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Date Description
20 Mar Ask Anything Wednesday - Economics, Political Science, Linguistics, Anthropology
21 Mar AskScience AMA Series: Artificial and Natural Intelligence
27 Mar Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science
3 Apr Ask Anything Wednesday - Engineering, Mathematics, Computer science
9 Apr AskScience AMA Series: Homegrown National Park
10 Apr Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology
17 Apr Ask Anything Wednesday - Economics, Political Science, Linguistics, Anthropology

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  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


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I know the colors in the Yellowstone Caldera exist because of the different kinds of bacteria that live in the varying temperatures, but why does the order exactly match the spectrum of light like a rainbow?

I can't tell if this a dumb question lol. I get that there's different types of bacteria as it gets cooler towards the edges, I know the inner ring of synechococcus are yellow, so it seems the gradient of blue water going into the yellow makes the green part. And the outer most bacteria are like a reddish brown so the orange comes from the yellow to red gradient. But what does it have to do with the spectrum of light? I'm sure it's not just a coincidence.

16:39 UTC


How do we know that (some) other galaxies aren't made of antimatter?

I don't think this is something merely assumed. Either possibility presents a conundrum: if all galaxies are matter, then the universe started with more matter than antimatter; if other galaxies can be antimatter, then the universe had an unbalanced distribution of the two.

What's our evidence that the remainder of the universe is all matter?

20:02 UTC


(probably an impossible question) what was before the big bang?

and what was before that? did the universe just come from literally nothing?

20:51 UTC


If DNA tells the cell what to do then what tells the cell how to read DNA?

It's important

11:55 UTC


Why doesn't Hawaii have widespread geothermal energy like Iceland?

Both Hawaii (the big island, anyway) and Iceland have significant volcanic activity, but Hawaii doesn't seem to have the level of geothermal energy availability that Iceland does.

Iceland has major percentages of its electricity and heating needs met through geothermal power. Hot springs abound, and are readily located throughout the country.

Hawaii doesn't have any hot springs that I'm aware of. I know they've had some geothermal power plants before, but it's nowhere near as widespread as Iceland.

What's different about these two? On the surface they seem like they should have similar features.

03:13 UTC


How did scientists come to the conclusion that the oldest fossils of some lifeform, found in Australia, were in fact cyanobacteria?

So I was studying about the oldest discovered fossils and happen to come across pictures of what scientists describe as cyanobacteria dated to be around 3.5 billion years old. My question is how did they come across such fossils and secondly how do we know they were in fact a form of life?

18:32 UTC


How can your immune system allergically react to a substance that hasn't entered your body/bloodstream?

e.g. if you get something on your skin and it gives you a rash, how would your immune system even know that something was on your skin? Not to mention I'm sure there's plenty of bacteria and stuff on your skin that the immune system also should be reacting to, even in a person without allergies, right?

18:50 UTC


Is it true CO2 emission sequestering is useless and we should only care about reduction or avoidance?

I've heard this several times, like sequestering (meaning, planting trees and protecting forests) is only delaying the emissions and the only way forward is reduction. How true is it?

13:48 UTC


Why did it take so long for Apollo 11 to reach the moon?

Something i was thinking about the other day.

It says that Apollo 11 reached a speed of 25200mph whilst travelling to the moon.

The moon is 239000 miles from earth.

It seems it should take around 10 hours to reach the moon but it took the astronauts 3 days, why is that?

08:31 UTC


Do fish have saliva?

20:05 UTC


Are the images from the James Webb telescope the true images captured or is there some rendering or interpretation added in?

The image of a protoplanetary disk that was captured amazed me, but the more I stare the more it reminds me of an AI enhanced or even photoshopped image. Do they touch these images? Maybe release epic artist interpretations to the public for what they find but in reality the telescope captures a crappy/grainy pic that just barely can tell scientists what they’re looking at?

11:45 UTC


How does testosterone levels during puberty affect the growth and development of the penis?

If a person had high levels of testosterone during puberty would they have a larger member in adulthood compared to people who had lower testosterone and can the reverse happen to people with lower than normal levels of testosterone have a smaller member in adulthood?

13:53 UTC


In 250 million years, how much longer will a year be?

Theres a lot of research papers and information about what the earth will be like in 250 million years when the next super continent forms, and it got be to thinking how long our years will be in the future? But I can't find any concrete answers and was hoping someone on here can help.

I know the moon is slowly pulling away from us and making our years longer by a fraction of a second, but how much do those milliseconds add up in 250 million years? I saw a source online saying that in 100 million years it will add half an hour to a day, but I don't know how true this is. If that is true and we would have an extra 1.5 hours per day, would that be that we would basically have 22.8 extra days? (I could be wrong here, math isn't my strong suit)

If anyone can help answer my question that would be greatly appreciated 🙏

21:55 UTC


What causes the phenomenon of 'brain freeze' when eating something cold too quickly?

I get brain freeze all of the time and it makes it difficult to enjoy ice cream

01:55 UTC


Will the moon ever be destroyed?

Hello, this is my first post on this site. I'm a 15-year old boy who doesn't know much, and this question is probably dumb to ask, but I'd had to. Here is the question now:

There are so many craters on the moon, is there still craters being made in the moon to this day? And if so, why aren't we worried that the moon will eventually become smaller and smaller until it gets destroyed or whatever by all the craters?

03:37 UTC


Windmills, why aren’t they always “on”?

As I was driving home from vacation, I drove through a windmill farm as I do every time I drive this way… I got to thinking after staring at them…

There are HUNDREDS of windmills in this one farm, yet only a fraction of them are actually rotating. Why? Why can’t the blades all be in the “on” position and just generate electricity as wind permits?

What/who (I imagine wind patterns and some engineer or AI software) decides which windmills are on? Being there are so many windmills, they’re all slightly varied angles, but there are many examples of two windmills facing the exact same direction, immediately next to each other, and one is on, one is off. Why?!

I must know why windmills are so mystifying! Thank you!

02:15 UTC


Is it possible to have an ice age and a supercontinent at the same time?

I ask this because while having a supercontinent you have a large amount of volcanic activity on land. And maybe the ice can’t form on the supercontinent. Thanks in advance.

21:55 UTC


Why does Delta IV set itself on fire when other rockets don't?

Delta IV and Delta IV Heavy sets itself on fire right before takeoff. This is expected behaviour and looks alarming but it's OK, they know it's going to happen and they've made sure the flames won't damage anything.

The usual explanation is that Delta IV runs hydrogen through the engines early on. The rocket has liquid hydrogen and liquid oxygen on board and they don't want excess oxygen to build up in the engines because oxygen is very chemically reactive and could damage the engine. So they run excess hydrogen through the rocket, especially early on. This hydrogen burns in a dramatic looking (but not actually very dangerous) fireball.

But then why don't other rockets set themselves on fire? The Shuttle, Ariane 5, Japan's H-II and China's Long March 5 are all using hydrogen on their first stages but don't set themselves on fire. I get that rockets using kerosene won't have the same fireball issue but why don't all hydrogen fueled rockets have a fireball?

I feel like it's been explained a hundred times but with only half an explanation. What does Ariane 5 do differently to Delta IV that means one has a fireball and the other doesn't?

18:38 UTC


If we say time is the 4th dimension, why don't we just attribute dimensions to other things, like "the 5th dimension is charge"?

12:24 UTC


Do any marine mammals have underwater sense of smell?

With divers working to find the bodies of construction workers killed in the key bridge collapse, wondered whether it would be possible to train “ cadaver sniffing” seals or otters?

14:08 UTC


How will a pathogen affect the body if there was no immune response?

Let’s say that someone caught a common cold virus, but for some reason the immune system doesn’t detect it and the virus just keeps replicating in the cells of the respiratory track. Will there be significant damage (eg lesions) if the virus keeps multiplying? Does this happen to different extents with people who have immunodeficiency issues?

11:38 UTC


Why does spinning your body in a circle result in dizziness, nausea, and vomiting?

It just seems odd. If anyone knows the science behind this, I’d love to know.

22:12 UTC


How does the lung expel germs?

Dust, as I understand, exits through mucus.

I also understand that the nostrils at least capture some of the foreign-bodies entering.

But how does the lung excrete germs? Also, while I sort of understand how the immune system might send in a response measure, what does this measure look like when germs enter the lung? Or does our body have a way to fully prevent any bacteria or gas from entering the lungs?

15:07 UTC


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!

14:00 UTC


Does the Amazon rainforest have an effect on the Sahara desert?

If so, does this change how Sahara affects the Amazon?

14:04 UTC


AskScience AMA Series: I am a biologist at the University of Maryland. My lab explores whether Hutchinson-Gilford progeria syndrome, a premature aging model, can be used to understand the aging process. Ask me all your questions about human aging!

Hi Reddit! I am a biologist from the University of Maryland here to answer your questions about aging. My research has focused on the molecular mechanisms of Hutchinson-Gilford progeria syndrome (HGPS), a premature aging disease, and the potential connections between HGPS and normal aging.

Kan Cao is a renowned scientist, anti-aging authority and professor of cell biology and molecular genetics at the University of Maryland. She has been studying human aging and in particular the molecular and cellular mechanisms underlying Hutchinson-Gilford Progeria syndrome (HGPS), a premature aging disease that claims most victims by age 13. While conducting research on aging and HGPS, Kan's lab discovered that a common dye, methylene blue, had incredible anti-aging properties for human skin. With support from UM Ventures, she started Mblue Labs and launched Bluelene Skincare, the first commercially available methylene blue anti-aging cream.

I'll be on from 1 to 3 p.m. ET (17-18 UT) - ask me anything!

Other links:

Username: /u/umd-science

11:00 UTC


How do we know what is normal for climate fluctuations throughout Earth's history if we only have limited data points rather than day to day statistics of pre-human weather?

I was trying to figure out how conclusions were made for climate normals (the 30 year sets) for prehistoric times (meaning millions of years ago) since we're only given snapshots of the weather and climate for those times as compared with today. Most articles I've read only mention the past 200 years or past 20,000 years. If you have any links to good articles on that or have knowledge yourself, it'd be appreciated.

01:10 UTC


The moon has many craters visible to the naked eye, what would the impact event that created the largest of them have looked like to the naked eye from earth?

Bonus points, is there any recorded history of mankind witnessing such an event?

03:05 UTC


Now that one of the three major strains of Influenza is effectively extinct, have the other two increased in prevalence to compensate?

Or has the flu in general become less prevalent?

03:11 UTC


Can dinosaur bones that are created in sandstone have a thin layer of sandstone covering the bones that make them not look like bones?

If a dinosaur fossil is created with a landslide of sand and dirt, etc. Could a dinosaur fossil have a thin layer of sandstone sludge or sandstone rock covering the outside of the bones? Meaning, if you were to find a dinosaur bone, could it be dismissed simply because it has a layer of sandstone sediment adhered to the bone itself? And furthermore, what happens if a dinosaur bone is fossilized with sandstone sediment? Can the bone themselves be fossilized bones made up of nothing but sandstone? Sort of like how wood is petrified by replacing the original wood with minerals and then having an actual copy of the wood itself, but only of other minerals that replaced the organic material over millions of years? Can that be possible? Sorry if this is an actual thing already I'm trying to learn about this process & what the possibilities are & I cannot find anything on the subject.And furthermore, what happens if a dinosaur bone is fossilized with sandstone sediment? Can the bone themselves be fossilized bones made up of nothing but sandstone? Sort of like how wood is petrified by replacing the original wood with minerals and then having an actual copy of the wood itself, but only of other minerals that replaced the organic material over millions of years? Can that be possible? Sorry if this is an actual thing already I'm trying to learn about this process & what the possibilities are & I cannot find anything on the subject.

07:15 UTC

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