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Monday, July 27, 2020

AskScience AMA Series: We're Preparing to Launch NASA's Perseverance Mars Rover and Mars Helicopter Ingenuity. Ask Us Anything about our #CountdownToMars!

AskScience AMA Series: We're Preparing to Launch NASA's Perseverance Mars Rover and Mars Helicopter Ingenuity. Ask Us Anything about our #CountdownToMars!


AskScience AMA Series: We're Preparing to Launch NASA's Perseverance Mars Rover and Mars Helicopter Ingenuity. Ask Us Anything about our #CountdownToMars!

Posted: 27 Jul 2020 04:00 AM PDT

On Thursday, July 30, NASA's Mars 2020 mission is scheduled to blast off, carrying the Perseverance Mars Rover on its six-month journey to the Red Planet. When it lands in Jezero Crater next February, Perseverance will look for signs of ancient life on Mars - and gather climate and terrain data that will help pave the way for future human Martian missions.

Tucked underneath Perseverance until landing, NASA's Ingenuity Mars Helicopter will be the first aircraft to attempt controlled flight on another planet; Perseverance will also collect rocks and sediments to be retrieved by a future Mars Sample Return mission, currently being planned by NASA and the European Space Agency. Nearly 11 million names from around the world will fly to Mars, etched on three small microchips Perseverance carries - but even if your name's not one of them, there's plenty you can do to take part in the mission virtually.

We'll be answering questions from 4:30 - 6:30 PM ET (1:30 - 3:30 PM PT, 2030 - 2230 UT). Thanks for joining us!

Participants:

  • Todd Barber, Mars Perseverance Propulsion Engineer, NASA's Jet Propulsion Laboratory
  • Pan Conrad, astrobiologist and scientific investigator for the Mars Perseverance MEDA and SHERLOC teams
  • Nagin Cox, Mars 2020 Engineering Operations Team Deputy Lead, NASA's Jet Propulsion Laboratory
  • Caleb Fassett, Planetary Scientist and Jezero Crater expert
  • Denton Gibson, Senior Vehicle Systems Engineering Discipline Expert, Launch Services Program
  • Jesse Gonzales, flight controls engineer, United Launch Alliance
  • Havard Grip, Mars Helicopter Chief Pilot, NASA's Jet Propulsion Laboratory
  • Greg Hula, Department of Energy
  • Angie Jackman, Mars Ascent Vehicle project manager, NASA's Marshall Space Flight Center
  • Jeff Sheehy, NASA Space Technology Chief Engineer
  • Roger Wiens, SuperCam PI

Username: nasa

submitted by /u/AskScienceModerator
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Is it possible to have a rectangle, that when divided in half vertically results in 2 rectangles with the same proportions of the bigger one?

Posted: 26 Jul 2020 08:32 PM PDT

Wouldn't the machine in the Schrödinger's Cat thought experiment be "observing" the state of particles, therby collapsing their superposition before doing anything to the cat?

Posted: 27 Jul 2020 01:52 AM PDT

I don't know a whole lot about quantum physics, so sorry if this question just reveals a fundamental lack of understanding :D But it always seemed to me like the obvious answer to why the cat is not simultaniously dead and alive. Observation in the Copenhagen interpretation doesn't require a human being to read the data, does it?

submitted by /u/StamatopoulosMichael
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Do microwave transmission dishes heat the air in front of them? Is there enough heat to cook birds and/or turn snow/rain/fog into steam?

Posted: 27 Jul 2020 03:13 AM PDT

At what point in American history did the quintessential "southern" accent take hold? Is this considered a softening of the British colonial accent or is it a result of a melding with "slave" English?

Posted: 26 Jul 2020 09:02 AM PDT

A lot of 1850-1900 American literature depicts poor, uneducated white characters and slaves as having a crude "southern accent". I'm just curious at what point in our nation's history, the British colonial accent evolved into what we know today, and why it occured regionally.

submitted by /u/AuDBallBag
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How long after cardiac cessation does the brain continue to function?

Posted: 26 Jul 2020 06:07 PM PDT

As sea level rises, does low tide level get higher (or lower)?

Posted: 26 Jul 2020 11:24 PM PDT

As sea level rises, obviously high tide gets higher. Does low tide also get higher because there's more water in the ocean, or does low tide get lower because the tides are bigger?

submitted by /u/ukkiwi
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Is radioactivity at nuclear weapon sites entirely from the material in the weapons?

Posted: 26 Jul 2020 02:40 PM PDT

My understanding is that radiation isn't 'contagious' in that the emitted radiation from an explosion doesn't make the substances it hits radioactive. Does that mean that the radioactivity around testing sites is entirely from the obliterated dust from the small amount of nuclear material contained in the weapons? Struggling to comprehend how do much material can otherwise be spread out.

submitted by /u/Smedlington
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How do the long term complications of COVID-19 compare to other viruses?

Posted: 26 Jul 2020 09:07 AM PDT

I've been hearing a lot in the news about the long term complications associated with COVID-19. Is it more likely to cause long term complications compared to other viral infections? My impression was that any viral infection has the potential to cause long term complications and that it isn't unusual that it's happening with COVID-19. Is there something unique about it?

submitted by /u/peri_5xg
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Are we going to have a flu vaccine this year?

Posted: 26 Jul 2020 09:52 AM PDT

Given all of the (rightful) push for a Covid vaccine, well we have a flu vaccine this year? Or, is everyone working on Covid?

submitted by /u/Working-on-it12
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How does a dye work?

Posted: 26 Jul 2020 10:51 PM PDT

Once my friend asked me how did transparent dye worked, like how can somethi a make a liquid turn incolor like water.

submitted by /u/JK_Cranker
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Can you trick a plant into growing faster by changing the duration of the day - night cycle?

Posted: 26 Jul 2020 05:44 AM PDT

In the simplest terms: if I have a plant who has 6 hours of light and darkness rather than 12, so experiences two shorter days for every 24 hour period, would its growth be any faster?

submitted by /u/WippitGuud
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What exactly happens to a bone for your body to increase it’s density?

Posted: 26 Jul 2020 02:32 PM PDT

I know that bone density increases with exercise and conditioning, but what actually happens to the bone?

With exercise, does the increase come from an increase in muscle mass, or does it come from the compressive stress on the bone from the muscle attached to it contracting?

Is the process of a bone increasing in density due to exercise and conditioning (like martial artists condition their shins) similar?

If it is due to stress applied to the bone, does the same occur with tensile stress as well?

I would really appreciate any response, as I'm having a very hard time finding information on this. Thank you!

submitted by /u/ProChad
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Why does the parasympathetic nervous system become active in vasovagal syncope and why does removing the stimulus reduce syncope?

Posted: 26 Jul 2020 12:01 PM PDT

My understanding is that the sympathetic nervous system (SNS) gets activated by some stress inducing stimulus, causing (among other things) a dilation of blood vessels in skeletal muscle. If blood pools in large muscles, the brain is not adequately perfused. Then I believe the body tries to "flip the switches":

  • The parasympathetic nervous system (PNS) is overactivated, leading to a decrease in heart rate.
  • The SNS activity is decreased leading to a drop in blood pressure.

The drop in heart rate and blood pressure on top of the already poorly perfused brain causes syncope. (I believe this to be accurate but, of course, I welcome any correction). Here are my questions:

  • How is the "flipping of the switches" (SNS off, PNS on) a mechanism to reperfuse the brain? Is it meant to cause syncope and put body in a horizontal position? Or does the body try to reperfuse the brain with these mechanisms but it isn't a perfect system and thus causes syncope in a subset of people?
  • If the nail in the coffin is the activation of the PNS and inhibition of the SNS, wouldn't removing the stimulus decrease the SNS and allow the PNS to become overactive leading to syncope? In other words, isn't the presence of a stress-inducing stimulus the only thing keeping the blood pressure up?

Thanks!

submitted by /u/VasovagalResponse
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Do plants that grow in very dusty/smoggy areas have any selection or adaptations for unnaturally reduduced levels of sunlight?

Posted: 26 Jul 2020 08:28 AM PDT

I regularly drive through brickyards in dusty areas in India and every plant I see is coated in dust. Does this affect their ability to convert sunlight into energy? Would transplanting them to areas without similar pollution result in super plants in any way? I imagine the dust isnt such to kill plants and allow mutations to really take over, but it seems nuts that they do just fine with that much dust on their leaves.

*...any sort of selection or other adaptations...

submitted by /u/keyilan
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What does it mean to say that the planet Uranus is laying on it’s side?

Posted: 26 Jul 2020 09:39 AM PDT

I'm watching NOVA and they just said this. This is probably a dumb question, but I guess I'm confused how a planet can be laying on its side if it's just floating in space? What are planets resting on that allows them to be laying on one side over another, does it have something to do with the sun?

submitted by /u/dch222
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If evolution takes millions of years and is very gradual, then how did wings evolve? Evolution has no intelligence so how did it gradually create wings, considering they wouldn't work until fully evolved.

Posted: 25 Jul 2020 08:51 PM PDT

I understand that evolution works by genetic mutations that allow an animal to be faster or stronger, which makes them more likely to reproduce more and spread those genes, but that doesn't explain how wings evolved. Like where did it even start? It's not like one day an animal was just born with wings. In order for it to gradually evolve, it must have started as a little bump, but that would serve no purpose and the animal would just die. I can't think of any explanation.

submitted by /u/_ep1x_
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Why is taxonomy and philogeny important?

Posted: 26 Jul 2020 07:30 AM PDT

I find the evolutionary history of organisms, specifically plants, to be awe-inspiring, but sometimes I wonder if it has any practical applications. Why is it important to map accurate phylogenetic relationships, or why does it matter if a group is monophyletic or not? Why is it so important to place species in the correct taxa?

submitted by /u/bobohiha1
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How are nutritional values actually calculated?

Posted: 26 Jul 2020 02:15 AM PDT

It may seem stupid but how do they calculate the energy and macronutrients in food? Especially in meats where depending on the food you give to the animal, its body composition changes

submitted by /u/Colon-elcolon
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How does the hair "know" when to stop growing?

Posted: 25 Jul 2020 11:10 PM PDT

Sunday, July 26, 2020

Why do mountains have peaks instead of having "flat tops"?

Why do mountains have peaks instead of having "flat tops"?


Why do mountains have peaks instead of having "flat tops"?

Posted: 26 Jul 2020 03:34 AM PDT

Could the quarantines in some countries decimate the seasonal flu or other diseases that rely on constant spreading?

Posted: 25 Jul 2020 12:55 PM PDT

So for example can we expect to have far less cases of the seasonal flu next year in those countries that had an actual shutdown? Of course it wouldn't be totally eradicated and start spreading again as soon as a covid vaccine/containment is done and the social distancing is stopped.

submitted by /u/Jarazz
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Do children actually learn languages quicker than adults or do we just put way more effort into teaching children than we do adults?

Posted: 25 Jul 2020 10:42 AM PDT

How can we prepare for the next novel virus now, so that we won’t need to take such drastic measures as we did for COVID-19?

Posted: 25 Jul 2020 07:28 PM PDT

Are there people who have natural immunities to diseases?

Posted: 26 Jul 2020 12:14 AM PDT

Best example I can think of are the zombie movie tropes when there are "immune"people. Is it possible there could be someone out there who is actually immune to something like the common cold? Or Cancer?

submitted by /u/Tribalbob
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How do we know that there aren't entire antimatter galaxies?

Posted: 25 Jul 2020 12:18 PM PDT

Do we know that there aren't?

submitted by /u/afcagroo
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Is there any kind of synchrotron radiation for electrons moving along a superconducting coil?

Posted: 25 Jul 2020 10:58 PM PDT

So, for electrons moving in vacuum in circles there is that phenomenon called synchrotron radiation. Which, theory says, is caused by the Abraham–Lorentz force or the "self-force". So the electrons lose their energy in a synchrotron because of it. But what about a superconducting coil? If the coil has a stable superconducting current, than there is the contradiction with the theory: electrons move with acceleration (in circles), but do not lose their energy because of the self-force! So there must be some kind of radiation and thus resistance in superconductors. Right?

submitted by /u/Eug9745
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Convalescent Plasma for COVID-19 treatment?

Posted: 25 Jul 2020 08:41 PM PDT

Has convalescent plasma been approved as a treatment for hospitalized COVID-19 patients? this site that was updated earlier in the month suggests it has not, however I keep seeing articles like these that suggest otherwise.

Thank you!

submitted by /u/butterball6-9
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What do other archaeologists think about the recent results from Chiquihuite Cave?

Posted: 25 Jul 2020 09:37 AM PDT

So I finally got around to reading the paper (Ardelean et al. 2020) and these are my thoughts:

Overall I think it's pretty convincing and probably the best evidence we've seen so far for a pre-LGM human presence in the Americas. The tools are definitely real and the dating seems solid.

That said, there were a couple of issues. First, I would have liked to see a third figure showing the distribution of piece plots in vertical space from the East or west. (Currently there are figures showing the plots in plan view and from the south). It's not entirely clear how the sediments slope from this direction and the provenience of the artifacts allegedly from the SC-C layer is absolutely critical to their argument. Second, from what I understand from the dating of the SC-C layer, 33Ka is a maximum age and the upper parts of SC-C could be as young as around 16Ka. Again seeing the full 3D positions of the piece plots and the dates would be very helpful in confirming the claim that some of the material is pre-LGM.

Still, overall I think this is good work and should at least be taken seriously. What do y'all think?

submitted by /u/elchinguito
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If having more cells means there is a larger chance of mutations and thus cancer, why is it that large animals like elephants and whales aren't dying of cancer nearly as much on the same level as humans who have less cells?

Posted: 25 Jul 2020 09:59 AM PDT

So basically yeah, that's my question, maybe there is a cancer treatment we can obtain from whales, elephants and other large mammals?

Just a thought

submitted by /u/KingJimXI
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What biological mechanism enables young creatures to grow such that all portions of the creature grow at the same rate? In other words how does the growth process avoid having some body parts grow at different rates then others?

Posted: 25 Jul 2020 11:09 AM PDT

Do solid planets need a molten core to have a magnetic field?

Posted: 25 Jul 2020 08:39 AM PDT

I'm doing an assignment that involves finding or getting a general idea of the mass of Hoth-6 from the Star Wars movies. Since the planet has snow and living creatures, it must have a magnetic field, right?

I'm hoping that if this is true, that it must have a molten core, so that I can say that it has a density similar to Earth's.

I don't need exact numbers though, because I know that Hoth should have a much weaker gravity than earth because of its diameter of 7200km.

Thanks in advance!

submitted by /u/Frosty1206
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Can we engineer "evolution" in small organisms (e.g. bacteria) in short periods of time?

Posted: 25 Jul 2020 01:14 PM PDT

For example, if we have heat up bacteria in a petri dish to 45 degrees celsius, are we genetically selecting for bacteria that can survive in that temperature? Or if we expose it to chemicals (like soap), are we creating super-bacteria? How long would it take to see meaningful changes in the genetic structure of this bacteria, as compared to larger organisms such as plants and animals.

submitted by /u/SensitiveRegion9
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Why are modern batteries still susceptible to damage when left plugged in for extended periods?

Posted: 25 Jul 2020 05:43 PM PDT

How close do two particles have to be for tunneling to occur, allowing fusion to happen?

Posted: 25 Jul 2020 11:25 AM PDT

So I have read that in our sun fusion would not even be happening without tunneling, which lead me to the question what distance is overcome by tunneling.

submitted by /u/neuromat0n
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Do comets like neowise lose mass and disintegrate eventually? Or do they somehow replenish lost material?

Posted: 25 Jul 2020 05:54 PM PDT

Do bites from different species of venomous snakes require different anti-venoms?

Posted: 25 Jul 2020 05:53 PM PDT

I guess I'm just wondering if there are certain anti-venoms that cover many different types of snakes or if each one needs it's own anti-venom. Also, I'm interested as to what happens if a person gets bitten but isn't sure what kind of snake did it.

submitted by /u/lenny3330
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How to trees pull up water so high?

Posted: 25 Jul 2020 12:18 AM PDT

A perfect vacuum only pulls water up about 10m. A video by veritasium explains that root pressure and capillary action aren't enough either, especially for trees like the giant redwood which are 100m tall. He says it's because transpiration creates a negative pressure. What even is a negative pressure and why are we not able to recreate it ourselves

submitted by /u/hawk-bull
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If the Oxford vaccine infects people with a harmless, live virus that looks like SARS-CoV-2, would it be contagious like normal viruses?

Posted: 25 Jul 2020 07:13 AM PDT

I hope this isn't a stupid question, but according to the BBC, the Oxford vaccine works by putting 'small sections of its genetic code into a harmless virus that infects chimpanzees. They appear to have developed a safe virus that looks enough like the coronavirus to produce an immune response.'

The way I'm interpreting this, the vaccine infects its host with an asymptomatic virus, and so surely if this is the case, could the host not spread it in the same way a normal virus spreads?

I'm guessing not, partly because if this were the case I'm sure a self-spreading vaccine would be headline news (not to mention the anti-vax uproar!) so could anyone shed any light on how this works? Thanks!

submitted by /u/auferstehn1894
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What do Captchas do?

Posted: 25 Jul 2020 01:06 PM PDT

I've heard they calibrate AI, is this true and if how?

submitted by /u/BlackBatmanSocks
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Saturday, July 25, 2020

Are cancers always fatal when left untreated?

Are cancers always fatal when left untreated?


Are cancers always fatal when left untreated?

Posted: 25 Jul 2020 03:44 AM PDT

Can cordyceps infect vertebrates?

Posted: 25 Jul 2020 03:21 AM PDT

As far as i know cordyceps infect only insects. If cordyceps can't infect vertebrates, what can keep it from infecting?

submitted by /u/Karandax
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If the immune response of Covid can cause pneumonia and ultimately death, why are immunosuppressed patients considered more vulnerable?

Posted: 24 Jul 2020 06:57 PM PDT

I've read multiple sources that describe how the body's immune response ultimately is what leads to death in Covid 19 patients so is there a scenario in which an immunosuppressed patient would fair better than others?

submitted by /u/kavorkaKramer1
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Why is covid-19 affecting miniority groups the most other than non-Hispanic whites in the USA and Australia?

Posted: 25 Jul 2020 03:00 AM PDT

I've realised that across the countries mentioned and many other white countries, miniorities seem to attract the coronavirus more, but why? Is it because majority white areas follow restrictions and social distancing more? Are whites staying home more?

submitted by /u/Joshdoop2
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Why is the rate of positive COVID-19 tests numbered so differently depending on the day of the week?

Posted: 24 Jul 2020 02:27 PM PDT

By this, I mean why do certain days have a much higher or lower positive test count than other days? In my home state for example, there were 760 positive cases yesterday. In the days before that, there were a mere 6-7 positive cases daily. The week before that, there were thousands. The graph is a very steep zig-zagged line, varying high/low every other day. Why is this?

I'm in Minnesota USA for context.

submitted by /u/se7en51ns
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If someone contracted the SARS virus, will that person be immune or better at fighting COVID-19 than people who did not contract it before?

Posted: 24 Jul 2020 02:02 PM PDT

Does the lymphocytopenia associated with SARS-COV, MERS-COV and SARS-COV-2 have a common cause?

Posted: 24 Jul 2020 12:47 PM PDT

Do Antipsychotics Cause Brain Damage?

Posted: 24 Jul 2020 08:48 AM PDT

Hi everyone,

I've read studies, from a few years ago, suggesting antipsychotics cause brain damage. Does anyone have any insight into this?

submitted by /u/mr_boxley
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How do the metal detectors at airports work?

Posted: 24 Jul 2020 11:12 AM PDT

It's not like they're using magnets to attract everything metal and it works even if the metal is under layers of other materials so how does it work? It seems strange and foreign to me but maybe I'm just missing the obvious.

submitted by /u/Heliosthetroll2
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What is the Roche Limit?

Posted: 23 Jul 2020 09:46 PM PDT

I heard about it and tried googling it but I still don't completely understand the concept.

Basically, Roche Limit is the closest a satellite can get to a mass's gravitational field before breaking up and becoming a "ring" of the mass..? That's all I understood from Wikipedia, but I still don't understand tidal forces, which is referred to in the article, and the entirety of Roche Limits

submitted by /u/alwaysdeadalways
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