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Friday, December 31, 2021

How easy would it be to crack Nazi encrypted “Enigma" machine with today’s technology?

How easy would it be to crack Nazi encrypted “Enigma" machine with today’s technology?


How easy would it be to crack Nazi encrypted “Enigma" machine with today’s technology?

Posted: 30 Dec 2021 10:08 PM PST

That seemed like unreal tech back in the day. I'm curious how easy it would be for us to crack it today.

submitted by /u/LJT84
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Thursday, December 30, 2021

Do we have evidence that Omicron is "more mild" than Delta coronavirus?

Do we have evidence that Omicron is "more mild" than Delta coronavirus?


Do we have evidence that Omicron is "more mild" than Delta coronavirus?

Posted: 30 Dec 2021 06:42 AM PST

I've seen this before in other topics, where an expert makes a statement with qualifications (for example, "this variant right now seems more 'mild', but we can't say for sure until we have more data"). Soon, a black and white variation of the comment becomes media narrative.

Do we really know that Omicron symptoms are more "mild"? (I'm leaving the term "mild" open to interpretation, because I don't even know what the media really means when they use the word.) And perhaps the observation took into account vaccination numbers that weren't there when Delta first propagated. If you look at two unvaccinated twins, one positively infected with Delta, one positively infected with Omicron, can we be reasonably assured that Omicron patient will do better?

submitted by /u/jdtrouble
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Two bowling balls are at rest 5 Megaparsecs apart, and connected with a cable. Is there any tension in the cable caused by universal expansion?

Posted: 30 Dec 2021 12:32 PM PST

According to Hubble's Law, at 5 Mpcs distance each bowling ball would see the other receding at 351.5 km/s, but the cable prevents that from happening. Does that mean there's a "cosmological stress" in the cable induced by the expansion?

submitted by /u/TheFuzziestDumpling
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How come men can lose their hair, while it rarely happens in women?

Posted: 30 Dec 2021 04:55 AM PST

What biological processes exist for women that make them much less likely to go bald?

submitted by /u/69420sixnine69
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How does half life work?

Posted: 30 Dec 2021 05:56 AM PST

What isn't whole life stated instead of half life?

submitted by /u/royhinckly
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Why does solar pressure cause rotations of the JWST instead of just pushing it away uniformly?

Posted: 30 Dec 2021 11:37 AM PST

I've been curious about this for a long time and I expected that when the Aft Momentum Flap was eventually deployed (as it was today), there would be more layman-accessible explanations of this; however, I've not found any.

My naive first guess about how solar pressure would affect JWST would be that the force would be uniformly in one direction: outward from the sun, and therefore cause it to move slightly away from the sun over time, but not cause any changes in rotations or orientation. So how, exactly, does solar pressure cause rotations of the JWST instead?

So far the only explanation I've found is what it says in NASA's blog, which doesn't explain how solar pressure causes rotations (https://blogs.nasa.gov/webb/2021/12/30/webbs-aft-momentum-flap-deployed/):

"The aft momentum flap helps minimize the fuel engineers will need to use throughout Webb's lifetime, by helping to maintain the observatory's orientation in orbit. As photons of sunlight hit the large sunshield surface, they will exert pressure on the sunshield, and if not properly balanced, this solar pressure would cause rotations of the observatory that must be accommodated by its reaction wheels. The aft momentum flap will sail on the pressure of these photons, balancing the sunshield and keeping the observatory steady."

One explanation that occurred to me is that the telescope is running into more solar wind in the direction of motion (like how a fast runner runs into more rain droplets on their front than their back), is that on the right track?

Bonus question: how does the Aft Momentum Flap counteract the force? (Although perhaps the answer will be self-evident after one understands the reason for the rotation.)

submitted by /u/stdio-lib
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what are periods like for people in space/the iss?

Posted: 30 Dec 2021 04:07 AM PST

In terms of number of planets, how big is our solar system compared to other planetary systems discovered?

Posted: 30 Dec 2021 08:36 AM PST

Do animals' seasonal adaption cycles (antlers, winter coats, etc.) change if the animal is transported from the northern to southern hemisphere? (or vice versa)

Posted: 30 Dec 2021 07:44 AM PST

How do you use the JWST?

Posted: 30 Dec 2021 03:45 AM PST

The JWST is on its way, it's make me wonder who and how do you use it? To all astronomers in this group who have used a space telescope, what is the bureaucracy and technical process of using such a device?

submitted by /u/Duchy_ofConstelation
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What exactly IS displacement current and why is it called current if its not actually a current?

Posted: 30 Dec 2021 09:53 AM PST

So I thought displacement current was essentially current per area, as those are its units, but RobusEtceterus pointed out, in another thread, that it doesn't actually jave anything to do current and is instead a time varying E field. But if it a time varying E field, why doesn't it have units of (E field)/time?

I did look up displacement current and Wikipedia says it's the time derivative of D. I learned about the D field a couple months in my intro to electromagnetics course and the definition I was using then, as it's the only one I could find that made any kind of intuitive sense, from www.byjus.com is: "Electric displacement, denoted by D, is the charge per unit area that would be displaced across a layer of conductor placed across an electric field. It is also known as electric flux density."

The term "displacement" make it sound like the charges are actually moving, which of course makes me think of a current, but thinking more careful about the above definition, it say "the charge per unit area that would be displaced", which makes it sound like there isn't any actual displacement. But, it would be displaced...if what? And if displacement current is the time derivative, that makes me think there has to be SOME movement going on, and if the charges are, moving, them wouldn't that mean a current? Furthermore, how is this related to the E field anymore than regular old current is? (That's not to say that current isn't related to the E field, but that we usually use voltage and current as higher level abstractions to avoid having to explicitly talk about fields, and I don't see how displacement current is anymore linked to the E field than the current is).

submitted by /u/dcfan105
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Can you get Covid from animals infected with the Sars-Cov-2 virus?

Posted: 29 Dec 2021 05:26 PM PST

ETA: I meant if you eat the flesh of the animal - ie: deer. Sometimes my mind goes faster than my finger can type lol

submitted by /u/AlphaMomma59
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Just how unique are HeLa cells?

Posted: 30 Dec 2021 07:26 AM PST

Simplifying the question, out of 8 billion people, how many would have this type of cell structure and behaviour? Do you have to have cancer for this kind of multiplication or can it happen in normal, healthy cells too?

I tried to google the question without success. I am guessing it might be impossible to answer correctly. Wikipedia says there are other immortalized cell lines, including from monkey kidney. I am curious about the occurrence of that behaviour in humans.

submitted by /u/VirtualMoneyLover
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Are there plane-filling curves that fill an infinite plane?

Posted: 30 Dec 2021 08:29 AM PST

How does Humira (TNF-a antagonist) differ from Skyrizi (IL-17/23 inhibitor)?

Posted: 30 Dec 2021 03:28 AM PST

I'm curious how these biologics relate to one another, and specifically how TNF-a influences skeletal muscle

submitted by /u/Perceptive_Peter
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How did scientists know about the presence of brain neurotransmitters and what they are made of?

Posted: 30 Dec 2021 12:10 AM PST

Like, we know about serotonin, dopamine, endorphin, etc. but how did the study of it all started? And how did scientists know what chemical compounds the neurotransmitters are made of?

submitted by /u/nomorewigstofly
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How Is adderall related to meth?

Posted: 30 Dec 2021 01:05 AM PST

I saw that the adderall has amphetamine salts but I've never taken a chemistry course so I'm wondering what exactly does that mean to it's relation with meth.

How are they the same? Are they different?

submitted by /u/DisappearLikeElChapo
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At what scale is the universe expanding?

Posted: 29 Dec 2021 11:52 PM PST

I understand (more or less, a lot less) that the universe isn't expanding "into" anywhere, but where within the universe is the expansion happening? Is the space between atoms, or the subatomic particles comprising atoms increasing? Are the particles themselves getting bigger? (Compared to what?) Am I getting bigger? (Besides the quarantine 15 I mean). Is the distance between the earth and the moon, or the sun, or the distance from New York to London getting bigger?

submitted by /u/1-900-USA-NAILS
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Does the James Webb telescope have an increased risk of dust or micrometeorites impacts at the L2 point?

Posted: 30 Dec 2021 04:22 AM PST

Does the L2 point have any significant attraction that would put James Webb at increased risk of damage to its mirrors from stray dust?

I'm not very familiar with the mechanics of the Lagrangian points...

submitted by /u/The_Brewer
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A fossilized therapod embryo named "Baby Yingliang" was recently discovered in China. How can scientists tell from a fossil that the embryo was a dinosaur and not a more modern bird?

Posted: 29 Dec 2021 05:32 PM PST

A fossilized therapod embryo named "Baby Yingliang" was recently discovered in China about a week ago, and the pictures of it look remarkably (to my untrained eye) like a bird. I know the link between therapods and birds is a big part of why this fossil is interesting, but how can they be so sure it's a dinosaur and not just some extinct bird? Can you DNA test a fossil? (I feel like you can't)

submitted by /u/Catatonic27
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Will the JWST sun sheild unintentionally act as a solar sail?

Posted: 30 Dec 2021 04:19 AM PST

I have heard of the concept of solar sails before and am curios (tried searching the subject) if the JWST sun sheild will unintentionally act as a solar sail and need to some how be accounted for and off set.

submitted by /u/keel_zuckerberg
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Wednesday, December 29, 2021

What is the incubation time of the corona virus?

What is the incubation time of the corona virus?


What is the incubation time of the corona virus?

Posted: 29 Dec 2021 03:31 AM PST

Two years ago it was explained that the great danger of covid was the long incubation of roughly two weeks between infection and outbreak/symptoms. So you would go around and spread it without realizing you were carrying it.

How is the situation now, especially regarding the new variants? Is the incubation time more precise now? Googling this info gave me a headache. Just too much about this topic. Any input if we are at the same spot as two years ago or more advanced is much appreciated!

submitted by /u/SpaceJinx
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How was cancer treated in the 1930s or 1940s did the treatments work or did you just die?

Posted: 29 Dec 2021 01:33 AM PST

How does my brain understand where pain is spatially located?

Posted: 29 Dec 2021 04:01 AM PST

Hi,

I understand the basics of how pain and nervous system work: when something bad happens, our nerves fire pain signals. However, the thing that eludes me is: how does brain know where the pain is spatially located? For example, when my stomach hurts, I usually can point at the location of the pain, I can feel in what part of stomach the pain is localized. As far as I understand and my basic logic tells me, the brain needs to know where certain nerve endings are located spatially, the mapping of nerves and organs and the mapping of organs and their locations in my body. Does the brain learn the mapping when we grow up? Or is there another way of localizing of pain? How does the brain know where, e.g., my stomach is located spatially in my body?

I honestly tried googling, but can't seem to find anything remotely helpful. Maybe someone can point me in the right direction what I can read about to understand the answer to my question (e.g., how is this phenomena called)?

submitted by /u/gnomeweb
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When we shine a light through coloured plastic/cellophane, the light projected assumes that colour. Does this mean that the photons themselves are being coloured as the pass through the plastic?

Posted: 29 Dec 2021 03:04 PM PST

How does a nuclear reaction actually begin?

Posted: 29 Dec 2021 10:57 AM PST

In a nuclear reactor, how do they get the uranium 235 to actually begin fission? I've tried to find out how but have no idea. I understand that you need a neutron to hit an atom of U235 which then splits into fission products and an average of 2.45 neutrons, but where does the first neutron come from?

Do we just stick the material into a moderator I.e. water, and let stray neutrons slowly begin the reaction then use the control rods to slow it down once it's going? Or do we inject a big spike of neutrons to begin the reactions? What goes on when we need to restart the reaction?

submitted by /u/Dannycrew106
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What types of liquids can form oceans on planets?

Posted: 29 Dec 2021 06:19 AM PST

Can explosives be detonated with sound waves?

Posted: 28 Dec 2021 05:59 PM PST

Can explosive compounds be agitated via sound waves (or really any type) so as to result in an explosion? If not, then why?

Edit: ultimately I'm curious if, in the future, sound waves could be used to detonate minefields.

submitted by /u/whereslyor
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Are there viruses that find sources of energy outside of cell synthesis (like eating) or are they created with a set amount of energy and must replicate before they "die"?

Posted: 28 Dec 2021 02:25 PM PST

Self explanatory.

submitted by /u/rougekilldrone
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Ask Anything Wednesday - Economics, Political Science, Linguistics, Anthropology

Posted: 29 Dec 2021 07:00 AM PST

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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Is there a difference in how energy is transferred due to AC current vs DC current?

Posted: 29 Dec 2021 02:29 PM PST

I was just watching this video about how capacitors work and the guy mentions at the end that the energy flow in a circuit isn't the kinetic energy of the electrons but the energy from the Pointing vector, which is perpendicular to both the E and B fields. I asked him for clarification in the comments, saying I thought it was because EM waves are transverse waves and he said that could work for AC but not DC, since there's no oscillation in the field with DC circuits and that he actually wasn't sure what the energy transfer mechanism is for DC current.

So now I'm confused. IS the energy transfer from electricity normally a result of EM waves? It seems like it has to be, because waves inevitably transfer energy, and I see no other mechanism for energy transfer in this context, if it's not the kinetic energy of the electrons. But how can it be for DC circuits, since, as the YouTuber said, the field doesn't oscillate due to DC current.

submitted by /u/dcfan105
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Who was the first person who discovered that moon has reflected light?

Posted: 29 Dec 2021 05:36 AM PST

I already searched on google but couldn't find any source. Some say that it was leonardo da vinci, and some say that it was Anaxagoras.

submitted by /u/skepticSapien
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How do interrupt handlers get context about what caused the interrupt?

Posted: 28 Dec 2021 08:48 PM PST

I've been reading about interrupts in a general sense and I understand the concept of devices or programs triggering an interrupt, which is handled by an interrupt service routine. What I don't understand is how the interrupt handler knows what exactly happened beyond "this device requested an interrupt".

By "context" I mean something like pressing 'K' on a keyboard as opposed to the space bar. The keyboard sends an interrupt request to the to a hardware pin but how does that tell the computer which specific key was pressed?

submitted by /u/TechnophiliusP
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What's the peak timeframe after a stroke when its most likely to show up on an MRI?

Posted: 29 Dec 2021 08:29 AM PST

Non-native English speaker here.

Does someone have a graph that shows the peak time range when strokes (or TIAs) are most likely to show up on an MRI? And the time range where the stroke (or TIAs) are least likely to show up.

submitted by /u/Experimentalphone
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Since the James Webb Telescope is collecting very low quantities of light, how do they decide where to point it?

Posted: 29 Dec 2021 06:06 AM PST

When archeologists find a fossil millions of years old, how do they determine its age if carbon dating has a limit of ~60,000 years?

Posted: 28 Dec 2021 08:03 PM PST

Does mRNA based protein synthesis happen at the same rate for everyone for a given volume of mRNA?

Posted: 29 Dec 2021 09:38 AM PST

I am just like fascinated by the advancements with vaccines that Covid brought.

So, the Covid mRNA vaccines I understand are mRNA encapsulated with nano lipids. Cells ingest them, the golgi apparatus takes in the package, ribosomes begin reading the mRNA and translating it to amino acids.

At some point the mRNA degrades.

This is all my layman understanding.

People have different reactions to the vaccine. It is normal, and just an immune response, it is safe and tested etc. Science effectively hijacked a specific process that happens anyway with a traditional vaccine with attenuated viruses or infection.

Are people effectively getting different doses of the payload, though, where the end result is spike proteins being produced? Can people be more or less efficient at transcribing mRNA? Or does a given volume of mRNA always result in the net same amount of protein synthesis?

Could that partially explain why people react differently?

submitted by /u/d13f00l
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Why do thinly cut foods stay hard when boiled but thicker cuts go soft?

Posted: 29 Dec 2021 07:34 AM PST

First time father here. I've noticed when stewing/boiling apples or carrots, the ticker I cut them, the softer the get when boiled. Anyone know why?

submitted by /u/Consequations
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Geologists and earth scientists here, what does it mean to say that a place is 60 m high from sea level? Can we dig that and get the actual sea?

Posted: 28 Dec 2021 06:41 PM PST

Context: I am from Nepal and it is a landlocked country with no sea or ocean. The lowest point on our geography is 59 m above sea level and i was wondering if we could dig a 60m deep hole and have sea water. I looked up The deepest hole and found it was 7 km deep. Surely it is possible to dig 60 m. Has it ever been done before?

submitted by /u/Salty_Constant_9878
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What are the chances of the James Webb Space Telescope being struck by space debris?

Posted: 28 Dec 2021 08:12 PM PST

The JWST launch has been so captivating! Its construction seems so delicate given the precision its measurements will require, though. What are the chances it sustains non-insignificant damage due to colliding with space junk over the course of its mission?

submitted by /u/Soontaru
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What's the point of rocket fuel in space?

Posted: 28 Dec 2021 12:54 PM PST

Ignoring everything else, and just looking at the third law of motion, then what's the point of using combustion in space?

Couldn't you just use hydrogen tanks that could just open and let the vacuum of space drag it out and create forwards motion?

I mean, lighting the fuel just seems like an awful waste of energy going into heat instead of kinetic energy

What is it that I don't get?

submitted by /u/xXugleprutXx
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Tuesday, December 28, 2021

It is reported that redheads, with their mutated MC1R gene, require about 20% more anesthesia than the average person. Are there other reported correlations between this gene and other effects (pain tolerance, drug tolerance, metabolism, etc...)?

It is reported that redheads, with their mutated MC1R gene, require about 20% more anesthesia than the average person. Are there other reported correlations between this gene and other effects (pain tolerance, drug tolerance, metabolism, etc...)?


It is reported that redheads, with their mutated MC1R gene, require about 20% more anesthesia than the average person. Are there other reported correlations between this gene and other effects (pain tolerance, drug tolerance, metabolism, etc...)?

Posted: 28 Dec 2021 05:44 AM PST

How does NASA and other space agencies protect their spacecraft from being hacked and taken over by signals broadcast from hostile third parties?

Posted: 27 Dec 2021 06:18 AM PST

What is the science behind CDC reducing quarantine to 5 days for covid?

Posted: 28 Dec 2021 07:27 AM PST

The CDC recently reduced quarantine guidelines stating: "The change is motivated by science demonstrating that the majority of SARS-CoV-2 transmission occurs early in the course of illness, generally in the 1-2 days prior to onset of symptoms and the 2-3 days after. ". Sounds good but they don't provide references. What is the actual evidence?

https://www.cdc.gov/media/releases/2021/s1227-isolation-quarantine-guidance.html

submitted by /u/deckertwork
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What symptoms of the virus are the virus and what are the symptoms of the body defending against the virus?

Posted: 28 Dec 2021 12:06 AM PST

How Credible is the theory of Flow?

Posted: 28 Dec 2021 07:47 AM PST

asking about how flow is described in the book: flow psychology of optimal experience

If so are there some scientifically proven methode to achieve flow no matter what

submitted by /u/BlintzKnight43
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Does contracting and overcoming COVID at some point after full vaccination boost your COVID immunity in a comparable way to a booster shot?

Posted: 28 Dec 2021 11:09 AM PST

Are there proteins that do nothing? Neutral things that natural selection didn't "care about".

Posted: 27 Dec 2021 09:45 PM PST

Surely it must be the case, just like we have useless bones, right? Or would such proteins be necessarily bad for our body?

submitted by /u/Stupid_Idiot413
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What's the human body tolerance for sustained lateral acceleration?

Posted: 28 Dec 2021 02:15 AM PST

Hello reddit. I was wondering what the limit is for lateral acceleration for the human body. I'm interested in sustained acceleration, like from cornering at high speed, not in peak acceleration, like from a crash. I would also be interested in repeated short periods of acceleration, so, again, like a car driving around a circuit, but I understand this information might not be available.

I've been looking around but there is much more research about vertical and longitudinal acceleration, which is understandable since that's more relevant for aircraft and spacecraft. So I'm having trouble finding what I want. Thanks in advance!

submitted by /u/MrTrt
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How sure are we that the "original" virus that causes Covid 19 identified in Wuhan was the "original" and not a mutation of an undetected coronavirus?

Posted: 28 Dec 2021 10:22 AM PST

Is it possible the "original" just went undetected and a more serious variant was the one identified at the start of the pandemic?

submitted by /u/mjthegreat
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How does the JWST slow down to stop in the L2?

Posted: 27 Dec 2021 03:52 PM PST

Title sorry that's all I got. Couldn't google anything that comprehended my understanding. Please link any articles if you have any. Would love to read up on this particular part of the JWST operation. Also sorry if I don't respond immediately. Just worked a 13 hour shift and got another 11 hour shift tmrw. Need some sleep...

submitted by /u/Adistrength
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Is it true that sitting in front of a screen for too many hours each day is bad for your eyes?

Posted: 27 Dec 2021 05:50 PM PST

How long does it take for a virus to replicate?

Posted: 27 Dec 2021 08:37 PM PST

Basically, once a virus enters a cell, how long does it take to do its dirty work and rupture the cell and releasing more copies? A few minutes? A couple days? Could it be broken down into essentially a chemical reaction?

submitted by /u/cracksintheegg
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Do allergens become less potent over time?

Posted: 27 Dec 2021 09:46 PM PST

For example, say I'm allergic to dogs, and I visit a friend's house that has dogs and some dog hair gets onto my scarf.

I wear the scarf the following week and sneeze a bit more due to the dog hair on the scarf.

Then winter is over and I put the scarf uncleaned away until next winter, will I have as much of a reaction from the allergens on the scarf than I did the past winter?

Comparing apples to apples and just the allergens on the scarf.

Do they lose potency over time as in do the allergens break down or are they just as potent?

Corollary? Should I be dry cleaning my scarves every winter?

submitted by /u/dtanmango
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Do birth defects cause more preterm births, or do preterm births cause more defects? If the latter, does the rise in preterm births due to COVID mean higher risk for birth defects?

Posted: 27 Dec 2021 09:06 PM PST

So after a bit of research I've found a few sources00019-3/fulltext) showing that women who had COVID during pregnancy have an increased risk of preterm birth than women who didn't have COVID.

And in the conclusion of this study it says "Birth defects contribute to the occurrence of preterm birth", suggesting that it is the birth defect that increases the chances of preterm birth. They found that 3% of full term births had defects and 8% of preterm (2.65x risk).

So the question is: do the babies born to a mother who was sick with COVID have a higher risk of birth defects, and that is causing the rise in preterm births? Or are they healthy babies that are just preterm?

The easy way to find out would be to see if the rate of birth defects has changed in total or in preterm overall. It the rate of defects for preterm births has not changed (or gone up), that would mean COVID is increasing risk of defects. But if the rate is going down, then COVID is not causing defects and they are otherwise healthy babies. Unfortunately I have not been able to find any data or studies with this yet myself.

submitted by /u/Solmors
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What determines the temperature of space?

Posted: 27 Dec 2021 11:23 AM PST

I read that the temperature of space is -270C, although I can't fathom why an empty vacuum would have a temperature. It doesn't seem like there should be any source of heat or cold to influence this, so ideally, it should be 0.

submitted by /u/69420sixnine69
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Diet planning based on genetic tests or blood genotype tests. Science or scam?

Posted: 27 Dec 2021 02:59 PM PST

I am wondering is there any sense in ordering genetic tests or blood genotype tests,

made by more and more private, commercial genetic laboratories? Is that evidence-based medicine?
Or it is simply a scam?

For example, today i have seen advertisement:
It is a genetic test that allows the determination of a unique nutritional profile and individual DNA diet.

The test consists of analyzing 20 genes - metabolism and obesity, vitamin and antioxidant metabolism, and food intolerances.

submitted by /u/alfokloda
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How do respiratory viruses spread in the body?

Posted: 27 Dec 2021 05:49 PM PST

I'm aware that viruses like an influenza or a common cold replicate in the respiratory tract, but my question is what is the mechanism for spreading? Is it confined to locally spreading from one adjacent cell to the next? (Is this how a viruses reaches the lungs for example) or can it get into the blood stream and get transported to other tissues?

If for example influenza can't get into the bloodstream, how/does it(?) infect other organs or cause organ failure?

I know that some viruses like HIV are found in the bloodstream, so what decides if the virus is able to get into the bloodstream or not?

Thank you so much

submitted by /u/mostinho7
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Is it possible to create a resonant („LC“) circuit that creates visible light? (At a wavelength of ~500nm)

Posted: 27 Dec 2021 05:52 AM PST

Is grafting plants hybridization?

Posted: 27 Dec 2021 09:03 PM PST

Is it just hybridization of plants by attaching a branch to a stem? Can almost any plant do this?

Further questions with an example: suppose I have a plant very known for taking in heavy metals and storing it, then I graft another plant to it where the leaves are known to grow in almost any weather. Would that work/exist?

submitted by /u/zepharoz
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Can crabs or other crustaceans catch prion diseases like Kurus or something similar? Whether yes or no, why?

Posted: 27 Dec 2021 05:13 PM PST

Why does a lower centre of mass correspond to higher stability ?

Posted: 27 Dec 2021 08:10 AM PST

A lower centre of mass for an object (ie) when the centre of mass is near the base of the object ,it has higher stabilty ,now why is this the case?

Is it because when the centre of mass is lower ,the potential energy is less ,so it's in a stable equilibrium ?

submitted by /u/EulerMathGod
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Does taking two lateral flow tests at the same time have a multiplicative effect on the results' specificity and sensitivity?

Posted: 27 Dec 2021 01:02 PM PST

I understand the lateral flow tests should, properly administered, detect COVID between 70 and 90 per cent of the time, perhaps slightly higher than that in the early days of syptoms.

Let's assume 90 per cent is correct. Does taking two LFs at the same time, and getting 2 negatives, mean you are approx 1% (90% * 90%) likely to have COVID and 99% likely not to have it? If it doesnt work like that, why not? Would taking the second test the next day change the answer?

Same questions but in reverse for sensitivity

submitted by /u/GooseOfTheLine
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Why do some birds (owls, eagles) have feathers on their legs while others (seagulls, corvids) don't?

Posted: 26 Dec 2021 08:15 AM PST

Is it to do with flight? Warmth? Other? Does this factor into taxonomy?

submitted by /u/fromthemakersof
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What conditions produce a predominately deciduous versus coniferous forest?

Posted: 27 Dec 2021 09:11 AM PST

Is it a matter of soil quality, water, sunlight, or some combination of all these factors?

submitted by /u/Kumquats_indeed
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