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We make our world significant by the courage of our questions and by the depth of our answers. -Carl Sagan, Cosmos


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Why are there multiple species of various life forms, but humans only have one? Are there other complex single-species organisms?

17:57 UTC


Is NaCl relatively common in the galaxy/universe?

Seems like almost all instances of water in the galaxy, it is likely salt water but I really ask because I came across this article:


that's a lot of salt, yes?

18:13 UTC


How does an ideal vacuum have a dielectric breakdown voltage of 10^12 MV/m? If there is nothing there, then how can electricity pass through it?

My question is more about why than how. I understand that electro-magnetism can transfer energy through a vacuum.

12:23 UTC


Are there any extant nonmarine carnivorous flightless birds?

I ask because I know that most extant birds (either flying or flightless) are omnivores.

I also know that the only two extant birds species that are obligate herbivores are the unique hoatzin and the strange kakapo, one is a poor flyer, the other is really flightless, but a great climber.

Formerly, there were nonmarine carnivorous flightless birds such as phorusrhacids (or terror birds, if you want), and the mysterious Jamaican caracara (these two examples are both australavians like the kakapo, but the former is related to seriamas, and the latter was technically the world's only flightless species from the order Falconiformes). Since they are all dead, the only living carnivorous birds are the famous penguins, and the critically endangered flightless cormorant. Both penguins and cormorants are marine obligate carnivores.

However, I think there still could be an extant nonmarine carnivorous flightless bird: the kagu (this species is exclusively found in New-Caledonia, which is part of the Fifth French Republic).

22:16 UTC


Do butterflies have any memory of being a caterpillar or are they effectively new animals?

15:26 UTC


Does drinking too much water put strain on the kidneys?

I understand that drinking a large amount of water in a short amount of time can potentially lead to other issues caused by upsetting the balance of electrolytes in our body.

I'm more curious about the long term effects on our kidneys when drinking large amounts of water throughout the day. I'm assuming this results in our kidneys having to work harder than usual, so that makes me wonder how that impacts their long term health.

05:10 UTC


During Electrolysis of Water, what happens to oxygen at the cathode and hydrogen at the anode?

Since you're splitting water you get both, but i'd imagine they be split at the same place. I don't mean "why is h2 at the cathode and o2 at the anode", I mean, the water molecule is split somewhere, and then the oxygen and hydrogen just... travel to the place where there be their charge? Are the water molecules split between the anode and cathode and just travel up at them? If they travel to the opposite end, why don't we see bubbles anywhere but the electrodes?

07:15 UTC


Is there a limit to the number of sounds you can hear simultaneously?

I was watching a YouTube on how 8K TV's are basically a waste because we can't see that level of detail. Is there a similar limitation for audio?

12:07 UTC


Is there some meteorological phenomenon produced by cities that steer tornadoes away?

Tornadoes are devastating and they flatten entire towns. But I don't recall them flattening entire cities.

Is there something about heat production in the massed area? Is it that there is wind disturbance by skyscrapers? Could pollution actually be saving cities from the wind? Is there some weather thing nudging tornadoes away from major cities?

I don't know anything about the actual science of meteorology, so I hope if there is answer, it isn't too complicated.

13:17 UTC


Rebound COVID after paxlovid. What do we know? What are the guidelines?

Does having rebound COVID make it more likely to end up with long COVID?

Does it tend to be worse then the first case?

Is the viral load the same?

1 Comment
21:02 UTC


In a double blind study, who knows which person gets what?

Specifically who is in charge of this? Is it a government organization, non-profit, business...

If so, can you give me a specific name?

08:45 UTC


Is there a quantifiable benefit to cooking food?

I believe there is a quality benefit in that I'm told that cooking many foods makes them easier to digest (how much easier?) and I'm aware that it is safer, meat in particular, to subject foods to enough heat to kill harmful bacteria.

What I'm interested in is whether there is a nutritional benefit. It seems plausible that cooking could actually harm nutrients, but is there a nutritional benefit that makes up for this?

Follow-up if nutrtion profile does not change: If I have the nutritional data for a food by weight, and I cook the food, it will have less weight. Will the resulting food have the same nutrition as the uncooked food I start with (is the weight loss only water?)

I started thinking about this while being pitched a raw food diet for my dog. The premise doesn't make sense to me for the same reason that dog owners who feed their dogs raw meet likely aren't eating raw meat themselves, but the claim is that it has a health benefit for the dog and I have no knowledge of that but am thinking that if it does, surely it would apply to humans as well.

Apologies if I have the wrong flair or have asked in the wrong forum. Seems like a biology question fundamentally.

17:24 UTC


When and Where did Tigers/Lions from 2.5 - 5 MYRs evolve at?

Every time I try to research about lions, tigers, leopards and other big cats, I get so many conflicting answers about where they came from and which species was there first.

For example: I have read that Cheetahs, Lions, leopards originated in Africa 3-4 million years ago, and after migrating to Asia, tigers evolved from leopards and only continued to migrate northeast and north west and never went to Africa.

However, elsewhere I have read that tigers evolved first slightly over 2 million years ago from snow leopards, and lions and cheetahs did not evolve until after that in Africa, eventually having lions come to Asia.

There are even more conflicting theories with dates differing in the millions, does anybody have a source that can answer this question with more accurate and research information?

TLDR; What continent and time period did big cats originate, who came first to earth, tiger or Lion?

Thank you!

18:46 UTC


Does a pool cover need to touch the water in order to reduce evaporation?

Does a pool cover need to be laying on top of the water (touching the water) in order to help reduce evaporation? or would a pool cover that's stretch across the top of a pool (roughly 2 inches above the surface of the water) reduce evaporation by the same amount?

I'm thinking that a pool cover that comes in contact with the surface of the water would reduce evaporation by a larger amount because the water isn't exposed to the atmosphere.

But I'm curious what the science says?

20:56 UTC


Do most animals have to worry about complications from cannibalization?

So I'm aware that, most notably, humans and cows suffer quite a debilitating condition if they partake in cannibalism, as Kuru and mad cow disease from prion infection.

But, I do see many other animals ranging from mammals, birds, and arthropods engage in cannibalism, even eating their own offspring. Are they also exposed to risks like prion diseases?

And, what exactly is the "norm"? Is it more common to not be affected?

Edit: Thank you all for the responses. I believe I misspoke when I brought up Kuru and MCD, as I was just trying to find a more... tangible disease than just "the jitters" that I'm familiar with. Most of the videos I've watched on the subject seemed to imply that cannibalism in any capacity will eventually cause some sort of extremely debilitating disease/condition, and was not aware how specific those two examples actually were.

That said, I am still quite confused on the actual chain of events when cannibalism occurs (without prior infection like Kuru and MCD), for species that are affected negatively.

21:54 UTC


Why not increase a capacitor’s energy density by increasing the voltage?

Dielectric breakdown is an issue but there are materials (diamond, Teflon, ultra-high vacuum) that only break down at absurdly high voltages.

If you want the most bang for your buck (both volume and mass wise) why not step up the voltage a capacitor charges at super duper high? Then the energy of the capacitor is proportional to the volume * permittivity * dielectric strength ^2. Why not have a centimeter of diamond between two plates with a potential difference of a million or so volts? That’s good energy density right there. According to my calculations, diamond capacitors should have somewhere around a hundredth the volumetric energy density of gasoline, which really isn’t that bad for certain applications

21:55 UTC


Why are nonhuman erect bipedal animals so rare?

What I mean is most bipedal animals (such as kangaroo rats and mice, ground pangolins, and macropods, and even extinct ones such as tyrannosaurs) have at least a somewhat hunched back.

The only nonhuman erect bipedal animals I know are penguins.

22:23 UTC


If there was a hole in the ISS, would everyone get sucked out like in Sci-Fi movies?

Just watched the movie Life, and like in every space Sci-Fi movie there's an open hatch at one point and all the air gets sucked out, threatening to pull everyone out into space. I can see some violent air movement when the decompression happens, but it doesn't seem possible that that movement could sustain itself for long enough to be a problem.

Does anybody know what would really happen? I know there was one small hole in the ISS and nothing happened - a slight drop in the pressure that they let the crew sleep through and a small patch.

23:10 UTC


Can you entangle more than two particles? Can entanglement be produced on a macroscopic scale to observe new physical interactions?

Particle entanglement is often described as spooky action at a distance. Where two particles interact regardless of the physical distance between them. Entanglement has also been described as a measurement of one particle that decides the properties of another because the interaction between them determines their shared properties that must be conserved. However, can the entanglement include more particles, can this be expanded to a macroscopic level to observe things like additional dimensions or new physics?

23:17 UTC


Did the Spanish flu cause long-flu symptoms similar to how Covid causes Long Covid?

00:58 UTC


Why does mild compression lead to paresthesia but not paralysis?

When a body part is compressed for a short period of time, why are only sensory neurons affected (paresthesia/anesthesia) by compression but not motor neurons (paralysis)? Like, the body part gets numb/tingly, but voluntary movement continues to function. Why is this the case?


Yes, I am aware that mild paralysis occurs with compression, but this tends to occur later. Also, by "compression", I meant like when your arm, thigh, etc., is squished, not like carpal-tunnel-like nerve compression.

Also, thanks for all your wonderful input, but I would really appreciate some sources.

02:39 UTC


Is there a difference in effect when dosing antibiotics?

So whats the difference in taking 2 pills of antibiotics at once rather than taking one pill and waiting 12 hours to take the second one? Im asking because my friend and i have the same infection and we got different dosing.

14:01 UTC


Does chronic depression during childhood and/or adolescence cause long-lasting problems with brain function?

I'm wondering since during childhood your brain is developing and making lasting connections, if having depression problems during this formative time have lasting consequences for brain function that you wouldn't see so much in adults with depression (who maybe didn't as children). I'm thinking things like chronic fatigue, attention problems, executive dysfunction, etc. But I would be interested in seeing information on any lasting effects from childhood depression.

14:54 UTC


Humans experienced a massive population expansion in a very small amount of time. What are the evolutionary consequences and benefits of such an event, massive popular of a species in a small amount of time?

03:57 UTC


Around 550 million years ago the earth's magnetic field almost collapsed, but then strengthened a few million years later. Scientists say this may have been due to the formation of the inner core. But why exactly would that cause the magnetic field to get stronger?

A few months ago I saw a few articles (I linked one below) that said around 550 million years ago the magnetic field weakened and almost "collapsed", but was strengthened later by the formation of the inner core.

The problem is that all the articles I've found don't go into why that formation caused the magnetic field to strengthen, only that it did.

What actually is it about the presence of the inner core that makes the magnetic field stronger than it would be without it? And how do we know?


06:54 UTC


If volcanoes go extinct because the lava flow got cut off, where does the lava flow next? Does it pile up and lead to something?

01:00 UTC


How did humans 10000 Years ago care about their Teeth?

19:44 UTC


What do ecologists mean precisely by species assortment?

I'm doing theoretical complex systems research with applications to theories of cooperation and altruism. I'm trying to contextualize my work properly, and need to understand what assortment means with respect to species differentiation and cooperation. I apologize if this lacks context, I'm a bit outside my wheelhouse!

1 Comment
00:07 UTC


How do laser measurement tools work?

I've heard about tools that use lasers to measure distance, and I feel like I've heard about ones that can measure atmospheric pressure or density? Is that right, and how do they work?

06:15 UTC


If sites like Karahan Tepe could date to potentially 12,000 years ago, where inhabitants where hunter gatherers (with maybe minimal early agriculture) and pre-pottery. Then why don't we see anything 15k, 30k, 50k, or even 100k years back?

Edit: since that stupid show "Ancient Apocalypse" is getting a bunch of attention at the moment, let me be clear the following has NOTHING to do with that. I do not believe there's some advanced lost civilisation, I do not believe in atlantians, I do not believe these sea people came and gave this technology to these people. I just don't understand how ~12k years ago we go from extremely simple building engineering, to Karaahan Tepe. The advancement to Göbekli Tepe a few k years later though makes total sense, you can see the gradual improvements they made from KT to GT, it's linear progress. But KT appears to suddenly jump into existence, during the younger dryas at that. It just feels to me either I'm missing something deep, or perhaps there could be a chain of similar sites going back 15k, 20k, 30k, etc years (but even then I ask why did it take between ~250k years or ~40k years to figure out the early ones?).

Karahan Tepe, the older sister site of the world famous Göbekli Tepe, appears to be around 12,000 years old.

All of the evidence we have found so far suggests they were hunter gatherers who may have been doing small amounts of agriculture (which is backed up by genetic tracing of our modification of species, which happened over thousands of years). And on top of that did not have pottery.

Of course I've heard that this may imply that it may not have been agriculture that allowed us the time and requirements to build structures like this, but structures like this that allowed us to start agriculture. Or (what I would lean to) is that it was a slow mix of each pushing each other along.

But what I don't understand, is if humans were capable of this back then with essentially pre/minimal-agriculture, then why don't we see any further back?

Why weren't we building these structures 15,000 years ago. Or 30,000? Or 50,000? Or even 100,000?

I understand about the ice age (although some of the PPN sites seemed like they may have developed in the younger dryas, which makes even less sense?). But there were still warmer climates with humans in them.

Why did it take us ~250k years to suddenly figure this out, and then when we do figure it out, we're suddenly pretty damn good at it? Or even if you follow that humans only became behaviourally modem 70k years ago, again why did it take 60k years?

It just doesn't make much sense to me. Humans who could figure out how to make stone weapons, fire, primitive homes, etc, surely absolutely understood that you could chip away and grind away stone.

Is it possible we just haven't found these yet? And that there's just fewer due to lower population? It feels obvious to me that there must be some missing as there's such a jump to the PPN ones.

Or is there a reason humans couldn't/didn't build sites like this. And something suddenly changed?

03:58 UTC

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