/r/askscience

Photograph via snooOG

Ask a science question, get a science answer.

Please read our guidelines and FAQ before posting

Features

Filter by Field

Title Description
Physics Theoretical Physics, Experimental Physics, High-energy Physics, Solid-State Physics, Fluid Dynamics, Relativity, Quantum Physics, Plasma Physics
Mathematics Mathematics, Statistics, Number Theory, Calculus, Algebra
Astronomy Astronomy, Astrophysics, Cosmology, Planetary Formation
Computing Computing, Artificial Intelligence, Machine Learning, Computability
Earth and Planetary Sciences Earth Science, Atmospheric Science, Oceanography, Geology
Engineering Mechanical Engineering, Electrical Engineering, Structural Engineering, Computer Engineering, Aerospace Engineering
Chemistry Chemistry, Organic Chemistry, Polymers, Biochemistry
Social Sciences Social Science, Political Science, Economics, Archaeology, Anthropology, Linguistics
Biology Biology, Evolution, Morphology, Ecology, Synthetic Biology, Microbiology, Cellular Biology, Molecular Biology, Paleontology
Psychology Psychology, Cognitive Psychology, Developmental Psychology, Abnormal, Social Psychology
Medicine Medicine, Oncology, Dentistry, Physiology, Epidemiology, Infectious Disease, Pharmacy, Human Body
Neuroscience Neuroscience, Neurology, Neurochemistry, Cognitive Neuroscience

Calendar

Date Description
31 Jan AskScience AMA Series: NASA OSIRIS-REx
2 Feb Groundhog Day
5 Feb Ask Anything Wednesday - Engineering, Mathematics, Computer science
12 Feb Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology
12 Feb Darwin Day
15 Feb Galileo's Birthday (b.1564)
19 Feb Ask Anything Wednesday - Economics, Political Science, Linguistics, Anthropology
26 Feb Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science

Related subreddits

Are you a science expert?


Header Information

  1. For more open-ended questions, try /r/AskScienceDiscussion | Sign up to be a panelist!

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

/r/askscience

26,017,875 Subscribers

185

Why do (some) people lose hair as they get older, but it seems that most can keep a beard growing?

Sorry if this is not a science question hah.

74 Comments
2025/02/01
16:23 UTC

1

What are the differences between the 18 Hemagglutinin and 11 Neuraminidase types?

It kind of seems like H relates more to what it can infect and N is relates to the severity of illness. But that also seems like maybe it's too simplistic.

Like from reading it seems like H1,2 and 3 are the only known to infect humans but does that continue for the remaining 15.

N1 and 2 seem to correlate to epidemics and 3 and 7 more isolated deaths.

Or is it just impossible to simplify it in that way? Like could a pathologist see H8N5 and know what species it could infect and how severe the infection and fatality rate would be?

1 Comment
2025/01/31
16:05 UTC

23

Why are pigs and humans so similar?

I remember that pig organs can be transplanted into human bodies, human and pig flesh are described as having the same taste and texture, I vaguely remember seeing a thing years back where pig cells were used to repair a damaged human heart. Why are pigs able to be used like this for humans?

30 Comments
2025/01/31
17:30 UTC

745

From my 6 year old: where does a fart go?

He asked why a fart stops smelling bad after a few minutes and I told him it's because the gas molecules spread out and spread out until they're spread too thin for our noses to detect.

But he then followed up with "so they keep flying away for ever and ever into outer space?" And I don't know! Do the gas molecules from farts break down and get destroyed or do they live an immortal existence where they wander aimlessly forever?

238 Comments
2025/02/01
14:07 UTC

1

Why is nascent mRNA so susceptible to degradation compared to mature mRNA?

Hey all, I was wondering what specifically makes nascent mRNA more susceptible to degradation than the post-transcriptional mature mRNA?

1 Comment
2025/02/01
14:41 UTC

104

Why shape of ice here (near waterfall) looks like lily pad?

Jiktang Falls, South Korea, I pictured this

Hello, I saw this kind of ice near waterfall, and I wonder why it looks like lily pad. Is there any name of this ice? I searched Internet with keywords "waterfall", "ice" but I cannot find this kinds of shape...

10 Comments
2025/02/01
13:24 UTC

65

Is it normal for rivers like the Euphrates to have major drought, even before the effects of climate change?

I've seen claims saying Euphrates will dry up in 2040,but I've seen the satellite history of the river and lakes in euphrates and it looks like they have been through moments of drought similar to now. So is it true that the claim of it drying in 2040 is actually false and is just a random guess?

7 Comments
2025/01/31
05:55 UTC

913

AskScience AMA Series: We just discovered the building blocks of life in a 4.5-billion-year-old asteroid sample through our work on NASA's OSIRIS-REx mission. Ask us anything!

A little over a year ago, NASA's OSIRIS-REx mission became the first U.S. spacecraft to deliver a sample of the asteroid Bennu back to Earth. Earlier this week, we announced the first major results from scientists around the world who have been investigating tiny fragments of that sample.

These grains of rock show that the building blocks of life and the conditions for making them existed on Bennu's parent body 4.5 billion years ago. They contain amino acids - the building blocks of proteins - as well as all five of the nucleobases that encode genetic information in DNA and RNA.

The samples also contain minerals called evaporites, which exist on Earth, too. Evaporites are evidence that the larger body Bennu was once part of had a wet, salty environment. On Earth, scientists believe conditions like this played a role in life developing. The sample from asteroid Bennu provides a glimpse into the beginnings of our solar system.

We're here on /r/askscience to talk about what we've learned. Ask us your questions about asteroid science, how NASA takes care of rocks from space, and what we can't wait to learn next.

We are:

  • Harold Connolly - OSIRIS-REx Mission Sample Scientist, Rowan University and American Museum of Natural History (HC)
  • Jason Dworkin - OSIRIS-REx Project Scientist, NASA's Goddard Space Flight Center (JD)
  • Nicole Lunning - Lead OSIRIS-REx Sample Curator, NASA's Johnson Space Center (NL)
  • Tim McCoy - Curator of Meteorites, Smithsonian's National Museum of Natural History (TM)
  • Angel Mojarro - Organic Geochemist, NASA's Goddard Space Flight Center (AM)
  • Molly Wasser - Media Lead, Planetary Science Division, NASA (MW)

We'll be here to answer your questions from 2:30 - 4 p.m. EST (1930-2100 UTC). Thanks!

Username: /u/nasa

PROOF: https://x.com/NASA/status/1885093765204824495


EDIT: That's it for us – thanks again to everyone for your fantastic questions! Keep an eye out for the latest updates on OSIRIS-REx—and other NASA missions—on our @NASASolarSystem Instagram account.

176 Comments
2025/01/31
12:01 UTC

498

Why don´t cows and similar animals get frostbite when standing most of the day in snow?

They do have some hair on their legs but not that much. If I did the same with greased thick socks, I am pretty sure I would get frostbite right? Are they able to maintain much better circulation then humans do? If so then they must be able to produce more body heat than humans right ?(relative to their body size).

66 Comments
2025/01/30
19:39 UTC

1,377

If teeth are bones, then why if you chip a tooth it cannot repair itself?

For example if you break a leg,the damaged bone can heal itself. Why not teeth?

240 Comments
2025/01/30
22:01 UTC

26

Do cities consider potential earthquakes(or other natural disasters) when they approve where subdivisions are built? Do they know where fault lines are or are there new ones popping up with earthquake?

I apologize if this is the dumbest question ever asked but I was wondering how scientists discover fault lines. Are there new ones being made? And if so what kind of programs are researching that stuff? I've lived in the Boise/meridian area of Idaho my whole entire life and just recently when I moved 3 years ago I've been able to feel every small earthquake in my home. And they are REALLY small! My windows have cracked and my walls are pulling apart at the seams. I have the USGS app so I'm certain that it is earthquakes I'm feeling. My question is why? Is my house built somewhere it shouldn't be? Do home builders look into that stuff before they build or do they not care? I feel like I'm going a little crazy but I feel like something is off. I've never experienced this the whole time I've lived here

12 Comments
2025/01/30
19:46 UTC

76

When a person with silicone implants dies and starts decomposing, what happens with/to the implants?

I saw this question as just a joke post but it left me thinking. I'll just ask it the same way the post said it: When someone with breasts implants dies, is there a point in the decomposition process where you'd see a skeleton with boobs?

Or to say it better, do the implants decay that much slower than flesh that they would stay there once only skeleton remains? And what happens with cremation? Is there any explosion risk with the implants?

45 Comments
2025/01/29
16:51 UTC

283

Where does the uncertainty of asteroid hitting Earth come from?

Recently an asteroid was discovered with 1% chance of hitting Earth. Where does the variance come from: is it solar wind variance or is it our detection methods?

88 Comments
2025/01/30
04:22 UTC

8

Are there any modern medical "uses" for the belly button?

While in the womb, the fetus receives nutrients, oxygen and pretty much everything to keep it alive exclusively through the umbilical cord. This leads me to believe that there must be some major arteries or some other other important structure with direct and easy access to the body systems right there.

Nevertheless, I have never seen any medical procedure taking advantage or even involving the belly button at all (except for some surgeries, but I believe that's mostly for aesthetic reasons).

Is there any specific reason for this?

26 Comments
2025/01/29
04:16 UTC

73

How did opening a bottle freeze the contents?

I put a bottle of mango bunderberg in the freezer for a few hours when I take it out and its cold but not frozen, but when I open it, it freezes as if the air froze it. Anyone know why? Keep in mind it was probably 30+ ish degrees celsius outside, not sure if thats useful information.

29 Comments
2025/01/29
04:33 UTC

5

How can we measure the energy of eaten foods?

The numbers (in Joule or calories) written on each food pack. How do we measure the calories of a chocolate snack?

8 Comments
2025/01/29
13:50 UTC

292

Are the ancient wild horses extinct? If so, when did that happen?

Anyone who knows anything about history knows that most modern horses are a far cry from what their wild ancestors used to be. But are their wild ancestors still around? Are there breeds that retain a lot of what the wild horses were, or are modern small ponies far removed from them?

Note: I was referred here from r/askhistorians where I originally asked the question.

66 Comments
2025/01/29
19:49 UTC

190

Question: why does oil and diamonds take so long to form?

I would like to have a question. I am NOT a young earth creationist, but i have heard that one of the argumentss for a young earth is that we can produce diamonds in weeks and months, and oil in days. My question is if we can do this, why does it take them so long to form in natural circumstances?

49 Comments
2025/01/29
17:04 UTC

112

Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Physics, Astronomy, Earth and Planetary 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!

95 Comments
2025/01/29
15:01 UTC

181

How do people measure the amount of vitamins in fruits?

I just started wondering this. I’ll hear something like “a red pepper has 5X the vitamins as a green pepper” how do they measure this?

30 Comments
2025/01/29
02:40 UTC

36

What causes 'steam' over a cold body of water?

When the temperature is near or below freezing, what causes the appearance of a steam-like cloud above the water? It can't be real steam which happens when the water is around 100C. Maybe just frozen evaporation from the water?

32 Comments
2025/01/28
00:54 UTC

350

What does "most species are rare, few are common" actually mean?

After going through a few research papers on species abundance, the notion that 'most species rare, few are common' has popped up in several papers. I simply don't think I understand the concept. Most of earth's biomass is comprised of rare species made of few individuals, rather than common species made of several individuals? How do I interpret this finding?

63 Comments
2025/01/28
15:36 UTC

339

What, if anything, will stop bird flu from wiping out most flocks of chickens?

From what I've gleaned, avian influenza is highly contagious, highly lethal to chickens, has reservoir populations in water fowl, and when it strikes a farm, farmers usually have to cull the entire flock. It seems infeasible to vaccinate all chickens for it, and since entire lots are culled to avoid risking latent carriers, there is no opportunity for learned immunity or evolving resistance.

Not to be a doomer, but what is there to stop it from just burning through every flock that it infects? Are some breeds naturally more resistant? Will the virus eventually evolve to be less lethal like how COVID did?

56 Comments
2025/01/28
07:00 UTC

76

Why are binary star systems the most common type of star systems in the universe?

I'd assume it's because of the gravity of a star pulling in more of the materials required to make another star but I'm not entirely sure. I found it really interesting since beforehand I always assumed most star systems weren't binary (what's the same? singular? idk)
Anyway if you could either confirm this my assumption, elaborate on my assumption or prove why my assumption is wrong it would be greatly appreciated, thanks ^^

25 Comments
2025/01/27
04:57 UTC

35

What triggers a sharks blood sense/scent? Is it different between iron or copper based oxygen carriers?

Is there anything that’s scientist have found that allows sharks to smell blood from so far away? And is it related to the type of prey’s blood tendency to be ferromagnetic?

13 Comments
2025/01/27
04:19 UTC

111

What happens when we think?

I mean it's like somebody is talking but there is no sound yet I can still hear it.

42 Comments
2025/01/27
04:09 UTC

Back To Top