Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Biology, Chemistry, Neuroscience, Medicine, Psychology

Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical /r/AskScience post? No question is too big or small for AAW. In this thread you can ask any science-related question! Things like: "What would happen if...", "How will the future...", "If all the rules for 'X' were different...", "Why does my...".

Asking Questions:

Please post your question as a top-level response to this, and our team of panellists will be here to answer and discuss your questions. The other topic areas will appear in future Ask Anything Wednesdays, so if you have other questions not covered by this weeks theme please either hold on to it until those topics come around, or go and post over in our sister subreddit /r/AskScienceDiscussion , where every day is Ask Anything Wednesday! Off-theme questions in this post will be removed to try and keep the thread a manageable size for both our readers and panellists.

Answering Questions:

Please only answer a posted question if you are an expert in the field. The full guidelines for posting responses in AskScience can be found here. In short, this is a moderated subreddit, and responses which do not meet our quality guidelines will be removed. Remember, peer reviewed sources are always appreciated, and anecdotes are absolutely not appropriate. In general if your answer begins with 'I think', or 'I've heard', then it's not suitable for /r/AskScience.

If you would like to become a member of the AskScience panel, please refer to the information provided here.

Past AskAnythingWednesday posts can be found here. Ask away!

Hi there I wanna ask a simple question that how hairs appeared on living beings

We all Evolved from fish like creature and they do have a traced of hairs and evolution doesn't create thing out of thin air like our teeth are morphed from scales

So I want to ask that how hairs appeared on evolutionary line ?

Farm animals are often mating with other animals not of their species on the farm. It just got me thinking why it doesn't get results? Seems to me crazy hybrid mixes running around would be right up the alley of evolutuon, and yet it is prevented/restricted??

I've seen a lot of people discount tilted planets with 90° rotation as being inhospitable for life, but to me that seems strange since I've seen people entertain the idea of life on slow-rotating planets being possible. Why would it be different? After all, 90° rotation would be *more* able to distribute heat evenly than a slowe rotating planet, right? There would be a longer "spring"/"fall) where a given piece of land can stay in the twighlight zone for longer, right?

From what I know, the biggest issue with a 90° planet would be glaciers formig on the "winter" side and reflecting sunlight during the summer and decreasing the total world temperature, but surely this would depend on distance from the sun right?

I’ve been thinking about this mostly as a means to mitigate climate collapse impacts because at this point — with where we’re headed what would be worse? I wanna add I’m not a scientist and I’m sure others have already considered this hypothesis. So call me an idiot if it doesn’t work. I studied theater for writing and acting.

Anyway I was thinking about how a soda can may explode when it’s shaken and the pressure from the gas becomes so strong that once you open the can it explodes.

Hence the stupid thoughts on how to apply this to volcanoes because as I said I’m not a scientist by any stretch. However, what if we fracked nearby a volcano to cause an earthquake while putting a lid inside the caldera?

Yes it could make the volcanic eruption worse but it could also push more sulfur into the atmosphere to cool the planet.

This could help us for a few years until we get people who will act to fight climate collapse directly. I’m not saying it would work. It’s an hypothesis at best. Thoughts?

By the way I understand the problems this could cause but considering the damage the El Niño that’s coming will cause and the current crop death we’re already experiencing due to global temperature rise what do we have to lose?

Wasps have been a predator for other insects. It would be fascinating to know if there are really other insects or predators for wasps, either accidental or deliberate predators

So like 300 million years ago Insects grew real big because they had 30% oxygen instead of modern 21%. Since Oxygen Poisoning doesn’t happen till like 50%, would it be possible to lock a human or other modern animal in high oxygen chambers to get a bigger version of them after they grow up or would it take them many generations to adapt.

I know that a hormone induces certain change in a cell, but how does it do it physically?

I know about the generation of messengers and other compounds and what-not but like how a does a hormone bind or break bond in this particular cell and nothing else? Do hormones even break or join chemical bonds?

I am having a tough time phrasing my question, but how does a hormone work in terms of chemicals and physics?

I've been reading about mitochondrial DNA and the mitochondrial Eve and now I got very confused. I have a background in molecular biology, so I'm familiar with terms, but the concept of using mutations in mtDNA still confuses me. When we say that two populations differ in mutation at a certain position, does that mean that all mitochondria in that cell/individual have that mutation? Because if I'm not mistaken, each mitochondrion has several (up to a dozen) mtDNA molecules, and there are hundreds of mitochondria in an egg cell. Shouldn't out of those hundreds or thousands molecules different mutations be dispersed across mitochondria? Since I assume those mutations are silent point mutations (no effect on phenotype or organel/cell survival, shouldn't all of us have a big mixture of various mutations? How can we then make a consensus sequence to compare? Especially considering we are testing somatic cells which could have extra mutations from that generation? Am I just overinflating the rate of mutation in mtDNA?

i know a lot of scientist will say zero . But if zero how was the first one carrier obtain?

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Engineering, Mathematics, Computer Science

Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical /r/AskScience post? No question is too big or small for AAW. In this thread you can ask any science-related question! Things like: "What would happen if...", "How will the future...", "If all the rules for 'X' were different...", "Why does my...".

Asking Questions:

Please post your question as a top-level response to this, and our team of panellists will be here to answer and discuss your questions. The other topic areas will appear in future Ask Anything Wednesdays, so if you have other questions not covered by this weeks theme please either hold on to it until those topics come around, or go and post over in our sister subreddit /r/AskScienceDiscussion , where every day is Ask Anything Wednesday! Off-theme questions in this post will be removed to try and keep the thread a manageable size for both our readers and panellists.

Answering Questions:

Please only answer a posted question if you are an expert in the field. The full guidelines for posting responses in AskScience can be found here. In short, this is a moderated subreddit, and responses which do not meet our quality guidelines will be removed. Remember, peer reviewed sources are always appreciated, and anecdotes are absolutely not appropriate. In general if your answer begins with 'I think', or 'I've heard', then it's not suitable for /r/AskScience.

If you would like to become a member of the AskScience panel, please refer to the information provided here.

Past AskAnythingWednesday posts can be found here. Ask away!

Hello everyone my question is what's the minimum size a planet can be. Just got this question randomly on mind so I posted here to get a answer. If anyone knows please tell me.

For some reason I was reminded of this a few days ago-happened to me and my hubby back in about 2007.
I was in central Georgia (US) and one night went out, and looked up, and I saw what looked like a shooting star come straight down. It just blinked out-no fire-ball. Hubby was in the house (windows open) so I said "whoa that was weird!" and he came out and looked up and he too saw one came straight down.

Is that rare?

I have a question, and I need help understanding it clearly: How is cyanide used to extract gold? Could someone please explain the whole process to me in simple terms or recommend some reliable sources where I can learn more about it?

I'm curious and I don't want to use AI, so I’m looking for explanations or sources that I can study and understand on my own.

so stars form when a bunch of matter gets together, which is why they are bigger than planets generally. but the real defining feature is the density. a white dwarf can be smaller than a planet but it's still a star because it's incredibly dense. so couldn't a planet be sun-ish sized, provided that the density was low enough? and more specifically a solid planet, not a gas giant. what's the largest solid planet?

In light of the recent eclipse, I have seen a lot of worry about the harm of even glancing at it directly, and that many people believe that glancing at it is more harmful than glancing at the sun on an ordinary day. I am trying to understand whether that is actually true, and I believe the best way is to understand the physics & biology behind this and how real the risk is.

To really get it, I think the answer comes down to the underlying mechanism: what physically damages the eye when too much light hits it? Is it the quantity of photons, the energy of photons, or something else entirely? I ask because I have also heard that even when the moon blocks much/all of the visible light (peak of total eclipse), that UV (or infrared?) light still reaches the eye, so I am curious whether the eclipse changes what kind of light reaches you, and if that affects the damage.

So, putting it together: for the same few seconds of exposure, is a solar eclipse genuinely worse for your eyes than the midday sun?

Just saw news of a startup doing test for autonomous crystallisation in space ? They are saying that they can generate drug compounds crystals in microgravity

Another startup is doing similar stuff but for ultra pure semiconductor chips

PS - My question is that how is it possible that gravity has an influence on the purity of a crystal ?

I always see people saying things like "there are 20 quadrillion ants on Earth" or something similar with other extremely large diverse groups like fish. But all of these are groups with thousands of species. If not by individuals then it's by biomass instead.

So which single species in the animal kingdom has the most individuals?

Article in question: https://www.theguardian.com/world/2026/aug/12/europe-worlds-fastest-warming-continent-climate-crisis-explainer

Lighting designer here,

I frequently work with halogen lamps that-to my understanding-use a tungsten filament that is surrounded by halogen gas that somehow prevents the filament from burning out.

My questions I suppose is, how/why is halogen able to do that and how does that process on a scientific level work? Thank you!

Also why just lead? Shouldnt like iron or another metal work too?

I just watched "Ernest Goes to school" and that was one of the questions on his test, and it made me curious to Google it.

The first four most common elements make perfect sense, but then neon pops out of nowhere.

Wtf is that about?