What does it mean to “solve” Einstein's field equations?

---

• What does it mean to “solve” Einstein's field equations?
• Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology
• If most matter gets hot as it expands and cools as it contracts, why is it that Freon refrigerant cools down as it goes through expansion?
• Since spacecraft are electrically floating ground, are there any issues with docking spacecraft that are a different voltage potential? And since near-earth space is filled with a very thin electrically charged plasma, does this cause a charge to accumulate?
• [mechanical engineering/planatery] why is 3 km/s considered as hypervelocity?
• How does zero gravity affect human physiological processes?
• Why is epinephrine a dopamine agonist?
• Is there any truth to the idea of the "lost continents"?
• Why are mid-ocean ridges “staggered” (leading to transform boundaries)?
• Why aren't the relative melting and boiling points of metals consistent?

What does it mean to “solve” Einstein's field equations? Posted: 26 Oct 2021 07:53 AM PDT I read that Schwarzschild, among others, solved Einstein's field equations. How could Einstein write an equation that he couldn't solve himself? The equations I see are complicated but they seem to boil down to basic algebra. Once you have the equation, wouldn't you just solve for X? I'm guessing the source of my confusion is related to scientific terms having a different meaning than their regular English equivalent. Like how scientific "theory" means something different than a "theory" in English literature. Does "solving an equation" mean something different than it seems? Edit: I just got done for the day and see all these great replies. Thanks to everyone for taking the time to explain this to me and others! submitted by /u/MichaelApproved [link] [comments]

Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology Posted: 27 Oct 2021 07:00 AM PDT Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Biology, Chemistry, Neuroscience, Medicine, Psychology Do you have a question within these topics you weren't sure was worth submitting? Is something a bit too speculative for a typical /r/AskScience post? No question is too big or small for AAW. In this thread you can ask any science-related question! Things like: "What would happen if...", "How will the future...", "If all the rules for 'X' were different...", "Why does my...". Asking Questions: Please post your question as a top-level response to this, and our team of panellists will be here to answer and discuss your questions. The other topic areas will appear in future Ask Anything Wednesdays, so if you have other questions not covered by this weeks theme please either hold on to it until those topics come around, or go and post over in our sister subreddit /r/AskScienceDiscussion , where every day is Ask Anything Wednesday! Off-theme questions in this post will be removed to try and keep the thread a manageable size for both our readers and panellists. Answering Questions: Please only answer a posted question if you are an expert in the field. The full guidelines for posting responses in AskScience can be found here. In short, this is a moderated subreddit, and responses which do not meet our quality guidelines will be removed. Remember, peer reviewed sources are always appreciated, and anecdotes are absolutely not appropriate. In general if your answer begins with 'I think', or 'I've heard', then it's not suitable for /r/AskScience. If you would like to become a member of the AskScience panel, please refer to the information provided here. Past AskAnythingWednesday posts can be found here. Ask away! submitted by /u/AutoModerator [link] [comments]

If most matter gets hot as it expands and cools as it contracts, why is it that Freon refrigerant cools down as it goes through expansion? Posted: 27 Oct 2021 01:10 AM PDT I'm learning about the refrigeration cycle and this is confusing to me as I've always read how objects expand when hot (metal, water, wood, etc) and contract when cool. submitted by /u/HumanPersonDude1 [link] [comments]

Since spacecraft are electrically floating ground, are there any issues with docking spacecraft that are a different voltage potential? And since near-earth space is filled with a very thin electrically charged plasma, does this cause a charge to accumulate? Posted: 26 Oct 2021 10:47 AM PDT submitted by /u/Luxuriousmoth1 [link] [comments]

[mechanical engineering/planatery] why is 3 km/s considered as hypervelocity? Posted: 26 Oct 2021 09:10 AM PDT going by this wikipedia article on hypervelocity wouldn't it be more accurate to describe it as hypersonic? afte rall in space we have hypervelocity objects flying closer to a few thousands of kilometers per second with the highest theoretically calculated being 48,000,000 km/h or 13,333 km/s which does make the hypervelocity limit on earth seem a bit too low to coin it as such submitted by /u/MLPorsche [link] [comments]

How does zero gravity affect human physiological processes? Posted: 26 Oct 2021 05:48 PM PDT I'm assuming that a lot of human body processes rely at least in part on gravity being a factor (blood flow, swallowing food, etc), does anyone know if astronauts have to do anything special to counteract this, or does zero G not affect those kinds of things at all? submitted by /u/-hellogoodbye-- [link] [comments]

Why is epinephrine a dopamine agonist? Posted: 26 Oct 2021 02:48 PM PDT I know epinephrine is made out of dopamine, so it makes sense that dopamine is an epinephrine agonist, but why the opposite is also true? What is the mechanism behind it? submitted by /u/Gabrielr66y [link] [comments]

Is there any truth to the idea of the "lost continents"? Posted: 26 Oct 2021 06:01 PM PDT I'm not talking about Pangea or Gondwana, but for example Zealandia, "the 8th continent". This video has a lots of views and likes and makes me confused. Are a lot of people being tricked into believing nonsense? https://www.youtube.com/watch?v=NmFUFnMj5Jw submitted by /u/Vargohoat99 [link] [comments]

Why are mid-ocean ridges “staggered” (leading to transform boundaries)? Posted: 26 Oct 2021 09:52 AM PDT I can picture how two offset spreading centers leads to a transform boundary, but why should they be offset in the first place? Why should there be many mini-transform boundaries along a mid-ocean ridge, instead of the ridge just being a uniform line (or curve in the Earth's case)? Just something that occurred to me when seeing a map of plate boundaries. submitted by /u/opteryx5 [link] [comments]

Why aren't the relative melting and boiling points of metals consistent? Posted: 25 Oct 2021 05:13 PM PDT Why does tin have a low melting point but a very high boiling point when zinc has a higher melting point than tin but a much lower boiling point? Shouldn't the inter-atomic forces that make a higher melting point also make a higher boiling point? submitted by /u/AshingiiAshuaa [link] [comments]

You are subscribed to email updates from AskScience: Got Questions? Get Answers.. To stop receiving these emails, you may unsubscribe now.	Email delivery powered by Google
Google, 1600 Amphitheatre Parkway, Mountain View, CA 94043, United States

Does the rainfall from once-in-a-lifetime storms help drought conditions?

---

• Does the rainfall from once-in-a-lifetime storms help drought conditions?
• Can "hybrid" caves form, in which some chambers are lava tubes, and others made by limestone dissolving?
• How is the magnetism of bar magnet the same force as in an electromagnet?
• How was the mRNA in COVID-19 vaccine created?
• How can fish be so active in cold water when other cold blooded animals like reptiles and amphibians need the Sun to warm up?
• What makes a caterpillar become a moth or butterfly?

Does the rainfall from once-in-a-lifetime storms help drought conditions? Posted: 25 Oct 2021 08:41 AM PDT Yesterday, the bomb cyclone that hit California dropped record rainfall on many locations in the state. My question is whether this record rainfall is as beneficial to overall drought conditions as a year that gets higher than average rainfall over a period of months? Like is this water able to enter the water table or does it just runoff into streams/rivers and eventually the ocean without being usable for consumers? submitted by /u/OStateDeadHead [link] [comments]

Can "hybrid" caves form, in which some chambers are lava tubes, and others made by limestone dissolving? Posted: 25 Oct 2021 02:13 PM PDT I'm wondering about speleogenesis - the formation of cave systems. As I understand it, there are really only 3 types of caverns - those formed when groundwater dissolves holes into limestone karsts, those formed by lava flows after the lava recedes, and the rare case of sub-glacial ice caves formed between a layer of ice and a stone floor as the glacier melts. What I am wondering is, could you get a situation where a limestone cave and a lava tube cave connect or overlap? Perhaps a way to think of this is "can you find both lava and limestone in the same place?". submitted by /u/Stewart_Games [link] [comments]

How is the magnetism of bar magnet the same force as in an electromagnet? Posted: 25 Oct 2021 11:58 AM PDT So I get how changing the E field generates the B field, and vice versa and how that lets us create electromagnets. I even get how SR explains the changing reference frames so that what's a B field w.r.t. one coordinate system could be an E field w.r.t. another coordinate system. What I don't get is how "classical" (for lack of a better term) magnets come in. What's the reference frame where a bar magnet actually generates an electric force instead of a magnetic force? I know magnetism in "classical" magnets and things like iron is due to the spin of electrons and if "spin" in QM actually meant "spin" in the usual sense, it'd made perfect sense how this is ultimately the same thing as how electromagnets work. But it's been emphasized to me MANY times that the "spin" of a particle does NOT mean the particle is actually spinning, but instead spin it's own separate property that doesn't have a classical analog. OK, so then how does it have the same effect on the E field at an atomic level as macroscopic movement does to the E field on a macroscopic level? To be clear, I'm not disputing that "spin" doesn't mean the particle is actually spinning. I'm just very confused about a force generated by some mysterious quantum property with no classical analog is the same as the force generated by electromagnetics. submitted by /u/dcfan105 [link] [comments]

How was the mRNA in COVID-19 vaccine created? Posted: 25 Oct 2021 05:34 PM PDT I was wondering if they used CRISPR Cas-9 to edit the mRNA for the vaccine. I couldn't find any sources how specifically how they made the mRNA submitted by /u/jac5423 [link] [comments]

How can fish be so active in cold water when other cold blooded animals like reptiles and amphibians need the Sun to warm up? Posted: 24 Oct 2021 08:35 PM PDT I have two fish tanks one half full of water with a turtle. The turtle needs to bask in a heat lamp for at least half the day to have the energy to go "hunting" around his terrarium. In a different cold water tank I have some very active and energetic fish that seem to swim non-stop and only have to eat every other day. submitted by /u/AnyOldUserNameWiIIDo [link] [comments]

What makes a caterpillar become a moth or butterfly? Posted: 24 Oct 2021 09:46 PM PDT submitted by /u/QuiEstLui [link] [comments]

You are subscribed to email updates from AskScience: Got Questions? Get Answers.. To stop receiving these emails, you may unsubscribe now.	Email delivery powered by Google
Google, 1600 Amphitheatre Parkway, Mountain View, CA 94043, United States

How do we actually know the number of protons in a nucleus/atomic numbers?

---

• How do we actually know the number of protons in a nucleus/atomic numbers?
• What is the meaning when people say “99.99% the speed of light” instead of just speed of light?
• Are there any avian species that haven’t evolved significantly since the Cretaceous mass extinction event?
• How long does it typically take for a planet to form?
• Are there any jet aircraft that carry their own oxidizer?
• How Do Engineers Work Around Material Fatigue?
• Does an allergic reaction to an ingredient in a vaccine make the vaccine less effective?
• The electrostatic deflection of water, and Can a stream of water be deflected by a magnetic field?
• How is it possible for a river to dry up completely then go back to normal without a mass extinction level event?
• Why are congenital brain deformities(i.e. Alobar Holoprosencephaly, Anencephaly, Syncephalus) so deadly and if physically possible can current medical technology keep these children alive beyond a few hours?
• With Covid-19 boosters rolling out, are we seeing a drop in antibody titres in the months after the third shot just as we did after the second?
• If tectonic plate elevation causes mountains to form, why are there valleys between mountain ranges?
• Lots of products claim to "boost" or "speed up" your metabolism. Is that actually a thing that can be done, and if so, what's the science behind it?
• What is the general effect of exposing a plant to continuous illumination?
• What treatment(s) does the US do to its water that makes it safe to drink that other countries don't do?
• How does sound travel after breaking the sound barrier?

How do we actually know the number of protons in a nucleus/atomic numbers? Posted: 24 Oct 2021 08:24 PM PDT I'm just curious as to the method by which atomic numbers for each element were discovered. We obviously don't have microscopes that can see down to that level, so it's clearly not known by direct visual means, but I've struggled to find a good answer through search engines. submitted by /u/Aggravating_Judge_31 [link] [comments]

What is the meaning when people say “99.99% the speed of light” instead of just speed of light? Posted: 25 Oct 2021 01:15 AM PDT I hear this phrase a lot and it doesn't make much sense to me. Since the speed of light is a big number, I know a lot can change in that last 0.01%, does something else significant happen when that transition is made? Also I know that in order to accelerate anything with mass to speed c, it would require infinite energy, but to accelerate to 0.9999c would that require finite energy? submitted by /u/sssinc [link] [comments]

Are there any avian species that haven’t evolved significantly since the Cretaceous mass extinction event? Posted: 25 Oct 2021 05:39 AM PDT I know that the cassowary emerged around 60 M.y.a but do you know of any avian species that go back further, preferably pre Chicxulub? submitted by /u/ReubFrFx [link] [comments]

How long does it typically take for a planet to form? Posted: 24 Oct 2021 10:13 PM PDT submitted by /u/MrBanana13 [link] [comments]

Are there any jet aircraft that carry their own oxidizer? Posted: 24 Oct 2021 10:39 PM PDT I know that during normal operation jet aircraft use air compressors to scavenge oxidizer from the atmosphere, but I'm wondering if there's ever a use case for carrying extra oxidizer on a jet aircraft. For example, suppose you had a fuel system that could dump more fuel into the combustion chamber than the air compressor could manage, you could add extra oxidizer directly to the combustion maybe for a higher performance boost than would normally be possible with a purely air-breathing engine. Or for another example, what if an aircraft at very high altitude wasn't able to scavenge enough oxygen to fully generate the thrust it wanted/needed. submitted by /u/EZ-PEAS [link] [comments]

How Do Engineers Work Around Material Fatigue? Posted: 24 Oct 2021 11:25 PM PDT I've yet to see bridges, towers, or roller coasters taken apart to be replaced due to material fatigue, yet I've seen several machines taken apart and parts replaced when fatigue sets in. Even the shop i used to work at had the roof cross members replaced when they became fatigued (granted, these beams were over 100 years old). Even my machine's dies need replaced when you start having them flex more during bending due to fatigue. There doesn't seem to even be much information on fatigue and how it's calculated. So how is all of this stuff figured out, prevented, and compensated for? If you have any book suggestions on this subject, I'd appreciate the recommendation as well. submitted by /u/djinbu [link] [comments]

Does an allergic reaction to an ingredient in a vaccine make the vaccine less effective? Posted: 24 Oct 2021 02:48 PM PDT submitted by /u/CharlieAlpha4 [link] [comments]

The electrostatic deflection of water, and Can a stream of water be deflected by a magnetic field? Posted: 24 Oct 2021 12:20 PM PDT A thin stream of water may be deflected or 'bent' by an electrostatic charge, and this can be demonstrated with a charged object such as a comb, and a thin stream from a faucet. Questions: Would the deflection be larger if de-ionised water was used? Given that water is affected both by electrostatic charge and by gravity, why is the water apparently not also deflected by a very strong magnetic field, say from a powerful electromagnet or neodymium permanent magnet? submitted by /u/a-renrael [link] [comments]

How is it possible for a river to dry up completely then go back to normal without a mass extinction level event? Posted: 24 Oct 2021 08:33 PM PDT So I was just reading up on some doomsday news and came across an article regarding the salmon stock in the Yukon River collapsing. I went and did some digging and came across another article saying it dried up within 4 days after glaciers retreated back in 2017. If thats the case shouldn't everything have died off? Also how did the river return to normal if the glaciers haven't magically gained new ice? I find this kind of stuff unfortunate but fascinating - any info is appreciated! submitted by /u/bermudaliving [link] [comments]

Why are congenital brain deformities(i.e. Alobar Holoprosencephaly, Anencephaly, Syncephalus) so deadly and if physically possible can current medical technology keep these children alive beyond a few hours? Posted: 24 Oct 2021 08:01 PM PDT submitted by /u/wiz28ultra [link] [comments]

With Covid-19 boosters rolling out, are we seeing a drop in antibody titres in the months after the third shot just as we did after the second? Posted: 24 Oct 2021 05:35 AM PDT I keep reading that we might find the boosters fade and that we could need to do them regularly etc - but there's little out there about how they are actually performing. Have meaningful patterns cropped up in the data, or is it too early to tell? submitted by /u/bnndforfatantagonism [link] [comments]

If tectonic plate elevation causes mountains to form, why are there valleys between mountain ranges? Posted: 24 Oct 2021 10:26 AM PDT I.e. why is it not a continuous line or 'spine' of mountain peaks? Is it because the tectonic plates are shattered beneath so collision causes more than one pieces to be elevated? Or is it that after they've formed a mountain, they move on and make another one a mile away, like a blunt knife pressing on dough? submitted by /u/nickoskal024 [link] [comments]

Lots of products claim to "boost" or "speed up" your metabolism. Is that actually a thing that can be done, and if so, what's the science behind it? Posted: 23 Oct 2021 04:11 PM PDT submitted by /u/knightofbraids [link] [comments]

What is the general effect of exposing a plant to continuous illumination? Posted: 23 Oct 2021 06:30 PM PDT I've seen some mixed results- some implying negative, some positive on the effect of constant light exposure on plants. Is the effect quite subjective to the species of plant, or can the trend be generalized? Can plants get "stressed" like animals do under constant light exposure-in a plant's physiological manner of stress, ofc. submitted by /u/parkeddingobrains [link] [comments]

What treatment(s) does the US do to its water that makes it safe to drink that other countries don't do? Posted: 24 Oct 2021 09:55 AM PDT submitted by /u/__ByzantineFailure__ [link] [comments]

How does sound travel after breaking the sound barrier? Posted: 23 Oct 2021 04:03 PM PDT As the title implies, how does the sound from a super sonic vehicle change after it's broken the barrier? Is there a significant difference in the way the waves travel/how the human ear perceives it? Does it change frequency? submitted by /u/AndoftheSevenSeas [link] [comments]

You are subscribed to email updates from AskScience: Got Questions? Get Answers.. To stop receiving these emails, you may unsubscribe now.	Email delivery powered by Google
Google, 1600 Amphitheatre Parkway, Mountain View, CA 94043, United States

Can the current Covid Vaccines be improved or replaced with different vaccines that last longer?

---

• Can the current Covid Vaccines be improved or replaced with different vaccines that last longer?
• What is the current accepted risk of Covid-19 infection through fomite transmission?
• Why do slabs of crust submerged into the mantle have lower temperatures than its surroundings?
• When will covid-19 vaccines be available for people under 12 years old?
• How does glow in the dark stuff work?
• Why are planets so bright?
• What is an amplituhedron and how is it useful?
• Why aren't moths of families like Castniidae or Sphingidae considered butterflies?
• How much protection does a single dose of the AstraZeneca vaccine provide against Covid-19 in comparison to getting both doses? Why are two doses even required?
• Do Light Sails work in the Atmosphere?
• Why do planets spin?
• If copper does not react with water, why does water stored in a copper utensil taste like metal?
• If antartica is the most dryest place on earth then why 99% of its land is water?
• What would happen to the brightness ranking of stars in the night sky if we could see all wavelengths? Is Sirius still the brightest star in the night sky?
• How impactful is a volcanic eruption on greenhouse effect gases?
• Does hot or cold water boil faster?

Can the current Covid Vaccines be improved or replaced with different vaccines that last longer? Posted: 24 Oct 2021 05:14 AM PDT submitted by /u/Helpful_Highlight198 [link] [comments]

What is the current accepted risk of Covid-19 infection through fomite transmission? Posted: 24 Oct 2021 02:12 AM PDT I apologize in advance because I know this has been asked before, but I would just like some clarification if someone is willing to give it. I have read the [CDC update that came out earlier this year which detailed how the virus is spread primarily through respiratory droplets and not surface transmission, which said the chance was around 1 in 10,000 for every infected touch](https://www.cdc.gov/coronavirus/2019-ncov/more/science-and-research/surface-transmission.html). After doing a little more digging though, I saw that [some of the studies tested outside objects, like traffic light buttons](https://pubs.acs.org/doi/10.1021/acs.estlett.0c00966). I'm wondering then, is the risk really considered that much higher without accounting for environmental factors like wind? The reason I ask is because I work at a grocery store that has basically done away with some of the early Covid safety precautions of last year. I go about my day touching self checkout screens, money, and even produce likely hundreds of times a day. I wash my hands frequently and use hand sanitizer a lot as well, but am I still putting people at risk? submitted by /u/Quirky_Analysis7336 [link] [comments]

Why do slabs of crust submerged into the mantle have lower temperatures than its surroundings? Posted: 24 Oct 2021 12:04 AM PDT I was wondering exactly why we have "colder" slabs of rock submerged into the mantle. Creationists state that it is because of the fact that the rock was submerged recently and the time it has been there hasn't been enough to warm it like the rest of the mantle and if it were millions of years it would be warmer now. I remember reading something about the material of the rock being the case and I found something here standing it's the compression of the crust and its materials but I'd like your thoughts submitted by /u/Hybrid_Momentts [link] [comments]

When will covid-19 vaccines be available for people under 12 years old? Posted: 24 Oct 2021 05:47 AM PDT submitted by /u/Korgoth420 [link] [comments]

How does glow in the dark stuff work? Posted: 23 Oct 2021 12:26 PM PDT As we aproach the spookiest part of the year, people wearing glowing skeleton costumes flock the streets and glowing skulls decorate windows throughout suburbs around the world, my question is: How do ''glow in the dark'' substances absorb UV light yet emit visible light?, Why don't they emit more UV light? & Why do they only emit light when in the dark? submitted by /u/The_noseless_Ginge [link] [comments]

Why are planets so bright? Posted: 23 Oct 2021 11:41 AM PDT According to the inverse square law, light gets dimmer at an exponential rate the further the receiver is from the object, and since they are reflecting light instead of emitting it, I don't understand why something reflecting sunlight from millions of miles away would be so bright, regardless of how large it is. submitted by /u/burntMYfingersONcat [link] [comments]

What is an amplituhedron and how is it useful? Posted: 23 Oct 2021 11:12 AM PDT submitted by /u/iDt11RgL3J [link] [comments]

Why aren't moths of families like Castniidae or Sphingidae considered butterflies? Posted: 23 Oct 2021 07:14 AM PDT They have clubbed antennae and are diurnal. They basically look like butterflies, albeit a bit on the chubby side. Is there a sensible explanation for that? Thank you in advance for replies. submitted by /u/Worekjarzyn [link] [comments]

How much protection does a single dose of the AstraZeneca vaccine provide against Covid-19 in comparison to getting both doses? Why are two doses even required? Posted: 23 Oct 2021 11:52 PM PDT submitted by /u/TastyBirdmeat [link] [comments]

Do Light Sails work in the Atmosphere? Posted: 23 Oct 2021 05:27 AM PDT I understand they've been designing light sails for a while now to catch the light from the sun in space, but I can't find a single thing about whether or not they work in an atmosphere. If light Sails don't work in air, do heat sails exist and do they work in the atmosphere? submitted by /u/AfricanToto [link] [comments]

Why do planets spin? Posted: 23 Oct 2021 02:54 AM PDT submitted by /u/Kir_a_ [link] [comments]

If copper does not react with water, why does water stored in a copper utensil taste like metal? Posted: 22 Oct 2021 08:49 PM PDT submitted by /u/junejanikku [link] [comments]

If antartica is the most dryest place on earth then why 99% of its land is water? Posted: 22 Oct 2021 08:06 PM PDT submitted by /u/ctnsgd [link] [comments]

What would happen to the brightness ranking of stars in the night sky if we could see all wavelengths? Is Sirius still the brightest star in the night sky? Posted: 22 Oct 2021 04:12 PM PDT submitted by /u/Full-Sweet-1299 [link] [comments]

How impactful is a volcanic eruption on greenhouse effect gases? Posted: 22 Oct 2021 05:08 PM PDT Cumbre Vieja is spitting lava and smoke for a month now and it got me wondering how impactful it is on our goals on reducing emissions on a global scale. Those events can significantly worsen our global warming situation? submitted by /u/chagin [link] [comments]

Does hot or cold water boil faster? Posted: 22 Oct 2021 02:48 PM PDT Not sure what the right type of science is for this question but yeah title explains it. I heard that frozen things are best thawed with cold/room temp water because of blah blah blah science stuff. So does it work the same way with water? submitted by /u/Cosmic_W0lf [link] [comments]

You are subscribed to email updates from AskScience: Got Questions? Get Answers.. To stop receiving these emails, you may unsubscribe now.	Email delivery powered by Google
Google, 1600 Amphitheatre Parkway, Mountain View, CA 94043, United States

The extended warm period during the "boring billion" between 1.8 and 0.8 Gya is proposed to have been the result of atmospheric N2O being 10x higher than it is today. Where did all the N2O during that period come from?

---

• The extended warm period during the "boring billion" between 1.8 and 0.8 Gya is proposed to have been the result of atmospheric N2O being 10x higher than it is today. Where did all the N2O during that period come from?
• Have there been any attempts to build a solid rocket motor that can be throttled or turned off?
• Why do some people who've recovered from covid-19 not develop anti-bodies?
• What is the difference between the original sars cov 2 and its variants?
• Is there a scientific consensus on optimal learning sessions and study time management?
• Are July and August borns disadvantaged in school and life?
• What happens EXACTLY at the triple point of a pure substance?
• Do other force particles have a spectrum like photons?
• How many, and which viruses are the cause of cold? And why is cold more likely to happen in cold environments?
• What new, ground-breaking technologies were first used in the creating of the first satellite (Sputnik 1)?
• Which oak species are most likely to successfully take during a graft? (Unfamiliar with cladistics)
• What was on the opposite side of the Earth when Pangea existed?

The extended warm period during the "boring billion" between 1.8 and 0.8 Gya is proposed to have been the result of atmospheric N2O being 10x higher than it is today. Where did all the N2O during that period come from? Posted: 22 Oct 2021 09:39 AM PDT During the boring billion global temperatures were about 4 ºC higher than today due to higher concentrations of greenhouse gases. Scientists have ruled out CO2 as the culprit due to the lack of evidence of ocean acidification. Methane has also been ruled out as it is only biogenic and methanogens are unlikely to have produced enough methane. So scientists seem to have settled on N2O as the offending greenhouse gas, with Proterozoic levels proposed to be elevated 10x over modern levels. Today, most N2O is either anthropogenic or biogenic, with only a small fraction being formed abiotically. If methanogens were unlikely to produce enough methane to significantly affect the climate, how would denitrifiers be able to produce enough N2O? If the elevated levels were abiogenic, why don't those processes continue today? submitted by /u/ghostoftheuniverse [link] [comments]

Have there been any attempts to build a solid rocket motor that can be throttled or turned off? Posted: 23 Oct 2021 07:43 AM PDT It seems like there would be a lot of applications for a small solid rocket motor that can go from ~0% to 100% or possibly greater. I'm imagining something like a JATO rocket in terms of size and the creative ways it has been implemented. It could be something simple such as a mechanism to destroy sections of the propellent and spit out the chunks. It couldn't throttle back up and will spike thrust briefly but it still sounds useful. submitted by /u/Ott621 [link] [comments]

Why do some people who've recovered from covid-19 not develop anti-bodies? Posted: 23 Oct 2021 12:36 AM PDT My basic understanding of immunity is that the first time you get a virus, your immune system makes anti-bodies, which then neutralise the virus, and the anti-bodies remain in your blood stream afterwards. Then if the virus re-infects you, the anti-bodies are already there, ready to neutralise it again. But there's a study which shows a third of people who've recovered from covid do not develop anti-bodies. Why/how does this occur? submitted by /u/Ok_Professional9769 [link] [comments]

What is the difference between the original sars cov 2 and its variants? Posted: 23 Oct 2021 08:22 AM PDT I'm basically asking about differences in spread/transmition and severity (hospitalization and deaths). Are there any data on that? Im more interested in the Delta Variant, but any data is welcome. submitted by /u/th4tsmyus3rn4me [link] [comments]

Is there a scientific consensus on optimal learning sessions and study time management? Posted: 22 Oct 2021 08:17 AM PDT Hello there, I've been having a hard time finding data regarding this side of psychology. While I've found actual papers regarding the usefulness of note-taking under the form of mind maps rather than usual note-taking methods, I can't find enough papers regarding focus time. We hear advices here and there - I've had high school teachers saying "we can't focus more than 1 hour at a time", I've seen the pomodoro (25 minutes of work / 5 minutes of rest + other arbitrary rules) technique, but it doesn't seem to be a strong research field. I'm mainly using google scholar for my researches, so maybe my method for searching papers isn't as good, which is why I'm asking for some guidance : does science say anything about how we should focus in order to maximise learning and optimize our time? Thanks! submitted by /u/Meljin [link] [comments]

Are July and August borns disadvantaged in school and life? Posted: 22 Oct 2021 11:13 AM PDT There is research suggesting that children born in July / August struggle more in school, struggle with reading and writing, more likely to drop out, and be diagnosed with ADHD. Here in England, a child born in September will turn five shortly after the start of term. A child born in July could will be four for the entire school year. How true is this and is your child doomed if born in July / August? Here is just one article talking about it. here Apparently parents are holding their children back a year to offset this problem but is this a good idea? link submitted by /u/crystalxuk [link] [comments]

What happens EXACTLY at the triple point of a pure substance? Posted: 22 Oct 2021 09:15 AM PDT I'm working on a problem for a binary mixture which is equivalent to the triple point of a single-component system, and that is this: What are the relative amounts of each phase EXACTLY at the triple point? Most descriptions you find say something along the lines of "all three phases can exist simultaneously," but "can" implies that they don't always. And if that is just bad wording, how do you calculate how much of each phase is present, i.e., the phase fractions? I know that both realistically and numerically speaking, this is not a meaningful question as you can never be exactly at any given point. My question is, then, a purely mathematical one, assuming that the equations used to model a system have an exact solution. At the triple point of a pure substance (or a three-phase point of a binary mixture with one state variable fixed), there are zero degrees of freedom which can be verified using the Gibbs Phase Rule: DOF = C - P + 2 For a pure component, you get DOF = 1 - 3 + 2 = 0, and the binary mixture with one parameter fixed, you get (DOF) - 1 = (2 - 3 + 2) - 1 = (1) - 1 = 0. This means that the thermodynamic state of the system is completely fixed and that all other state variables can (theoretically) be determined from those conditions. However, in practice, most systems that I'm familiar with which have more than one phase present have at least 1 DOF, and varying that DOF changes your phase fraction(s). For example, a binary mixture with two phases has 2 DOF. Specifying, for example, temperature and avg. composition fixes the system state and allows you to calculate the individual phase compositions and thereafter the phase fractions from a mass balance/lever rule. You can also do the same with a ternary mixture and three phases using two independent equations to calculate the two independent phase fractions (all three sum to 1, so two are independent). You can't, however, do that here because there is not enough information available to calculate two independent phase fractions. There couldn't possibly be; not with state variables anyway. If you try (and I have), you get infinitely many solutions/a line in the space of the phase fractions. Plot of mass balances for 3C/3P system (axes are the independent phase fractions). Plot of the same for 2C/3P. All this is leading me to one of the following conclusions: Phase fractions have no meaning at such invariant points. Under these conditions, phase fractions are path-dependent quantities. The first of these makes a sort of logical sense to me but doesn't really make physically sense, because this would imply that either phases don't exist (which seems ridiculous) or the whole system is at all three phases simultaneously (equally ridiculous). The second is more likely in my mind, and I can find some analogues in systems with fewer phases, e. g., a single component at two phases has 1 DOF (e.g. pressure) yet still needs a value for work/enthalpy supplied to determine a phase fraction. That said, I haven't found any evidence to support this nor have I found any discussion of it online or in the scientific literature. Any thoughts would be greatly appreciated! submitted by /u/Imagine_Baggins [link] [comments]

Do other force particles have a spectrum like photons? Posted: 22 Oct 2021 09:04 AM PDT Photons carry the electro-magnetic force and operate on a spectrum based on their energy, giving us things like heat and x-rays. Do the force particles that carry the other natural forces also behave differently at different energy levels? Is there (or could there be) a spectrum of the nuclear forces, or of gravity? submitted by /u/docbob84 [link] [comments]

How many, and which viruses are the cause of cold? And why is cold more likely to happen in cold environments? Posted: 22 Oct 2021 12:50 PM PDT submitted by /u/eyebrow911 [link] [comments]

What new, ground-breaking technologies were first used in the creating of the first satellite (Sputnik 1)? Posted: 22 Oct 2021 08:46 AM PDT creation* made a typo in the title. Sorry! What technologies made Sputnik 1 so special? submitted by /u/Student-Somewhere [link] [comments]

Which oak species are most likely to successfully take during a graft? (Unfamiliar with cladistics) Posted: 22 Oct 2021 08:10 AM PDT https://imgur.com/gallery/7W0fZxD Marked is the species that I want to work with. I imagine that the oaks between and including Quercus lyrata to Quercus Muehlenbergii would successfully take. But how far up, and how far down, do you suspect that the trees are similar enough to successfully graft? submitted by /u/TaxMan_East [link] [comments]

What was on the opposite side of the Earth when Pangea existed? Posted: 22 Oct 2021 08:01 AM PDT submitted by /u/drugdealer604 [link] [comments]

You are subscribed to email updates from AskScience: Got Questions? Get Answers.. To stop receiving these emails, you may unsubscribe now.	Email delivery powered by Google
Google, 1600 Amphitheatre Parkway, Mountain View, CA 94043, United States