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

[User] eli5: Why is co2 the gas used to pressurize drinks. Why cant something like nitrogen or atmosphere air be used.

[Assistant]
Carbonated water creates carbonic acid which gives a little sting and sourness to your drink and tickles your nose when the bubbles burst at the top.

Nitrogen infusion gives a creamy texture and it's used in beer and coffee.

Oxygenated water is advertised as having health benefits, but at high amounts of infusion you start getting hydrogen peroxide, with is not good to drink.

Just using regular air is basically nitrogen and oxygen.


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

[User]
CMV: It doesnt make sense that good people who dont believe in God go to hell anyways.

My boyfriend is very religious so Ive tried to keep an open mind to Christianity. Personally, I think we live in a simulation. Not going to explain all the details since its not the subject but its not very far from being religious: if were in a simulation there is a creator and if were conscious we might just change realities when we die. So the idea of God isnt that far fetched especially when taken metaphorically.

I just dont get the part about Christianity where non-believers are automatically thrown to hell no matter how good of a person they were. I dont get the devotion part of it where its more important to believe and pray than to be a good person. Why would God wants to have this place in our lives? And if we dont do that were just not good enough. I feel like it defeats the purpose. An omniscient God would know we have barely any proof to believe in him so he would not really hold it against us would he? But no, for most religions being a good person isnt enough and youre expected to do all these things in addition otherwise bye bye.

It only feels like its this way to manipulate people into believing. If there was no fear of hell I bet a lot of people would stop believing. Why would we need to be coerced into believing?

There are many other things I find not so logical but this one is a pretty big one.

[Assistant]
Alright, hear me out.

In Christianity, hell is for people who screw up. Anybody who has ever screwed up is supposed sent to hell. Which is basically all of us.

Then Jesus comes along, and sacrifices himself to cover the cost of our screwups. Basically each person's sin accumulates a debt, and any debt gets you sent to hell. But Jesus' sacrifice is now like a infinite check. God, through Jesus, mailed us an infinite check to cover our "sin debt" because, you know, he loves us. Doesn't want us to go to hell forever.

God told us about the check. All you have to do is believe that he sent it and go the mailbox, pick it up, and cash it. But we all have free will, and if we decide not to cash this check (or not to believe that we have any debt in first place), that's on us, not God.

That's the gist of the main idea of what Christians actually believe.


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

[User]
Why do peoples nipples get hard when its cold outside?

I don't know how much more I could elaborate on this.

[Assistant]
They are trying to preserve heat.

When a nipple is exposed to cold temperature skin reflexively contracts, causing the nipple to become smaller, wrinkled and "hard." The ultimate function of this reflex is to decrease the amount of surface area on the nipple that is exposed to the cold.

Decreasing surface area is the ultimate reason why nipples get hard in the cold. It is not caused by erectile muscle, but rather by simple contraction of smooth muscle. The process is most similar to that of a hair follicle standing up on end...


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

[User] ELI5: How did the Nixon Shock cause the change in the Productivity-Pay gap?

[Assistant]
It didn't, or at least you're not going to find many economists who agree that it did.  Pay and productivity didn't begin diverging until 1984 - 13 years after the Nixon Shock.

The overwhelming consensus as to the cause of the Productivity-Pay gap is that in 1983 the US re-designated China as a "friendly" nation.  This both allowed for the export of advanced US manufacturing technology to China and significantly reduced US trade barriers to imported Chinese goods.

Following that change, US workers began having to compete against Chinese workers, who were working under a system in which the government fixed their wages to be the equivalent of ~$350 per year, with workers in small, private Chinese factories often earning less than that.

The world before 1990 was a much different place than it is now.  Outside of the US and Europe infrastructure was generally non-existent, governments were wildly corrupt, and guerilla movements were widespread.  China was one of the only third world countries with a functional government, well developed infrastructure, and no ongoing guerilla war within its borders.  What prevented it from developing was its international isolation - the West didn't recognize it and the Soviet Union was openly hostile towards it.

China was able to rapidly develop once the US opened up to it.  This injected a billion ultra-low wage Chinese workers into the international economy who were roughly as productive and competent as those in the West.  If you're an unskilled laborer in the West then you're competing for jobs based on the wage you want to be paid.

After China opened up, you suddenly found yourself competing against ~5 times as many laborers for the same number of jobs as you were before, which exerts an extremely strong downward pressure on wages.  This downward pressure has gotten even worse as you get closer to the present and more third world countries have been able to develop their governments and infrastructure to the point that they're able to participate in the global economy.


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

[User]
Are solar systems known to collide with each other? Is it possible?

As we're sat here merrily spinning around the galaxy, is there the possibility that we could collide with another solar system? Would two star systems get close enough over time that the conflicting gravitational forces of the respective stars throw both sytems into chaos or maybe even 'strip' one star of its orbital bodies and place them around the star with the greater gravitational pull?

I assume this would have been more common in the distant past?

[Assistant] Yes, they can 'collide', but it's unlikely any body would impact another. This is because a galaxy consists mostly of space. (think about how big our solar system is and the relative size of the sun and planets for that massive volume).


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

[User]
ELI5: How do systems on the other side of a phone call know what buttons you're pressing.

For example: I just called a phone number to activate a visa gift card, and the system told me to enter the number of the card on my dial pad. How does that system know what buttons I'm pressing?

[Assistant] Your phone beeps when you press the buttons - the same beeps that tell the phone company which number you're dialling on a landline. The system on the other end listens for the beeps and knows which button you pressed. Each button actually makes two tones together - one for each column and one for each row.


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

[User] Do imaginary numbers have any practical applications?

[Assistant]
Of course, why wouldn't they? They're just as real as normal numbers, which is to say not at all. Complex numbers are a nifty way to encode 2D translations, 2D rotations and scaling compactly as addition and multiplication. Very convenient.

Electrical engineering, fluid dynamics, quantum mechanics and much more all explicitly use them.

At the core, though, Complex Numbers are just the part of the basic vocabulary needed to speak "math". This is true of everything in math. All the math that you learn in high school and college is just the basic vocabulary of math. And *that* is the real application: To make you fluent in a complicated and precise communication scheme.


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

[User]
Why don't the armed forces in Attack on Titan use shotguns, explosive flechettes, or some other ranged weapon to destroy the weak spot on the necks of the titans?

By armed forces I mean the ones with 3DMG, who are getting up close and personal to the titans.

[Assistant]
They don't seem to have advanced much in personal firearms tech. The guns they had in the anime were breechloaded flintlocks.

That means slow rate of fire, horrific accuracy, inability to be loaded while moving or being jostled around, and no special munitions.


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

[User] ELI5:If I develop a website for a wedding photographer, the website belongs to the photographer, because it's a work for hire. Why, then, if he takes photos of my wedding, do the photos not belong to me?

[Assistant] You could work out a contract with a photographer where they assigned the copyright to you. But most photographers don't do it that way because reasons. Mostly because if you ever wanted reprints back before digital they could charge whatever they wanted.


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

[User]
[40K] How did Astropaths navigate the Warp before the Astronomicon?

So it seems to me that the Golden Throne was built during the later stages of the Great Crusade, for the purposes of constructing the Human Webway project and projecting the Astronomicon. I believe that the Emperor could navigate the warp without the Astronomican, but what about his other expeditionary fleets?

Edit: Please replace 'Astropath' with "Navigator" in the title.

[Assistant]
So first off Navigators are the ones who navigate through the warp, not Astropaths. Astropaths send messages through the warp.

To answer your question it is possible to travel through the warp without the Astronomicon, it's just slower (Rogue Traders sometimes have to do this when traveling to areas beyond its reach). Without the Astronomicon's light you basically have to travel in the "best guess" direction and then drop out of the warp every few light years to check your location and reorient. Navigators are still helpful here since they can use their powers to give a better estimate for the ship's travel then a normal human could but they are still a lot less accurate than they would be with the Astronomicom.


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

[User]
CMV: The use of pharmacological stimulants as a treatment for non-chronic obesity and binge-eating disorders is unfairly socially stigmatized, and because of this is underutilized by patients and medical practitioners in a non-trivial amount of cases wherein it would do more good than harm overall

To start off, my scenario: I dropped like 35 pounds in 2 months using stimulants for weight loss with absolutely no effort. I had no history of addiction to amphetamine derivatives, no heart or cardiovascular conditions, had the capability to pay for my stimulants and medical consultations financially, had no major side effects or pharmacological contraindications, and had short-term weight gain due to the bad mental health that came with COVID over the past 2-3 years.

I understand that I have very specific circumstances. However the argument that I'm making is that due to social stigma specifically, there exist a non-trivial proportion of obesity cases wherein drug treatment does not come to mind or is otherwise not considered by both patients and medical professionals, even though it could be determined more probabilistically likely than not that it would have done more good than harm than the alternative treatment (or lack thereof) in that specific demographic:

Many different people use and are prescribed by medical professionals traditionally addictive drugs to treat conditions they were both meant and not meant to, and for reasons they were and were not originally synthesized for.

Why is weight loss the only scenario wherein people who are uninformed pharmacologically outright reject the treatment for themselves in situations where it may have caused more good than harm overall, and pass judgement on people who have specific circumstances where they state that it was the best medical decision?

Obesity kills so many fucking people per year, imagine if people reacted to medical therapy for heart disease or vaccines for inectious diseases in the same way they reacted to drug treatment for weight loss.

It's not as if stimulants aren't prescribed for binge eating disorder and obesity, it's just that it doesn't happen widely. The idea that "there's no magic pill that will make you lose weight without effort" is literally false, it's just that those magic pills come with negative side effects that will a decent amount of the time outweigh the positives.

[Assistant]
I think there are two main reasons that stimulants aren't used a lot more for obesity.  First, obesity goes hand in hand with cardiac complications and there are no stimulants powerful enough to affect weight loss without placing significantly increased strain on the heart.

Second, stimulants can be very useful as an aid to weight loss, but they do not cause weight loss without behavioral change in vast majority of cases.  Doesn't matter if you take Adderall or vyvanse if you also eat 2 buckets of KFC for every meal plus ice cream and constant snacking.  You still have to do *some* calorie restriction, otherwise you won't lose any weight at all.  This is especially true when you consider that the patient will eventually go off the stimulant and will need to make behavioral changes to maintain any weight loss.  So the majority of cases, stimulants do not eliminate the need for underlying behavioral change, they just make that part easier and improve results somewhat.

Ultimately, that means for many if not most overweight or obese people, stimulants can present significant risks without much possibility of long term reward.  Or at least no reward that couldnt be achieved with behavioral change by itself.  Which is why stimulants aren't used more frequently than they are currently.


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

[User]
Are most advancements in AI from better hardware or more advanced formulae?

Theoretically, a computer could brute force a problem to figure out every possible optimal solution, but that is absurdly infeasible in most instances, so systems use tricks such as classifiers and error minimization to get a "best guess."

When new milestones such as Deepmind's recent victories are reached, is this more due to faster processors allowing for deeper/wider searches with existing algorithms, or have the algorithms themselves improved? (I'm sure it's a little of column A and a little of column B, buy I'm asking for a little more specific than that)

[Assistant]
Most of today's computer science theories were created way before the creation of efficient computers. But ANNs (Artificial Neural Networks) only began to be a research topic in the 1960s.

The new powerful hardware allows the researchers to think of new algorithms that previously seemed ridiculously inefficient, so it's a bit of both. Without good hardware, no one would bother to do ANNs, and without new theories, no amount of hardware would produce these results.

Also note the impact of the Internet : many ANNs are trained using massive amounts of data (especially ANNs that use images), and most modeln data storage and manipulation algorithms were created in the wake of the creation of the Internet.


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

[User] What is the likelihood of a major food crisis? How can we stop it?

[Assistant]
Due to the oil intensive nature of modern agriculture, major food crisis will likely be precipitated by significant disruptions to oil markets and supplies, i.e. trouble with Iran and the Straight of Hormuz. Modern agriculture is increasingly consolidated into the hands of fewer and larger companies. Really the only way to avoid large scale food crisis is to promote decentralization of food production such that a significant portion of food production is shifted into ones own backyard or neighboring small farms. This will mitigate the oil reliance and the risk of putting too many eggs in the mega farm basket.

TL:DR-Grow a garden.


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

[User] ELI5: How does "my bones hurt when the weather is changing" work? (scientifically)

[Assistant] It has to do with the changes in air pressure. When the weather changes from higher to lower pressure it usually brings bad weather, but also the joints in your body expand just a little bit and that can allow for more inflammation to occur.


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

[User] ELI5: What Fermat's Last Theorem is and why its important that it's solved.

[Assistant]
Fermat's last theorem states that for integer values a, b and c the equation a^n + b^n = c^n is never true for any n greater than two. So for example a=1 b=2 c=3 n=4 gives you  1+16=81 which is obviously false. This is rather simple, but proving that it was true turned out to be an utter bear.

Proving Fermat's last theorem itself wasn't all that important, although it was very interesting since the proof had eluded mathematicians for nearly 400 years. Which actaully makes that pretty important in it's own right given that Wiles managed to solve something some of the smartest people in the world had failed at, and had mostly given up on as unsolvable.

The more obviously important part comes from the methods Wiles' used in the proof itself, which involved approaches and tools brand new to mathematics. In particular those tools could be applied to solve other difficult problems. Wile's didn't just prove  Fermat's last theorem, in doing he kicked open a whole new door in the field of mathematics.


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

[User] ELI5: What happened to Blackberry and why did they go from a sensation to being a rare sight?

[Assistant]
They failed to adapt.

Blackberry was the *only* option for business users, really.

Then the iPhone came out and suddenly everyone wanted a friggin iPhone. Now us IT people went "Dude, Blackberry has a lot of business and, more importantly, *security* features that are really, really important, so no, you can't have an iPhone" which was OK for a while... but then the middle-managers wanted iPhones, and then the managers, and then the VPs, and then the CEOs... so suddenly the iPhone was an option for business users, too, and Blackberry seemed -- rightfully -- old and clunky.

Blackberry didn't take the threat seriously, and when they finally got up and did something it was too little, too late and too crappy (Blackberry Storm, anyone? Ugh).

The real surprise is that they're still around at all.


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

[User]
[WH40K] What would happen if a tyranid hive fleet attacked Cadia?

Would the pylons on the surfice fuck with their hivemind?

[Assistant]
Tyranids have shown to be highly resilient to standard Psy defences and attacks, so there's a good chance that their 'Silent Shadow' thing would fuck over the pylons, leaving it down to a purely military scrap.

The Imperium would win that fight, after a looooong grind. We won by the skin of our teeth at Maccrage, and Cadia is better defended, has more troops and is a higher priority than that planet. That part of the galaxy is occupied by way more SM Chapters than the space around Maccrage, and Cadia itself is strong enough to be the lock on the door to Chaos's bedroom.

Like any good fight, billions die and humans win in the end.


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

[User] ELI5: If an amputee, such as Oscar Pistorius, goes to prison, are they allowed to keep their prosthetic limb since it could be used as a weapon?

[Assistant]
This is going to be a country specific answer.  In the United States, both 42 USC 1983 and the Americans with Disabilities act are the controlling law.

Basically, a state actor like a prison guard can not abuse prisoners.  Not giving an amputee some means of mobility would be abuse.  Therefor, a wheelchair, prosthetic, or crutch would need to be given.  It may not be THEIR blade runner leg, but it must be some means to get around.


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

[User]
[Dragonball Z] Did Goku know what was happening when he was going Super Saiyan for the first time?

When he transformed fighting Frieza it was because he was angry. He stops and struggles with what seems like his emotions as a storm surges, and he screams, transforms, then was "calm" (as calm as you can be in that situation I guess) and gets ready to fight

Did Goku realize what had happened to him? Was he somehow able to know that a transformation was coming?

[Assistant]
He was only thinking of one thing. Revenge. He was so emotional because his friend was dead and he knew he could do nothing about it. Frieza would then kill his son and himself. Goku fully believed he had lost.

After the transformation Goku has a lot more power. He doesn't know why he has more power, he doesn't care why. All he cares about is going after frieza.


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

[User] ELI5: With most countries so far in debt, how does China have all this money to loan other countries like the U.S. and U.K.

[Assistant]
That's not how sovereign debt works.

Sovereign debt exists as bonds. A country offers bonds on the market, and other countries buy them as investments. A bond is basically a contract between the bond issuer (usually a government) and the bond holder (whoever buys it) that says "The issuer agrees to pay the holder the value of this bond plus X% interest on [DATE]." US Treasury Bonds are seen as a **very** safe investment because the US **always** pays when and what it says it will pay. This means that the US can offer incredibly low interest rates on its bonds.

A US T-bond is safer than a bank account, safer than gold, hell it's safer than burying your money in the yard. If you have a whole bunch of money and you want to keep it safe for a decade or so, you can't do better than buying US bonds.


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

[User] ELI5: Some jobs are unpleasant but fundamental to society (eg: janitor, bus driver). Why aren't these the best paid jobs?

[Assistant]
Because anyone can do them.  They are low skill and lots of people can fill that role.

Sometimes they do get better pay because the job is undesirable (I think trash collectors get paid decent, at least compared to minimum wage).


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

[User]
CMV: Its understandable why many vegans are so loud and preachy about how bad consuming animal products is.

If you had really come to the conclusion that billions of animals are slaughtered every year, animals who are conscious and have souls and experiences and emotions and feelings, obviously you would want to let everyone know the moral tragedy that they are partaking in every single day by consuming animal products. In fact, if you really thought that millions of innocent beings are dying every single day and the world is basically doing nothing about it, I would be surprised if you didnt try and tell every single person you met and interacted about it, and how being a vegan is the only moral choice one could make.

Of course, for those of us who dont really care to much about animal murder and stuff like that, this all comes across as really annoying, but I at least get where they are coming from. I think a lot of the hate directed towards vegan communities and such which are simply trying to spread their message (from their perspective, a very noble message) to the outside world is unjustified as we all have our moral convictions which we attempt to impart on those around us.

[Assistant]
This is exactly why evangelical Christians proselytize. Millions of souls go to Hell each day and they're just trying to prevent it.

Do you like when Christians proselytize by telling you your going to Hell? Is it effective?

This is the same for anti-abortion advocates as well.


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

[User] I have a volume slider on my headset, a volume silder on youtube, and a volume slider just on my computer. Which one should I maximize for the clearest audio?

[Assistant]
Youtube should be at maximum.

PC volume as high as possible without clipping/distortion. That may be all the way up.

Control listening level with headset control.

You want to use all the dynamic range of your PC's digital to analog converter. Then attenuate it as needed with the headset control.

In practice, just do what's most convenient. Youtube and other streaming audio is compressed and not super high quality, so why bother?


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

[User]
How do/can black holes "grow"?

Perhaps this has been answered here or elsewhere, but I can't seem to find a clear answer.

Maybe this is a dumb question, and maybe I've already read the answer before and forgotten, but: How is it that black holes can "grow" by consuming matter/mass? If matter beyond the event horizon is "gone" (though, I guess Hawking radiation would suggest otherwise?) why should the ingestion of matter after creation of the singularity cause the black hole to "grow" or otherwise become more dense? It makes sense to me that the aggregation of massive objects would do so, but does a singularity have mass, in the traditional sense? I guess what I'm struggling with is the idea that such mundane rules could apply to something so seemingly peculiar - is it just that simple, or is the actual phenomenon also appropriately exotic?

[Assistant]
Are you asking about a mechanism?

Because if so, they just *do,* by conservation of mass/energy.

When matter (or energy, such as photons) cross the event horizon it is absolutely doomed to end up at the singularity. That's just the way spacetime works in the black hole. Basically, geodesics (which are orbital trajectories in general relativity) terminate at the singularity. It means that stuff just piles up at that point. By conservation of mass/energy, the mass/energy of the particle that went in is now a part of the singularity, and thus the black hole.


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

[User]
ELI5: How is it that Manhattan doesn't collapse under all the weight of its buildings?

As a non-engineer, I wonder how it is possible that Manhattan, with hundreds of massive skyscrapers and high-rises, does not simply collapse. There are a series of tunnels underneath that go quite deep, and even if they are in a grid and don't run directly underneath the buildings, I still can't wrap my head around it.

EDIT: Removed the word "island" so the question would not be misconstrued. Sorry for the confusion.

[Assistant]
If you replaced the Empire State Building with a similar mass of granite, it would only be about 50 feet high.

Bedrock is thousands of feet thick.  It has no problem supporting buildings because it has not problems supporting itself.


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

[User]
ELI5: Can you own land on the moon? Could a nation form on Mars?

What laws get in the way of these things?  I know that no nation can claim the moon, but is private ownership restricted, and if not, how does that play into activities such as the mining of the moon?

[Assistant] Right now all of space is more or less agreed to be neutral territory. Whenever the day comes that someone starts forming permanent colonies on extra-terrestrial bodies, there will likely be a very serious and very important global discussion on how ownership of these bodies will work. Right now there is no clear plan in place.


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

[User]
CMV: Canceling student loan debt is not a progressive priority. Warren, AOC, Sanders, etc shouldn't be championing it.

Hey peeps. I'm a progressive voter who supported Ilhan Omar and Elizabeth Warren (I'm in MN). I have a masters degree and about $20K in student loan debt. However I don't understand why canceling student loan debt is a progressive policy that is being championed by the likes of Warren, Bernie, AOC, and others. Change my view that this is a policy that won't address underlying issues with student debt but it will further divide class lines.

I understand that total student loan debt (>$1.5 trillion) has now surpassed total credit card debt (<$1trillion) to become the second largest form of debt in America (after mortgages). I acknowledge that's a concern. This has been driven by increases in the costs of higher education, increased/eliminated caps on borrowing for students and parents, the rise in for-profit colleges, the increasing number of people attaining college and especially graduate school, and more.

However, only about 1 in 8 Americans has student loan debt and the average amount is about $32K. While I understand that some people drop out of college and get the debt without the benefit, that is not emblematic of people who have student loan debt in general...an individuals who graduate college tend to make significantly more than those who don't (\~$75K/year vs $45K/year). Additionally there are income-based repayment plans for student loans that are an option which tie your repayment to your discretionary income and forgive anything you have left after a set number of years. Why should we cancel, on average, $30K in student loan debt for citizens who make, on average $30K more per year than non-college graduates?

So, again, why is canceling student loan debt seen as a progressive policy being championed by the likes of Warren and Bernie and AOC, etc?

Someone change my view that it would be more progressive and effective strategy to:

1. Address underlying issues causing the increase in student loan debt. Simply canceling student loan debt simply resets our debt back towards zero but then it will start accumulating all over again. Congress needs to address how we got in this situation.
2. Give every American a big ol' check. If someone wants to spend their big bailout on paying off a bunch of student loan debt, that's their prerogative. And if I want to spend it paying down credit card debt first, that's my choice based on my biggest need. And if a low income family wants to use it to buy a car to have reliable transportation to a better job, that's their opportunity to get ahead.

If we could lift every American out of poverty and provide universal healthcare and check a whole lot of other boxes then I'd be all for moving down the list to eventually forgiving student loans...but I don't understand or support why it's an issue that is getting so much attention now.

Forgiving student loans will disproportionately help middle and upper class Americans while providing no benefit to our most impoverished and marginalized citizens, and it will do nothing to address the systemic issues that created the debt in the first place. Change my view.

[Assistant]
Part of the priority, is that it is actionable. The debt is owed to the federal government itself, and hence can easily be voided. Other than the process of debate itself, the act of doing this would only take a few minutes.

This is in contrast to other problems, such as addressing underlying problems, solving poverty, solving homelessness, etc. These problems cannot simply be solved by a single act of congress, in a matter of minutes.

Do the easy things first, get a few wins under your belt, and then move on to some harder things, Go for the low hanging fruit first. You get the idea.


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

[User]
If you put a live power cable in the sea, how far away could it electrocute someone?

What got me thinking about this in general was wondering about my house flooding and whether or not the electricity box becoming compromised with water could cause all of the water to become electrified.

Also, I remember a scene from Ozark, the Netflix show starring Jason Bateman, where something similar to my original question happened in a large body of water.

[Assistant]
Electricity goes from high voltage to ground. If you put a live power cable in the sea it would act a little strangely. If you included a ground the electricity would run from between them.

Current kills, but depends on a lot of factors. You could wear a chain mail suit and would be safer because the electricity would run through the chain mail not you.

If instead you grabbed a live wire with one hand and ground with the other, you might die. The current would pass through your heart and cause cardiac arrest.

If you stepped in the water and got shocked, your muscles could seize up and you could drown.


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

[User] [Final Destination / Final Destination 2 / Final Destination 3 / Final Destination 4: The Final Destination / Final Destination 5] Why can't Death simply give people heart attacks or brain aneurysms, rather than concocting elaborate (and potentially defeatable) kill traps?

[Assistant] The entire point of the Final Destination is that those who cheat Death dont do so for long. To that point, Death is incredibly pissed that they cheated him in the first place. For all intents and purposes he is a sentient and malevolent force hellbent on claiming his due in the most vindictive and vicious way possible, usually with a healthy dose of irony thrown in. The point isnt just to kill them; its to drag them screaming into the afterlife.


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

[User]
Has anyone worked with IBM Watson? How is it like?

Has anyone worked with IBM Watson? How is it like?
Is it a set of programmable APIs?

[Assistant]
In terms of branding, "Watson" is like "Docker"; it refers to a set of different and unrelated things under the same umbrella name:

* Watson Assistant, an API for building chatbots and virtual assistants
* Watson Studio, an IDE for AI modeling and analysis
* Watson Knowledge Catalog, a storage engine optimized for data collection

and so on. With a few exceptions, all of these tools and services are effectively separate things and don't have anything to do with each other.

In general the tools are proprietary, aren't open source, and can't easily be trialed or downloaded except through an enterprise sales contract. So no one has any experience with them except IBM. Effectively this means your company pays IBM a boatload of money to be expensive consultants to train you on their own tools.


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

[User] (Astronomy) When fusion begins in a star, is at an immediate happening where the entire star bursts to life or does it slowly build energy and therefore light emission?

[Assistant]
The main thing to understand here is that fusion is not on/off effect. Its probabilistic effect. And it depends on temperature/density. So the more dense the gas, the more probable it is for it's atoms to fuse and more energy is produced.

This means, that as the proto-star grows more dense, the rate of fusion increases and so does amount of energy produced. Then at one point, the star reaches equilibrium between energy pushing out and gravity pulling in. Also, this equilibrium changes over time, as composition of the star changes.


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

[User] As Voyager leaves the solar system, is there any chance it could still be carrying active biological contaminants?

[Assistant] Well, it's hard to say that the probability is 0.  So yes, there is *any* chance.  Although NASA takes care to sterilize its probes, it has been shown that life can survive a trip through outer space.


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

[User]
ELI5: Why have major countries not taken to teaching Esperanto in classrooms to allow people to communicate internationally?

To rephrase my question; Why haven't we all agreed on a language that everyone should know so every human on Earth can talk with one other?

[Assistant]
Because English largely fills this role, albeit incompletely. In general it's far more practical to get everyone to speak a language that at least some people already speak.  It's at least incrementally harder to get people to speak a language that essentially _no one_ speaks.

As for why we aren't "all in" on this, it's largely because it's vastly easier and feels better to communicate in a native tongue.  Would you give up the ability to have a natural communication with your child in order to satisfy some utopian global communication ideal?  Would you divert what little resources are already available for education in much of the world in order to learn a hypothetically useful language?  Or...would you spend those resources on something more immediately practical?


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

[User] How did the cicada's mating cycle come to be 17 years long? Wouldn't a cycle of only a few years be necessary to avoid lining up with predatory mating cycles?

[Assistant]
It's very beneficial to take a prime number as the length of your mating cycle. If you'd take 4 years for example, any predator that has a cycle of 1, 2 or 4 would eat a large part of the population. If you take a prime number like 7, then predators with a cycle of 2, 3, 4, 5, 6 will all miss you.

The bigger the prime number the less you will be eaten. 19 would probably be an even better cycle, and 23 even better.

If a predator's cycle happens to synchronize with that of the cicada, they will probably evolve to have a different cycle again (or they will shift their cycle by one year.) 18 years won't make it better though, so they will probably choose 19 years.


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

[User] ELI5: Why do some cuts leave a scar and others dont?

[Assistant] A big reason some injuries leave scars is the depth of the wound.  The more layers of tissue damaged by a knife, for instance, the more likely a more prominent scar will result.  Also, some people have more of a tendency to scar than others.


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

[User]
ElI5: How do they make machines that make proprietary product?

i was watching How It's made, and there was a dedicated machine for a particular part of the product something as little as a proprietary bottle cap. and it was a huge machine. Who got the time to sit and invent the machine for that little piece. think of the variety of such designs, so does that mean you need a different new machine for any other special design?

also machines that make machines like robot machines making robot machines.

[Assistant]
Engineer here. We design these machines, we've got the time to do it because it's our job.

It makes sense for the company to employ us to do this because of scale. 1 or 2 things being made, it's probably faster and cheaper to do it by hand. Thousands or millions of these being made, you're going to want a machine that makes it.

>does that mean you need a different new machine for any other special design?

Yes, kinda. Many machines share 95% of their design, concepts, etc with other existing machines. So we usually start with a bunch of the work already done.


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

[User] ELI5: how are smart phones and tablets able to keep getting faster without ever needing a fan, when older computers with the same performance needed big fans?

[Assistant]
The reason for this is that the electronics get smaller. Smaller electronics have less electric resistance, so they're able to do the same work without consuming as much power and therefore also without developing as much heat. Processing power has doubled without increasing power consumption every 18 months on average for the past 40 years. Within the last 10 years, power-to-performance ratio got good enough to allow us to develop phones that are as advanced as we have now.

That said, the CPUs mobile phones and tablets are well behind the performance of laptop and desktop CPUs from the same year. They don't have the same requirements for multitasking and long term performance. A phone isn't pushed to its limits over a long period of time. It loads a website or an app, which consumes a bit of power for a very short time, then the cpu goes back to power saving.

A desktop computer from 2012 is still more powerful in raw computing performance than a 2017 flagship phone. It's just that mobile phones never need that level of performance to do the tasks a phone typically does.

If you make a mobile phone keep processing at 100% capacity for a long time, it will soon get very warm,and the performance of it will be more and more limited to avoid overheating.

A laptop or desktop computer, on the other hand, are designed to be able to run at 100% capacity pretty much indefinitely. To achieve this, they require much more extensive cooling solutions, usually with active fans to remove the heat.


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

[User]
ELI5: Why is it usually recommended not to take medicine on an empty stomach?

(Sorry if I used the wrong flair, didn't know whether this was a biology question or a chemistry one)

[Assistant]
Some medicines require that you take medicine after a meal as the medicine may cause nausea or stomach irratation when taken on an empty stomach.

Some medicines require the opposite, that they be taken on an empty stomach and this may be due to precise dosage affected by food or vitamins/chemicals in the food reacting with the medicine.


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

[User]
[Marvel/MCU] Is Captain America the smartest a human can possibly be?

I know the combination of the super soldier serum and vita-rays was designed to make everything about him the peak of possible human perfection, but does the same apply to his mind as well as his body?
On that note, exactly how much did the process effect his personality and way of thinking? Is he still the same person as before or is he someone new?

[Assistant]
It gave him a peak human mind as well as body, but it did not make him any smarter technically. It really just made him a genius, in the sense that he has the ability to learn faster than the average human. He has used this ability to be a great battle tactician and pretty much a leader among any ranks.

It has changed his thinking to that of a more easily taught person. He might in the past go into a battle situation with a plan, and I'd that fails he regroups and thinks of a new one. With the way he is now he would go in with a more developed plan, that develops even more so over the course of the battle, and if he inevitably did have to retreat, he'd be retreating with a plethora more infor action than he would have gotten previously.

He's a new person, a greater version of himself.


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

[User] [Call of Cthulhu] What were the beings Jack met/became under the farm and before entering the city of Dagon?

[Assistant]
Those were Yithians, also known as the "Great Race of Yith" in some other works. They existed over 200 million years before humans did, and had strong psychic abilities and precognition. Yith itself was destroyed in a war against another, evil race known as the Flying Polyps (seen themselves in the game), but the Yithians were able to escape their fate through a limited form of time travel. By sending their consciousness forward in time they could swap minds and inhabit the bodies of species from the future, including humans. The minds of creatures hosting a Yithian are transported back to Yith in their place, where they basically can enjoy a relatively normal life (by Yith standards) once they overcome the culture shock. By doing this the Yith have gained untold amounts of knowledge about nearly all species both past and future, and store it in great libraries which visitors can access in exchange for cooperation with the mind swap thing. When the Yith eventually swaps back the host loses all memory of their time with the Yithians, save for scraps and bits of knowledge in dreams.

As said, Yith was eventually wiped out but the species lives on in some form. Knowing their doom was unavoidable the entire species up and disappeared. No one knows what became of them, but it is speculated they may have swapped with some other species from the far far future. Most physical traces of the Yithian society have been lost to time, but be careful who you talk to, lest they be a Yith in disguise.


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

[User] [Star Wars] How bad is life under the Empire for the average joe?

[Assistant]
It depends a lot on what planet you are on and what species you are.

If you're on Coruscant, it's probably indistinguishable from the heyday of the Old Republic, but with more racism against non-humans. If you're non-human, you're more likely to get shunned to the slummy lower levels.

If you're on a fairly important and independent planet, like Corelia, you'll witness a lot of aggravating police-state actions. Imperials insert themselves into government and law enforcement, against the will of the people, perform warrantless raids on anyone they suspect could be a rebel sympathizer, that sort of thing.

If you're on an unimportant planet, things are probably fine. There's probably some local Imperial governor, but they probably don't really have enough power to affect most people's lives. Without having some interest in either acquiring or eliminating something, the Empire is simply too busy to go around mucking with the lives of average yokels.

If you're a Noghri of the planet Honoghr, then your homeworld was deliberately contaminated and kept in a state of ecological disaster by the Empire. The Empire tricked the Noghri into providing their services as skilled assassins, by convincing them that they were helping repair their world, when in fact they were making sure it remained dependent on the Empire.

If you're on Thyferra, the supplier of bacta (super medicine), then you're living the dream, because you are such a hot commodity that the Empire will even tolerate you playing both sides of galactic conflict. You're making money hand over fist.

If you're an Alderaan, then your life will be very explodey and abbreviated.


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

[User]
How can audio be sped up without increasing in pitch?

For example, say that you increase the speed of a recording of a voice. Normally, the pitch of the voice would increase as the sound gets sped up, but some software allows you to increase the speed of an audio file while maintaining the pitch. What's the difference between these two functions regarding how the sound waves are behaving?

[Assistant]
Understanding Fourier analysis is key to knowing how this works. Any complex wave signal (like a sound wave) can be represented by a sum of pure sine waves at varying amplitudes. This collection of equivalent waves as a sum constitutes the frequency spectrum of a sound at a given instant.

The frequency spectrum is constantly changing, as pitch, volume, and sound quality change over time. However, in small slices (say, 10 milliseconds), the spectrum is relatively constant.

What the software is doing is finding the frequency spectrum for a chunk, and reproducing that spectrum for a slightly shorter amount of time. So say for each 10 millisecond block, it generates that spectrum's wave for 8 milliseconds and then moves on to the next block, giving you a 20% increase in speed without changing pitch or sound quality.

This process isn't perfect. It causes distortion with low sounds, distortion with rapidly changing sound, and distortion from errors joining the chunks together which will naturally alter the final spectrum. It can be improved with sliding window averaging, clever joining of sections, dynamic chunk sizes, or any number of tricks.


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

[User] [Batman] What happens if Batman takes someone under his wing to be a Robin and it turns out theyre just not.good enough? What job does he give them?

[Assistant] Tim Drake started off doing research and figuring things out from inside the Batcave to keep him out of danger. If he'd never gotten up to the physical abilities necessary to be Robin, he'd probably have become backup and assistance for Oracle.


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

[User] ELI5: Why does a word no longer seem like a word to our brain after we say it so many times?

[Assistant] It's not fully understood why, but its called semantic saturation. Effectively the part of your brain that knows the sound of the word and the part of the brain that knows the meaning of the word are different. Through repeated use, the pathways between these two parts get "tired" and so you don't associate the sound to a word right away. You brain hears the sounds just fine, but its a bit slower to find the meaning so it just interprets it as meaningless sound at first.


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

[User] Why does egg turn white when you cook it?

[Assistant]
Proteins are shaped with hydrophobic parts of the molecule on the inside and hydrophilic parts on the outside, allowing them to be water soluble. When the egg white is clear, you're seeing a solution with dissolved proteins in it.

Proteins are very large molecules that are typically designed to function in a certain range (of temperature, pH, ...). For most proteins, that range does not include typical cooking temperatures. On a molecular level, the heat imparted by cooking is enough to undo some of the bonds that give protein its structure.

Then the protein loses its shape, so it is no longer water soluble. Then the proteins come out of solution as a solid. This solid happens to have a white color.


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

[User] ELI5: Why are steroids such a big problem in the MLB but not in every other professional sports league?

[Assistant]
The major reason is that in no other major sport does brute strength play such a significant role. In most other sports strength has to be balanced by other factors such as speed, agility, and endurance- all of which can be negatively affected by putting on excessive muscle mass. However in baseball, for half of the game you have one task and one task only- hit the ball as far as you can.

The other factor is baseball's consistently spotty enforcement of steroid rules. This requires a bit of a history lesson.

Baseball went through a mini-crisis after the '94-'95 strike- baseball had long been declining in popularity, and add on the public outrage of millionaires squabbling with billionaires over money, and interest in baseball was at a nadir. However, baseball went through a mini-revival in 1998 when two power hitters, Mark McGuire and Sammy Sosa, went neck-and-neck through the entire the season to not only break the long-standing single-season home run record, but to beat their rival and set the new record. Just a few years later, Barry Bonds beat them both and set a new record that still stands today. Exciting stuff right? Except now it's become abundantly clear that all three players were using steroids to achieve their records, and that most officials and sportswriters at the time were aware or at least highly suspicious, but didn't care. As you can see, baseball has a perverse incentive- home runs are exciting, viewers tune in to watch them, but enforcement of the steroid bans would have kicked out the players most people were excited to watch. Thus it wasn't until the late 2000s and really recently that baseball got it's act together about drug testing, but for a long time they basically closed their eyes to much of the steroid use.


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

[User] Eli5: why overwatering plants can cause roots to rot, but growing plants in just water dont?

[Assistant]
So not all plants can grow in with their roots submerged in water. Many will just die.

That being said, for those plants that CAN grow in water or soil, care needs to be taken. Although roots look the same to our eyes, roots that are grown in water and grown in soil are different, and if you take a plant that was grown in water and put it into soil it very well can kill the plant. You need to transition the plant properly from one to the other.

Second, you might think that something like hydroponics just means growing food in water, but it is actually a little more complicated than that. Typically hydroponic and aquaponic systems have water levels that cycle up and down. So a plants roots will be submerged for awhile, then the water will drain and the roots will be in air (or the media), and then they will get submerged again.


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

[User]
[Superman] Could Krypton have been saved?

I've seen a few threads that deal with the possibility of Krypton being saved, either by a Green Lantern or a time traveler or some other method. But... Even if it were possible for someone with extreme superpowers to get to Krypton in time, what could they have done?

I can see a mass evacuation being somewhat successful, but the planet itself is boned, right? Most likely with extreme loss of life?

And even if you did evacuate, Yellow Suns seem to be more common than Red ones, so have you just filled the universe with a bunch of Supermen, many of whom may not have the morals that Kal-El did?

Please advise.

[Assistant] A popular way for heroes to 'save' Krypton is to hammer lead rods into the core, rather like a nuclear reactor. Kal-El did this once with a Green Lantern ring in one Elseworld, and Tomar-Re planned on doing it before he got blinded by a supernova and recovered in time to see the planet explode.


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

[User]
[Star Wars] Why was Anakin so mad that he didn't get promoted to Master when he knew he wasn't selected?

I find it strange how Anakin told Palpatine that him being placed on the Jedi Council wouldn't work because they elected their own members and that the chancellor doesn't have authority on the Council.

But he then gets mad and complains to Obi-Wan about how it's not fair that he would stay as a Jedi Knight when they decided to accept him. Like doesn't Anakin realize that even though he got accepted he was never really chosen to be on the Council?

[Assistant] His entire time at the Jedi order they basically didn't trust him while calling him the chosen one and while he did their dirty work by going on countless missions and fighting in the Clone Wars. Aside from a few jedi like Yoda, Windu, and Obi Wan, he was one of the most skilled jedi in the entire order. After years of being faithful to them he felt like he deserved to be promoted to Master but instead they asked him to spy on his friend/father figure Chancellor Palpatine and continue doing more dirty work for them while they refuse to aknowledge his skills.


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

[User]
[Super heroes] Do lesser known C-list super heroes have fans in their own universe ?

Is there a Question fan club somewhere in the DC universe?

Or people who rather get autographs from Booster Gold than Green Lantern?

[Assistant]
There are certain people who are just fans of heroes in general, and they chase after the biggest names.

But a lot of people become fans because of a personal interaction they've had. Mitch Anderson didn't think much of Superman until Big Blue saved him.

So a lesser superhero who still saves people on a regular basis will have a somewhat significant fan base, even if it doesn't rival those of the "blue chip" heroes in the world.


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

[User]
[WH40k]How to get the most Dakka?

Attach Gatling Guns to the barrels of a larger Gatling Gun? Or maybe put even more Gatling Guns onto those Gatling Guns?

Then paint it red to make it shoot faster?

[Assistant]
TVTropes had a prolonged discussion on the subject of "enuff dakka". I'll save you from the rabbit hole by summarising:

You need to have a gun made out of all the matter in space and time, which fires all the matter in space and time as ammunition, at a target of all the matter in space and time. Repeatedly, with an infinite rate of fire.

And then you need to attach a loudener (like a silencer, but orkier), and maybe an underslung grenade launcher.


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

[User]
[Avatar TLA & LoK] Is the sun like the real-life sun (i.e. a radioactive ball of plasma), or is it some kind of magical, nonradioactive ball of actual fire? In either case, would a firebender be able to "bend" the sun?

In a lot of fantasy universes, the sun is just a big ball of fire, not a radioactive ball of burning plasma like it is in real life. I can't recall any of the ATLA or LoK characters ever explaining if their solar system's sun is a magic fireball or a radioactive plasma ball.

Regardless of which type of sun the Avatar universe has, one thing is still known for sure: Firebenders draw power from the sun. It can also be safely assumed that fire is still a plasma in the Avatar universe, just like it is IRL.

All this leads me back to my original questions. Is the Avatar universe's sun magical or realistic? In either case, could a firebending astronaut fly close to the sun and bend solar energy/rays/essence/whatever the same way they can bend a conventional fire?

[Assistant]
The sun is never confirmed either way.

We know the moon is a spirit though, and that is given as the reason why water benders are able to draw power from it.  It would stand to reason that the sun is actually a spirit as well, and that is the reason why firebenders are able to draw power from it.

It may well be the case that astronauts flying to the sun will instead have a conversation with a lonely, probably grumpy spirit.


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

[User]
ELI5: When going over a hill in a car, what causes that fluttery feeling in your stomach?

My daughter asked me this question while we were driving earlier today and I was completely stumped.

[Assistant] That's your stomach jumping up in your abdomen. You might be (hopefully) strapped in with a seatbelt, but your organs as such aren't. They can move a little bit when you're in a car going over a hill, and that's all it is.


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

[User]
So I know that heat rises, but why is that so?

It's almost an adage at this point, however what is the reasoning between heat rising? Does it have to do with air pressure?

[Assistant]
Hotter fluids like air and water generally have a lower density. This means that a given volume of the hotter fluid is lighter than the cooler fluid. The heavier fluid sinks forcing the warmer one to rise.

Heat doesn't rise. This is why you don't see heat "rising" in solids. This is also dependent on the differing weights, which is why you don't see heat rising in zero-g.


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

[User]
A few questions on Abortion (Thomson and Mary Anne Warren)

1. Does Thomson agree, for the sake of argument, that the foetus is a person that has a right to life?
2. Does Thomsons view distinguish morally between cases of abortion depending upon the hardship to the mother required to bear the child?
3. Is Thomsons Henry Fonda case supposed to illustrate that Fonda would infringe Thomsons right to life if he does not save her?
4. Does Mary Anne Warren think that infants should be afforded moral protection solely on the basis of being sentient?
5. Does Mary Anne Warren maintain that relational properties are irrelevant to the ascription of rights?

[Assistant]
In response to the questions about JJT:

1. Thomson wants to show that, even if the fetus is a person with the right to life, that doesn't entail the right to use the mother's organs.
2. If she's right, then even given the fetus's rights, the mom doesn't have to endure significant hardship to bring the fetus to term. Saving the violinist involves hardship. But the Henry Fonda cases don't. To save Judy (in the second version of the case, where he's on the East Coast rather than the West), he just has to walk over and wipe the sweat from her "fevered brow" (lol), but -- controversially -- Judy thinks he still isn't morally obligated to do it.
3. Judy thinks Fonda \*wouldn't\* infringe her rights by not saving her. Again, super controversial, but there are some views that kind of follow up. Taurek's "Should the Numbers Count?" and Anscombe's "Who is Wronged?" are both interesting examples.

Hope that's helpful!


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

[User] ELI5 Saw a video of a squirrel getting rescued via CPR and it made me wonder... If CPR on humans has a specific "cadence" to it that is said to be best, would CPR be more efficient on an animal if the cadence was much faster (to match their normally quicker heartrate)? Thanks!

[Assistant] Indeed it is. There have been some research into this on dogs and cats which are the animals most often receiving first aid. And they have found that the optimal cadence is much faster then on humans. In addition the heart is not in the exact same place and the ribs are different so you end up performing the CPR routine completely different on different animals. However doing anything is better then doing nothing so you should not be afraid of doing the CPR wrong. It is also worth noting that CPR does not cure someone from a stopped heart but instead keeps them alive until they can be healed. There are some cases where the body can heal a stopped heart on its own after a few seconds or even a minute or two but in general you should continue with the CPR until professionals tell you to stop.


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

[User] Eli5: Why do we use clean, potable water in toilets?

[Assistant] A separate water supply system for toilets would cost too much to build and maintain in a city. The water in it can't so dirty to cause gunk to deposit in storage tanks, pipes and the toilet, or be toxic for plant life that it can't be used for watering a garden.


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

[User] ELI5: Why does every car have a different type of battery when every car takes a 12-Volt battery?

[Assistant]
different sizes.

the bigger the engine, the bigger the amperage is needed for the electric starter motor to turn the engine.  the bigger the amp requirement, the bigger battery you need.

bigger batteries also happen to be more expensive and more heavy.   so you use the size battery that most appropriately matches your engine starting needs.


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

[User]
is it possible to move an object in circular motion using magnets?

hello I'm trying to make a device which uses magnetism. my device is like a windmill but instead, I'm planning to use magnets to move the blades. I created a miniature using a pc fan and a dynamo generator. So far it doesn't work. Is it possible to move an object in circular motion with the use of two opposite magnetic poles?

[Assistant] Absolutely, this is how most electric motors work. They have a coil of wire around the magnet, and adding a current makes the magnet attract or repel other magnets on a part that spins freely.  (unless i misunderstood your question!)


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

[User] Are adult children morally obligated to care for ailing parents?

[Assistant]
Do you have a general moral theory within which you want an answer to this question?

Part of this is the extent to which you think familial status can itself cause a moral obligation.

edit--just adding a little elaboration.

Myself, it seems very unlikely that we can actually argue the "parentage" can be the cause of the obligation to take care of one particular ailing person.  There certainly seem to be lots of things involved in parenting that make potential reciprocity morally right; but only in virtue of the nature of the parenting.

For instance, its plausible that you owe something to a parent who ensured you had access to great education and thus professional success.  it seems extremely plausible to me that the same obligation would not attach to a parent who abandoned you at age 2 and never spoke to you for twenty years.

By extension, you would have to be arguing that there is some moral obligation arising from the mere genetic similarity.  This seems very strange.


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

[User]
ELI5: Why when we think about breathing we start breathing 'manually'?

And how do we forget about it suddenly 'automatic' breathing starts?

Thanks!.

[Assistant] Breathing is regulated by two different pathways, an automatic center that originates from your brainstem that controls your natural breathing when you are not actively thinking about breathing. There is also an area that comes from your cortex allows you to have active control of the muscles that are related to breathing (your diaphragm, your intercostals, your abs). When you actively try to take a deep breath/breath harder, you are overriding your autonomic breathing center, and actively using more of your secondary respiratory muscles.


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

[User] [Harry Potter] Hogwarts students enter at 11 and stay up to 7 years. Even the most advanced students never learn very powerful magic like the kind dumbledore and Voldemort use. Are there universities for young students who want to further their education?

[Assistant]
Its more an apprenticeship based civilization. A student might graduate Hogwarts and be interested in Wandlore, so they would go to Olivander's or some other such place and apply for an apprenticeship.

Either that or there are low level ministry style jobs where you get additional training.


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

[User]
If the coronavirus keeps mutating to evade our vaccines, like the South African mutation, and we keep on updating vaccines to protect against the new variants, would the virus ever run out of new mutations to try?

Just thinking of the worst case scenario where every time we create a new vaccine the coronavirus mutates again to get around it. Is the number of possible mutations that could affect vaccine response limited in any way?

[Assistant] Influenza is effectively doing this. It's constantly mutating. Every year, vaccines are adapted in an attempt to catch the latest mutation. Problem is the latest mutation can be quicker than our efforts leading to larger outbreaks of influenza once every couple of years.


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

[User]
ELI5: If the Earth's crust is divided into tectonic plates, all bordering the adjacent plates, how is it that continents manage to move away/towards each other?

Are there gaps between the plates that allow this constant movement?

[Assistant]
At the scales we're talking about - very long timeframes, very large forces - even rock is somewhat "squishy". The plates compress and stretch as the forces below them push them against one another or pull them apart, so the horizontal size of the plates does not have to remain exactly the same over time.

In some cases, the compression is enough to create tensions that overwhelm the mechanical strength of stone even in the short term, before the rock can "flow" under pressure (which it will, given enough time). In those cases, the stone cracks and moves in different directions on either side of the crack - a "fault". The largest faults are the divisons between the plates themselves (e.g. the famous San Andreas fault, which divides the Pacific plate from the North American plate), while smaller faults occur within plates all the way down to the scale of individual stones you could examine in your hand. These faults can force pieces of land upward, allowing a plate to shrink horizontally while rising vertically.

In other cases, one plate is heavier than another, and the heavier plate (typically an oceanic plate) sinks below the lighter one (typically a continental plate). The sinking plate sinks down into the mantle of the Earth and melts, which replenishes the mantle material that erupts through volcanoes at the surface.

In general, the idea of plates as rigid objects is a reasonable way to think for the purposes of everyday understanding, but plates are neither completely well-defined things nor completely rigid nor permanent over geological timescales. They have substructure (the major plates tend to contain smaller microplates, especially around their edges), they can warp (especially when compressed as in mountainbuilding), and they can be created or destroyed (e.g. when an existing plate splits or is pushed down into the mantle).


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

[User] [Star Wars] Why was the death star built when you could just carpet bomb planets using giant space ships?

[Assistant]
It's about fear.

A fleet of ships. That's an understandable thing.  Something you can get your head around.  A fleet comes to glass your planet, you think maybe you can fight.  Maybe you can drive them off, or maybe there will be enough left after to rebuild.

A moon-sized space station that can reduce your whole planet to rubble in an instant?  There's no reaction to that thing except fear and desperation.  At least that was the idea.

There's other advantages too though.  With a fleet, you have to trust your Admirals and Captains to operate loyally without you.  Something like the Death Star, one strong leader can control that directly.


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

[User] How fast is the sun moving through space and how can we measure that?

[Assistant] Speed is relative. "Space" isn't some substance or terrain through which the sun is moving. Nothing moves relative to space. So you must choose another object to compare the sun's movement to. The sun moves in it's circular orbit around the galactic center at something like 800,000 km/hr. But you might also choose to compare it to other nearby stars, for example.


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

[User] [General] If a werewolf was stabbed with a silver-plated blade, would it be as effective as pure silver blade?

[Assistant] Yeah. Silver is silver. As long as the silver is on the outside, then it's going to do harm. The problem with using silver plated items is that the playing can wear away with repeated cleaning, which is going to happen a lot of you are a hunter, and may become ineffective.


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

[User]
How did the functions of super computers change over the years? Is a super computer just a stack of the newest hardware?

This field is something that always interested me a lot and I do have many questions about it:

How did the functions of super computers change over the years? Is a super computer just a stack of the newest hardware? How long does it take to build one, did the time needed change?

Are super computers doing the same things they were doing 20 years ago, just more in depth and complex? And lastly: how does the future of super computing look like? Will it "just" be faster and much smaller in 20 years?

Thanks a lot, I always enjoy reading the answers in here.

[Assistant]
I can speak (a little) for the climate/weather oceanography group.

A lot of the basic code (for large scale climate system) was written over the last 30 years, and we still use that same Fortran.

The advances are running on finer and finer grids, or running more simulations to get better "average" properties.  So yes, pretty much "same thing but faster/smaller".  Scientifically though that's a big thing, being able to do statistics over multiple runs of a model is very different than just having a single run of a model.

We're basically on the same newest hardware (or often one level down from the best) in terms of raw CPU or GPUs as what you buy for a single computer.  But a lot of the advances (hardware and software) are in inter-CPU communication (bus speeds, network backbone, improved compilers, etc.)


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

[User]
ELI5: Why do we want to listen to a specific song multiple times and afterwards don't want to hear it for weeks?

Everyone has that, finding a song particularly mesmerizing that you listen to it on repeat for days. But then all of a sudden you get tired of it and can go without for months. Why is that?

[Assistant] People want a feigned sense of newness. People often don't like a song because they haven't heard it enough to become familiar. Then you listen to it a lot, because you know what to expect then it becomes the boring because you know it too well and there is no growth.


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

[User]
[Comics Marvel/DC] How do enhanced geniuses like MODOK, Leader, or Hector Hammond (DC) stand up to there "world smartest" baseline humans? People like Lex Luther, Reed Richards and Doom.

This was a question I had for a long time, and it was never really answered in a satisfying way, as far as I know.  To me, it would only make sense that these enhanced minds are smarter than humanly capable, but comics don't really handle intellectuals too well.

[Assistant]
Reed Richards is recognised as being the smartest character in the marvel universe and consistently outsmarts his opponents.

I'd say MODOK and such probably outthink any "normal" human, which means they can plan ahead incredibly well, develop crazy tools and weapons and be sneaky enough about it to do a lot of harm.

When they get caught by the likes of Richards, Ironman or even Spiderman, however, they're done.


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

[User] ELI5: Why induce labor in pregnant women past their due date instead of just letting the baby come on its own?

[Assistant]
1. When the baby gets too big, it can require surgery to get it out.

2. You can make less of what the baby needs.

3. What the baby is using to live (placenta) can begin to fail.

4. Insurance reasons: Since is is now standard practice to induce if you are a bit late, any complications arising when they deviate from that norm leave doctors a target for law suits.

5. Business reasons:  The doctor only takes on so many pregnant women at a time, with the assumption that most will deliver by their due date.  It messes with the practice's schedule to have a bunch of ladies going late.  This is not going to a primary reason, but if keeping the woman on her schedule can be justified medically, it is certainly a business perk as well.

6. Pregnancy is hard on the mother's body, so if she is having any significant health effects (high blood pressure, sugar level problems, etc), it might be safer for her to deliver sooner.

I think it is important to mention that there are significant risks to inducing as well.


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

[User] [Beast Wars] How come neither the Autobots or Decpticons found any relics from the Beast Wars?

[Assistant]
Both the Axalon and Darksyde were destroyed with the remnants either long buried or recovered and packed up when the Maximals left Earth.

Other things that may have being left behind, such as Tarantulas's lair, would have been near impossible to find if you didn't know to look for them; buried under the ground or at the bottom of the ocean for millions of years and even when operational had a fraction of the energy signature of Autobot/Decepticon technology.

They'd have had to have some clue that something was there and where to look to even have a chance at digging up anything left behind by the Predicons or Maximals.


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

[User] ELI5: which bodily processes are first to shut down as a result of under-nutrition? And what is the progression from there?

[Assistant] The body shuts down pretty much from least vital to most vital. The first system to shut down is the reproductive. Then the digestive, then organ failure. If you make it to organ failure, you are probably at the heart failure stage.


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

[User] What purpose does leg jiggling/bouncing serve?

[Assistant] There is no clear answer to this question.  However, there are some who hypothesize (myself included) that "leg jiggling" *does* serve a purpose.  We understand that persons with attentional deficits have an underactivation of certain brain networks.  Meaning, those brain areas don't activate at the same level as they do in otherwise normal individuals.  The hypothesis is that "leg jiggling" may serve to help activate those brain areas, thereby subtly improving cognitive abilities/attention.  The neural mechanisms underlying this hypothesis are certainly in place (i.e., corticothalamic projections), however there are some assumptions that must be made for which there isn't yet scientific backing.  I've not seen this hypothesis studied directly, but I've heard enough people talking about it at conferences to imagine that someone will make a stab at it in the not so distant future.


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

[User]
[Warhammer 40,000] Would a chapter serf worship the Emperor?

I know that it's considered unusual for brothers of Adeptus Astartes chapters themselves to worship the Emperor as a divine figure: "Grandpa, not God", as a guy in my gaming group put it. My question is, would a *serf* of a chapter likely share this belief due to the "command environment", or would they probably still believe in the Emperor's divinity the normal Imperial way?

RP question for a chapter serf PC in a *Dark Heresy* 2E game my group is doing this weekend. Voidborn origin (a Strike Cruiser), I kitbashed the Imperial Navy background with GM permission: altered the lore skills to Common Lore (Imperium) free, and paid for Scholastic Lore (Adeptus Astartes) to reflect training as an implant surgeon (Chirurgeon role).

[Assistant]
In most cases, serfs who are brought into a chapter are also inducted into their specific customs. Since most marines do not hold the Emperor in a specifically divine light, their serfs also hold the same belief. Although given that serfs are unaugmented humans walking amongst the Emperor's finest servants, they could very likely hold the Emperor in higher regard than the marines they serve. Some might privately hold beliefs in the Imperial Cult, but they might not speak of it openly.

On the other hand, some chapters might be lenient enough to allow their serfs to believe in the Emperor's divinity even if the marines themselves do not. So long as the work is done and done properly, the serfs can refer to the Emperor however they wish.


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

[User] [Superhero] Any advantages of having a cape?

[Assistant] It makes you seem more imposing. Draws attention away from civilians. Superman uses his to steer. Batman uses his to glide. It also conceals his body language and makes him seem creepier than he actually is.


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

[User] [The Culture] and [General Fiction] - Which societies have a higher standard of living for the average citizen than the Culture?

[Assistant]
In the culture you can have your head knocked off by a freak accident of industrial machinery then have stealth drones fly in out of nowhere to take your head off to be attached to life support while they regrow you a clone body, all before your head hits the ground.

That's a pretty impressive social security safety net. It'll be hard to find a society with a higher standard of living than the Culture. It might come down to philosophical discussions of 'best'.


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

[User] ELI5: If Google Maps uses location data from android phones to predict journey times how does it know the difference between those on a bus and those in a car as they share the same road? How does it arrive at the different estimates for car and bus journeys of the same route?

[Assistant] Google knows where bus stops are. Based on that, it's not difficult to pick out which android devices come to a complete stop at specific intervals along a journey, and can therefore be used to calculate a base time along those routes.


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

[User]
CMV: A minimum wage that is directly linked to the cost of living/living wage for an area would solve many issues that come with minimum wage increases

So, the main thing I see when the topic of a living wage comes up is that companies will just jack up the prices to compensate for the lost revenue, which then negates any increase in wages.

However, a minimum wage that is directly linked to what the living wage is for the area that the business is located would make it so if companies drive the prices up, then the cost of living goes up, then the living wage goes up and so will what the workers are paid.  This way companies can't just jack up the prices, because doing so will mean that they need to pay their workers even more.  Keeping prices lower will be in their best interest

Edit:  Reddit is being weird and not letting me see all comments, and not letting me reply so I'll get to the replies when I can!

Edit 2:  I see a lot of "what about small businesses" comments.  If a business needs to exploit its workers in order to survive, then it should not survive.

Edit 3:  Reddit is still being weird and won't let me see the majority of the comments so if I don't reply, I apologize!

[Assistant]
Its not that companies increase prices with an increase in the minimum wage, its that landlords increase prices. Rent is not a fixed price like goods and most services are - its highly flexible based on demand.

You would create a feedback loop - minimum wage goes up, rent goes up, so minimum wage goes up again because cost of living increases, so rent goes up again.

As an end result, you actually put companies out of business because they would then be paying astronomically high wages, while the landlords are the ones benefiting.


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

[User]
If increased kinetic energy = perception of heat/high temperature, why does using a fan to blow around air (increase kinetic energy) cool us down?

Rather than some mind-blowing physics, I'm expecting this to be more of a common-sense kind of solution, but I've been stuck puzzling over it for a while.

[Assistant] Fans cool in two ways.  First, they increase the rate of evaporation of water from your skin.  The heat of vaporization of water is quite high, and this reduces the temperature of your skin.  Second, if the air temperature is less than 37C, your skin transfers thermal energy to the air molecules.  The speed of the wind from the fan is much smaller than the average speed of air molecules at room temperature (roughly 1500 km/h).


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

[User]
What makes a gene dominant or recessive?

What is the difference between a dominant or recessive gene? I know that dominant genes prevail over recessive ones and this is also the stuff I find on the internet. But I can't find an explanation of what makes a specific gene prevail over other ones in the fist place.

[Assistant]
It depends on the details of what the gene does and how each allele (different version of the gene) works or doesn't work.

For example, lactose intolerance happens when _neither_ of your two genes for making lactase are functional in adulthood, so a single lactase-persistence allele will be dominant over a normal lactase-only-in-childhood allele. Or say you have a mutation in your ACE receptor that stops SARS-CoV-2 from binding: this COVID immunity allele would be _recessive_, because one copy of a normal ACE receptor would be enough to let the virus in.

Then there are other situations, like making red pigments to color a flower petal, where having one allele just gives an intermediate phenotype (pink) compared to 0 (white) or 2 (red).


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

[User] If there are stick liquids and sticky solids, are there any sticky gasses?

[Assistant]
Molecularly, yes. Different gases have different binding affinities to different surfaces. Binding very weakly is called physisorption, binding very strongly so theres nearly a chemical bind is call chemisorption. How sticky the gas is depends on the gas and the surface its sticking to, just like liquids and solids.

I work with scientific instruments under high vacuum and can watch (using the instrument) as water slowly gets removed from the system. Whats happening there is that water molecules in the gas phase (because of such a high vacuum in the system) are binding to the metal surfaces inside the instrument and slowly release. If we can heat some of the surfaces the water unbinds faster. This is physisorption.

Other molecules like hydrogen sulfide, which is a gas at room temperature and atmospheric pressure, will much more strongly bind to metals like stainless steel. This is close to and may be chemisorption. Ammonia can have similar behavior.

I also used to do research trying to make materials that would bind hydrogen gas (one of the least sticky gases!) More strongly, but not so strongly that it chemically reacted. Its a very difficult sweet spot.


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

[User] Do all flying insects share one common flying ancestor, or did flight evolve multiple times in the different insect families?

[Assistant]
> Insects were the first group of organisms to take wing and their flight appears to have evolved only once.

Wheat and Wahlberg. 2013. Phylogenomic Insights into the Cambrian Explosion, the Colonization of Land and the
Evolution of Flight in Arthropoda. *Systematic Biology* 62(1): 93 - 109.


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

[User] [Avatar] Why is it that some Benders don't need to move to Bend?

[Assistant]
Bending is all about the manipulation of the flow of chi within the body and using it to affect the outside world and the element(s). The various bending arts and styles help to focus the chi into doing specific things, depending on the movements of the body.

Some particularly powerful benders, however, have such control of their chi, either from a lifetime of training or just winning the genetic lottery, that they can focus and manipulate their chi with the most minimal of movements. And in rare cases, no movements at all. Of course it's still easier for them to bend using the proper forms and stances than to do without them.

Think of bending stances and moves as sort of physical/spiritual mnemonic devices, those little tricks you learn to help you remember more complicated things; like singing the alphabet or using a phrase to remember the order of the colours of the rainbow. Most people use them a lot starting out but eventually don't need them as much. Some people never stop using them. And some lucky people just have good memories and don't ever need to use any.


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

[User] [Pippi Longstocking] How did Pippi managed to get to Sweden with her horse in the first place? Didn't she got shipbroken in the pacific?

[Assistant] Pippi's father had disappeared at sea and her mom was dead so the ship's crew sent Pippi to her family home at manor of Villa Villekulla because they thought that the sea was not a suitable place for a child growing up without parents.


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

[User] ELI5: Why do cut apples, pears and other fruits become brown and mealy on the surface of the cut when left untouched for a while?

[Assistant]
Its because the flesh of the fruit oxidizes.  Oxygen from the air interacts with the fruit.  Its not unlike how metal will oxidize (rust).

Oxygen is actually a fairly dangerous and destructive element.  The skin of the fruit protects the meat from oxygen (among other things).


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

[User]
[Battlestar Galactica 2003] Where do Cylon Centurions store their ammunition?

They have three collapsible, projectile guns per hand, and can appear to continue firing for extended periods of time. Close examination reveals the guns to be relatively high caliber as well. The newer toaster models are rather thin and don't appear to have external ammo storage.

[Assistant]
There are few pictures of the back of centurions. They do show a large cover on the upper back, leading to the thought that some ammo could be stored here- where there is interior open space between structural components of the torso. Depending on the interior of the abdomen, more could be stored here. Think of a belt- fed high caliber weapon - with the "belt" feeding projectiles up from their tightly compacted storage in the torso, up through the upper back, shoulder and down the arms to the firing mechanisms.

For extended missions, centurions could be equipped with replaceable "magazines" housed in the abdomen and behind the plate on the upper back. Space is also available on the thigh and calf for magazines or a total body belt- fed system.


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

[User]
[Star Wars] What would Palpatine have done had Count Dooku killed Anakin and Obi Wan in Episode 2?

It seemed like Palpatine had been grooming Anakin since episode 1 to be his apprentice, but Dooku wasn't in on this plan. In episode 2, Dooku nearly kills Anakin and Obi Wan were it not for Yoda appearing just in time. How would Palpatine have proceeded were Yoda to arrive too late?

[Assistant] Continue training Dooku whilst making moves on Mace Windu. Anakin's death would be a pitty, like the deaths of all of Palpatine's apprentices. but Palpatine can move on. The real tragedy with employing Count Dooku as his apprentice is just how old Dooku is.


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

[User] Why are bruised spots on fruit sweeter than the rest of it?

[Assistant] Bruising on fruits occurs because parts of the fruit cells' cell wall are ruptured, releasing the enzymes. This causes accelerated ripening, a process that involves breaking down enzymes, but more importantly, hydrolyzes storage polysaccharides. Those polysaccharides convert to smaller sugars (glucose, fructose, sucrose) which have a sweeter taste than the originals.


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

[User]
[Futurama]Why does everyone in the year 3000 have such an incredible knowledge of the 20th century

I understand why they might know about the major events (some presidents, wars) but how do they know about all the pop culture that they reference?

[Assistant]
The second coming of Jesus destroyed all video tapes on earth, all that was left was print media.

The longest lasting print media was glossy magazines since newspapers and books generally disintegrated or rotted. This resulted in the only "history" available being tabloids and propaganda material.

People read this and this alone, resulting in a period of sixty or so years being the only history known in the future.


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

[User]
how does over-the-horizon radar work? bounces off the ionosphere like shortwave radio?

or what?

[Assistant]
In short, Yes

You just need tremendous transmitter Power and an ultra sensitive receiver. That's why they do NOT use the same antenna but are spatially separated. The intense transmitter Signal would spoil the receiver in the vicinity. You also need to check the state of the Ionosphere by sending a beam straight up and check for latency as well as dispersion. The last point is why you sometimes use chirped pulses as well as a channel coding scheme to avoid any countermeasures.


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

[User] ELI5: Every time I buy pre-sale concert tickets, or log on immediately during public sale times, I always get terrible seats, even when using the "Best Available" option and searching for the highest price. How are other people getting their good seats closer to the stage?

[Assistant]
A lot of seats are already accounted for even before they go on sale. You've got VIP seating, tickets that are given to various local radio stations, internet sites, magazines, etc., for contest giveaways. You could potentially have corporate accounts that get a block of seats automatically for events.

Plus, many scalpers use programs to buy up tickets when they go on sale that are able to buy them much faster than any human could.


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

[User]
[Game of Thrones] Since Starbucks is confirmed to have an outlet in Winterfell, what other franchises can be found in Westeros?

I'm pretty sure there's a Long John Silver's in the Iron Islands. Dorne probably favors Taco Bell.

[Assistant]
Lyft and Uber are making good money driving people across Westeros at ridiculous speeds, thus explaining how certain characters are able to get from Kingdom to Kingdom seemingly overnight.

Every KFC in Westeros has been destroyed by the Hound.


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

[User] [Genetics] A and B are identical twins. C and D are identical twins. A marries C and B marries D. A and C have a kid, B and D have a kid. If I tested the DNA of A/Cs kid, would it show that A/C are its parents as well as B/D?

[Assistant] Variation in crossing over in the production of gametes would lead to differences in the genetic makeup of child A/C and B/D. However, since the parental or recombinant gametes could be the product of either couple, there's no way to detect paternity (assuming there are no significant epigenetic changes in any of the parents).


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

[User] How do we know for sure that there is molten lava in earths core?

[Assistant]
Earthquakes and some other events like nuclear weapon explosions set off seismographs. These record the pattern of the ground waves that reach it. Earthquakes create 2 different kinds of waves which travel at different speeds. Sometimes the direct line from the seismograph to the event goes through the earth. When this happens, they can use the timing and data from multiple seismographs in different locations to make conclusions about the material inside the earth.

Also lava.

Edit: not lava.