general relativity. Most of his other work involves simulations of black holes colliding, which is also really cool.

edit: One other thing: people, including Alcubierre, often cite the Casimir effect as evidence of negative energy density. It is not. It is a relativistic van der Waals attraction, which can be derived much more easily in a non-rigorous way using a toy model of negative energy and vacuum fluctuations.


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

[User] [Always Sunny In Philadelphia] Why have none of the gang faced jail time? How have they not faced jail time? They did community service for a short amount of time and nothing after that... Why?

[Assistant] Frank is a cash cow. He has untold wealth somewhere in the 8 figure range. And they are all white... in Philadelphia. The old saying goes money talks and bullshit walks. The gang has an impressive blend of a financial backing and some strange toonforce. So their bullshit can slide by.


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

[User]
[MCU] "The Time and Mind Stones are safe on Earth. They're with the Avengers." Exactly how powerful are the Avengers compared to other forces in the universe? Thanos easily defeated Xandar and Asgard within a few days. Did Thor really think the Avengers would be enough to keep the stones safe?

The last time Thor was with the Avengers was 2015. At that time the roster was Iron Man, Captain America, War Machine, Falcon, Vision (with the Mind Stone), Scarlet Witch, and Hawkeye. In 2017 he learned Doctor Strange held the Time Stone, and he could assume Hulk safely got to Earth via the Bifrost. Did Thor really think this would be enough? When Thor said this Thanos had two Stones and was on his way to get a third. It took less than that to decimate Xandar and Asgard. Did Thor really think the Avengers would be able to fight off Thanos, or was it more of a "They're our last hope for two of these Stones so they'd better be enough"?

[Assistant]
I think this is the usual advantage given to humans in fantasy/sci-fi: creativity and/or dedication.  Also, they're an entity Thanos is unused to dealing with and one he can't predict.  It's not that they're more powerful, it's that they have some traits that may help.

He was right, in the end, while Earth didn't keep the stones safe, creativity and scientific experimentation of humans is what restored the universe, not those other, more technologically and socially advanced groups.


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

[User]
cmv: Man should be able to terminate child support and parental duties if he does it within legal window that the woman could have an an abortion. (Per locality)

Is this a solid view? Are there any counter arguments?

Im not interested in debating abortion ethically on this one. I'm just saying that IF the woman has rights to an abortion, man should have similar rights.

A man shouldnt be able to force anyone to get an abortion, but he SHOULD have rights to TERMINATE CHILD SUPPORT and other parental duties, if he does it within the time that the mother could have gotten an abortion. And if she doesn't tell him she's pregnant, he should not have to pay at all. Also I would even extend it to -- she must  tell him within the first trimester so he can make the most informed decision, because his own ethical concerns about abortion are at stake too.

What do you think?

[Assistant] It's not about giving parents the right to not be a parent, it's about providing an environment for the child to prosper in. Abortion and not paying child support are not the same because in one, you cancel the needs of the child, whereas in the other, you merely ignore them.


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

[User]
I love SPAM.  No really, the actual product.  How did it become associated with junk email?

Spam get a bad reputation, however it's really just salted ham and pressed pork shoulder.  The Hawaiians are crazy about it. Slice it really thin and pan fry it, it's almost as good as bacon.

[Assistant] IIRC, junk e-mail got nicknamed "Spam" as a reference to a Monty Python sketch in which two women are talking and they mention Spam (the product). Over the course of the sketch, Spam is mentioned more and more frequently. By the end, virtually every word spoken was "Spam".


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

[User]
[Shang-Chi And The Legend Of The Ten Rings] Is [character] a good guy now? [Minor Spoilers]

Abomination seems to be on friendly terms with Wong, who is a good guy.

Is Abomination good now?

[Assistant] Abomination until his Harlem rampage was a "good" soldier and didn't turn mindless.  There is a good chance the time in Cyro Cells helped him figure out that fighting Hulk was a bad idea and he reformed.


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

[User]
[Superman] what is the daily planets stance on people showing up late?

Do they get disciplined for it hours cut and such because Clark has been showing up late since day one and here I am sitting in your office Mr. White about to be fired.

[Assistant] Listen, Clark Kent may be the source of a lot of problems at the Daily Planet, but he's also a damn good reporter. Possibly the best we have, next to Lois Lane, and that's only because she's a better writer. He has a knack for knowing the exact details of every disaster, and there isn't a story that he isn't able to research thoroughly and swiftly when we ask him to. He often gets us scoops on stories that nobody else in the city even knows about, and that kind of exclusivity is what keeps the Daily Planet a thriving publication in the internet age.


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

[User]
ELI5: If I could legally build a 10 km yard extension out of dirt and sod off the coast of new Brunswick, have I officially increased the land area of Canada by 10 km?

Essentially? Is Canada (or any countries) land area a fixed number or are people responsible for making sure the number stays as accurate as possible?

[Assistant]
Theoretically, but since 10 km^2 is only about 0.0001 percent of Canada's total land area, it doesn't really put a dent in the official number.

The problem with measuring the land area of a country, especially one with an astronomically long coastline like Canada, is that it's functionally impossible to accurately measure to even a relatively large margin of error.


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

[User]
[MCU/Marvel] Is the full set of Infinity Stones truly omnipotent? Can it bring back dead people who died a long back?

Like could Thanos just not bring back the titans?

[Assistant]
>Is the full set of Infinity Stones truly omnipotent? Can it bring back dead people who died a long back?

Yes. While we've never explicitly seen the stones exhibit that kind of power, (Endgame spoilers)>!Thanos' plan to remake the entire universe, and his vast knowledge of the stones makes resurrecting someone seem relatively trivial. The only exception seems to be the sacrifice made to acquire the soul stone.!<

>Like could Thanos just not bring back the titans?

He could. He chose not to.


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

[User] ELI5: the Christian relationship to the Old Testament. If the New Testament came along and changed much of the OT's doctrines, why is the OT still considered just as valid? Why isn't Christianity just based on the NT?

[Assistant]
This is actually a pretty big question in some Christian communities. There is a question as to whether or not the Old Covenant is still "legally" binding to Christians. There are generally three trains of thought;

1) Christ's New Covenant was sealed and put into effect at the Sermon on the Mount, nullifying the Old Covenant.

2) Christ did *not* nullify the Old Covenant at the Sermon on the Mount, and the New Covenant only came into effect either at the Last Supper, the Crucifixion, and/or after he rose from the dead after the three days, at which point the Old Covenant was nullified, and the New Covenant sealed, with the Last Supper being the traditionally held moment of importance. This is also the primary view held throughout most Christian denominations.

3) The Old and New Covenants are both binding, although the New Covenant obviously takes precedence if there's a conflict of doctrine.

This also calls into question what nullifying the Old Covenant means; some believe it means that literally everything in the Old Covenant is no longer important (other than the bits that the Rabbinic Jews refer to as the Seven Laws of Noah, which are basically covered in the 10 Commandments), while others believe that the Old Covenant should still be respected even though it's not important anymore. Furthermore, there are some that believe that the moral codes of the Old Testament are still binding, but the ceremonial codes aren't (which is how you get shellfish-eating homophobes, as well as other cases of people selectively following Old Testament rules).

So in short, to many Christian communities, the Old Testament *isn't* as valid, and is merely taught as a background needed in order to understand the New Testament and the New Covenant (particularly given that Jesus' authority at least partially comes from the prophecy of the Messiah, which is given in the Old Testament).


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

[User] [Game of Thrones] After Sam's greyscale treatment, did Jorah still have a functioning dick/balls?

[Assistant] First of all the precise status of Jorah's dick and ball is not made explicitly clear in the show. Also, the greyscale hadn't reached his entire body yet, so we don't even know if his dick and balls were even affected in the first place.


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

[User]
Could an electric vehicle stand a chance in a racing event?

Telsa released their new roadster just a bit ago, which is a very powerful car, and completely electric. Would an electric vehicle have any benefits in a race? Fuel efficiency or decreasing the weight of the car maybe?

[Assistant]
The energy density of batteries is much lower than that of gasoline (or similar fuels). So to bring the same amount of total energy, an electric car will be heavier than a fuel-powered car. In addition, as the race progresses, fuel is burned and the fuel-powered car gets lighter. The batteries stay at the same weight, full or empty. So even though an electric engine is more efficient than a combustion engine, you'll need to drag more mass around the track for it to work.

However, electric engines do have a large advantage over combustion engines that could be useful in racing. A combustion engine produces it's highest torque in a specific RPM range. When accelerating from low speeds with a combustion engine, it may take some time to reach the point of maximum torque. Electric engines, on the other hand, can deliver their full torque immediately from the start. This difference is so significant that a modest full-electric vehicle can match high performance fuel-cars at a typical traffic light sprint.

So in a race that covers only a short distance (not much battery needed) and has many sharp corners that have a large reduction in speed (so the value of rapid acceleration is extra noticeable), an electric vehicle may come out ahead. In longer races with larger sections of straights or high speed turns, their advantage is rapidly nullified.

However, some race and sports cars use the best of both worlds. Many of the high-end sports cars are becoming hybrid-electric, using the electric engine for that extra punch, but relying on the good old fuel-burner for the longer haul. Formula 1 engines have incorporated a hybrid electric system for several years now (with battery management and deciding when to employ the electric boost becoming relevant skills for a driver).


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

[User]
How do dolphins leap so high out of the water?

They seem extremely capable of jumping great heights too, almost as if there is some evolutionary purpose.

As a bonus question if I may, WHY do they jump out of the water?

[Assistant]
It's just a function of being able to swim fast.

Compare it to the ability to jump high by NFL tryouts.

They don't need the ability to hump high per se, but it comes with training for high speed running.

They even can jump higher than NBA players...


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

[User] ELI5: In the United States, why are positions like Attorney General, Secretary of State, etc. appointed by the president at the federal level but elected by the people at the state level? Had it ever been proposed to do this differently?

[Assistant]
The federal government was designed to primarily be a representative of the States, while the States would represent the People.

This is apparent in how the Federal Senate was initially chosen by the state legislatures (prior to a constitutional ammendment), and the Electoral College was initially also selected independent of the popular vote (that's screwy ATM because of state-level laws). Indeed, the House of Representatives still gets 0 say in federal nominations, appointments, or treaties.

As the State governments were viewed to be much closer and more relevant to the People, their state constitutions generally reflected this in directly voting in many more positions.


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

[User]
[LOTR] How are they always getting sausages to eat?

Throughout the films you see the hobbits cooking sausages at least 3 times.  Where are they getting the sausages from?  Don't they spoil?

[Assistant] Smoked and dried sausages last a very long time, being fairly effectively sealed away from bacteria and preserved. They make decent travel rations, not as long-lasting as hardtack or lembas, but still quite good.


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

[User] [Marvels MCU Black Panther 2018 Movie] Earths resources are not evenly distributed. Some places have oil, others gold, etc. How does Wakanda seem to have all the resources needed for an industrial society? They don't trade with other nations, so are they just building everything out of Vibranium?

[Assistant]
Wakanda has a couple things going for it.  It is in one of the most resource-heavy parts of the world.  Sub-Saharan Africa is DENSE with natural resources.  And Wakanda is the most resource-filled part of that section of the world.

They also *do* trade with outside nations, they just pretend to be poor.  Their largest export is textiles, so they do have some sort of trade going on.m

Their technological development was also built around Vibranium, so it's probably that they just didn't go the combustion engine route and never needed oil.


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

[User]
ELI5: Why is the word "used" pronounced differently with different meanings? Ex: I used the bathroom (yoozed) VS I used to go there (yoost).

Google doesn't seem to turn up anything. It boggles the mind.

[Assistant]
It's not because the meanings are different, it's because of the word that follows them.  When "used" is followed by "to", it's easier to make a "t" sound at the end of "used".

This is just us being lazy.


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

[User] ELI5: I read that North Korea is "entering a state of war" with South Korea, but few believe North Korea would risk "full-out war". What is the difference between a state of war and a full-out war? Aren't they both bad?

[Assistant]
Until the North Korean army starts bombarding Seoul, you don't really need to worry.

Entering a state of war means that they're preparing for war, while being in full-out war means they are at war. You can prepare to go to war, and then change your mind.

They're both bad, but getting ready for war isn't as bad as having a war.


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

[User] If we express different genes through our lives because of epigenetics, does that means we transfer different genes to our kids depending on the time of our lives we had them?

[Assistant]
No (but sort of yes).

What you're describing is epigenetics, which are not genetics per se, but does influence which (and how) genes are expressed through epigenetic markers usually made from proteins. It has been found that (at least some) epigenetic markers can be passed to offspring; so while the genes that are passed won't change through aging, the epigenetics may.

One pertinent example of this is the finding that extreme stress can leave epigenetic changes that are passed to offspring (in mice).


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

[User]
ELI5: Why are electric chairs not able to kill people instantly?

You see stories of people getting accidentally electrocuted in everyday life and dropping dead instantly, why arent electric chairs engineered with that amount of power?

[Assistant]
Electricity kills you quite randomly. Sometimes it stops your heart, sometimes it doesn't. There have been cases where people survived touching high voltage lines with their face and skin burned off.

The amount of power required to guarantee immediate death is basically the amount needed to cook/evaporate you. It would get very messy that way, with no recognizable corpse left. At that point you could simply drop a truck on people for the same effect.


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

[User]
How is an actual memory different from a memory of an imagination or fantasy?

For example, if a person is given a lie detector test and instead of focusing on his actual memory the person focuses on an alternate imaginative version of that memory. Will this person's body still react as though he is telling the truth or will it react like he is lying?

[Assistant]
Lie detectors, atleast modern ones, do not determine whether your memories are correct or not but rather it's a form of pseudoscience of measuring how your body reacts to both external and internal stimuli.

An "actual" memory can be, in completely technicality, no different than a memory of an imagination or fantasy if you believe the latter mentioned to have truly occured. To add, we humans have extremely flawed capabilities of keeping memory since they change in detail (adding/removing/editing elements) each time we recall them, so in a way they always end up being imagination of how our brains perceived said events and later processes them in the future.

It all depends on how your brain categorizes said memories in the first place. An interesting fact is that this is why some frequent lucid dreamers can sometimes not tell apart their dreams from actual reality.

Background: Masters programme in Biomedical Engineering.

Did this answer your question?


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

[User]
[Marvel] How did Captain America react whenever he was thawed out of ice and he saw black people eating in the same restaurant as him?

I dont know much about Captain America, but I do know that he was alive during the WW2 time period. This means that he was a caucasian American male, and most likely, even if he didnt intent this, was racist.

Back in those days you were brainwashed to be racist almost, it was literally everywhere. Every restaurant, bus, water fountain, etc., divided. To think that Captain America was on some moral high-ground just because hes our most patriotic superhero is asinine. He was born and raised in racist America, there was no way he wasnt even a little.

Do you think Captain America was shocked to see this, or shocked to see anything else when he came back?

[Assistant]
Steve Rogers definitely was born and grew up during the period of segregation - but he was in Brooklyn, when New York City was one of the most multi-ethnic, cosmopolitan urban spaces on the planet. He entered a military that was largely segregated - and was sent overseas where American forces came up hard against local conditions, because Black British were *not* treated in the same way as Black Americans, and much the same could be said about France. Captain Rogers even served in an integrated unit - Nick Fury's Howling Commandoes being an exception to overall US military policy at the time.

So while he may have noted the difference, as someone who probably never shared any deep racial prejudice against black people, who had served alongside black Americans that fought and died for their country, I'd like to think that he welcomed the change that had come over his homeland.

It is also to be remembered that some years later, Captain America discovered that an African-American man, Isaiah Bradley, had been used as a guinea pig during an attempt to re-create the super-soldier serum - and suffered permanent disability when the untested, unrefined slowly crippled him over time. He learned of this from that man's grandson - the superhero known as Patriot - and visited his counterpart in an effort to reconcile and face that part of America's past.


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

[User]
I don't believe the mayor of a major city should be expected to resign simply because he smokes crack. CMV

As many have guessed from the title of the post, I'm referring to Rob Ford (current mayor of Toronto), though I think the principle could apply to any mayor of a major city. I disagree with pretty much every single policy of Rob Ford's. I think he's a complete idiot. I believe he's done some shady things that should have got him kicked out office.

However, I don't believe smoking crack is one of those things.

I believe the mayor of a city should be able to smoke crack or use any recreational drug of their choosing so long as it doesn't demonstrably affect their work performance. While it would be pithy to claim that Rob Ford's idiotic policies are a result of him smoking crack, I haven't seen any evidence of that, and I believe Rob Ford's policies would be just as stupid if he didn't smoke crack. I.e., his work performance is not being affected by his drug use.

I should say I'm fairly ignorant about crack. I have no experience with it at all. I've never come across anybody in my life who's used it (to my knowledge). I've heard the sentiment that anybody who uses crack necessarily has their life in disarray and can't sustain a productive life. I don't know if that's true or whether it's possible to be a "high-functioning" crack user or not.

I really dislike the man and would like to see him go, which is why I'd like my view changed. The principle of the thing is more important to me, though, and my principles right now tell me a democratically elected man shouldn't be forced to step down simply because of what drugs he uses on the weekends. I use recreational drugs (albeit not any illegal ones) and I feel it would be hypocritical of me to demand my mayor not use any recreational drugs.

[Assistant]
Suppose you are a wealthy and have servants, like cooks, butlers, gardeners etc.  You are satisfied with all their work.

Now suppose someone told you that you saw the cook hanging around questionable people and said that he saw him smoke crack.  You address this with the cook and he say says that he doesn't smoke crack.  A little later, a police officer tells you find out that he did smoke crack.  It appears that the cook lied to you.

Now this cook has control of your money (to buy food and other kitchen goods) and has full access to your home and feeds yourself, family and guests and works with your other staff members.

Do you let him go and find someone else that can cook to your satisfaction or continue on with him working for you?


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

[User] ELI5:Why do TV news camera people carry around gigantic shoulder mounted cameras when there are so many smaller options?

[Assistant]
It's certainly be possible to make broadcast-quality cameras much smaller and lighter than those used by news crews, but there's not much point.  Even a 1 inch sensor will have ample performance and the high-quality, high-ratio zooms required will be expensive but not very large.

As long as you have a guy who's one job is to be the camera man then that's all he's going to be carrying about anyway.  Having it large has advantages:

 * Carrying a large camera makes it obvious that you're media (mostly, but not always a plus);
 * Large, heavy objects are more stable so there's less camera shake;
 * Shoulder-mounting is a comfortable way to shoot so the camera needs to fill the space between your shoulder and your eye;
 * There's space for large, discrete controls for everything.  Cameramen don't want to be delving through a maze of menu options to change their settings;
 * You can have a big, comfortable and high-quality viewfinder; and
 * You can comfortably attach big video lights.


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

[User]
How do lasers cool things?

I've always been under the impression that lasers exclusively transfer heat to a subject ("I expect you to die, Mr Bond"), but with the recent article about the force microscope allegedly multiplying it's magnification via laser cooling, I have to wonder how that works? Can anyone help?

[Assistant]
The basic principle involves using the absorption spectrum of a specific material. If you shine a laser that is at a slightly lower frequency than the absorption spectrum then atoms that are moving towards the laser will 'see' their own absorption spectrum due to the relativistic doppler effect. Through this mechanism we can force atoms to be having opposite momentum to the photon as it is absorbed so each absorption event results in the loss of momentum from the atom.
The atoms then emit photons spontaneously in a random direction which the net result of which is zero change in average motion. If you apply this technique from several directions you end up lowering the average kinetic energy of the atoms and by definition their temperature.


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

[User]
What makes Doctor Strange so powerful?

I'm limited on knowledge but he is still just a man so what makes him stand out so much from those who have studied magic their whole life?

[Assistant]
What makes him stand out from others who study magic, like Doom, is that he has both studied longer and harder and has a greater natural aptitude, so much in the way that anyone becomes the best at anything, he is the best at magic.

He was also lucky enough to study under the previous Sorcerer Supreme, so he was taught by the best.

In addition to these advantages which might only put him a little bit above the second best, by virtue of  being the best he get's access to a bunch of other stuff. He has access to various extra dimensional entities, like Cyttorak that will only deal with "The Sorcerer Supreme" because everyone else is beneath them, and he is entitled to certain magical artifacts, like badges of his office.  These include, but are not limited to, the eye of Agamotto, the cloak of levitation, and Books of Vishanti.

TL;DR he got to be the best the same way anyone gets to be the best at anything, but his job comes with a ton of perks once you get to be the best.


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

[User]
Are there any parasites that inhabit a valuable ecological niche?

Do we need parasites? Are leeches and ticks necessary? If we eradicated botfly would another species suffer?

[Assistant]
There is some speculation that the eosinophilic aspect of the human body which functions to target parasites (and is also responsible for the development of allergies, asthma, and other histamine related conditions) needs exposure to parasites and other infections to be properly trained.

In the modern world, we have barely any exposure to parasites, so the theory is that the eosinophilic arm of the immune system doesnt have anything to target, so its more prone at targeting the self which contributes to allergies and asthma and eczema, etc.

This is corroborated by the finding that the developed world has significant rates of these conditions whereas parts of the world that are much less developed and do regularly encounter parasites have minimal rates of these conditions.


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

[User]
How do magnets REALLY work?

Their power is unlimited. How are they made? Where does the charge come from? How can they be so powerful? Do they work with the Earth's own magnetic field or are they separate?

So many unanswered question which I hope AskScience can answer.

Thanks.

[Assistant] A moving charge creates a magnetic field. You can treat an atom has having an electron moving around in a circle (this isn't literally the case, but it can be useful to look at it this way). This means each atom may have a little magnetic field associated with it. If you have many atoms together, all the fields will point in different directions and cancel out. In certain materials, however, the atomic spins align with each other, so there is a net magnetic field.


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

[User] ELI5: Why did Barack Obama win a Nobel Peace Prize?

[Assistant]
There is a lot of confusion as to why a president could win a Nobel Peace Prize into their first year in office. It is especially confusing when there are so many people around the world who are dying for peace, and have arguably made a greater impact.

**Contrary to popular belief, Obama was *not* awarded the Prize due to him being elected as a black president and people getting "caught up in the moment". It had a lot to do with what he *said* and *did* leading up to October 2009. We must look at the Norwegian Nobel Committee's reasons in order to understand why he won.**

The Norwegian Nobel Committee says that they gave him the prize **"for his extraordinary efforts to strengthen international diplomacy and cooperation between peoples."** What are they referring to here? It takes several months for Nobel Committee Members to write up a report to nominate and select someone for the Prize. Obama gave a very important speech to Egyptians (called "A New Beginning") in June 2009 at Cairo University. He was selected in October 2009. So the Cairo speech had a lot to do with what they refer as "international diplomacy and cooperation between peoples".

How did "A New Beginning" foster international diplomacy and cooperation? After 9/11 and the prolonged Iraq War, one of the most hostile relationships in politics was between the United States and the Arab World. The Israel/Palestine issue is one of the most difficult problems to solve. Egypt is the largest Arab country, and seen as the centre of the Arab world and influential in the outcome of Israel/Palestine peace. So Obama shot for the stars. He went to Egypt to try to ease US-Arab tensions, and kick off a strong Israel/Palestine peace process.

But there's more! In the past, American presidents have used very strong, unapologetic language, like that of President George W. Bush. In "A New Beginning", Obama didn't do that. His speech was one of mutual respect, something an American president hasn't done in a long, long time.

He also quoted from the Quran! But so what! What does that mean anyway? Well, the concept of recognition is crucial toward building trust. By quoting from the Quran, Obama is implying that he *recognizes* Islam and respects it. Respect is the first step toward peace as it opens up diplomacy.

The Norwegian Nobel Committee also said that Obama's **"vision of and work for a world without nuclear weapons"** was a reason. This is not particularly important because a lot of presidents have talked about reducing nuclear stockpiles internationally. Particularly, in 1991, there was a treaty called START which started this process. The Nobel Committee saw that Obama was taking this *even further*. He started writing and talking about a new START treaty to reduce nuclear weapons even before his "A New Beginning" speech in June, so the Nobel Committee had a lot of time to consider it. If Obama let the last treaty expire in 2012, more nuclear weapons would spread around the world. Although he criticized Iran here, he was sure to be fair. And his efforts to be fair were astounding: he admitted that the United States overthrew a democratically elected leader in 1953, which was very fair. The Nobel Prize committee saw this as him being the "bigger man" about the problem.

Also, the Norwegian Nobel Committee said he got the prize because as a result of his speech, **"democracy and human rights are to be strengthened"**. Obama talked a lot in Cairo about human rights, religious freedom, and the rights of women in his speech. And in Hosni Mubarak's front door step as well! That takes nerve. Did his speech have an impact on the Arab Spring? Certainly. The Egyptian youth were listening to this speech. They wanted democracy before Obama came in, but Obama's speech gave them support. Obama didn't create the Arab Spring by any means, but it helped a little and set the tone in the Arab world: an American supports and respects Muslims, so how bad could democracy be? The Norwegian Nobel Committee certainly didn't predict that this would lead to the Arab Spring, but as a group of politicians and students of international relations and political science, they sure understand the impacts that such a speech could have.

The Norwegian Nobel Committee also felt that Obama is helping the USA play **"a more constructive role in meeting the great climatic challenges the world is confronting"**. There is very little evidence of Obama addressing climate change in time of the October 2009 decision, but by September, Obama proposed new regulations on industry polluters to curb emissions--something George W. Bush wouldn't have done, or didn't do. He strengthened the EPA.

Although not directly mentioned by the Committee, Obama also launched the debate on better healthcare in 2009, and talked strongly about closing Guantanamo Bay and ending the Iraq War.

Herein lies the problem of giving the award to Obama for many people. Before ending the Iraqi war, the war was scaled up. Indefinite detentions were scaled up by 2012, not retracted. And the Obama administration took up a smaller role on renewing the Kyoto Protocol than many had expected. Although Obama did **a lot more for global diplomacy and democracy by October 2009 than many presidents in their entire term** (which the Norwegian Nobel Committee noticed), in retrospect of three years, a lot of this has been undone by drone strikes, the relative failures of the Copenhagen summit on climate change, and the passing of the National Defence Authorization Act. This is why people like to wait before awarding a Nobel Prize, and why there was criticism.

**TL;DR: The fact that he's black and liberal usually overshadows Obama's achievements up to October 2009, when he was selected. The truth is that he has done a lot of good in the international community through his speech in Cairo, ratcheting up the reductions of US/Russia nuclear stockpiles, and scaling up emissions regulations through the EPA. A lot of other Peace Prize winners did a lot more in earning their Peace Prize, but some others have done a lot less than Obama to earn their's.**

**EDIT**: People will inevitably want an analysis on the individual views and biases of those individuals on the Norwegian Nobel Committee. This doesn't mean much because it's speculative, and the Committee members have no reason to lie in their original report, but lets take a look.

**Chairperson Thorbjrn Jagland** is a politician for the Norwegian Labour Party. He is pro-European consolidation and president of the Council of Europe. He is known to have preferred the European Union for the Nobel Peace Prize since 2008. If he had it his way, the EU would've beat out Obama.

**Deputy Chairperson Kaci Kullmann Five** is a politician for the Norwegian Conservative Party. The Conservative Party is a neoliberal party for tax cuts and smaller government. Ironically, despite all the socialists on the committee, **she is responsible for championing Barack Obama for the Prize**.

**Sissel Rnbeck** is a politician for the Norwegian Labour Party. Her expertise lies in how she is the Minister for Environmental Affairs, and deputy director for the country's body on Cultural Heritage. She is a socialist.

**Inger-Marie Ytterhorn** is a politician for the Norwegian Progress Party. The Progress Party is the main *right wing* party in Norway and supports the growth of the oil industry and lower taxes. It supports a Christian heritage, and relatively anti-immigrant.

**got Valle** is a politician for the Norwegian Socialist Left Party. The  Party is pro-environment and advocates for larger government responsibility.

**TL;DR 2: There are three socialists and two right-wing leaning politicians on the committee that selects the Nobel Prize Laureate. Ironically, it was a right-wing politician that championed Obama for the Prize, while the Chair was championing the European Union. There was no clear consensus between the committee members as to whether Obama should be chosen as the winner.**


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

[User]
Is inflation just an increase of prices? Supply and demand?

Im new to the study of economics. But from what I understand, prices increase when either demand increases, or supply decreases. So if inflation is just an increase of price, then the cause of inflation can only ever be a decrease in supply (which has many causes) or a increase in demand (which also has many causes)?

[Assistant]
It's somewhat more complicated. Inflation is typically defined as an increase in prices for some bundle of goods, yes, but your pronouncement about supply and demand is really about *real* prices.

As an example: say that everyone tomorrow collectively agreed that a quarter was now called a "dollar" and a "dollar" was now called a "fourd". Inflation has happened because the nominal price level as increased (the currency was devalued, at least in theory) but the ratio of prices might very well be the same.

The supply and demand charts that you see with "price" on the y axis are really saying some sort of relative price because nominal price level doesn't matter for the utility of consumption choices, only the consumption bundle itself.

Therefore, devaluation of currency can be a cause of inflation.

As others have aptly noted, decreased in supply or increases in demand *can* be causes of inflation though; if relative prices change as a result of demand or supply disturbances, this can change the nominal price level of the reference bundle of goods as well.

To further complicate things, there are frictions in the economy which means revaluations of currencies have *real effects* because it takes a while for people to adjust prices, so the inflationary effect may also be somewhat real and not just nominal as well.

Hope this helps.


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

[User]
[WH40K] I want to be an engineer but I think the Admech and their worship of technology is nonsense. What can I do?

Let's say that I, Imperial Citizen number 90B12V750Z, want to be an engineer, and I have the aptitude to become one, as I am good with tinkering and understanding how machines work and I'd love to do research and development work.
However, the Admech's dogmatic stance towards technology is offputting for me, as I want to do research, not just keep old things working without ever making questions about *how* they work. Also, I think that Techpriests in general are creepy, elitist jerks.
What can I do to realize my career ambition? Is there some scientific organization that do research independently from the Admech?

PS: I'm still a loyal Imperial citizen and I absolutely won't consort with either Xenos or Chaos.

[Assistant]
So if you're lucky and already showing tremendous talent you'll be picked up by an unorthodox tech-priest who will mentor you in the ways of true engineering while simultaneously training you to *keep your damn mouth shut about this.*  This is what happens to one of the protagonists of the Mechanicum novel.

This is a bit of a crapshoot however.  The tech-priest in question makes it clear most people who talk about this kind of heresy openly just get turned into servitors.


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

[User]
I think Ive made a terrible mistake. Wondering (hoping?) if any faculty can give me advice

I recently quit a cushy, well paying, secure job to take a tenure track position at a university.  Although my previous job was well paying and cushy, it was very depressing and offered no room for growth, so I bailed.

So I accepted the uni job in summer, and I have an idea of what classes I'm teaching in the fall, but nothing confirmed. Due to some circumstances that could have been prevented, there was a mandatory overload that all teachers had to deal with. Long story short, come the first day of classes, my schedule has changed 4 times, and I am signed up for 17 credit hours (2 grad classes, 1 undergrad, a few labs ).  The last change was the day before classes start.  I have never taught before, and 2 of the classes I never even took in school.  The material is very technical, so its not something I can wing.

So I am in the first lecture, completely unaware / unprepared, and fumbling along and 30 people are just staring at me.  I just stopped for about 15 seconds and starting freaking out - there is no way I could do this for 17 credit hours.  Ive done some tough projects before and can hustle, but that course load is too much.  I literally thought, and highly considered, just picking up my bag and leaving/quitting.  I didnt, but had one foot out the door. Ended class early since it was the first day.

By the end of the day I am down to 11 credits plus advising time (I am only supposed to have 9 as a first time teacher). So I have a manageable schedule, but now I am having second thoughts about if I made the right decision.  The other faculty were professional and supportive, and definitely looked out for me.  What is really messing me up is the fact that they even had me for that many hours in the first place.  Now that the dust has settled and I can think about the situation, I am pretty pissed off that it even happened. Its amateur hour!  I was excited to start this job, but now I have this awful taste in my mouth I cant get rid of.

[Assistant]
You're in this now, might as well make a go of it. Don't panic, the stuff is way harder the first time around than ever after. Here are a few things life has taught me:

* It takes about 3 hours to prep each lecture hour. Plan accordingly.
* You only really need to be one textbook chapter ahead of the students. So do that.
* Get another textbook of the same course, and use that one for your examples given in lecture. That way you're not lecturing right out of the textbook, and it might help you understand the material better as well.
* Many textbook companies have auxiliary materials, and those can help in prepping lectures and tests. Make sure you have those (see above about finding another textbook for the course, you can use it for auxiliary materials as well).
* If find yourself totally lost in a lecture, that's fine. Move on and say something like "we're going to cover this in another lecture, so we'll move on for now". Or "I have an appointment, so we'll have to stop early today". Really, it's not the end of the world as long as you don't do it every day.


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

[User]
Why don't doctors get sick more often?

Why don't doctors who work with contagious patients get sick more often?  Are their immune systems superior or do they simply protect themselves to the utmost extreme?

[Assistant]
Well, we wash our hands all the time, use antiseptics and such, we're required to take flu shots among other things, and most importantly, if we do become ill we stay home.

Granted, if a patient came in with a very contagious very serious infection (something like VRSA) we would take extra precaution around that patient.


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

[User] [Fistful of dollars] Can a metal chest plate really protect you from the guns of the wild west? What is the minimum thickness required to not gain a few new bellybuttons in a gunfight?

[Assistant]
The case of Ned Kelly in Australia says that you can armor up against mid/late 1800s firearms. Hell, Civil War officers wore half-cuirasses.

The part where it gets unlikely is not that the plating works, but that the shot *only* hits the plating. This is where they finally got Kelly, too- he didn't armor his *legs*.


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

[User]
What is the difference and/or relation between the 4 dimensions of spacetime and the 4 dimensions involved in the notion of objects like tesseracts (4 dimensional cubes)?

I have a very basic conceptual knowledge of the two ideas but I never really considered them together.

When we talk about tesseracts and their 4 dimensions are we really implying that they have at least 5 dimensions (x, y, z, w, and t)? Any insight or resources would be greatly appreciated.

[Assistant]
a minus sign.

To be specific, say you want to find the distance between a point and the origin in 3 space dimensions: ds^2 = dx^2 + dy^2 + dz^2 . And you could keep tacking on additional space-like dimensions if you wanted with more plus signs.

But when we deal with time, and we want to know the distance between an "event" (point in space at some time) and the origin (origin of space coordinates and at time=0) then ds^2 = -dt^2 + dx^2 + dy^2 +dz^2 .


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

[User] Does light that barely escapes the gravitational field of a black hole have decreased wave length meaning different color?

[Assistant]
Yes.

In particular, shifted towards the red, or... redshifted. That's gravitational redshift. That's for going up; going down it's blueshift. You don't need a black hole, btw, you can do it in Earth's gravitational field, read up on the Pound-Rebka experiment.


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

[User] ELI5: Why are certain foods (like sugar) nearly universally pleasing to the human mind, but other foods can be delicious or disgusting to different people?

[Assistant]
Prehistoric humans didnt have a ton of options for food because there was no agriculture- most of the fruit and veg we eat are created by humans. And spices def werent a thing.

So we love fat because when they had a successful hunt they had to gorge themselves- get as many calories as possible since there was no guarantee of their next meal. Same with sugar- when fruiting plants were in season and ripening they had to eat as much as they were physically able - they had limited time and many of the nutrients werent available to them any other time of the year.

Thats why its super easy to plow through a bag of chips or a pint of ice cream but not over eat other foods that might be tasty but not sugar or fat heavy. Were literally genetically engineered to binge on fat and sugar.


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

[User] ELI5: Why is it not necessary to refrigerate peanut butter? It seems like such an ideal environment for bacteria/mold to grow.

[Assistant] It might seem so, but it's not.  While peanut butter seems liquidy, it is that way due to peanut oil.  There is virtually no moisture within peanut butter and a high salt content.  This makes it a difficult environment for bacteria.  It's also so dense that bacteria can't move around in it.


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

[User]
When sliding a pipe into another pipe thats a tight fit, why do we rotate the two?

Like the title says, when sliding a tightly fit pipe into another one, why do we often rotate them to push in further? Why is it often easier to do so rather than to just push straight in?

I was speculating that this might have something to do with static/kinetic friction, and that by rotating the pipes that overcomes the force of static friction and makes it slightly easier to push in further? Although Im asking to see if anyone knows the real reason. Thanks!

[Assistant] It does have to do with friction, but not in the way you think. Friction always acts opposite the direction of motion, and so when you try and slide it in directly, it will oppose it 100% in the opposite direction. But adding a twisting motion adds a rotational component to the friction, as it must resist that as well. As a vector, it will be pointing at an angle now, so you only need to fight the component of that vector facing along the pipe, which will be smaller than the previous vector that was pointing along the pipe.


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

[User]
CMV: The USA should reduce spending on the military from 24 on the tax dollar to 21 on the tax dollar.

Currently, according to multiple independent sources that track US tax spending public education gets 2.2, law enforcement is buried under several different areas, and vet benefits are about 6 per tax dollar.  We still would have the largest military in the world, seconded and by less than half currently by China. We would still be over prepared for literally anything the world could throw at us.

The money could be used to fund so much more educationally, and literally increase all schools budgets by 30%+. This could help solve some states like Arizona who have teachers with only high school diplomas doing emergency certifications entice highly qualified teachers with better pay, increase student learning with better funding for technology, and education programming.

Additionally, it would allow psychologists and social workers to expand into law enforcement and bring much needed training and extra support for law enforcement. It simply isn't fair to expect police, detectives, agents, and other officials to also be well versed fully in mental health and social/emotional issues. Let's get them the funding they need to be better supported, paid, have more of them, and have the staff positions they need to do this. They make almost double their salary in overtime. We are asking highly stressed people to be as effective on your 80 as they are on hour 20. How about no?

Also, increase in spending on vets can only help them with retirement, health benefits, and being taken care of after serving their country.

Someone please tell me why any of this is a bad idea.

[Assistant]
I doubt it... but are you taking into account federal versus state versus local spending?

Because a vast majority of schools are fully funded off the property tax by those who live in the area. The education part of the federal is lower because not all school require federal funding. They are able to take care of themselves. Many state public colleges/universities are also able to take care of themselves with local and state tax funds, tuition fees as well as alumni donations.

Failing schools are the ones that will request federal aid to make ends meet. And if a school is failing, there are probably many more issues in that community.

Law Enforcement is in the same boat. The feds will cover all the federal law enforcement, like FBI, ICE, DEA, ATF, SS, US Marshals & so on. City, town, county and state police are funded on the local level. Again... if they need help, they can also request federal aid. Not all of them need or want federal aid. If it is their own money, they are able to do with it what they want.

So when it comes to education and police, that funding is not handled by the feds. So if you increase the spending for those area, it would only be for the cities and towns that are struggling. Not everyone needs or even wants federal money.


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

[User] Why do smart TVs decrease in price while smart phones increase in price? There is a lot of overlap in their functionality as technology improves for both, but yet changes in price diverge overtime. Why?

[Assistant]
Good question. It's a phenomenon which is pretty unique to the particular products and the technical barriers to each of them.

The overwhelming largest cost in a smart TV is the display, not the other components, and not even the product design. The display in a TV today comes in one of two forms: LCD or OLED. The market dynamics of these two forms essentially guarantees that prices will fall over time. The top end of both these markets are made from two Korean companies Samsung Opto-Electronics and LG Display, who used to dominate the entire industry. The LCD market is no longer dominated by them, as the emergence of Chinese manufacturers with equivalent capabilities but cheaper production has basically squeezed them out. The OLED market was still dominated by them, with Chinese companies unable to match their technical expertise. This was quite short-lived with the emergence of BOE Tech, a Chinese company which is rapidly ramping up OLED capacity. As a consumer this just means we get cheaper TVs at the same or even higher quality.

The other components in a TV are relatively inconsequential. Much of this is because of the size of the TV, which is so large that your components can be whatever size you want them to be really. Also with an external power source, you can basically also make them as inefficient as you want without worrying too much.

A smartphone on the other hand, has component costs which are increasing in every generation. There are so many components, all of which are top-end, that it's difficult to pinpoint exactly which components are responsible. Broadly, you have new components which were not in the previous generations; for example the iPhone 12 features a LiDaR module manufactured by Lumentum, which gives it the ability to measure distance by shooting lasers. You have components which you've had to add more of; for example the five cameras in a Samsung Galaxy S21, or the multiple extra antennae required to enable MIMO technology for 5G connections. You have components which need to become more high-functioning; for example, the most cutting-edge commercially-available chips in the world are 5nm chips manufactured by Taiwan Semiconductor or Samsung. Today they are almost exclusively used to make processors (CPU/GPU) for Apple, Samsung, and Huawei.

A lot of this has to do with the size of a phone. As components get more numerous and more powerful, they consume more power. Improvements to battery efficiency have lagged the increasing power requirements, so most phones have resorted to increasing the size of the batteries since they can't increase the size of the phone. About 70% of the space inside an iPhone 12 is just the battery, up from 40% in the iPhone 6. Interesting solutions have been devised to cram more modules into a smaller space; for example, by stacking two boards on top of each other from the iPhone X onwards. However, the fact remains that components need to get more efficient, higher performance, more numerous, while taking less space - which means more expensive.


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

[User] ELI5: If sweating is supposed to cool you down, why is high-humidity heat more unpleasant or draining than "dry heat"?

[Assistant] Both of those are true because your body tries to cool itself by having water evaporate off the skin. Your body creates sweat so that the sweat will evaporate, taking heat with it and leaving the skin cooler than before. When the air around your body is *already* high in humidity, then the air is saturated and won't "take" or absorb the sweat as easily. So the sweat sits on your skin, instead of evaporating away, and you don't get any cooler.


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

[User]
How would Nuclear Propulsion work?

I want to know how it would work. But most of all, how it could successfully be done without damaging the ship. Also would it be in space or on the ground?

[Assistant]
The most basic form of nuclear propulsion is a Nuclear Thermal Rocket (NTR). There was actually a program to develop this back in the 60's it was called NERVA. In this case, all you do is use a nuclear reactor to heat an inert gas (like CO2) and blast it out the back. So an NTR is really nothing more than a nuclear powered flying tea kettle.

You do however, get performances 2 to 4 times better than the best chemical rocket engines, so there's that.

Another very basic, but amazingly effective, idea is to use nuclear warheads. Project Orion would geared towards this before Cold War treaties banned the use of nukes in space. The idea is simple, have a rocket (with a huge buffer on it) drop nukes behind it which would then explode, and push the rocket forward. Provided they explode fairly close together (about 5 per second) then the acceleration is fairly uniform its not jarring. Its also one hell of a propulsion system. It's quite feasible for an Orion rocket to get up to 4 or 5% of light speed.

It would, obviously, only be used in deep space you couldn't use that on the ground, but since there's plenty of radiation in space anyway, setting off nukes isn't an environmental hazard.


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

[User]
ELI5: Why does watching flash videos/streams in Google Chrome slow down other tabs?

AFAIK Google Chrome runs each tab in a separate process. So if something hogs one tab, other tabs remain responsive.
Why is it that watching twitch streams slows down my other tabs. For example it's especially noticeable when twitch.tv is open in one tab and i'm scrolling down reddit in another tab.

When i use another browser to stream twitch then Google Chrome tabs remain responsive.

[Assistant]
I first had a very technical explanation which was very hard to understand i will now try it with an analogy.

Imagine your computer is a supermarket and every CPU core is check-out. Every customer is a process and the things they buy are the commands which every task needs to execute. If a task like the twitch tab needs to execute many commands it can block the check-out for longer therefore other processes need to wait longer and feel slower.

One of the techniques to mitigate this problem (so that one process can't hog the CPU core for to long) is scheduling.
It works by setting a limit on how much goods at a time can be checked out so that other processes get some time as well.

I hope this makes things a bit clearer and feel free to ask questions and i try to answer them as good as i can.


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

[User]
ELI5 Why does skin heal more slowly the older you get?

I'm turning 40 this year, and I'm noticing that the nicks and cuts I'm used to getting which have always healed really quickly are leaving more scars and lasting longer than they have in the past. Im outdoors active, and accrue more than a few cuts often on my lower legs. Is this a natural part of growing old, which is in line with my observations of my parents' skin as well, or am I not caring for my skin well?

[Assistant]
Think of your cells dividing as a printer making paper copies. A copy can only be as good as the original but usually you lose a bit of quality.

Over time, the original document wears out and you're making copies of copies. Each copies need to be a certain quality level or else they're rejected. As you make more and more copies, the reject rate increases over time.

Your dividing cells undergo a check to make sure they're copied properly. If they fail, they undergo planned cell suicide (apoptosis) and are recycled. As you age, a larger percentage of dividing cells fail the check because of DNA wearing out from copying, making it harder to increase the number of good cells to heal a wound.


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

[User]
Why do two icecubes freeze to each other in a glass of water?

If i place two ice cubes in a glass of water, after a short while they will be stuck together. Why does water between them freeze to connect them?

[Assistant] Usually ice is done at -20C.. when you put them in water they can suck up heat from the surrounding layer of water so, before they melt, they can freeze a thin layer of water. If the layer is thin enough (cubes touching), the ice they create is enough to glue two of them.


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

[User] ELI5: How does the Internet weigh around the weight of a strawberry if it's just data, how can the data have mass?

[Assistant]
Data is stored as magnetic charge (on a hard disk, SSD, SD card,etc).
Magnetic charge is  a collection of electrons.
Electrons have mass.

Meaning Magnetic charge has mass.
Meaning Data has mass.


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

[User]
Is the world outside our eyes blurry?

We have lenses that bend the light to our retina, but if those aren't set up properly everything is blurry. So if the lens is what makes us see sharply, does that mean the light on the outer side of the lens blurry? Does the real world look more like a gaussian blur in Photoshop?

[Assistant]
Without a lens to focus light on a point or a cavity to limit light detection to a certain direction, a photosensitive cell would only be able to detect light intensity.  The world would appear essentially featureless, as photons from any object within the incident angle would all be detected at the same time.  If an object were extraordinarily close to the photodetector, so that it would block the vast majority of light from other objects, some blurry details could be made out.

If you take photosensitive cells and put them at the end of a cylinder, still without a lens, the world would indeed appear blurry, but featured.  Objects within the diameter of the cylinder would be detected by all the cells, while objects within a cone outside the cylinder's diameter would be detected by only some of the cells.

If a large field of photosensitive cells were behind an opaque membrane with a small opening, a fairly decent amount of detail could be discerned even without a lens.  Each cell would only detect light from a very specific angle, and though it would be a blurry image, it would likely be detailed enough to navigate and manipulate objects.  However, there's a tradeoff between the sharpness and intensity of the detected image, as narrowing the opening to increase sharpness would decrease total incident light, and vice versa.

Edit - forgot a word.