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Saturday, November 6, 2021

How deep is the Sahara deserts sand, and what's at the bottom of the sand?

How deep is the Sahara deserts sand, and what's at the bottom of the sand?

How deep is the Sahara deserts sand, and what's at the bottom of the sand?

Posted: 05 Nov 2021 01:45 PM PDT

Like is it a solid bedrock kind of surface, or is it a gradient where the sand gets courser and courser until it's bedrock?

submitted by /u/asmosdeus
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Does sweat wicking fabric really exist? Or is this simply marketing, and an inherant trait of any fabric due to capillary action?

Posted: 05 Nov 2021 08:30 AM PDT

absolute zero is the coldest temperature. is there a hottest temperature?

Posted: 05 Nov 2021 08:17 AM PDT

My science teacher in high school said this was a stupid question I asked him. This was 25 years ago. I remember.

submitted by /u/howevertheory98968
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How do components of the immune system move towards foreign invaders?

Posted: 05 Nov 2021 11:04 AM PDT

Is there a chemical pathway behind how leukocytes are able to move to where they need to go?

For example, when skin is broken, the leukocytes in the area know to aggregate at the injured tissue. Or when bacteria invade, immune cells all over the body know to go towards the invader to kill it. I understand that there are certain ways that the immune system differentiates between bacteria and body cells, and that those differences are able to "signal" the immune system to destroy it. But I have a hard time wrapping my head around how a cell detects a far off disturbance (or antigens), and orients itself to move in that direction. How are they able to do this?

An explanation based in chemistry/biochemistry would be preferred, but biological mechanisms are so complex that I understand if a chemical explanation is too complicated to explain.

submitted by /u/VeXedZenith
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Is there a physical Limitation on how dense we can store data on a HDD Platter?

Posted: 05 Nov 2021 05:48 PM PDT

Ok, from my understanding, correct me if im wrong, we are currently reaching the physical limitation of cpu transistors.

But what about good old HDD's? They seem to manage to cram more and more data onto 1 platter, but is there a phyical limitation on how much information we can store on 1 platter?

submitted by /u/offron1
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Do antibodies recover after long periods of extreme stress have ended ("recovery immunity")?

Posted: 05 Nov 2021 07:25 AM PDT

I have read that after vaccination or infection, there is a decrease in neutralizing antibodies (what I saw referred to as humoral immunity) after extreme stress.

The paper on it I found referred to something called "immunity recovery." But the paper said it was not aware whether antibodies returned after a period of extreme stress.

So my question is, if you were to get COVID or get vaccinated for COVID then have an extended period of seriously extreme day-in, day-out stress, but then recovered from the stress, would your body start making neutralizing antibodies again or does the stress kill them off permanently?

To clarify, this is referring to periods of extreme, long-term stress and the aftermath. Short-term stress from what I read appears to improve immune response.

submitted by /u/finestartlover
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What is the mechanism behind mie scattering in pores with similar diameters to wavelengths?

Posted: 05 Nov 2021 03:59 PM PDT

In porous materials, if the pores of the material have diameters roughly equivalent to that of the light waves entering into the material, the light will mie scatter and reflect away from that porous material.

My question is (without a lot of math) what is the mechanism exactly that causes the pore diameter to have this influence for mie scattering?

I know a bit about quantum electrodynamic reflection off of two interfaces (like an oil slick) and I'm wondering if something similar happens when the pores are the size of the wavelength. How does the pore diameter related to the lights interference to cause reflection/scattering?

submitted by /u/thejeran
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Since combining waves can by constructive interference amplify amplitudes, is it also possible to amplify (create higher) frequencies by combining beams or simmilar?

Posted: 05 Nov 2021 07:43 AM PDT

What are eye floaters?

Posted: 05 Nov 2021 06:08 AM PDT

How do topical medications like Advantage Multi get rid of internal parasites?

Posted: 05 Nov 2021 04:06 PM PDT

Title.

submitted by /u/IoGibbyoI
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Is deep cycling a Lithium Ion battery worse than keeping it at 100%?

Posted: 04 Nov 2021 08:35 AM PDT

I recently got a new phone, and its battery lasts around two days. I'm trying to maximize the lifespan of the battery, so is it better to charge it every night (going from around 50-100% daily) or every other night (going from around 20-100%, but half as often?)

submitted by /u/epicface2304
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Friday, November 5, 2021

Does sleep deprivation during teen years have permanent effects?

Does sleep deprivation during teen years have permanent effects?

Does sleep deprivation during teen years have permanent effects?

Posted: 04 Nov 2021 10:18 PM PDT

For 2 years between the ages of around 14-16 I got almost no sleep most nights, on average it was around 1-3 hours on school nights and 6-9 hours on weekends. I'm almost 17 now and working on getting better sleep but I'm wondering if that period had a permanent effect on my life. Is it possible that I have a permanent lower mental ability, height or health since my development was interrupted by this?

submitted by /u/FortnightDance
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What causes the sensation of one's "blood running cold"?

Posted: 04 Nov 2021 10:14 PM PDT

I got a call from my confused and hysterical girlfriend in the hospital last night, after she gave her head a good crack on the floor, falling down some stairs. The combination of SOMETHING being wrong, but NOT being able to tell me herself because of memory loss/confusion, made me experience the most novel sensation. The nape of my neck, down and around my shoulders, and some of my back and then down deep deep in my tummy, I simultaneously felt something like a bizarre cool icy stingy feeling. The phrase "my blood ran cold" suddenly made sense.

Is this side effect of some sort of hormonal stress response? Is it related to the "freeze" response in prey animals? Is the experience of this sensation universally similar?

submitted by /u/AcclimateToMind
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We are scientists from the Society of Vertebrate Paleontology coming to you from our annual meeting — which is virtual this year! We study fossils. Ask Us Anything!

Posted: 05 Nov 2021 04:31 AM PDT

Hi /r/AskScience! We are members of the Society of Vertebrate Paleontology, here for our 8th annual AMA. We study fossil fish, mammals, amphibians, and reptiles — anything with a backbone! Our research includes how these organisms lived, how they were affected by environmental change like a changing climate, how they're related, and much more. You can follow us on Twitter @SVP_vertpaleo.

Joining us today are:

Matt Borths, Ph.D. (/u/Chapalmalania) is the Curator of Fossils at the Duke Lemur Center at Duke University in Durham, NC. His research focuses on the evolution of carnivorous mammals and primates, especially in Africa and North America. He is also part of several teams working to network natural history collections. Dr. Borths co-produced the paleontology podcast series Past Time (www.pasttime.org).

Clint Boyd, Ph.D. (/u/PalaeoBoyd) is the Curator of the North Dakota State Fossil Collection and the Paleontology Program Manager for the North Dakota Geological Survey. His research focuses on the evolutionary history of ornithischian dinosaurs and studying Eocene and Oligocene faunae from the Great Plains region of North America. Find him on twitter @boydpaleo.

Stephanie Drumheller, Ph.D. (/u/UglyFossils) is a paleontologist at the University of Tennessee whose research focuses on the processes of fossilization, evolution, and biology, of crocodiles and their relatives, including identifying bite marks on fossils. Find her on Twitter @UglyFossils.

Mindy Householder (/u/mindles1308) is a fossil preparator with the State Historical Society of North Dakota. She has cleaned and repaired many fossil specimens for public museums and institutions over the past 18 years. Some well known specimens she worked on include "Jane" the juvenile Tyrannosaurus rex and "Dakota" the Edmontosaurus sp. fossilized natural mummy.

Josh Miller, Ph.D. (/u/PaleoJosh) is a paleoecologist and Assistant Professor at the University of Cincinnati. His research focuses on Pleistocene paleoecology, taphonomy, and using fossil and subfossil records to help conserve and manage modern ecosystems (Conservation Paleobiology). Find out more at JoshuaHMiller.com.

Jennifer Nestler, M.S. (/u/jnestler) is an ecologist who works on landscape-level modeling of coastal and wetland ecosystems. She also studies the morphology and ecology of fossil and modern crocodylians, and uses quantitative methods to inform conservation decisions.

Adam Pritchard, Ph.D. (/u/vertpaleoama) is the Assistant Curator of Paleontology at the Virginia Museum of Natural History in Martinsville, VA. His research focuses on the evolution of reptiles during the Permian and Triassic periods, a time of great change that saw the rise of the dinosaurs. Please check out the Virginia Museum of Natural History at vmnh.net. Dr. Pritchard has also co-produced the paleontology podcast series Past Time, available at www.pasttime.org.

Gabriel-Philip Santos, M.S. (/u/PaleoParadoX) is a paleontologist and educator at the Raymond M. Alf Museum of Paleontology in Los Angeles, California. His previous work focused on the paleontology of Southern California, particularly the evolution of marine mammals. Today, his research has shifted to education and DEI in STEM as a National Geographic certified educator and cofounder of the Cosplay for Science Initiative. He was recently named a Grosvenor Teacher Fellow with National Geographic and Lindblad Expeditions. You can find him online as @paleoparadox.

We will be back to answer questions starting around noon (Eastern Time/4 PM UTC) to answer your questions. See you soon!

submitted by /u/VertPaleoAMA
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Will the Appalachian mountains erode completely?

Posted: 04 Nov 2021 05:25 PM PDT

I've read that they could've been as high as the Himalayas, but the mountains dont have any more activity that keeps them from eroding, will they vanish completely in the future?

submitted by /u/Impressive-Car-9044
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Why are vaccines not sugar cubes anymore?

Posted: 04 Nov 2021 01:37 PM PDT

My daughter is about to get her COVID vaccine and she is wondering why does it have to be an injection and not a sugar cube (like back in the polio vaccine).

I wondered myself, was the sugar cube idea only possible for polio? Have other vaccines used that method? What are the benefits or detriments to delivering a vaccine via sugar cube?

submitted by /u/P-Albundia
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Does the air inside the wheel rotate with the wheel itself?

Posted: 04 Nov 2021 10:04 PM PDT

It's a simple question, but I really couldn't answer it.

submitted by /u/the_qazaq1
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What is a rescue group in research?

Posted: 04 Nov 2021 06:15 PM PDT

Hi I am critiquing a paper and they said that they are using different treatment groups, a control group, and a rescue group. What is a rescue group and what is it's purpose? The paper I am critiquing is linked in this post. article

submitted by /u/taljov123
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Where does the potential energy come from, in osmosis?

Posted: 04 Nov 2021 10:35 AM PDT

So, when osmosis happen the molecules of water move from one side of the semi-permeable membrane to the other, in some cases it moves in a vertically up direction, seemingly defying gravity and gaining potential energy. So, since potential energy cant just show up out without an instigating factor, due to that being a violation of the law of conservation of energy; Where does the potential energy come from ?

submitted by /u/FakelyKorean45
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How do you model a gas when P, V, and T can all vary simultaneously?

Posted: 04 Nov 2021 11:04 PM PDT

For example, if you take the Ideal Gas Law

PV = nRT

and adjust everything with a scaler to describe a percentage change in each variable,

(P * a)(V * b) = nR(T * c)

you aren't able to get an insight into how each variable is changing with respect to each other. (As V is decreased by a factor of b, what is happening to P and T? etc.)

My understanding is that the Ideal Gas Law requires one of these variables to remain constant to be applicable. If I want to see how dP, dV, and dT all change with respect to each other, what model should I be using?

submitted by /u/sgt-stutta
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[relativity of simultaneity] What does it mean to say that the light reaching us from e.g. Alpha Centauri was emitted 4.37 years ago?

Posted: 05 Nov 2021 12:40 AM PDT

My question has to do with the relativity of simultaneity. Was the light reaching me now emitted while I was sitting down for coffee exactly 4.37 years ago? The simultaneity of these two events depends on the observer. Is 4.37 a good-enough approximation for all humans on earth? How about aliens orbiting Alpha Centauri on their planet? Can they expect the light they emit to reach us after 4.37 years of their time? Is there an impartial observer that can time these events?

submitted by /u/isolli
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If a supermassive black hole (for example Sagittarius A*) consumes one hydrogen atom, how much this would increase black holes event horizon circumference?

Posted: 04 Nov 2021 03:53 PM PDT

Would this make black holes event horizon circumference increase at least one Planck length in size?

submitted by /u/ButterscotchNo2074
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Do fungi get infections/diseases?

Posted: 03 Nov 2021 08:17 PM PDT

We know that plants and animals can get diseases/infections (e.g., from pathogenic bacteria, viruses, fungi, etc.), and bacteria themselves can also be infected by viruses. My question is whether fungi are susceptible to "infection" (however that may be defined), and if so, what the causal organisms (or non-organisms) might be.

submitted by /u/adagietto
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What is the chemical difference between dry erase markers, permanent markers, and tattoo ink?

Posted: 03 Nov 2021 07:05 PM PDT

What makes tattoo ink so permanent? What makes dry erase markers so not permanent? I know the dry erase markers has a solvent with a very low boiling point so it dries quickly but why does that make it eraseable compared to a sharpie?

submitted by /u/jackyman12
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Thursday, November 4, 2021

AskScience AMA Series: I'm Iñigo San Millán, a researcher who trains world-class athletes, including the two-time Tour de France winner, with the goal of learning more about cancer, diabetes and other diseases. I've learned exercise is the most powerful medicine in the world. AMA!

AskScience AMA Series: I'm Iñigo San Millán, a researcher who trains world-class athletes, including the two-time Tour de France winner, with the goal of learning more about cancer, diabetes and other diseases. I've learned exercise is the most powerful medicine in the world. AMA!

AskScience AMA Series: I'm Iñigo San Millán, a researcher who trains world-class athletes, including the two-time Tour de France winner, with the goal of learning more about cancer, diabetes and other diseases. I've learned exercise is the most powerful medicine in the world. AMA!

Posted: 04 Nov 2021 03:37 AM PDT

Hi, Reddit! I'm Iñigo San Millán. I am an assistant professor in the Division of Endocrinology, Metabolism and Diabetes and Medical Oncology at the University of Colorado School of Medicine and associate research professor in the Department of Human Physiology and Nutrition at the University of Colorado, Colorado Springs.

I've also coached Slovenian cyclist Tadej Pogačar to two consecutive Tour de France victories and I try to provide the most precise, scientifically-based training for athletes at the top of their game. But that's only part of it. I also work with elite athletes to better understand the intersection of metabolism and disease, and I've developed new insights into how regular exercise shapes our long-term health.

I'm here to talk about and take your questions on a variety of topics including:

  • What is metabolic health?
  • What's the relationship between exercise and cancer? Or Type II Diabetes and Alzheimer's?
  • Why is exercise the most powerful medicine in the world? And how can different exercises affect how our mitochondrial functions?
  • What kind of training do elite athletes do in order to perform their best?
  • What is the nutrition of a Tour de France winner?

My research is trying to help to identify the role that metabolism could play in the development of different diseases characterized by mitochondrial impairment or dysfunction. I can elaborate on the connection between Type II Diabetes and Alzheimer's, as well as the role that lactate plays in cancer development. I can also explain the most effective form of exercise to maintain metabolic health and how fueling and exercise efficiency looks different for everyone.

I'll sign on around 10AM MT (1 PM ET, 17 UT), AMA!

More Info:

submitted by /u/AskScienceModerator
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I got both a flu shot and a covid booster yesterday, how can my immune system learn from both vaccines at once without getting confused?

Posted: 03 Nov 2021 10:20 AM PDT

I tried to look up "how can I get 2 vaccines at once" but nothing I found answered my question, it was just saying it's safe to have multiple. What I'm curious about is how exactly it's working. Does the fact that they were injected into different arms have something to do with the effectiveness as well?

submitted by /u/Manmade-Object
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In a frozen lake, is the water closer to the surface colder than the deeper water?

Posted: 04 Nov 2021 06:15 AM PDT

I know in the ocean the colder water is denser and therefore closer to the bottom. But if this is the case in a lake why would the ice be at the surface?

submitted by /u/RagnarBaratheon1998
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Are there any places where massive earthquakes might go undetected?

Posted: 04 Nov 2021 12:07 AM PDT

As I'm sitting in the dark next to the water on an island In the middle of the pacific, I started to wonder if its possible for underwater or remote earthquakes to go undetected. Is it possible for an earthquake to occur on an underwater or remote fault line and there's no warning until a tsunami or other subsequent catastrophic event occurs? Do seismographs detect earthquakes everywhere? Are there blind spots?

submitted by /u/loderman
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Is possible to get 2 viruses at once? If so, would one be more dominant than the other?

Posted: 03 Nov 2021 03:13 PM PDT

For example, if you got a flu-like illness but also a cold, would they combine to make you more ill, or would one dominate the other to produce the majority of your symptoms?

Likewise, if you got a viral sickness bug, is it possible to get a bad cold at the same time and have both viruses expressing symptoms simultaneously?

submitted by /u/candytuftalice
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How is heat distributed in the deep ocean compared to shallower parts?

Posted: 03 Nov 2021 04:47 PM PDT

I'm not sure how accurate this is, but I remember learning somewhere deep sea creatures would be the first to cause a major food chain disruption due to global warming and the rise in water temps. However, I was researching the coral reefs and saw the raise in water temp is partly why they're dying. So— do the typical ocean heat patterns apply to the deep sea? If there is a x° change in measurable ocean water temps, does the same apply to the deep sea? Basically I wanna know how doomed we actually are :,)

submitted by /u/bootyysniper
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Influenza testing covid-19 swabs?

Posted: 03 Nov 2021 10:44 PM PDT

I read an article saying that a strain of Influenza-B might have been wiped out. How do we know what strains are out there?
Are swabs for Covid-19 tests also checked for strains of common influenza?
eg "Covid-19 not detected, Influenza-A detected"?

Or do health departments check a percentage of swabs for influenza and other anonymous research?

submitted by /u/lutris_downunder
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What effect did the tree coverage have during high CO2 eras in Earth's history?

Posted: 03 Nov 2021 09:31 PM PDT

So I've always had this question in the back of my head. At one point, the CO2 levels were naturally at extremely high levels. It's the argument that climate deniers used to say that the CO2 spike we have now is just cyclical.

But back when the CO2 levels previously spiked, that was when the earth was covered by much more CO2 absorbing trees/forests/jungles.

Were the high CO2 levels of the past offset by the high number of trees absorbing it? Has the reduction in trees impacted what the floor for a safe CO2 level could be?

submitted by /u/ecchi83
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Differences between 2 peoples EEG scan to the same picture?

Posted: 04 Nov 2021 04:59 AM PDT

If u show 2 people the same picture and scan them with an EEG will they be the same or is there a measurable difference like a fingerprint?

or am i having this completely wrong in the first place?

and is this like a fingerprint?

submitted by /u/dubfighter
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What is the benefit of ELT if PIONIER has a smaller angular resolution?

Posted: 03 Nov 2021 07:14 PM PDT

Good time of day to all. Just as the title says. I was under the impression ELT would blow every other existing optical or near optical telescope out of the water with its' resolution, but I was reading about PIONIER and I'm assuming that combined with VLT's adaptive optics, the virtual telescope that it produces outperforms the capabilities of ELT in resolution.

So

A: What is the benefit of building the ELT as opposed to a larger virtual telescope instead?

B: Does PIONIER make ELT obsolete?

C: Would it not be cheaper and/or quicker to build a PIONIER style virtual telescope with an angular resolution surpassing both ELT and PIONIER?

submitted by /u/NOTvIadimirPutin
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Does blood viscosity increase after a meal? (postprandial blood viscosity)? Does it increase especially highly after fatty meals?

Posted: 03 Nov 2021 12:08 PM PDT

Even meals high in olive oil?

submitted by /u/inquilinekea
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Why does postprandial hyperglycemia damage the cells more than usual even when given a glucose distribution with the same AUC (area under curve)?

Posted: 03 Nov 2021 12:03 PM PDT

Is there any material on Earth that is common here, but rare elsewhere in the universe (Excluding organics, like protein and wood)?

Posted: 02 Nov 2021 06:41 PM PDT

What causes the sand dunes in the desert?

Posted: 02 Nov 2021 07:05 PM PDT

I know wind blows all the sand together in to basically big ass piles. But what causes the piles to start where they do? I guess my question is - when you see one of those really big piles of sand, why did it start there? Did it blow around a rock or a bush or something that gathered all the sand?

submitted by /u/cakebug321
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If computers are completely deterministic, how do irreversible cryptographic hash functions work?

Posted: 02 Nov 2021 04:42 PM PDT

When you encrypt a message, it gets put through some kind of cryptographic hash function that is completely deterministic - put the same message in, you get the same hash. If every step in the process to create the hash is known, why is it so hard to simply walk backwards through the process to obtain the initial message?

submitted by /u/Gimbloy
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What happens when a planet has more than one moon?

Posted: 02 Nov 2021 09:45 PM PDT

I know Jupiter has many moons. How do they orbit ? Do they all orbit the same time or just one goes slow than the others? Does this affect time ? Like longer nights?

submitted by /u/Angela275
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Wednesday, November 3, 2021

Ask Anything Wednesday - Economics, Political Science, Linguistics, Anthropology

Ask Anything Wednesday - Economics, Political Science, Linguistics, Anthropology

Ask Anything Wednesday - Economics, Political Science, Linguistics, Anthropology

Posted: 03 Nov 2021 07:00 AM PDT

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Economics, Political Science, Linguistics, Anthropology

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!

submitted by /u/AutoModerator
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Where is the dark matter in our solar system?

Posted: 02 Nov 2021 11:24 PM PDT

I'm reading this book on astrophysics where they explain how we discovered the presence of an unknown dark matter in distant galaxies. Planets are revolving around stars in a speed much higher than their apparent escape velocity and yet they're bound to orbit that star. Same is the case with smaller galaxies revolving around the bigger ones. So, the remaining mass that is holding those bodies in orbit is coming from something unknown we call dark matter. But, what about the same scenario inside our solar system? Newtonian laws seems to be working fine between earth and sun and we're probably sure that earth would have either escaped or collapsed within sun if we change the speed of revolution. Why there's no similar undiscovered mass or energy holding nearby planets and earth around sun where one of them might have been detected moving at speeds higher than escape velocity and yet managing to stay within a stable orbit due to that same unknown dark matter scientists claim to be everywhere?

P.s: I'm no expert in this field and not sure if I was able to quote my query properly. Thanks in advance

submitted by /u/the_logical_bot
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Can prion diseases be transmitted via a bite from a wild animal such as a squirrel?

Posted: 03 Nov 2021 06:28 AM PDT

Do doctors learn and\or use cauterization in these modern times?

Posted: 02 Nov 2021 10:19 PM PDT

Other than a scar and risk of infection, what are the downsides of this strategy? And is it a valid medical procedure?

submitted by /u/EndrWggn12
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what percentage of a population must be vaccinated for herd immunity against the influenza virus?

Posted: 02 Nov 2021 06:53 AM PDT

How do electromagnetic waves travel through materials? Different wavelengths determine which material it can travel through, but is it a probability thing?

Posted: 02 Nov 2021 09:42 AM PDT

UV light travels through more skin than visible for example but not through glass. doesn't make sense to me. Is there a nice list of which em waves penetrate which matter?
and how do they do it? wouldn't all waves hit some atom at some point? and is it true that only if they hit the atomic nucleus they will be absorbed?

submitted by /u/Jesus_in_Valhalla
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Can a hand grenade detonate underwater?

Posted: 02 Nov 2021 10:32 AM PDT

Say you pull the pin, release the spoon, and toss a grenade into a pool full of water. It seems like the water would put the fuse out. Is that true? If not, why? Is the fuse self-contained or will it burn while wet?

I tried looking into how grenade fuses work, but google isn't much help on this subject.

submitted by /u/kabo72
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