You'd think a blood drinking parasitic bird would be a high priority to defend against, and that such a small bird would be easy to attack. Is there just not much evolutionary pressure because the parasitism doesn't kill the host?

Hi everyone,

I’ve noticed that COVID-19 has led to a wide range of persistent symptoms in many people, often called Long COVID: including things like fatigue, brain fog, dysautonomia, and more. Meanwhile, other respiratory illnesses like the seasonal flu don’t seem to cause such widespread or long-lasting effects in most cases.

What is it about SARS-CoV-2 or the body’s response to it that leads to these prolonged symptoms? Is it related to the virus itself, the immune response, or something else? And why don’t we see similar post-viral syndromes as commonly with other viruses?

Thanks in advance for any insights or explanations!

Will a world more aware of this mean people have to be even quieter?

Thiamin deficiency in severe form causes Wernicke encephalopathy, vs metronidazole encephalopathy which rarely happens when a patient takes said drug. The two conditions look really similar on MRI and have a decent symptom overlap, and have pretty subtle differences. Is metronidazole toxicity actually an induced thiamin/vitamin b1 deficiency affecting the brain/nerves that mostly goes away after the drug is withdrawn and the person eats a regular diet, or is it more complex than that? Why does it happen to only a select few patients? I tried reading literature but it doesn't seem to have a set answer, so I'd like to hear some expert opinions

Sorry if this might be a bit of a stupid question, but I've been trying to understand exactly why the ears/eardrum catches all kinds of sounds via vibration when, say, another thin membrane like the surface of a balloon or a tissue, doesn't vibrate.

I started wondering this because of what I’ve learned about urine. From what I’ve been told, urine is used to flush waste and harmful chemicals out of the body, which is why drinking lots of water will end up with more clear pee, because there’s less chemicals that need to be flushed out. That got me to thinking, well, what if a person drank only absolutely molecularly pure H2O, what would it look like then? Well, probably not fundamentally different, because there’s still other chemicals they consume or that the body creates that need to be flushed out. So, what if they only ate purely (on a chemical level) the basic fundamental nutrients needed to function?

This isn’t a question of quantity, but of quality. In this hypothetical, the person is not on starvation rations eating barely enough to cling to life, they’re eating enough to function healthily, but this person is just somehow chomping down on blocks of pure sodium and whatnot for lunch (disregarding however they would manage to do that). As the body constantly uses up different nutrients at different times, the person would be eating different amounts of whatever chemicals on different days based on what their body most and least needed at the time.

Would they just barely ever need to use the restroom, and flush out close to nothing when they did? Or would their excrement still at least slightly comparable to that of a normal persons?

I'm watching a post-apocalyptic show. if there are no tests, no hospitals, no ultrasound etc how soon would she know? I guess when her period won't show up but if it's a post apocalyptic world there's also food insecurity that would make your period irregular.

I assume that there must be a ceiling to when natural hypertrophy stops providing additional health benefits.

I'm sure this is a gross oversimplification, but is it fair to say that for every pound of muscle gained and kept, your health outlook improves? And if so, what is the point where one has gained enough muscle where this stops being true?

I'd love anyone who could point me to some studies. I don't think I know enough to ask the question properly.

I already know a simplified version of this, but I'd like someone with more experience to run it down for me.

Both of these chemicals are rapid contributors to the climate crisis, but at the same time are currently necessary to run AC units. I'm not up on the science of AC engineering, nor refrigeration, so this is outside my wheelhouse. Has anyone proposed a serious alternative?

EDIT: OK this post got locked, I'm sorry for making people mad.

Most of us have heard about our over-use of antibiotics causing bacteria to become more and more resistant over time and that eventually, they might hardly even work against certain microorganisms.

This may be a stupid question, but what about bacteria and mold that likes growing on food? We all keep our food in the fridge, so are we unintentionally promoting cold-resistant microorganisms slowly over time? Accidentally keeping food in the fridge so long that it gets bacteria colonies growing in it, you’d think would be full of bacteria that’s somewhat okay with being in a cold environment.

Building on that, are there other “everyday” ways we’ve been accidentally promoting microorganisms with certain characteristics or resistances?

Counter question to the common one about diseases for which we're close to creating a cure/vaccine.

I’ve been doing some learning about human pre-history and one question I have is what made humans only evolve in Africa? I know there were other hominid groups like Neanderthals and Denisovans but I don’t know as much about them. Did some of the other hominid groups spring out of other parts of world independently but just didn’t make it through the evolutionary arms race or did all hominids come out of Africa. If so, why? When lots of animals seem to have developed independently into similar ways like the different types of anteater type animals. I’m coming at this from a perspective of just liking to learn about human history and pre-history. The science behind evolution isn’t something I’m versed in

I don't know if this is stupid or not, but a character I'm making has the base of their horns starting over their eyes and that brought up the question of if there could or would be eyes under the horns, and if there were, would they even be functional? For example, if you ripped a horn off (not damaging whatever's under it for the sake of the question.) could there be a functional or non-functional eyeball under it? Part of me thinks this is obviously a no, unanswerable, or very, very stupid yet I'm really curious. A little part of me also wonders if that eye could see but it wouldn't be able to with a horn covering it.

Cancer is purely localized disease to my knowledge, so it is very weird to me why it would be deadly in non vital areas. Ig if it presses on some blood vessels it makes sense but otherwise I am confused

Edit: thank you guys for the responses it makes sense. I guess clarifying my question will be useful, since from my understanding cancer is cell type specific, for example skin cancer is for skin cells, I have a hard time imagning cancer spreading to other vital areas. Like does skin start to grow on the lungs? Does it now become lung cancer with lung cells?

Reading the responses yeah I heard in passing cancer can travel through blood vessels to other regions but never thought about it, still dont understand how it speards to other organs with different cell types

Edit2: a kind stranger cleared up a lot, shoutout to the comment section

Cats : 185,000-200,000 per kidney Dogs: 400,000-425,000 per kidney Humans: 900,000-1.5 million per kidney

Hi, did always read this recommendation to let tap water stand, so that hopefully if chlorinated, it'd degassify.

I know not all waters might be chlorinated with chlorine but rather with other compounds, but just wondering if there are some bases to have standing tap water become healthier for watering plants?

1. Increased CO2 dissolution, hence becoming slightly acidic?

2. Degassified or treatment chemicals breaking down due to air and sunshine?

3. Some other chemical breakdown, making it less sanitized (to the point that algae etc could grow if left long enough) hence less aggressive on roots?

Thanks for your help

I’m thinking that my apple tree had hundreds of flowers on it and has produced 20 apples. If there were more bees, i assume the tree would have produced more apples as the time of flowers didn’t have enough bees to pollinate them before the flowers withered? From this, if this is so, does that mean that our obsession with prioritising honey over harvest is reducing fruit and nuts yields? If so, this sounds like the biggest opportunity in increasing food production with no effort needed besides abstaining from eating honey.

I specifically mean a heart that stopped beating. I've been on a bit of a research binge, bouncing between google results and then google scholar to compare it to studies I can find that are way above my paygrade as a writer.

Because my mom who works in a hospital says that a defibrillator doesn't start up a heart, it stops and restarts it, and now I'm even beginning to doubt that. I thought they used epinephrine for it, but after reading some studies on it I'm seeing some concerning information that it might be more dangerous over the long term (These are the studies I read, in case anyone is inclined to fact check them: Study 1, Study 2, Study 3.)

So what actually gets used when a heart stops beating? Because I keep hearing this saying you're not dead until you're warmed up again on my research escapades, and medicine is something I really can't afford to get wrong.

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I understand that the Earth rotates once every 24 hours, which means at the equator we're moving at approximately 1,040 mph (1,674 km/h). Yet we don't feel this motion at all - no sensation of spinning or moving through space.

What physical principles explain why we can't sense this constant rotational motion? Is it related to inertia, reference frames, or other physics concepts?

This question may sound stupid, but I once read that some bacterias can be 0.5mm long, making them visible to the human eye. Proportionally, this bacteria would be huge next to an insect like a fruit fly, hence my question.

Additionally, why does it foam when spot-applied to a stain, and when it doesn’t foam, does it mean it cannot remove that stain because it’s not reacting to it?

Like does a lion call itself a lion, like we call ourselves human. Or have animals not reached the level of intelligence.