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

[User]
CMV: Arguing/debating doesnt work, isnt a sufficiently supported claim.

I hear this said quite a bit, but the information in totality does not bear this out. People point out things like the backfire effect, ignoring that these studies involved percentages, which means that giving facts did work on some people. They also ignore that the backfire effect has been studied numerous times with different results.

Another thing I find interesting is when I speak to people who think like this, I often come to find out that they (like me) used to believe very different things that what they do currently, and through some sort of discussion with a person that took a different position than them, they started to think differently.

Hell, I think this subreddit is a whole testimony to the fact that debating and argument work and people do change their minds quite a lot. You just cant expect that its always going to work in the way and time that you want.

Finally, a strange part of this is that people who say arguments/debates and/or conversations with the people whom you disagree are pointless or dont work, these people are never simply sharing facts. It usually comes with a heavy tone of agitation, aggravation, and an air of superiority.

Given all of the information and attitudes, I think its a likelier explanation that when someone says arguing and debate dont work, what they are really saying is arguing with people who disagree with me on certain topics frustrates me, but notice this is much different. This isnt so much about the effectiveness of debate and arguing as much as it could be about you just not being a very good debater or you not being able to control your emotions when people disagree with you. So if this is the deal, then just say I dont like arguing or debating. Its incorrect to project that onto the whole of communicating with people with whom we disagree.

Leave those of us who see purpose and value in debating alone. Certainly dont say things that may lead to an argument and debate about how ineffective argument and debate are. If you struggle with debates and arguments, consider studying how to effectively engage in them or do some work on your emotional control. Dont pigeonhole society based on an unsupported claim because of your emotions. Not all of us have those issues, and we like to see society change as individuals interact to try to mutually come to understand what is true on very important matters.

Basically consider, if you havent already, that this is more a you issue than an issue with debate and argumentation or those who engage in them.

This in CMV instead of off my chest because, well, I have a certain view of people like this, and I want to see if anyone can change it.

[Assistant] Your entire position appears to assume that both parties involved in an "argument/debate" argue and/or debate in good faith. This is oftentimes not the case, as even evidenced in this sub by the sheer amount of posts that are removed for violating rules b and e. Normally, when people say "arguing/debating doesn't work", what they mean is that arguing and/or debating with a party who does *not* hold a rational view and refuses to engage in a *rational* discussion does not work.


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

[User] ELI5: what exactly is the science behind a 'second wind'?

[Assistant] in the first portion of the exercise bout the "second wind" refers to your bodies switching from a majority of Anaerobic energy systems to primarily aerobic energy systems. when you first start running your body doesn't really know how long this shindig will last so it pulls out all the stops on providing oxygen and ATP to your working muscles (anaerobic) but after about 15 (energy plateau) mins or so it gets the idea that this isn't going to be a sprint and begins to switch from the more powerful anaerobic systems to utilizing the aerobic energy systems that are more efficient.


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

[User]
Do you think the School of Life video series on philosophy oversimplifies and idealizes philosophers and their works?

I've generally enjoyed the philosophy videos -- I think I've seen them all now. Most of the ideas and philosophers were already familiar, to me, at least a little. In many cases, I ended up thinking, "Philosopher X is much more inspiring, reasonable and easy to understand than I had previously given him credit for." But, I wondered if the author of the video had over-polished the philosopher and philosophy.

When I saw the video about Thoreau (in the political theory series), I became much more skeptical about the whole series. I recently read a biography of Thoreau. The School of Life video about Thoreau seems extremely naive, at best. The short version of my concern -- Thoreau didn't reason out anything. He merely did what he liked to do. He acted on impulse when he declined not to pay his poll tax. The idea that government should be small and that citizens should decline to fund it if they didn't like its actions was well-known by then. He wasn't reclusive -- he dined with Emerson's family, or his own family, almost every evening. He planted beans and caught some fish from the pond, but he was not self-sufficient by any means. He produced very little of his own food. His writings superficially sounded philosophical but they were more poetical and polemical, and were written for the purpose of impressing Emerson, possibly impressing some girls, and selling books. He actually wanted and needed to make money, though he wasn't fond of conventional employment.

I don't expect the authors of The School of Life to say all of this in a short video, but I wonder how much I've been misled by some of the other videos. Your comments?

[Assistant] I don't think I've ever seen a *good* philosophy video from School of Life. Their descriptions of philosophers aren't just facile and inaccurate, sometimes they're downright *offensive*. In the Foucault video de Botton implies that the reason Foucault 'hates the bourgeois' is because they remind him of his father! And they seem to miss out on like, the thing Foucault repeats over and over, that you can't just 'get out' of power relations by being aware of them. So de Botton ends up saying things like "Foucault was trying to create a Marxist anarchist utopia" when it's clear that Foucault was aggressively resistant to making sweeping claims about what the "right" political aim should be.


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

[User] [DC] can superman destroy green lanterns constructs?

[Assistant]
GLs constructs are based on will power, and different Lanterns have different levels of will power.

So, whilst its possible for the constructs to survive against Superman, Supes can generally smash through Hal Jordans after a couple swings.

In the New 52, one of the early Justice League arcs has the two facing off and Superman winning. The fight was also adapted into the animated movie Justice League War.


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

[User]
ELI5: What type of differences would there be if an obese person was stabbed in the belly compared to a fit person being stabbed in the same place?

Would the obese person technically receive a less life threatening injury because of the fat?

[Assistant]
Blood vessels that carry nutrients to the skin and wastes away from the skin (capillaries) are on the surface, thus on the outside of the fat. Therefore the surface damage and bleeding between the two people would be similar.

However, the internal organs and muscles of the obese person are under their fat deposits. Therefore, the knife would most likely not reach much of their vital organs or muscles, thus causing less internal damage and bleeding. This would also reduce the number of nerves stimulated by the wound (as there are no nerves in fat deposits), meaning the obese person would feel less (but still significant) pain.

The damage sustained by the obese person is much more easily and quickly healed, as it primarily requires skin healing. Whereas the fit person would require muscles and organs to heal, which can often be too slow and fatal.

In short, the obese person would be less severely harmed, as the fat (which serves no vital purpose) would act as a protective layer. Therefore preventing significant internal damage.

Note: On a side note, the healing capacity of the obese person is often impaired by their obesity, such as the reduced efficiency in their circulatory system to deliver clotting factors. Which could definitely play a role in their ability to heal their wounds and chance of survival.


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

[User]
[Paddington] Why is nobody surprised that Paddington Bear can talk?

When the Bear arrives in a London train station he immediately tries to engage people in conversation in hopes that someone will take him home and care for him.

Yet people seem to just either ignore him or kind of rudely brush him off. Why does nobody seems shocked in the slightest that there is a andean bear standing on two-legs, wearing a bucket hat and speaking British english?

[Assistant]
Well its rather rude to comment on someones appearance, and nobody wants to make it THEIR problem to escort this short furry man somewhere.

So, the politest thing to do without putting yourself out is to ignore the problem and hope someone more generous comes along to deal with it. As any true Brit would.


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

[User] [Any Metro] How are folks living underground for decades not dying from lack of vitamin D and other essential nutrients beyond Vodka and cigarettes?

[Assistant] UV lamps kept around shelter locations and high nutrient foods. They're not super healthy but they're getting by. They're eating lots of root vegetables and some of them are able to reach the surface for supplies. Things like UV lamps and seeds as well as canned goods would be of utmost priority for maintenance and collection. The people are still malnourished but not to an extent that rabbit starvation is imminent.


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

[User]
Why don't people just pull out of the market when the yield curve inverts?

The 3-month-10 year yield curve inverted for what a week or so before going above water again? I've seen the argument's that this time is different but regardless it's not a positive sign. Why don't people exit the market when this happens for a sustained period and keep their assets as cash or, if you are an eccentric libertarian, gold? They could always reenter the market after the bottom falls out.

For instance if you have these two rules- you will withdraw from investment positions after a full quarter of yield curve inversion, and you will reenter after three quarters of sustained positive growth based on the S&P 500 perhaps- then you would be out of the market \~Nov 1999-Jan 2004 and \~Aug 2007-Dec 2009 I reason this would net you more returns in the long run and would mean that if you needed access to those funds during a recession, you would not be taking a loss.

[Assistant]
The market averages an increase of 20% between the inversion of the yield curve and the start of the recession AND no one can predict when the recession is truly over and the recovery starts.

To time the market correctly, you need to both pick the right time to exit AND the right time to go back in. Even if you exit today, there's no guarantee that even with the drop it will come out to lower than today - and it's entirely possible you'll miss the bottom and end up having to buy again at higher than today's prices.


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

[User]
[AvP/Aliens/Predator]So, who created the Xenomorph after all? (SPOILERS)

I was giving this matter some thougth and I couldn't come across the fact that across multiple films and other media, we've been given or hinted at *multiple* origin stories for the Xenomorphs existence.

I'm assuming both Predator and Alien/Prometheus franchises exist in the same universe, hence why I assume AvP is cannon.

I'm not considering the latest "The Predator" movie cause that was garbage. Honestly. I think most agree with with me. Other movies were bad, but not *that bad*.

So, AvP tells us the Yautja have existed as an extremely advanced species long before humans were a thing. They even helped us evolve in return for volunteers to be seeded with the Xenomorph. This implies the Xenomorph in it's more recognizable facehugger/egg form also existed long before humanity, since the Yautja have been using them for sport for a while now.

Prometheus introduces us to the Engineers, and it is hinted Engineers not only seeded life on Earth, given the "their DNA is identical to ours" line in the movie, but it's hinted they did so in other worlds. It's heavily hinted that the Black Goo is the mutagenic agent that starts the Xenomorph life cycle, however it's also the thing that destroyed the Engineer in the beginning and caused him to seed life on Earth.

Prometheus also implies the Engineers worshiped a Xenomorph looking creature given the altar scene.

We also get a Deacon from an Engineer at the end and it looks awesome. I have no idea what a Deacon is, what it's purpose in bringing the Xenomorph into life.

Other media shows that the Engineers and Yautja are enemies, so from this I gather the Engineers did not *seed all life in the universe*, rather were just advanced enough to do so.

From Predators, we can see the Yautja also seem to be advanced enough to the point they can terraform planets to be used as hunting reserves. The crashed Engineer ship on that same planet not only reinforces the notion all franchises share the same universe, but also implies the Engineers and Yautja are on similar degrees of technological advance, given the Yautja could shoot down the much larger Engineer ship.

From this I assume the Yautja may also be able seed life on planets. They seem to cooperate with other species (and even  aid their development, as indicated by AvP) if they can get something out of tjen.

Note: I only assume it's an Engineer ship on Predators because I've seen it refered as so by most of the fandom and even youtube movie analysts.

While all the black goo, Engineer religion stuff, and Yautja rituals further serve to prove that Xenomorph-like creatures existed in the universe long before the crew of the Nostromo was attacked by one.

HOWEVER, Alien Covenant casts an entire wrench into nearly everything that I gathered from all the other movies by having DAVID be the creator for the Xenomorph as we know it.

Why? Because in expanded media (I now point to all Alien lore youtubers) it's stated that David made the Xenomorph Eggs using Elizabeth Shaw's DNA and the Alien pathogen. They even have the lil'xenomorph have a lil' "hug me daddy" moment when David sees him come to.

So how come the Xenomorph could exist long before Mankind came to be, as implied and shown in all movies prior to Covenant... but at the same time... *be the creation of David's engineering* in Covenant?

We know Xenomorph's don't naturally occur via Black Goo infection. Those result in Deacons. Again, I don't know their relation to Xenomorphs, but David seemed fond of them, even tho he did not create them.

How could the Xenomorph even exist in it's iconic form previous to mankind existance, if David *used human DNA* to fabricate the Xenomorph?

Above all, how could the Yautja be lugging around Xenomorph eggs while all this is happening?

Thus, questions:

Did the Engineers create the Xenomorph and the Yautja just farmed them for sport, and David just happened to discover how to make one?

Did the Yautja invent/create the Xenomorph, which in turn was worshiped by the Engineers, much like David worships the Deacons/Xenos, and again, David just happened to find out the Xenomorph recipe.

What the hell is a Deacon and where do they fit in all of this?

Or is it more plausible that the Xenomorph simply always existed as a creature somewhere, and was both farmed by the Yautja and worshiped by the Engineers (hence why both species are enemies) who in turn created the black goo from it's DNA, causing the Deacon thing as a side effect.

Or could it be even more plausible that there simply are a fuckton of plotholes Ridley Scott is choosing to ignore?

EDIT: Could it simply be that Prometheus and Covenants are intended to retcon everything?

[Assistant]
Xenomorphs are a biological weapon created by the Engineers, which can make aliens that destroy an ecosystem. They can take many forms depending on what they infect. They grow pretty easily, so David making them was easy. Just stick them in a source of biological matter and they grow.

The Yautja hunt them, they didn't make them. They seem to have a common ish form, as shown by the Deacon, so if they prehumanity hunted ones that looked normal, they were probably born from humanoids.

The Deacon is a xenomorph born from an engineer.

It's not that complicated and weird.


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

[User] After you die, how long does it take the various cells in your body to die? What happens to your gut bacteria?

[Assistant]
Not very long - cells require oxygen to function, so moments after your brain and heart stop, your cells may begin dying in a upwards, collective motion that can span days, weeks, or even months. Usually, starts with the liver and the brain, since they are enzyme rich.

When cells die, they leak digestive enzymes that participate in putrefaction, and causes collapses of capillaries for red blood cells.

As for the gut bacteria, they also help in the process of decay by digesting your organs - until they can freely leave the body either by spilling out of your decaying body, or being carried by maggots, botflies, or other organisms.

Edit: Removed "signaling other cell death." Depending on the kind of cell death, surrounding white blood cells become receptive to dead cells. Cells in apoptosis (cell suicide) for example typically will distance themselves.
With most somatic cells dropping like flies with the lack of oxygen, cells contents can leak out and damage neighbouring cells.


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

[User] How do meteorologists calculate wind chill or feels like temperatures?

[Assistant]
There is actually a wind chill formula that is typically used (it's different depending on where in the world you are, there is no standard).

In the United States we have one

T= 35.74 + .6215(Ta) - 35.75 v^.16 + .4275 (Ta) v^.16

Where T is the final, (Ta) is the air temp (f), and v is the wind speed in mph.

Australia has a far more complex one, involving humidity as well as wind velocity and ambient temperature.

The American model only works under certain temperatures and in low humidity, the Australian one has a wider range.


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

[User] ELI5: Why do our bodies find certain positions comfortable at night.

[Assistant]
We get the urge to shift our sleeping position almost entirely to prevent blood from pooling. It is an innate thing.

People are bedridden and don't shift around, like those in a coma, can get bruising or even terrible ulcers if not cared for properly. These are bedsores. In the worst case scenario you can lose a limb to them.


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

[User] [Star Wars] Why didn't the Rebels fly directly to the weak exhaust point on the first Death Star rather than travelling to another location and then flying across the trench?

[Assistant]
The Death Star is a sphere, with many surface-to-air blaster embankments. The closer you are to the sphere's surface, the fewer of those can fire upon you.

Contrary to what many think, the Empire was well aware of the potential weakness that the exhaust port presented. But it was a necessary port, so their solution was to cluster many more blaster embankments in that area. So approaching that area would have meant flying through thousands of kilometers of full blaster spread if done directly - but coming in on a lighter-defended area and then taking the trench meant the Empire had to be more reliant on fighters for defense, which was the Rebels' only chance.


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

[User] Why do commercial airliners fly at the altitude they do (35,000')? Could they potentially save $ lowering their average altitude slightly?

[Assistant]
They fly at that altitude precisely *to* save money!

In very (very!) simple terms, denser air creates more drag on a plane, but it also provides more lift. The most efficient use of fuel is to go higher, as the drag is substantially reduced. However, there's a limit to how a plane can fly based on the reduction in lift as you go up.

To fly higher, you need either a lighter plane, one with bigger wings, or one that goes faster. An example of the first two is the U2 spy plane. An example of the second is the SR-71 blackbird.

Passenger planes can't be all that light, and faster = more fuel = more expensive to run. They can fly a bit higher, but 35,000' is a general sweet spot for efficiency for the 747 class. The 787, for example, has a 43,000' service ceiling, and will regularly fly at 38,000' or more. Smaller passenger planes often have ceilings capped at 30,000', and will regularly fly lower if they aren't flying as far. Once again, there's a balance between the high altitude drag reduction and the fuel needed to get up there. For long flights, it's very much worth flying as high as the plane can go.


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

[User]
[Skyrim] Bandit economy?

So, with all the war and general chaos going on, it's prime time to become a Bandit, Skyrim is filled with the bastards, some of them operating on what should be main roads. So they ambush travellers and merchants that travel the place, I get that much, but what do they do with the stuff they steal?

I mean, do they sell the valuable stuff on? Or do they just live out in the wilderness and enjoy being free men and women? Who deals with bandits if they do need to trade? Is there a secret bandit economy, like an underground black market kind of thing? Do the Thieves Guild have a place in that arrangement?

Just really want to understand how all the bandit clans work exactly, that's what interests me.

[Assistant] Most bandits have a fence available. Some unscrupulousn merchant that'll trade coin for slightly bloody goods. Or they simply travel to town for supplies infrequently and unless they left witnesses or trade noticeable items they're just another hunter/ sell sword in from the road to the townspeople.


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

[User]
ELI5: If I had more brain cells, would I be smarter?

Or is it something else in the brain that makes people smart?

I assume there is no way to "grow" more brain cells either, is there?

[Assistant]
Potentially smarter, yes. While the brain is very scarcely understood, it's fair enough to say that with better infrastructure, you'd be potentially more capable as a learner.

But if your personality (and other environmental factors) doesn't push you to learn new things, you obviously won't know much more than you do now. Well, why does how much you know matter? The question is how smart you will be, isn't it? The thing is: "smartness" is typically associated with how quickly you learn new information, and learning ability grows as you amass more knowledge of the same kind.
If by "smart", you just meant the base potentiality, then the amassed body of knowledge probably doesn't matter.

---

I don't think you can actually develop more grey matter significantly by any available means, but you can enhance the links between concepts in the theoretical neural network for quicker access to information in general.
ELI5 version of the previous sentence: Practice makes ~~perfect~~ better, even for thinking.

Future generations have the scifi-esque stem-cell manipulation, but there's little hope for us.


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

[User] ELI5: Why can't we treat deseases like depression with happiness hormones like dopamin?

[Assistant] Because too much dopamine causes psychosis (as seen in people who overdose on levodopa, a dopamine drug used to treat parkinsons). And giving people regular doses of dopamine have no beneficial effect on mood--as you must send the dopamine directly into the pleasure centers of the brain for it to work--and pills can't do that.


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

[User] ELI5: Why do bees die when they lose their stinger?

[Assistant]
The stinger of the most common bee species has a barb in the end, and the connection to the abdomen of the bee is physically weak enough that the bee is able to tear its exoskeleton/skin by crawling/pulling away.  The resulting wound damages the bee's internal organs and allows loss of vital fluids.

The advantage to this is two fold - the stinger retains enough body organs to continue injecting poison into the stung thing (thus teaching the lesson "mess with bee hives and you will regret it!") and the bee is (briefly) able to fly away, thus spreading the pheromones associated with dying through the local area.  This scent brings more angry bees (and more lessons) to the immediate area.

Wasps have a barbless stinger, as do queen bees, reflecting their relative worth to their groups.  (The queen is the mother of all bees in the hive, and wasps do not have a non-fertile gender as do bees, so the loss of a single wasp means the loss of that genetic line.)


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

[User]
ELI5: How do horse racing odds work and why can some work out to 3-5, where you can only lose money?

I was watching the Preakness and saw that the horse Nyquist, who had won the Kentucky Derby had odds of 3-5. This seemed to mean that betting $5 would net a payout of $3. If so, why would anyone bet on that horse, even if the previous victory means they are more likely to win?

[Assistant]
you almost have it correct, but you are forgetting an important part of the equation.  You always return the original bet.

So, with 3-5 odds, if you bet $5 to win, and the horse wins, you get back your original $5. Plus you get the $3 profit on the 3 for 5 part of the odds.

So on a $5 bet that wins, you get back $8 at 3-5 odds.

Of course, such small payouts are unusual because it means a horse is expected to be much the best, but as we saw today, any horse can lose... today the track was deep and the early speed pushing Nyquist was too fast and took it's toll... he tried his guts out but tired late.


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

[User]
Why does the US have a rule that no President can do more than two terms?

As an Aussie, I've always wondered.. If they are still liked after two terms and the public want them to continue doing a good job, why not let them?

[Assistant]
In most parts of the world, when there is a power transfer from one leader to another (or from one party to another), it's a risky time. There are often coups or power-grabs or even civil wars. In the U.S., the transition of power has always been peaceful (with the partial exception of Lincoln), and we really would like to keep it that way.

People in positions of power often find ways to hold onto that power (like forging relationships, crafting laws that favor them in subtle ways, or even just relying on the inertia of voters). This is why senators are and governors frequently keep their jobs until they retire or seek an even higher office. But as the public face of the country, the president's role is unique. Without a tradition or rule that limits presidents, it would probably be normal for presidents to remain in power for decades, often ending mid-term with the president's death or incapacity. This would make power transfers less common, more jarring, and more risky. By having a specific law (and before that, an honored tradition) of a 2-term limitation, everyone knows that a president can only do good or harm for eight years. It lowers the stakes, and lowers the turmoil, which is good for the stability of a democracy.


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

[User] Could there ever be a situation where a poisonous/toxic creature could be harmed/killed by its own poisons/toxins?

[Assistant] The first green plants appeared in a world were oxygen was toxic to all life. The geological record shows that green plants would periodically wipe themselves out if they were too successful and oxygenated the Sea water. One day a sufficiently mutated plant appeared that could survive it's own toxic oxygen, causing the first great extinction event on Earth.


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

[User]
[DC Comics] How would the Lasso of Truth affect someone with Alzheimer's?

Since Wonder Woman's Lasso of Truth forces a victim to truthfully answer a question (at least from what I recall), I'm wondering how would it affect someone with Alzheimer's which is known for giving people mild to severe memory loss thus they might not remember the truthful answer to a question.

[Assistant]
It's the lasso of truth not the lasso of Omniscience and Truth, you couldn't tie someone up and ask them what're tomorrow's lotto numbers are because they don't know it.

Most fictions do not define truth as platonic truth but rather what the person in question believes to be true.


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

[User]
[Star Wars] How come R2-D2 is so good at what he does compared to the other astromechs? Even compared to later models, he's still massively overpowered.

Also, is R2 sentient?  He seems to be able to make jokes, poke fun at people (especially 3PO), make decisions, defy orders, and most importantly, he is able to have friends.

Is he that good *because* he is sentient?

[Assistant]
Astromech droids are routinely reset, to have to perform as they're supposed to, not develop other traits, and do their job properly.

Anakin Skywalker was fond of R2-D2, so he never did that, so a form of sentience emerged, and you can clearly see why they wanted to prevent this, he frequently disobeys commands given to him. But he was also able to learn new things, add new experiences, and form a conciousness much better at problem-solving.

R2-D2 is probably a good-case scenario for an astromech going off programming.


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

[User]
[Futurama] So why is the sky in Universe B psychedelic?

Did God flip a coin to decide what to color the sky?
Did some industrialist flip a coin to decide whether or not he would become an environmentalist?

[Assistant] Theres a scene in the episode where they zoom in on the whole Earth. Only the skies above New New York are like that, so maybe someone there flipped a coin to decide whether to decorate the sky or not.


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

[User] ELI5: Why does the sound of poured water gets higher and higher as you keep pouring?

[Assistant] Because the sound you're hearing is sound coming out of a round chamber. When the glass fills with water, the size of the chamber changes, so the pitch changes. Large chamber, low pitch. Small chamber, high pitch. It's why digieridoos are deep and rumbly while ocarinas are high pitched and whiny.


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

[User]
Is it possible to "silence" a gun like they do in TV/movies?

I know a suppressed gun does not sound like most media make it sound. Would it actually be possible to suppress a gunshot to this extent? If so, what would be required?

[Assistant] Currently no. In fact, "silencer" is the less preferred term to "suppressor" because the device only lowers the report by at most 40ish decibels. The use of sub-sonic ammo helps to dampen the sound, but at the cost of bullet speed and accuracy. The most effective suppressors that achieve the most noise reduction to levels comparable to movies (but still much louder) are only good for a few shots. Wikipedia has a pretty comprehensive article on the construction and mechanics of suppressors.


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

[User] ELI5: what caused the Great Depression and how did it end?

[Assistant]
It all started with a big stock market collapse. Speculation had been rampant for years, and labor laws brought more and more money into the investor class. Consumer debt rose, and real spending decreased. Manufacturing jobs around the world started to vanish as people who had been buying on credit suddenly couldn't afford to buy, and with no one buying, no one could make or sell anything.

Congress sealed the world's fate shortly afterwards, announcing that with manufacturing jobs in decline, they would pass legislation to bring jobs back to America through a tariff. It did nothing to solve the causes of the depression - lack of consumer purchasing power, shrinking wages, and crippling debt. Instead, it created shortages in goods and parts and drove the country into the darkest years of the depression.

The Great Depression lasted until Roosevelt passed a series of laws called the New Deal. He took on massive government debt for public works and infrastructure projects, injecting cash back into the economy. He established a minimum wage to ensure that workers would always be able to afford to buy the things that they produced so that there wouldn't be a consumption crisis again. And, coincidentally, a war was fought in which many Americans died and major competitors were leveled.

The result was a well-paid American work force with access to industrial equipment unavailable anywhere else in the world. The policies of the New Deal spread, and economic recovery took place around the world.

There are some haunting familiarities to that tale, but be forewarned there are also some key differences to ours. For example, it's no longer possible to enforce a minimum wage without some level of protectionism - the people who make our goods cannot afford to buy them. Government debt is much higher than it was in the 20s, and it may destabilize those debts to take more. It's unclear as a result what we can do today about the great recession, even if hauntingly plausible that things are about to get a whole lot worse.


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

[User]
ELI5: What do the aperature numbers on the camera mean exactly?

I understand how the settings work. f/2,8 creates a big aperature and f/14 creates a small one.

What I don't understand is that the value's are exactly.

Given that a smaller number gives a larger result, I assume that it is a fraction. But what is it a fraction of?

[Assistant]
f/16 means one sixteenth, not sixteen. And f/4 is a quarter, not 4.

It uses the focal length of your lens to give you the width of your aperture opening.

So with a 200mm focal length, an f/4 aperture has a diameter of 50mm (i.e. a quarter of 200mm)


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

[User] ELi5: Is there a simple explanation as to why the numbers that govern our universe (pi, atomic weight, speed of light, gravitational constant etc) are not simple round numbers? Is this a function of our number system or something more complex?

[Assistant]
Pi is a constant that is determined purely by geometry. If you measure distances using the usual "shortest straight line" method in the plane, your circles will involve pi.

Numbers like the speed of light and gravitational constant depend on your choice of unit (they are not *dimensionless* constants). You can make them integers by choosing particular units, in the same way that you can make the 16.9 miles to a friend's house an integer by simply saying it's "1 friendistance".

Atomic weight is, for most elements, an average of the weights of several different isotopes. An average, at random proportions, is very unlikely to be an integer in the first place.


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

[User]
How do astronomers account for the mass from dark matter when calculating the mass of a star/planet?

From what I understand a common way of estimating a star/planet's mass is to observe is gravitational effects on other objects around it. How do astronomers distinguish this effect between the object being observed, and the gravitational effects from dark matter?

[Assistant]
The mass of dark matter on such a small scale is negligible. The density of dark matter in our part of the galaxy is 10^-2 solar masses per cubic parsec (10^-12 kg per cubic km), so all of the dark matter in the entire volume of the solar system within the orbit of Neptune only has the mass of a small asteroid. On the scale of a single planet it's even less important--there is roughly a kilogram of dark matter in the entire Earth.

It's only when you look at a much larger volume of space, for example an entire galaxy, that there's enough dark matter to matter.


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

[User] Why does the ISS point the same direction relative to the Earth at all times in its orbit? Wouldn't it be more energy efficient to NOT adjust its rotation/tilt/pitch/axis with reaction wheels?

[Assistant]
It doesn't consume any energy to rotate at a constant speed i.e. it only need to start rotating once, it doesn't need to keep the rotation up. For all things in space they will keep moving in the same way until some force is applied. If the space station rotates by one revolution per orbit it will have the same side against earth at all time.

 If we look at our moon it have the same side against the earth at all time without any reaction wheels changing its angular velocity.

Unfortunately some force will still need to be applied after the a while because the space close to earth (or anywhere in space for that matter) is not a perfect vacuum, but creating the angular momentum is quite marginal compared to the force needed to keep it in orbit.

Edit.
As corrected the orbital time is very much less than a earth-day so it has to be about one revolution per 90 minutes instead i. e. one revolution per orbit.


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

[User] ELI5: when using cellular data (3G,4G), are we essentialy using a modem with a huge range?

[Assistant]
A cell phone is just an advanced radio, and these radio signals have to be modulated before transmission and demodulated upon receipt.

Any communication being done through a cell phone will require both modulation and demodulation.

Their useful range is relatively low compared to lower radio frequencies.


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

[User]
How do lakes, ponds, and rivers, and even puddles retain water without it seeping away into the ground, as if I dug a hole and poured water into it?

I know how people make their own artificial lakes, but they need to put a tarp down to keep the water from draining away. How do rivers and such not have water seep away through the ground?

[Assistant]
All of these have water sources that refresh their losses. The ground under those things is already wet so it drains much slower.

When it starts to rain the ground usually eats up all of the rainfall at start, but after a while places can start flooding.


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

[User]
ELI5: How does epigenetics work?  How much can
your actions change the genes you pass on, and in
what way?

What's it all about? How much can your actions change the genes you pass on, and in what way? Can I use this to influence physical and/or mental capability of my offspring?

EDIT. For clarity.

[Assistant] Your genes are made of DNA. We think of DNA as a pretty static molecule, that never changes or varies once we've inherited it. As it would turn out, there are lots of chemical processes that can happen to the DNA (such as chemicals sticking to it and whatnot). These can happen at any moment in our lives and might have to do with our lifestyle. For example, having a high blood-sugar all your life might sway theses "DNA tweaks" a certain way. These changes are different for each cell, and can also happen in the copies of DNA that get passed on as we're discovering that it seems that sometimes these "DNA tweaks" can get passed on too! This means that we might be passing on effects of a certain lifestyle genetically to our kids. With their DNA pre-tweaked a certain way. It's hard to know how big the effect will be and in what way because we're still trying to understand the exact nature of these tweaks and there's also the nature vs nurture debate where we wonder if they'll have that much of an effect anyways.


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

[User] ELI5: How do "Mood Rings" work, and where did they come from?

[Assistant]
When the first discovered liquid crystals (the stuff that we now use for LCD displays) back in the 1970s, we weren't really able to do much with them.  The first application was to use them as thermometers.

A mood ring is just a ring that measures your body surface temperature.  There's no real meaning behind it but, back in the 70s, people were into all sorts of New Age bullshit and they became a major commercial success.


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

[User] [X-men] Why did wolverine lose to a hand to hand combat against mystic?

[Assistant]
Mystique\*

Wolverine isn't trained (or at least his training and experienced are muddled through all of the stuff happening with his brain). He primarily operates off of instinct and rage which can be exploited. Mystique clearly has training (or at least has the ability to fight like it) and her moves are controlled and calculated.


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

[User] [Star Wars]Why didn't Darth Vader just clone replacement body parts/limbs?

[Assistant] Cybernetic replacements have many advantages over organic ones. They don't degenerate with age, they're heat and pressure resistant, they're fully customizable, they have low risk of being rejected by the body, and it's very possible to make them into enhanced versions of what the limb used to be. That being said, Vader didn't have much choice in the matter. Although he was awake for the process, it was not by choice. Sidious made sure he was kept awake so that the pain would enrage him. Vader was delirious throughout most of it. By the time he was fully aware again, the procedure had already been finished and Vader had his prosthetics. By doing this, Sidious was able to make sure the prosthetics given to him were heavy and unwieldy, which made it difficult for Vader to ever attempt to overthrow Sidious.


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

[User]
[Star Trek] Which Starfleet captain has the highest enemy bodycount?

Of Kirk, Picard, Janeway, Sisqo, and Archer

Or anybody else that has taken the helm temporarily or permanently like Riker or Sulu.

[Assistant]
Confirmed kills would be Sisko. Being in the Dominion War, they took out entire fleets of ships and bombarded planets.

Unconfirmed kills would go to Janeway. She may have killed every Borg (we don't know at this point).


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

[User]
[Captain Planet] What if the Power of Heart was Replaced with the Power of Liver

The ability to make people intoxicated would have quite a bit of overlap with the empathy that Ma-Ti has, but it seems like captain planet would have been much cooler to hang out with.

[Assistant] The Power of Liver would be greatest asset the Planeteers could have. Think of the liver's main function: detoxification. With the power of liver, the Planeteers could break down pollutants that would take centuries or millennia to biodegrade on their own. Instead of getting weakened by pollution like a total lightweight, Captain Planet could metabolize it, bouncing back from a face full of toxic runoff with nothing but beer farts and a slight hangover. In the end, the Earth would be granted the liver's greatest power of all: the ability to heal and regenerate.


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

[User] Would it be possible to detect objects that are just outside the Observable Universe by the gravitational influence they would have on objects that are near the edge of the Observable Universe?

[Assistant]
Not in the way you are probably asking. Gravity and light travel at the same speed - if something can have a gravitational influence on something we see then we can also see it directly.

Caveat: The earliest light we see was emitted about 380,000 years after the big bang. All the light before was scattered around and didnt survive. This is different for gravitational waves. It could be possible to see the effect of gravitational waves emitted earlier and therefore at slightly larger distances.


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

[User]
ELI5: What are we smelling when it smells 'hot' or 'cold'?

For example, if a hair straightener is left on, you can smell it, but it smells 'hot', not like anything specific. Or sometimes if you go outside, it smells cold.

[Assistant] You're not smelling the heat, your smelling the heat's effects on the environment. That hair straightener singed some hairs and lofted some lovely burnt flesh scent into the air, you smell it and immediately know that there is a hot element around somewhere because your brain has made that association many times before.


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

[User] [Star Wars: A New Hope] "There goes another one." "Hold your fire, there's no life forms. It must have short-circuited." Wait, what? Another one? How many escape capsules were jettisoned from the Rebel corvette Tantive IV? What happened to the other ones?

[Assistant]
Once it was clear that the battle was lost and the Empire was going to take the *Tantive IV*, any rebel soldiers or officer near an escape capsule made an attempt to flee.

Despite Vader *specifically* ordering that capsules not be fired upon, in case the rebels attempted to flee with the plans to the Death Star in one, an over zealous officer instructed the gunners to shoot down these capsules in a blood lusted thirst for more destruction.

It was only when an unmanned capsule was detected that the officer finally lost interest and decided not to bother destroying this last one, although it did not save him from a damn good force choking when Vader found that he'd shot down a bunch already.


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

[User] ELI5: How come a circle is 360 degrees instead of an easier to calculate 100?

[Assistant]
Because 100 doesn't make it easier, it makes it harder.

360 has factors of 1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24, 30, 36, 40, 45, 60, 72, 90, 120, 180, and 360.

100 has factors of 1, 2, 4, 5, 10, 20, 25, 50, and 100

That makes 360 much easier to divide into fractions that end up being whole numbers.


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

[User]
ELI5: Why can't we have one currency for the whole world?

i get that it might be difficult at first and the change may take a while but would it be possible?

[Assistant]
Who decides how much of that currency is printed?

Some countries have rampant, terrible inflation.  If they share the same currency as their neighbors, both they and their neighbors have to keep up with the inflation.  If they have a *separate* currency from their neighbors; their inflation effects only themselves (and people that rely on them strongly).


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

[User] eli5 Why it's bad for country to default on it's debt?

[Assistant] It's bad for any entity to default on their debt. When you default suddenly you lose any trust that you're a reliable entity, and the terms of the future debts will be far less favorable and more difficult to obtain future debt. Generally it will be more expensive and have higher interest payments.


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

[User] Why couldn't a submarine sent to Titan tap into the methane seas for the energy to explore it endlessly?

[Assistant]
Energy is released when you combine methane with oxygen. There is plenty of methane, but no oxygen on titan.

Hydrigon is very flammable aswell, and its ultra abundant in the gas planets, but due to lack of oxygen its not a source of fuel.


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

[User] ELI5: Why does our body sometimes moves or shakes when We remember a cringy situation from the past?

[Assistant]
If the situation triggers a flight or flight response, the body's first impulse is movement.

A loud noise behind them will cause most people to start. This is your brain telling your body to fire up its muscles and get ready for whatever is about to happen.

Remembering a sufficiently unpleasant situation could trigger a similar flight or fight response, firing off muscles for the hardcoded classic danger response that nearly all mammals share.


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

[User]
[AtLA] If Koh stole my spirit's face, what would happen to my physical body?

Without a face, I can't breathe, so would I die while my faceless spirit runs around in the spirit world?

[Assistant]
Well, we know a couple things.

1) Koh is a spirit monster

2) You can still survive without a face in the avatar world.

We know the first one from the show, and the second from the comics.

However, we also know that Kuruks girlfriend was killed by Koh, so there seem to be multiple possibilities.

Koh could either steal your face and your soul, or he could steal your face and not your soul. So you come back to the normal world without a face, but are still somehow able to survive.


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

[User]
ELI5:If 1 burger takes 1300 gallons of fresh water to produce, how can I buy them for under $5.00?

I've been seeing a billboard in LA that reads: Save 1300 gallons of water. Dont flush your toilet for 6 months or dont take a shower for 3 months or For lunch today, dont eat 1 burger.

Even at 2 cents a gallon, it would cost $26.00 for the water alone - forget about shipping, packaging, workers that butcher cattle and then sell the product, overhead costs for the stores etc.

[Assistant]
Farms don't use treated city water, they use well water. They dig a big hole and bury a $2000 pump at the bottom and they have all the groundwater under their property for 30 years or so. It's vastly cheaper than the cleaned and fluoridated wonder-water we feed humans, because we really don't care if our cows have bad teeth.

There's a lot of controversy about cows and water, but it's important to remember that water doesn't travel all that well. Most places in the Americas have excess water, with great underground flows carrying rainwater out to sea. Farms in non-arid parts of the world do not change the level of the water table, and pose no environmental or water hazard. A cow raised outside Seattle can drink and drink and not make a lick of difference because there's just so much water that feed rather than water becomes the limiting agent on raising them there.

If you're concerned about California's water situation and think farmers are to blame, go ahead and boycott beef grown in southern states. That's probably an ecologically sound move. But Montana doesn't have a water crisis, and saving their water by not eating their beef isn't going to help anyone.


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

[User] ELI5: Why do science labs always so often use composition notebooks and not, for example, a spiral notebook?

[Assistant]
One of the primary rules for science labs and GLP (good laboratory practice) is to NOT destroy data.

If there's an error, you can't use an eraser, pencils are not allowed, white-out is not allowed; a correction must be made by crossing out the error (with a single line so that what was written is still visible), and then initialing and dating the correction.

Also part of "not destroying data" is that the official lab notebook has pages that are numbered (from factory), and the QA department and other auditors (FDA for example) will definitely question, and possibly invalidate the lab work performed or even close the lab, if there are pages that are missing.


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

[User]
Does a computer monitor consume energy at different levels depending on the color of the items being displayed?

Basically, I'm wondering if a monitor displaying bright, white colors most of the time will consume more energy than one displaying mostly dark colors. Assuming all else being equal, of course.

[Assistant]
To a first approximation, the answer is that it doesn't matter. Almost all modern computer monitors consist of a liquid-crystal display in front of a white backlight (either LED or fluorescent). Each pixel of the display has transparent electrodes on the front and back, and when an electric field is applied, the pixel changes from transparent to opaque. But very little current actually flows through the liquid crystal itself. Almost all of the power is consumed by the backlight, which is always on.

One major caveat: these days, some monitors have a dynamic contrast feature, which adjusts the brightness of the backlight based on the overall average brightness of the image. So with that feature turned on, a dark image would consume less power. (This isn't primarily motivated by power savings, though. The liquid crystal can't become 100% opaque, so if you try to display a dark image in front of a bright backlight, it looks kind of washed-out. Dimming the backlight improves the apparent contrast a bit.)

Higher-end OLED monitors work differently: instead of a backlight, they have a separate LED for each subpixel of the display. OLEDs have a much better contrast ratio, but they're more expensive to manufacture. On one of those monitors, displaying a pure-black image should consume virtually no power at all.


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

[User]
CMV: Military spouses and dependents should not be regarded as heroic as their military sponsor.

I keep hearing the same rhetoric, that just because someone is an immediate family member of someone who serves, that they are also owed a debt from our country(USA, but it may be true in other parts of the world.)
Although I know it has been changing a lot over the years, military spouses and dependents do not go through the physically grueling and emotionally challenging basic training that service members do.
They do not have to wrestle with the decision to join, and basically give up a predetermined portion of their life for something they may not want to do in a year, but have to keep doing it for 3 more under contractural obligation.
They do not have to risk their lives overseas fighting for a cause they do not understand or dont agree with.
I understand being in a military family can be stressful, but we should not regale the husbands and wives, or the sons and daughters of those who are actually fighting for their country.

[Assistant]
While you are correct that they don't do the things you listed, military spouses and families do make sacrifices that are worth noting. Military spouses basically become single parents for years at a time. Military families are often uprooted and have to move frequently because their military-serving spouse gets transferred. If their spouse is deployed, they live with the constant fear that they will at any moment receive the notice that their husband/wife is dead.

Yeah, these aren't the same as fighting in conflict, but they are certainly worth appreciating.


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

[User]
ELI5: Why and how does the seatbelt lock at certain points and not others?

I feel like I can't be the *only* person who has had the misfortune of attempting to bend forward slightly to retrieve something off of the floor just to be choked by a locked seatbelt. So, why does the seat belt lock then, but if you release tension and then lean forward again, it doesn't lock? What determines this pattern?

[Assistant] The speed at which you pull the belt. In its very simplest form the seatbelt is rolled up somewhere and that roll has some teeth that go outwards if it turns too fast and grab into locks/notches in the surrounding metal. If you pull normally, everything goes smooth, if you pull fast (like in a crash) it locks. Once you release the tension, the teeth snap back in and you can use it normally again.


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

[User] ELI5: Are humans the only animal that cries? If so, why?

[Assistant]
Most animals that are social have some behavior that indicates emotional or physical distress (such as your dog whining) but as far as we know the physical act of shedding tears for a purely emotional reason, and not due to irritation, appears to be a uniquely human way to express feeling a strong emotion. Chimps and other primates have vocalization and behaviors that let their group know they are experiencing distress, but they haven't  been shown to shed tears for a purely emotional reason.
Human tears serve a few purposes. The behavior (and noise) lets the people around you know you're in trouble and the actual tears help ease pain by releasing a natural painkiller called leucine enkephalin. However the jury is still out on how this natural coping mechanism evolved in humans uniquely.


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

[User]
ELI5: Why are completely unrelated issues (like abortion) able to be tacked on a bill about an unrelated issue like motor cycle safety to be voted on? Why is this legal?

I only give that this as an example as North Carolina is currently attempting. My issue is not what is be voted on exactly, but how two completely different things can be slapped onto the same bill?

[Assistant]
Its usually an attempt to either:

1.) get a controversial action (that probably wouldn't succeed on its own.) passed by the legislature and/or executive by attaching it to a high-profile bill that is likely to pass.  Since in many cases, removing a provision from a bill is next to impossible, there is a good chance the whole bill will be passed anyway.

2.)  Sabotage:   Attach a controversial amendment to a high-profile bill in hopes that the whole bill will be rejected because of the amendment.


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

[User]
[Star Wars] Why would the rebels fly across the surface of the Death Star, instead of straight at it?

I was just thinking, why would you approach the Death Star, and fly as close as possible to all the guns? Why not start your attack until you are diving straight down onto the exhaust port? It seems like it'd end up being much easier, and with much fewer casualties.

They way they did it would be the equivalent of a WW2 bomber flying 20ft above an entire fleet just to hit a destroyer on the far edge. Rather, they could dive-bomb in, hit the target, and pull up and out of range of enemy fire.

Also for that matter, why did the Death Star have trenches on it, lined with guns?

[Assistant] by flying directly at the DS, you allow all the weapons to be brought to bear on your ship. By flying down the trench, where the port was located anyway, the fighters are below the firing arcs of many of the guns, and only a few guns that happen to be in the trench are able to be brought to bear on the fighters.


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

[User] why do religions have similar stories and morals?

[Assistant]
There's a couple of reasons.

Some evolve from the same origins. For example, a lot of religions believe that there was a man called Moses and he was chosen by God. They followed his stories. Then a man called Jesus arrived and said he was the son of God. Some people didn't believe him, and they carried on as they were. Some people did, and Christianity was born. Then, out of those that were left, in around the year 600, a man called Mohammed arrived and said he was a prophet of God. Some people didn't believe him and carried on as they were (Jews). Some people did (Muslims and Islam). Christians and Muslims don't disagree about what happened before their chosen person arrived, they only disagree on what happened after.

Also, some new religions arrived in areas where there were already religions. And because these were more primitive times and not everybody could read and write, things weren't recorded but instead retold from memory and occasionally they got confused and their backstories combined.

In other cases, when a new religion arrived in a land where there was an old religion, it made sense to 'rewrite history' and include stories that the native population strongly believed in and them incorporate it into their own religion. So they adopted the old stories to get people believing.


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

[User]
ELI5: How come plants in AeroGarden don't get root-rot?

Hello,

In an AeroGarden, the roots to a plant are submerged in water pretty much 24/7 (unless you let your Garden run dry which is a no-no). Yet I've never had a plant get root-rot.

Yet when you over-water stuff in a plant-pot, the plants are very likely to suffer/die from root-rot. Why?

Thank you!

[Assistant]
The fungi that cause root rot thrive in high moisture, low oxygen environments. This is why overwatering causes issues; you remove the air pockets that are in normally watered soil.

Hydroponics consistently aerates the water. This removes the lack of oxygen issue associated with root rot. However, if the water isn't aerated, you can absolutely end up with root rot.


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

[User]
[STAR WARS] My six year old posed an interesting question...

So my boy says to me why doesn't Luke Skywalker just cut the death star in half with his Light Saber? Obviously not a feasible plot twist but it got me thinking would that be even possible, and if so how long would it take? Assuming no baddies to slow you down, suit to withstand the vacuum of space etc....

[Assistant]
The circumference of the Death Star is over 300km.  It took Qui-Gon about a minute to cut about a two meter length to a depth of one meter.  At that rate, working 18 hours a day, you could cut around the entire circumference in about 5 months.

Then you'd have to cut through all the interior walls, ducts, pipes, and cables on every level all the way down through 100km.  Might take a while.


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

[User]
[Star Wars] why did Luke throw is saber away after defeating his father in EP VI?

I mean, didn't Yoda warn him about the Emperor's powers? The force lightning? The general danger that comes from Sidious? And now don't tell me because he "wanted to resist the dark side" because i think trying to defend yourself is allowed as a Jedi...

[Assistant]
Well, Luke had already felt the growing conflict within his father.

The biggest reason was that he wanted to save his father, and he assumed that no circumstance where he killed the emperor would get him to that point, it would teeter Anakin back towards the Sith way of thinking, that vengeance and anger can be used to achieve positive goals.  It is what trapped him in the first place.

He put all his faith in his father saving him, and prepared himself to bear whatever the Emperor threw at him to get that to happen.


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

[User]
[Star Wars] My wife and I have tried for years to have a child and now he is 4 they want to take him away. Can't I just tell them no?

It not right. How do they know he will have a better life. We have a good home here. We live on Dantooine and they want to take him all they way to the core world.

[Assistant] You don't have to give your child to the Jedi, however raising a force sensitive child can be difficult. Weird things will happen around them. They might know things they shouldn't know, move things without touching them, be unnaturally good at certain things, etc. Raising your child will be a hassle. You won't know how to handle it, but the Jedi do. Your child will want for nothing and they will learn how to focus and use their power for the good of the Republic and the galaxy. The Jedi know what they're doing, maybe you should trust them, maybe consider adoption.


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

[User] ELI5: If Gandalf knew Bilbo has the ring, why did he let him keep it?

[Assistant] He didn't know it was The One Ring - it was thought to be destroyed. In The Hobbit the ring was nothing special (other than the invisibility), and in the Lord of the Rings books it took Gandalf 17 years from Bilbo's farewell party to discover that it was in fact Sauron's ring.


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

[User]
How dense are asteroid fields and would they pose a problem flying through?

I was watching StarWars episode V and was curious if asteroid fields were seriously that dense? Also am I right in assuming most of the asteroids should be moving in the same direction?

[Assistant] No danger, at least not for an asteroid belt such as the one in our solar system. The average separation between asteroids is approximately 16 times the distance between Earth and the moon. If you  were on a random asteroid,chances are you could not see another asteroid without a telescope.


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

[User]
[Final Fantasy and Kingdom Hearts] Why is Cloud the only person who can defeat Sephiroth?

Sephiroth states in Kingdom Hearts II that "But apparently, Cloud is the only one who can eliminate me." He shrugs off a beating that Sora gave him with no apparent physical damage.

Is Sephiroth that skilled that the only other person of his caliber is Cloud, or is there something else involved?

And does this also apply for the source material (Final Fantasy?)

[Assistant]
Cloud and Sephiroth in Kingdom Hearts have a somewhat more nuanced connection than they do in Final Fantasy VII.  Cloud often refers to Sephiroth as an embodiment of his own darkness, and he has a demonic wing on one shoulder to parallel Sephiroth's angel wing.  So while we don't know their specific origin, we do know that they're intimately connected and that, maybe, Sephiroth's life is tied to Cloud's in such a way that even a Keyblade can't take him down.

In Final Fantasy, while Sephiroth and Cloud are connected through the Jenova cells that they share, there's nothing else special that binds them together; in fact there are dozens of people throughout the story who also have those cells inside of them, though none are able to survive and fight their influence to the degree that Cloud does (besides Zack).  Anyone could take down Sephiroth, in theory, though Cloud and his friends are the only ones with the power and plan to take down Sephiroth in the end.


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

[User]
How does the brain isolate a sound when we focus on it?

Say you were sitting in the car listening to music and someone is talking to you. We can choose to focus on the music the person or say the engine of the car, but how does the brain isolate the sound we want to hear rather than it just all seeming like one big noise?

[Assistant] The auditory cortex amplifies the signal your consciousness (prefrontal cortex) directs it to focus on, and dampens the rest if it can. If the undesired noise is too loud and overwhelming, you can't filter it out and thus can't concentrate or even hear the noise you want to.


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

[User] [medicine] how come you can't just cut off a wart?

[Assistant] HPV causes warts by infecting the cells of stratum basale (Basal layer) of epidermis which is the very bottom layer of skin at the epidermal dermal junction. These basal cells are stem cells that continuously divide and form new keratinocytes (Skin cells) that migrate upwards as new cells are continuously created. When you cut off a wart, you are generally only getting rid of the upper cell layer (Stratum corneum) which consists of dead cells filled with keratin. But the HPV infected basal cells are still intact and are still actively causing epithelial hyperplasia (Increase in the number of cells).


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

[User]
[Marve] Can Mystical beings chose not to lend their power to sorcerers when they phrase their names?

You know Sorcerer in Marvel tend to Phrase the name of Mystical being when they want to borrow those entity powers. However, can the entity chose not to let the sorcerer borrow their power?

Do those entities even aware when people are borrowing their power?

[Assistant]
I think thats what a pact is for.

You make a deal with an entity to use their powers, they agree with terms and conditions, you get to invoke their name and tap into their power briefly.

Its not like they get a notification every time Strange tries to invokes someone.

They will however more often than not keep tabs on each other and keep tabs on how their power is being used.

Death might be like hey "Vy'th'oo'ik you know that dude in sector 12 dimension 77812-A has been killing a lot of kids with the juice you gave him"


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

[User]
ELI5: What exactly is an Arduino and how does it work?

Also, why is it used in what seems to be 90% of home-made electronics projects?

[Assistant]
Okay... like you're five..

An Arduino is a small device called a micro-controller that is like a very small computer that allows programs to talk to and control other devices that do things like move stuff or measure things. Examples of things it could control: Motors, Levers, Lights, Speakers. It can talk to other things too, like: sensors such as thermometers, light meters, cameras and so on. The programs that do the thinking for the Arduino are created on a personal computer, and then generally stored on memory attached to the Arduino. If you want to make a program physically move something or interact with something, chances are you want to use a micro-controller like the Arduino.

You could use an Arduino to make a small robot like a car. Or you could use it to make a spy sensor for your bedroom door. Or if you really wanted to get crazy you could make a robotic nerf gun turret to shoot your sister when she gets into your stuff.

EDIT: tchebb is correct, Arduinos have onboard memory, and don't use memory cards.


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

[User]
Can all mathematical operations be chalked up as complex systems of addition operations?

Is there a known proof for or against this assertion?

Or more broadly:  What does operator theory say about the uniqueness or the necessary and sufficient condition of operators?

[Assistant]
No!

As an example of a valid mathematical operation that can't be chalked up as a complex system of addition consider the operation the takes a number between 1 and 26 and returns the letter whose place in the alphabet corresponds to that number.

As another example. Consider the operation that take an positive integer and returns the first letter of the integers name. (operating on 2 returns t). Both of these are perfectly valid mathematical operations than can't be chalked up as some complex system of addition.


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

[User] ELI5: What is the difference between mixing and mastering a song?

[Assistant]
The most basic explanation is mixing is making adjustments to the individual tracks/instruments so that they mesh together best (adjusting volume of tracks against each other, adjusting eqs or the panning of certain tracks.)

Mastering is adding whatever final touches/effects to the track as whole once the individual tracks have been mixed together. This could be making the track fade out, adjusting the overall eq, or adding reverb to the entire track.


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

[User] What stops Sauron from creating a new Ring of Power?

[Assistant] According to Gandalf in the RotK:  "If it is destroyed, then he will fall, and his fall will be so low that none can foresee his arising ever again. For he will lose the best part of the strength that was native to him in his beginning, and all that was made or begun with that power will crumble, and he will be maimed for ever, becoming a mere spirit of malice that gnaws itself in the shadows, but cannot again grow or take shape. And so a great evil of this world will be removed."


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

[User] ELI5: Why can doctors reattach the nerves in limbs but they cannot reattach a broken spinal cord?

[Assistant]
Simply because there are way too many nerves to connect in a spinal cord and it is difficult to see which nerve connects wo which. 31 nerve pairs, all compacted in the space of a few centimeters, compared to 10, all spaced out, there is no margin for error, so doctors leave nerve connections.

Take it like this. You're friend is holding 20 sticks and you can only see the middle, not the ends. Your friend then breaks all 20 sticks and, without looking at the ends, you have to connect them all together again. It's time consuming, hard and expensive.


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

[User]
[Superman] [DCAU] How strong is DCAU Superman?

Everyone says hes the weakest version of him out there. I agree to an extent. But this feat I just realized may make him stronger than most people think.

He knocked Grodd who looked around 500 pounds halfway across a football field (they looked like they were towards the end of it, but to be fair, Im gonna say they were at the very center of the football field).

Now bare in mind, athletes need to throw with all their might to throw a ball halfway across a field. But Superman did it with his finger like he flicked a booger.

Also, i dont mean to be gross or anything but even a flick of a booger couldnt make it halfway across a football field. I dare someone to do an experiment where you take a tiny piece of toilet paper and roll it up in a ball and see how far you can flick that. For me, its only a few feet.

If 500 pounds is to Superman is the weight of a piece of toilet paper. THATS impressive. But its WAY LESS than a piece of toilet paper! That means his flick of a finger is DOZENS times more stronger than an average human could to a tiny piece of toilet paper to a 500 pound gorilla!

Im not that good at math, but Im curious how strong exactly that would be? And whatever the answer is, multiply that with how much more times stronger someones punch is to a flick of a finger. Its probably at least 100 times stronger. So I dont even WANNA know how strong his punch is then!

[Assistant]
In JLU's finale Supes talks about how he can finaly let loose against someone like Darkseid, who weighs in at 1815lbs (823kg), and one punch sends him flying 20 or 30 blocks.

Mind you, Darkseid is an actual god and is quite literally built different, so that's worth considering.


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

[User]
What exactly is the Weak Nuclear Force?

What does it act on?  I have tried to get an explanation for nearly a decade, but all I've been able to glean is that it's responsible for beta decay.

[Assistant]
I find it misleading to call it a force. The word "interaction" is much better. To me, "Force" gives me the impression that you can draw little vectors on particles or something, which is definitely not possible with the weak force. It doesn't attract or repel things. It just interacts.

For the rest, see Elektrophorus's explanation.


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

[User]
[MCU] The Ancient One stated that the infinity stones needed to be returned to their respective timelines ASAP. But not doing so would only (potentially) doom other timelines; would it really be a concern for the main timeline?

From a moral standpoint, of course the Avengers don't want to potentially doom other timelines.

But if they didn't return the stones, would it really be that bad? The "main" timeline should be fine, right?

[Assistant]
It wouldn't be a problem until people from the timelines that fell apart started coming, heroes looking to save their crumbling universe and villains looking for revenge.

You'd end up creating at least four doomed universes full of people who have a lot of reasons to come looking for you. In some cases, alternate versions of yourself.


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

[User] [Marvel] What would have happened if Bruce Banner found the gem of Cyttorak after becoming the Hulk instead of Can Marko?

[Assistant]
The Hulk would receive the powers of the Juggernaut, the Avatar of Cyttorak's power on Earth. The same thing that would happen if Tony Stark, Clark Kent, or you had found it.

The most interesting thing here is the question of whether or not the Gem would differentiate between the Hulk/Banner. The answer to which is a resounding... maybe.


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

[User]
Two questions about black holes (quantum entanglement and anti-matter)

Question 1:

So if we have two entangled particles, could we send one into a black hole and receive any sort of information from it through the other?  Or would the particle that falls in, because it can't be observed/measured anymore due to the fact that past the event horizon (no EMR can escape), basically make the system inert?  Or is there some other principle I'm not getting?

I can't seem to figure this out, because, on the one hand, I have read that irrespective of distance, an effect on one particle immediately affects the other (but how can this be if NOTHING goes faster than the speed of light?  =_=).  But I also have been told that observation is critical in this regard (i.e. Schrdinger's cat).  Can anyone please explain this to me?

Question 2

So this one probably sounds a little "Star Trekky," but lets just say we have a supernova remnant who's mass is just above the point at which neutron degeneracy pressure (and quark degeneracy pressure, if it really exists) is unable to keep it from collapsing further.  After it falls within its Schwartzchild Radius, thus becoming a black hole, does it IMMEDIATELY collapse into a singularity, thus being infinitely dense, or does that take a bit of time?  <===Important for my actual question.

Either way, lets say we are able to not only create, but stabilize a fairly large amount of antimatter.  If we were to send this antimatter into the black hole, uncontained (so as to not touch any matter that constitutes some sort of containment device when it encounters the black hole's tidal/spaghettification forces [also assuming that there is no matter accreting for the antimatter to come into contact with), would the antimatter annihilate with the matter at the center of the black hole, and what would happen?

If the matter and antimatter annihilate, and enough mass is lost, would it "collapse" the black hole?  If the matter is contained within a singularity (thus, being infinitely dense), does the Schwartzchild Radius become unquantifiable unless every single particle with mass is annihilated?

[Assistant]
So, for your first question: as people have mentioned, quantum entanglement does not transfer information- and is probably not what you might think it is. Science writers, when covering this concept, have greatly oversold what the entanglement means. The classic example is a particle that decays into two particles. Say the parent particle had no angular momentum (zero spin, in the quantum world). By conservation of momentum we know the two child particles must have a total of zero angular momentum, so they must either both have no angular momentum (boring for this discussion) or opposite angular momentum (spin up and spin down in quantum mechanics). Quantum entanglement simply is a discussion of the fact that if we know the angular momentum of the first particle, we then know the angular momentum of the second. The cool part of quantum entanglement is that until one is measured, neither particle has "chosen" yet and until one is measured, either particle could be measured to have spin up or spin down (aka- it isn't just that we don't know which one is which until we measured, but that it hasn't happened until we measured). That's really it. It is cool, but the science writers who claim quantum entanglement will allow new types of measuring tools are doing a great disservice.

Now for the second question. First, matter does not exist inside of a black hole. A black hole is a true singularity, it is mass, but without matter. Any matter that falls into a black hole loses all of it's "matter characteristics." Now, conservation laws still remain- mass, charge, angular momentum, energy, etc are still conserved, but there is no "conservation of matter" only a conservation of mass law.

However, even if a black hole still had matter in it which could react with anti-matter, it wouldn't matter. We think of mass of being what causes gravity- but it is really a different quantity called the stress-energy tensor. For almost all "day to day" activities, the stress-energy tensor is analogous to mass, but in your case- it really isn't. The stress-energy tensor, as the name implies, is also dependent on energy. And while normally you never notice- in a large matter/anti-matter reaction, you'd have to take it into account. In fact, when matter and anti-matter react, the value of the stress-energy tensor is the same before and after the reaction. Normally, the energy spreads out, at the speed of light, so that "mass" is spread out really quickly as well, and thus you don't notice the effects. But in a black hole, that energy cannot escape, so all of that "mass" is retained.

The confusion comes from people mis-teaching the interpretation of E = mc^2 . This is a long discussion, but in summary, E=mc^2 doesn't mean "mass can be converted into energy" but that "energy adds to the apparent mass of the object." You probably first heard of E = mc^2 when talking about nuclear reactions, say a nuclear bomb. And it is said "some of the mass is converted into energy, and then boom!" But really, it is better to say "in a nuclear reaction, mass is carried away from the bomb by the energy." So, for instance, put a nuclear bomb inside a strong, mirrored box, put it on a scale, and blow it up. The scale will read the same before and after the explosion. Then, open up that box, allow the heat and light to escape- and at that point you will notice the scale go down.


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

[User] [Star Trek] Why don't the Klingons consider their cloaking devices cowardly and dishonorable?

[Assistant]
Any hunter will know that camouflage, hiding from, and stalking your prey is part of the hunt. A warrior knows that subterfuge and stealth are the hallmarks of the greatest combatants. Only the brash young fools charge headlong into every battle. Some of them survive long enough to become wise to tactics.

A Klingon grows to learn that there is a difference between dishonor and stupidity.


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

[User]
[Every Action Film Ever] Are these heroes all psychopaths?

I understand that sometimes people get killed, especially when they are bad guys. But damn- whats with all the witty lines said to what are now corpses after these fights? Seems like these heroes really love killing.

[Assistant]
To quote Dr. Perry Cox:

> You see Dr. Wen in there? Hes explaining to that family that something went wrong and that the patient died. Hes gonna tell them what happened, hes gonna say hes sorry, and then hes going back to work. You think anybody else in that room is going back to work today? That is why we distance ourselves, thats why we make jokes. We dont do it because its fun  we do it so we can get byand sometimes because its fun. But mostly its the getting by thing.

Talking smack in the face of danger is often a stress reaction, an attempt to manage the strain on the mind. People who *can't* cope in some way tend not to perform well in high-stress situations. If the hero loved killing, they wouldn't crack wise to take their mind off it; they'd just reload with a smile on their face (compare John McClane from Die Hard trying to keep his shit together in Nakatomi Plaza versus Zenia Onatopp from GoldenEye doing literally *nothing* to conceal how much satisfaction she gets from gunning down computer techs and strangling people).


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

[User]
ELI5: Why in 2014 is the ocean still such a mystery. We overcame obstacles to space travel 50+ years ago but can't figure out water.

I understand water pressure. I just wondered if there were any explanations as to why more money and effort hasn't been put into this over the years, or has it?

Edit: Thank you for your answers, and yes I am well aware that space is infinite and we have barely cracked the surface.  But just imagine if the "space race" never occurred and all the time/money/resources put into getting a man into space was spent on exploration of Earth's oceans.

[Assistant]
We actually can do some pretty cool things in water.  We get oil from miles below a surface that is miles below the waves, we explore at tremendous depths, and we lay cables that stretch the length of the oceans.

It's true that there's still a lot left to do, and we certainly could do a lot more.  But the reason we seem to be behind compared to space has less to do with pressure than with light (or electromagnetic waves more generally).

The reason we know so much about space is that we can see really far, and what we see contains a lot of information in the form of light spectrums, positions, speeds, etc...  Also, most of the things we look at are really big, and stand out clearly from the background.

Water, on the other hand, blocks all of that.  It scatters light, scatters heat, and makes info gathering a much more personal and in your face endeavour.


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

[User]
ELI5: How do oil rigs work?

And are they stationary platforms or do they move around?

[Assistant]
There are various kinds of oil rigs. It is important to position the drill rig, the drilling machinery over the hole it is drilling.

A common practice is to build the oil platform somewhere, tow it to the drilling location, then anchor it by lowering the platforms legs to the bottom of the sea.

Alternatively the rig can be positioned precisely using several propellers powered by engines to keep it exactly in place.

Drilling rigs are built so that they can be reused elsewhere.

The legs do not actually sink down to rock which might be miles down. They generally sink into mod deeply enough to be good anchors for the platform.

New Orleans bridges are built with their foundation sunk into mud. The amount required to keep the bridge floating is calculated. The foundations have that much floatation. The bridges can rise and fall.


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

[User]
[Harry Potter] - Are the spoken incantations universal or do all countries and languages have their own versions of the same spells, said with different words?

I'm thinking about Ron and Hermonie's exchange with regards to the spell; "Wingardium Leviosa".  During that scene (and in the book) Hermonie is trying to teach Ron how to properly say the "leviosa" part of the spell.

So it got me into thinking about a Japanese student trying to speak these same words in their own school, "Mahoutokoro".  It's pretty established that "l's" and "r's" are difficult sounds to make if you're not a native speaker of the English language.  So are they working on saying Leviosa properly there, or have they created their own levitation spell, to be spoke in Japanese?

it was a pretty reoccurring theme in HPGoF that Fluer's accent was very thick in how she spoke throughout the book (ie: " What do I care how 'e looks? I am good-looking enough for both of us, I theenk! All these scars show is zat my husband is brave!") How well did the French Students perform at Hogwarts with their heavy French accents?

[Assistant]
AFAIK, different cultures have different focuses on types of magic. For example, Native Americans were much more specialized potionmakers than European wizards. They also practiced wandless magic.

I don't think Rowling has yet shed light on the question of whether spells can do the same thing in different languages, but I'd presume they can - namely for the reason that adept wizards can cast spells without saying them. Learning the words is important for beginner wizards because it helps them to focus on the idea of the spell and conceptualize it. To me, that makes it seem as though spells are more like ideas that wizards have put words to - ideas which a wizard in Asia or South America or so on could have conceived using a different language.


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

[User] ELI5: How do we have the equipment to picture and see cosmos and stars millions of light years away, but cant just zoom-in to examine and view the surfaces of our interplanetary planets in the solar system?

[Assistant]
There's a limit to how far you can "zoom in" on something to picture it. The maximum resolution is restricted by the wavelength of light used to capture the image. You can compensate by using a larger lens, but even the largest telescopes in the world aren't anywhere near being large enough to have anything close to high-resolution photographs.

This question comes up when people ask why we can't use a telescope to see the flag on the moon which is significantly closer than the planets but still very far away. Turns out just to identify that, you would need a telescope with a lens miles in diameter. If you want to look closely at planets, the lens would need to be larger than the diameter of Earth.

Now there are some neat tricks astronomers can use. Not too long ago, astronomers managed to take a picture of a black hole. The resolution to make this picture indeed would require a lens about the size of Earth, making it seem impossible at first. But what they did is synchronize a bunch of telescopes from all over the world then stitch the resulting data back together in software. Thus they were able to create a picture with sufficient resolution to identify what they were looking at. A similar technique could be used for getting some better precision for imaging other things as well, but it takes a lot of coordination and resources, and while it improves resolution, it still wouldn't compare to sending over a probe with cameras to take pictures at a closer proximity.


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

[User]
[Star Wars Prequels] Why didn't the Gungans get a Gungan senator?

My understanding is that Naboo has only one senator (Palpatine), who is human. Yet when they pan across the Senate in the movies, it's basically one race/delegation. You don't see a bunch of delegations run by human ?colonists. What makes Naboo different?

[Assistant] Senators don't represent single groups of people from single planets, they represent entire sectors. The Gungans are technically already represented by the Senator for the Chommell Sector, which Naboo is the capital of.


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

[User]
Why do some fruits grow in 'slices'?

For example, the clementine or the orange, they come in slices that each have a sort of skin separating them from other slices. Why do these and many other fruits grow like this?

[Assistant] Fruits develop from the female part of a flower called an ovary (like the ovary in animals, but only by analogy). Each ovary contains one or more smaller structures inside it called ovules that will develop into the seeds, while the ovary itself becomes the fruit. A lot of fruits are actually made from several ovaries fused together and even when they're mature fruits you can still see the separate ovaries. This includes the citrus fruits you mentioned where each section matures from a separate ovary. You can also see separate ovaries in apples, tomatoes, melons, cucumbers, bananas, and lots of other fruits if you cut them the right way, though they're not quite as distinct as in citrus fruits.


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

[User] ELI5:Why do some small electronics such as a router have a bulky adapter plug, but a large appliance such as a vacuum cleaner have a regular plug?

[Assistant]
Your small electronic devices all need low voltage DC power, they generally run off 24V or less so they need a power supply that can take the 120V or 230V AC power from the wall and convert it into the 5/12/24V DC that the device needs.  This can be done with a wall wart(big plug on the wall), a power brick in the middle of the power cord, or inside the device.

If you want to make a small device then you want to move the bulky power supply to a power brick or a wall wart so it doesn't bulk up your primary device.

Your vacuum just runs straight off the AC.  AC runs into the motor, AC runs to the secondary motors, everything runs directly off of power provided from the wall.  Even for bigger things like a stove which may have a display, they're large enough that fitting a small power supply inside the device isn't going to require a larger device.


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

[User]
How do T-cells know which cells they've already inspected?

From what I understand, T-cells are constantly traveling in the body, inspecting cells by looking for antigens. If they're self antigens, then the T-cell doesn't attack, whereas if they're non-self, they attack. My question is how does a T-cell know when it just inspected a cell? Does the T-cell leave something behind on the cell to mark it as checked or does the cell itself present something on its surface to indicate that it has just been checked? If there is no such system, then what prevents the T-cells from being stuck in a loop, and just inspecting the same cell over and over?

[Assistant] It doesn't know.  And it doesn't loop because it's not like the T-cell specifically waits until the current cell under investigation has "passed inspection" before moving on.  The T-cell just moves around, continuously coming into contact with other cells in the neighboring environment, and if it happens to brush shoulders with bad antigens then it triggers an attack.  But if no attack is triggered, it'll just keep on happily moving about.  The key is that the time it takes to trigger an attack is much less than the time it takes a T-cell to "move over" any given cell.


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

[User]
[Batman] What sort of precautions does Bruce Wayne have against someone trying to kill him while he's asleep?

I've read various things like how he only needs 3hrs sleep, something about micronaps or whatever. But even then, what if someone who knows Batman is Bruce Wayne plans to murder him in his sleep, carefully planning out when to strike. Who is to wake up Bruce if someone was standing over him with a knife or gun?

[Assistant]
Well, firstly if he's sleeping in Wayne Manor there's all sorts of anti-intrusion measures and alarms built into that place to hopefully detect someone long before they could reach his bed. It is possible to get around them if you're exceptionally skilled (pretty sure Cassandra Cain's done it, and a couple of others from the batclan. Ra's Al Ghul has. Deathstroke and others of his level could).

But if they do get through his security without being detected, Bruce is as much meditating as he is sleeping, so he's not so deeply unconscious that he couldn't hear or otherwise detect someone coming up on him. The intruder would have to be very skilled and lucky to hit him without waking him. Honestly, they'd probably have a better chance if they just sent a missile at the house (although Bruce probably has some sort of emergency defense for that built into his bed too).