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Tuesday, November 26, 2019

AskScience AMA Series: We are experts on NASA's efforts to grow crops in space including a harvest just in time for Thanksgiving! Ask us Anything!

AskScience AMA Series: We are experts on NASA's efforts to grow crops in space including a harvest just in time for Thanksgiving! Ask us Anything!


AskScience AMA Series: We are experts on NASA's efforts to grow crops in space including a harvest just in time for Thanksgiving! Ask us Anything!

Posted: 26 Nov 2019 04:00 AM PST

Since 2015, using NASA hardware, scientists and researchers have worked with astronauts on the International Space Station to conduct a series of experiments to grow, harvest and eat a variety of crops in space with seeds sent from Earth. The most recent experiment has the ISS crew growing Mizuna mustard using two different light recipes and multiple harvests, with the experiment's final harvest scheduled for later this week. This work builds upon decades of NASA and international research into growing plants in space.

These experiments are advancing the knowledge required to successfully grow a large variety of crops on long-duration missions, such as a crewed mission to Mars. Being able to crops grown in space provides many benefits including supplementing the astronauts' packaged diet with essential nutrients and combating diet fatigue.

Here answering your questions are:

  • Ralph Fritsche, Space Crop Production Project Manager, NASA's Kennedy Space Center
  • Jess Bunchek, Pseudonaut and Associate Scientist, NASA's Kennedy Space Center
  • Lashelle Spencer, Research and Development Scientist, NASA's Kennedy Space Center
  • Jacob Torres, Technical and Horticultural Scientist, NASA's Kennedy Space Center

We will see you at 2:30 p.m. Eastern Standard Time (19:30 UT), ask us anything!

submitted by /u/AskScienceModerator
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Can an organ be replaced twice?

Posted: 25 Nov 2019 05:41 PM PST

Like, the organ recipient dies unexpectedly after getting a new heart. Any reason the heart can't pass on again?

submitted by /u/VerticalYea
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How is it possible to reach points higher than 255 in an 8-bit game?

Posted: 26 Nov 2019 04:49 AM PST

Considering 8 bits can only count to the number 255, how is it possible to be awarded more than 255 points in a 8-bit game? For example in Pac-man, the highest reachable level is 255, but you still get 400 points for eating a ghost. The game should not be able to count that high

submitted by /u/AlienFrogThing
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Can an elevated water tank be used like a battery?

Posted: 25 Nov 2019 04:53 PM PST

Could electricity from say solar panels be used to power a pump that would put a bunch of water in an elevated tank, and then when the sun goes down, can that water be released to drive a turbine for power again?

submitted by /u/kellyedodge
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How is a bacteria immune to a virus without its corresponding spacer?

Posted: 26 Nov 2019 02:45 AM PST

I just watched a documentary about CRISPR and Cas9 called Human Nature.

They explained that they looked at bacteria which were exposed to viral infections. While most of the bacteria died, a few survived. The surviving bacteria now had an altered genome. It had added a spacer corresponding to the virus' RNA acting as part of an immune system for the bacteria. You'd now have Cas9 in the bacteria, armed with a copy of that spacer protecting against that same type of virus.

However, they never explained how those surviving bacteria survived in the first place without the spacer already in place. Was it just chance? And if so, what was the random element?

submitted by /u/rizzon
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Why did all living organisms on earth descend from a single common ancestor? Could there be more evolutionary trees evolving in parallel?

Posted: 26 Nov 2019 02:32 AM PST

In the distant past, when the first living cell on earth spontaneously emerged, why couldn't a different living cell emerge at the same time somewhere else on the planet? These two cells could then become roots to two unrelated evolutionary trees. Could a new evolutionary tree emerge today?

submitted by /u/BasomTiKombucha
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Could a single human spermatozoon break through the zona pellucida?

Posted: 26 Nov 2019 03:16 AM PST

Could a single human spermatozoon digest 15μm of zona pellucida with its 1μm acrossome? It doesn't seem possible yet one of my biology teachers told me that it was. ( and another one told me that a multiple assault is required ) Are multiple acrossomes needed to get through? If so, could we say that they are, in some way, cooperating by digging their way in for another one to fertilize the egg?

submitted by /u/Spinner23
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If Commensal Bacteria in our microbiomes help us, why are they called commensals?

Posted: 26 Nov 2019 02:36 AM PST

From my understanding a commensal organism is one that lives alongside a host benefiting from it without helping/harming it. However commensal bacteria in our microbiomes have many helpful functions:

  • Suppressing growth of pathogenic bacteria
  • Metabolise indigestible compounds
  • Stimulate development of immune system

So why are they classed as commensals?

submitted by /u/giingey
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What happens to the human mind and body when a projectile passes through the brain?

Posted: 25 Nov 2019 06:55 PM PST

As an example, if you were shot in the head, what is the sequence of biological/neurological events that lead to body functions and consciousness to fail?

Does everything shut down immediately? What causes the mind to cease so quickly? Do some body functions continue for a time after being shot? What scenario would lead to someone being conscious after seeing brain trauma like that?

submitted by /u/Crestyles
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Why does rabies affect such a broad range of species with similar symptoms while other diseases, such as HIV, only affect one species?

Posted: 25 Nov 2019 09:51 AM PST

How does stomachs of people living on IV cope?

Posted: 26 Nov 2019 01:49 AM PST

I mean do they produce bile and stuff? Do people not develop ulcers due to stomach being empty for a long time?

submitted by /u/jabhiram
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Why is lithium the best element to use for batteries?

Posted: 25 Nov 2019 06:05 PM PST

Like what molecular properties make it the best? Or are there other elements or compounds that are just not being used?

submitted by /u/JoeyBobBillie
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Our irises retract to block more light and open to let more light in. Does this affect our field of vision?

Posted: 25 Nov 2019 07:20 PM PST

How the very first code was created, since there were no ways to make a computer register a letter on the keyboard and no prior code?

Posted: 25 Nov 2019 10:32 AM PST

How do eyeballs rotate?

Posted: 25 Nov 2019 10:24 PM PST

Like how to your eyes turn on their own or look side to side? Is there some kind of muscle to move them, or is it something else?

submitted by /u/Clever_Name_17
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Location of Atolls, Atlantic Vs Pacific? And several other Atoll related questions

Posted: 25 Nov 2019 11:42 AM PST

Hello I've recently been creating a fantasy map and was looking up Atolls and I've several questions about them.

The first, is why are there so few Atolls in the Atlantic (only off the coast of Belize) while the Pacific Ocean and the Indian Ocean are chalk full of them. I presume this is due to lack of Volcanic activity in the Atlantic ocean in area where reefs can form but then that leads to another question about the lack of Volcanic hot-spots in the Atlantic.

The second question I have is the removal of the former Island that the coral reef rings around. How does this precisely happen? I recall watching a video where it was stated that the weight of the reef somehow has something to do with it, or is it more to do with Erosion (wouldn't a barrier reef prevent erosion to a degree)?

And the last question I have is concerning the make up of islands. Since New Caldonia (>40MYA) is older geologically speaking than Midway Island (27MYA) and the two are completely different (one is an Atoll the other is a proper island). Which is a roundabout way of asking, is the geological makeup of an Atoll more prone to erosion than a "regular" island?

submitted by /u/Wilco499
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Can a sedimentary rock transform directly to an igneous rock without transitioning first to a metamorphic rock?

Posted: 25 Nov 2019 02:52 PM PST

I'm seeing resources that either show all three rock types freely transform into one another OR that sedimentary rock has to become a metamorphic rock before transforming into an igneous rock. Which interpretation is correct? Thanks.

submitted by /u/sturmeagle
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Do herbivore animals have plants with special prefered taste like sweets for humans?

Posted: 25 Nov 2019 10:03 AM PST

Biology taught me that cells proactive aerobic respiration by default. This means every individual cell needs oxygen. I know that blood is carried by red blood cells, but how does the oxygen from the blood get into a single cell?

Posted: 25 Nov 2019 02:39 PM PST

Are there little tiny blood vessels that branch into every single cell? This doesn't seem likely because otherwise the tiniest cut would bleed which isn't what I've observed when getting small surface cuts.

Edit: title should say "practice"

submitted by /u/Tresky
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Do computers get slower over time?Why?

Posted: 25 Nov 2019 08:46 AM PST

Monday, November 25, 2019

Does an obese person have more blood in their body than a person with a optimal body mass index?

Does an obese person have more blood in their body than a person with a optimal body mass index?


Does an obese person have more blood in their body than a person with a optimal body mass index?

Posted: 24 Nov 2019 08:51 AM PST

How did scientists think the sun worked before the discovery of nuclear fusion?

Posted: 25 Nov 2019 02:46 AM PST

We often hear that we modern humans have 2-3% Neanderthal DNA mixed into our genes. Are they the same genes repeating over and over, or could you assemble a complete Neanderthal genome from all living humans?

Posted: 25 Nov 2019 06:20 AM PST

Since it’s been getting cold, when I get in my car in the morning and turn my music on it seems like it’s playing 1-2 pitches lower and a tiny bit slower. The best theory I can think of is the cold. Do we perceive our senses differently in colder climates?

Posted: 25 Nov 2019 07:01 AM PST

Is sociopathy developed over time through social interaction or is there a specific biological, congenital cause that's been discovered?

Posted: 25 Nov 2019 06:50 AM PST

Put another way: is one born with the trait or could a non-sociopath develop the 'condition'.

Apologies for any incorrect use of terminology.

submitted by /u/I_Always_Talk_Shite
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Would a persons feeling towards a drug inhibit it’s ability to work, like a nocebo?

Posted: 25 Nov 2019 03:51 AM PST

Does a medicine or tablet. E.g. panadol, have a lesser effect on a person if they are sceptical about it.

even though the drug works would the effect be felt less by the body depending on the persons feelings toward either the person who administered it or the drug itself.

Also if this has been studied what would the name of the effect be or would it just be referred to as nocebo

submitted by /u/4ouR__
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How would you calculate the true distance between LA and NYC, the straight line distance not including the curvature of the Earth?

Posted: 25 Nov 2019 06:13 AM PST

I'm pretty sure this can be mathed out with numbers pulled off the internet, but was just curious as to what mathematical steps you would take to do so.

submitted by /u/Dayumnn_Daniel
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How does one induce a strong shockwave instead of a weak shockwave?

Posted: 25 Nov 2019 04:37 AM PST

For a supersonic shockwave two solutions exist for a given angle; the strong and weak shockwave. Nature prefers the weak shockwave, but the strong shockwave is not impossible.( i think)

submitted by /u/nicecreamdude
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Does crenation affect red blood cells membrane structural stability?

Posted: 25 Nov 2019 05:25 AM PST

From my understanding when a red blood cell is exposed to a hypotonic solution it bursts (so red cell lysis). I know that when exposed to a hypertonic solution they shrivel up as water leaves them via osmosis,so I was wondering if this shrivelling up has an affect on the red blood cells membrane.

submitted by /u/TheSecondBlueberry
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If a disease is eradicated by vaccination, does that mean that the pathogen is extinct by natural selection? Will I get the disease if I dont get vaccinated?

Posted: 25 Nov 2019 03:01 AM PST

What is the difference between an alloy and a composite?

Posted: 24 Nov 2019 12:45 PM PST

Do sensory neurons at the top of our head send their messages straight to the brain or do the messages go through the spinal cord?

Posted: 25 Nov 2019 12:50 AM PST

What percentage of salt in solution is needed for something to taste salty?

Posted: 25 Nov 2019 12:43 AM PST

I was not able to find anything on google that answered this for me.

Does normal saline solution (0.9% NaCl in water) taste salty?

If not, at what concentration of salt will the solution taste salty?

Thank you!

submitted by /u/holyvegetables
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Do magnets really harm computers?

Posted: 24 Nov 2019 07:33 AM PST

Why does hair change colors? Why does facial hair follow suite at a faster rate.

Posted: 23 Nov 2019 09:17 PM PST

So I was born with red hair. By 1st grade it had changed to a blond so pale it glowed in light. After that it's been darkening ever since. Starting in September I was finally able to start growing a beard. It's been growing a deep red but I noticed today that now it's almost 2inches thick......its turning blond..... it looks exactly like dyed hair and the roots growing undied...

Long story short- why did my hair change color and whys it doing it so fast on my beard?

submitted by /u/spartan8440
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To what extent is the housecat a product of human intervention?

Posted: 23 Nov 2019 02:03 PM PST

Did/do house cats as we know them live naturally in the wild?

submitted by /u/UdderTime
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How is there a river at the bottom of the Grand Canyon if it is below sea level and not flow to an ocean?

Posted: 23 Nov 2019 02:31 PM PST

I understand that most rivers flow the the sea, and that the grand canyon reaches below sea level. So where does the river flow to and could the river essentially keep eroding deeper and deeper?

submitted by /u/radiofreduk
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Sunday, November 24, 2019

For light to qualify as a laser does it have to be emitted in a beam or does it just have to be of one wavelength?

For light to qualify as a laser does it have to be emitted in a beam or does it just have to be of one wavelength?


For light to qualify as a laser does it have to be emitted in a beam or does it just have to be of one wavelength?

Posted: 23 Nov 2019 12:38 PM PST

If it does have to be a beam, what is the maximum spread it can have and still qualify?

submitted by /u/quadraspididilis
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Change in temperature as you increase in elevation is called a lapse rate, but what is the reverse called?

Posted: 24 Nov 2019 05:26 AM PST

I know that lapse rate is defined as the decrease in temperature as height (elevation) increases. So what is an increase in temperature as elevation decreases called? For some reason extensive searching has not yielded me anything yet.

submitted by /u/melvilleismycopilot
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will a nuclear bomb produced 20 or 30 years ago still detonate as it is planned?

Posted: 24 Nov 2019 04:53 AM PST

i always wondered what would happen if you deploy a nuclear bomb produced long time ago. obviously nobody has ever tried this so it all very theoretical. to get full force all components have to be very precisely calibrated but nuclear materials decay with time. is there a chance that it will go off but just create a lot of pollution without proper detonation?

are the active materials supposed to be renewed once in a while? if so is anybody is doing this in reality?

submitted by /u/edmundspriede
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When an electron in an atom is excited, does its probability distribution instantly change from one shape to another, or is there a transitionary period?

Posted: 24 Nov 2019 04:22 AM PST

If the latter, what does the distribution look like as it is shifting and how long does it take?

submitted by /u/baquea
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What exactly is color superconductivity?

Posted: 24 Nov 2019 04:02 AM PST

I've googled it, but I'm having a hard time visualizing what exactly happens.

submitted by /u/IAmCaelestis28
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Is it possible for asteroids to contain incredibly huge gemstone cores?

Posted: 23 Nov 2019 10:01 AM PST

Im not familiar with the conditions required for precious stones to form, I know diamonds require a lot of pressure for the crystal structure to take form but not much else, could the conditions in an asteroid belt allow for lets say an emerald geode with a diameter in the dozens of meters?

Also I see this sub doesnt consider geology a real science, really funny guys, bazinga...

submitted by /u/BaconDragon69
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Can Carbon Dioxide exist as a liquid?

Posted: 23 Nov 2019 08:57 AM PST

I understand that carbon dioxide can deposite as dry ice, and sublimate back to a gas, but can it melt or condense into a liquid? Is any place that carbon dioxide can be found naturally as a liquid, or is it only possible through artificial processes?

submitted by /u/Funky7Monkey
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Did the gauge bosons, from before the fundamental force separated into four, persist?

Posted: 23 Nov 2019 12:34 PM PST

When the fundamental forces were unified they had different gauge bosons, such as the W1, W2, W3, and B particle for the electroweak force. All of which are massless and therefore stable.

Would any of them have survived the separation of the fundamental forces?

submitted by /u/daimonjidawn
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I’ve heard that quantum computers can break encryption easily, why?

Posted: 23 Nov 2019 08:21 AM PST

You can assume that I've a 101 level understanding of AES and Qbits.

submitted by /u/GrannyRUcroquet
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Are we living in on higher ground than people in the past?

Posted: 23 Nov 2019 05:06 PM PST

As i was watching some documentaries, i saw some pattern. All these ancient buildings beneath the ground completely buried ( for example giza pyramid, moai heads, gobeklitepe) or cities being under sea. It is certain that sea levels changed all the time during earth's life. So these buildings were not buried by someone but earth itself. So layer upon layer, earth in the air, or carried from somewhere else or from volcanic eruption just fills this land and we think that it was always this high.

submitted by /u/cenkiss
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How common are induced earthquakes?

Posted: 23 Nov 2019 04:04 PM PST

I've heard that humans can induce earthquakes through mining activity and fracking (although usually not enough to be felt) but I haven't been able to find any information on how much of all earthquakes worldwide are induced.

submitted by /u/Kilo_G_looked_up
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Is it possible to use a audio port to transmit data to a usb (bear with me I’ll explain it)?

Posted: 23 Nov 2019 09:09 AM PST

So basically could you theoretically hook up the right sound to data in, microphone to data out, a battery or something for a power source and some crazy stuff with audio drivers/usb drivers to receive and transmit data through the audio jack. Idk it sound hypothetically possible I just feel like it would've been done by some hobbyist already.

submitted by /u/mattreinstl
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Can talking parrots have accents like us?

Posted: 22 Nov 2019 08:32 PM PST

Does space itself have any type of pressure?

Posted: 22 Nov 2019 09:10 PM PST

How do various sea creatures know when they have swum as deep as is safe for them?

Posted: 22 Nov 2019 08:11 PM PST

Animals live at various depths of water. Some stay closer to the surface. Some stay on the sea floor. What about the ones that swim to different depths? How do they know what their "comfort zone" is and that they are about to leave it?

submitted by /u/1cecream4breakfast
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