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Friday, July 26, 2019

Do space stations lose air from using air locks?

Do space stations lose air from using air locks?

Do space stations lose air from using air locks?

Posted: 26 Jul 2019 05:15 AM PDT

If an astronaut needs to repair something outside, doesn't the air in the air lock room come out with them? Wouldn't that limit the amount of times it can be used?

submitted by /u/bullerick
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Is there any theoretical reason why the sun/moon relative sizes and distances are nearly the exact same?

Posted: 26 Jul 2019 05:57 AM PDT

It seems insanely unlikely that the sun and the moon apparent sizes are nearly identical in the sky. Is there any even theoretical reason that this happens, or is it truly pure chance?

submitted by /u/joe40001
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How is the instantaneous efficiency of nuclear reactors measured by nuclear power plant operators?

Posted: 26 Jul 2019 05:29 AM PDT

When a black hole is said to be spinning, does that refer to the accretion disk or can we actually make observations about the behavior of matter below the event horizon?

Posted: 26 Jul 2019 06:45 AM PDT

How does Mars look from the Moon, assuming that the Moon is at the point in it’s revolution where it’s closest to Mars?

Posted: 25 Jul 2019 02:50 PM PDT

If light slows down in water, then does causality also slow down?

Posted: 25 Jul 2019 06:24 PM PDT

Nothing can travel faster than light, and my elementary understanding of the speed of light is that it's also the maximum speed at which two particles can have a causal impact on one another. With that in mind, since light slows down in water, does causality also slow down? If so, it is possible to make a solution that further slows causality?

submitted by /u/cincycusefan
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How do those arm band blood pressure machines work?

Posted: 25 Jul 2019 12:14 PM PDT

I got a check-up today and realized I have been wondering this for basically my entire life up till this point.

submitted by /u/ramenayy
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How did paleontologists come to the theory that dinosaurs are more closely related to modern birds than reptiles? Does this hold true for all dinosaurs, or does this only apply to certain species?

Posted: 25 Jul 2019 03:47 PM PDT

If I = V/R, and we want to use the smallest amount of current in power transmission lines, then why do we use high voltage? Using the equation wouldn’t that result in high current?

Posted: 25 Jul 2019 08:15 PM PDT

What does it mean for an electromagnetic wave to be linearly polarized?

Posted: 25 Jul 2019 06:57 PM PDT

I was going through one of my textbooks from last year and found this from my waves and optics class: https://imgur.com/a/w8YbBn3

It says that when an EM wave is linearly polarized in a certain orientation, that corresponds to the plane of the electric field. Why is it the plane of the electric field in particular rather than the magnetic field or any other direction? Is that just a convention or is EM in general more "relevant" to things with electric charge? I assume that the latter could be the case because magnetism arrises from the spin of electrons, but I don't know for sure as I haven't yet taken electrodynamics.

submitted by /u/_Sunny--
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What kinds of geological processes could result in a desert with blue sand (lapis lazuli or azurite) over a strike slip fault?

Posted: 25 Jul 2019 04:55 PM PDT

How do we get digits for pi in the hundreds of thousands place and actually know if they are accurate?

Posted: 25 Jul 2019 05:25 AM PDT

I just can not understand how it is even possible to measure anything to that sort of accuracy. furthermore the digits have virtually zero impact on the value of pi once you get that far out into the decimals so how can you even validate your findings?

submitted by /u/Metroidman
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How are Martian dust storms able to occur?

Posted: 25 Jul 2019 08:20 AM PDT

Winds are caused due to uneven heating of the ocean and the earth. In Mars this phenomenon obviously does not exist. So, how are massive dust storms able to take place.

submitted by /u/sastachappati
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How is the Hubble Telescope still finding things after 30 years?

Posted: 25 Jul 2019 05:29 AM PDT

I saw in the news today that Hubble found a huge spiraling galaxy zillions of miles away. What I don't understand is why it takes nearly 30 years to point the telescope in that direction. It's just 360 degrees to turn it slowly around and then doing that same turn on its axis to cover its 3D space. Doesn't that take like a week or two? Maybe a month? But 30 years? So no one ever pointed it in that direction for all this time?

submitted by /u/parquet7
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Why do men have nipples?

Posted: 25 Jul 2019 12:57 PM PDT

How many X-rays are emitted and absorbed in a standard medical X-ray radiograph?

Posted: 25 Jul 2019 01:35 AM PDT

This seems like it should be easy to find out, but most of the data talks about dose, rather than number of photons, so I hoped someone here would be familiar with doing that conversion!

submitted by /u/nick_hedp
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Thursday, July 25, 2019

AskScience AMA Series: We're from the Pacific Northwest National Laboratory and we research pumped-storage hydropower: an energy storage technology that moves water to and from an elevated reservoir to store and generate electricity. Ask Us Anything!

AskScience AMA Series: We're from the Pacific Northwest National Laboratory and we research pumped-storage hydropower: an energy storage technology that moves water to and from an elevated reservoir to store and generate electricity. Ask Us Anything!

AskScience AMA Series: We're from the Pacific Northwest National Laboratory and we research pumped-storage hydropower: an energy storage technology that moves water to and from an elevated reservoir to store and generate electricity. Ask Us Anything!

Posted: 25 Jul 2019 04:00 AM PDT

We are Dhruv Bhatnagar, Research Engineer, Patrick Balducci, Economist, and Bo Saulsbury, Project Manager for Environmental Assessment and Engineering, and we're here to talk about pumped-storage hydropower.

"Just-in-time" electricity service defines the U.S. power grid. That's thanks to energy storage which provides a buffer between electric loads and electric generators on the grid. This is even more important as variable renewable resources, like wind and solar power, become more dominant. The wind does not always blow and the sun does not always shine, but we're always using electricity.

Pumped storage hydropower is an energy storage solution that offers efficiency, reliability, and resiliency benefits. Currently, over 40 facilities are sited in the U.S., with a capacity of nearly 22 GW. The technology is conceptually simple - pump water up to an elevated reservoir and generate electricity as water moves downhill - and very powerful. The largest pumped storage plant has a capacity of 3 GW, which is equivalent to 1,000 large wind turbines, 12 million solar panels, or the electricity used by 2.5 million homes! This is why the value proposition for pumped storage is greater than ever.

We'll be back here at 1:00 PST (4 ET, 20 UT) to answer your questions. Ask us anything!

submitted by /u/AskScienceModerator
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Why are beta blockers restricted to prescription only?

Posted: 25 Jul 2019 12:42 AM PDT

I am struggling to find answers online as to why they are not sold over the counter.

submitted by /u/dontknowhowtoprogram
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How does the Peltier effect work?

Posted: 24 Jul 2019 03:14 PM PDT

So i keep finding really general science answers of WHAT it is. But Im looking for a step by step of what is happening and why to full comprehend how heat or cold is being turned into eletricity

submitted by /u/hansolo951
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Is Ceres a dwarf planet or an asteroid?

Posted: 24 Jul 2019 08:45 PM PDT

I was wondering what the largest asteroid known to man currently is.

Google says Ceres but often labels it as either an asteroid or a dwarf planet.

I am beginning to think it is both?

submitted by /u/louisprimaasamonkey
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If two tornadoes who rotate in opposite directions collide, what happens?

Posted: 24 Jul 2019 01:54 PM PDT

I have a few questions about temperature?

Posted: 24 Jul 2019 10:55 AM PDT

  1. Does it take the same ammount of energy to heat something from 5°C to 6°C as it takes to heat that same thing from 1002°C to 1003°C?

  2. As I understand it, atoms can turn their internal energy (temperature) into photons through blackbody radiation. Is there a bottom cutoff at which temperature they dont do that anymore? And if so, what limits it?

  3. If I had a group of atoms (all of the same isotope) that I keep at a constant temperature would the photons they produce all be at the same wavelength or would their wavelengths (graphed) look more like a bell curve?

  4. (kinda related to question 2) Assume a perfect vacuum with no cosmic rays, sunlight, gravity or anything. In that empty space Ill "put" a single atom (preferably an element that wont decay soon) at 1000°C. Whats the lowest temperature itll ever reach (through blackbody radiation)? Are there other phenomena that would also cool it somehow? How long untill it reaches that lowest temperature?

  5. Is it even correct to say a single atom has a temperature like I did in question 4?

Thanks for any answers.

submitted by /u/Lacksi
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What effect does the shifting Magnetic Field(movement of Earth’s Poles) have on Earth’s Climate?

Posted: 24 Jul 2019 03:01 PM PDT

I read recently that there might be some correlation between Climate Change and the movement of the magnetic poles and was wondering if someone could help explain any possible effects.

submitted by /u/Blkskorpion
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How does relative speed at or near the speed of light work?

Posted: 24 Jul 2019 05:16 PM PDT

If we assume there is something that is moving at 0.75c relative to a stationary frame of reference, let's assume Earth, and that a projectile is launched from it at an additional 0.75c, how is that projectile still moving slower than the speed of light? I understand that special relativity applies here but I can't quite wrap my brain around why it is like this. I also understand that there's a "speed limit" of sorts through the universe and the energy issue and such- but hypothetically, if it was possible to do such a thing... How does it work?

​

Like if a car is moving away from me at 5 mph a person throws a ball 5mph out the front, you take into account the energy that the ball already has, since it is already moving as 5mph relative to me, and then when it's thrown it gains the additional speed of the throw.

submitted by /u/torohangupta
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To my best understanding, space is (for the most part) absent of matter, meaning the Earth has no place to conduct heat. How, then, do CO2 and other gases contribute the the Greenhouse effect, if the Earth already exists as a natural Greenhouse?

Posted: 24 Jul 2019 09:00 PM PDT

Can someone explain the tennis racket theorem?

Posted: 24 Jul 2019 12:37 PM PDT

If the event horizon is the region in space wherein the escape velocity of the singularity exceeds that of the speed of light, would there be a region in space beyond this wherein the velocity required to maintain a stable orbit reaches precisely the speed of light?

Posted: 24 Jul 2019 06:31 PM PDT

And would this allow particles to travel short distances away from the singularity above it?

submitted by /u/bigmaxporter
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Regarding the cause of climate change, why is all the emphasis on greenhouse gases? What about all the thermal energy being produced from electricity and other technology?

Posted: 24 Jul 2019 01:23 PM PDT

How does a air cooler work?

Posted: 24 Jul 2019 01:53 PM PDT

When water evaporates, it cools something down

so how does a dehumidifier male the air cool then? (or a AC unit drip out water)

submitted by /u/notrealjamescharles
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How does the brain decide when to do a heart pump?

Posted: 24 Jul 2019 01:53 PM PDT

Is the brain just running an infinite loop in the background that sends a signal to the heart for each pump?

submitted by /u/BologneseDeveloper
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What gas is inside a sealed coconut?

Posted: 24 Jul 2019 10:29 AM PDT

Assuming I understand correctly that a coconut:

  • Is a sealed unit before it is opened
  • Is not 100% full of coconut water (else it'd be pretty heavy, and not slosh)

What is the gas? Is it a waste product of the cells within?

submitted by /u/FifteenFifty
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Is there anything that can make the moon red-colored aside from lunar eclipses?

Posted: 24 Jul 2019 10:41 AM PDT

I live in Japan and tonight I observed a reddish-colored moon, similar to what I've seen during lunar eclipses (here's my attempt to capture it with my phone). It seems that the last lunar eclipse was about a week ago from now, so I am somewhat puzzled. What am I seeing? What makes the moon appear red this time?

Another interesting thing is that it seems that the moon tends to appear reddish around this time of the year in japan. Here's another one I captured about a month ago on June 19th.

Are these all delayed(?) lunar eclipses? Strange weather conditions? Or something else?

submitted by /u/apolotary
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How do we take images of our own Milky Way Galaxy when we are INSIDE of the galaxy itself?

Posted: 24 Jul 2019 01:20 PM PDT

I've always wonderred about this. I understand how we can get an image of other galaxies. But how is it possible to get a full image of our own galaxy when we are inside of it?

submitted by /u/eutum
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How do we know that there aren't anti-galaxies?

Posted: 24 Jul 2019 08:36 AM PDT

I'm given to understand that antimatter behaves with itself in the same way that the equivalent regular matter does. So a large mass of anti-hydrogen could form a star, with antiproton-antiproton chain fusion forming anti-helium. Anti-photons aren't really a thing since photons are not charged particles, so such an anti-star would produce light that appeared just like a regular star of equivalent mass. How would it be possible to tell the difference between an anti-star and a regular matter star from a distance?

It's fairly safe to assume that none of the stars in our galaxy are made of antimatter as if both were present in our galaxy we'd be able to witness annihilation reactions occurring as matter and antimatter collide. Yet, it seems as though it could be possible for a faraway galaxy to exist made entirely of antimatter. How would we be able to tell the difference between this and a normal galaxy? How do we know the assumption that all visible galaxies are made of normal matter is correct?

submitted by /u/Lemonwizard
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Are hypervelocity stars only possible in a binary star system?

Posted: 24 Jul 2019 10:38 AM PDT

Whenever I saw stuff about hypervelocity stars it always said they came from a binary star system and one got launched into space by a massive blackhole. Is it possible for a singular star to be launched or can it only come from a binary system?

submitted by /u/fff628
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Wednesday, July 24, 2019

Humans have "introduced" non-native species to new parts of the world. Have other animals done this?

Humans have "introduced" non-native species to new parts of the world. Have other animals done this?

Humans have "introduced" non-native species to new parts of the world. Have other animals done this?

Posted: 23 Jul 2019 05:33 PM PDT

When someone is dying of hunger or thirst, is there a "point of no return" after which they are still alive but if they were given food or water their body would not be able to absorb it fast enough to survive?

Posted: 24 Jul 2019 08:35 AM PDT

And if this point exists, would someone who's past it still be conscious/aware?

submitted by /u/ArchmageIlmryn
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Are there invasive species that benefit the local ecosystem?

Posted: 24 Jul 2019 08:40 AM PDT

Some human organs, e.g. liver and skin, have regenerative properties. Why don't other tissues, e.g. heart or stomach, also have similar regenerative properties as the liver and skin have?

Posted: 24 Jul 2019 08:19 AM PDT

How was the NES Duck Hunt game able to work on a tube TV with no sensor bar?

Posted: 23 Jul 2019 11:25 AM PDT

Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science

Posted: 24 Jul 2019 08:13 AM PDT

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Physics, Astronomy, Earth and Planetary Science

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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Just like humans can pull muscles without proper stretching, can animals have pulled muscles with sudden movement?

Posted: 24 Jul 2019 07:55 AM PDT

What separates a “speedy” metabolism from a “slow” one?

Posted: 24 Jul 2019 07:32 AM PDT

Does a beard grow at the same rate everytime or is it impacted by factors such as sleep, health, diet, Etc?

Posted: 24 Jul 2019 05:44 AM PDT

In large timescales, energy is not conserved because of the expansion of the Universe. Given energy was conceptualized before relativity, is there a way to redefine energy to keep it conserved even with GR?

Posted: 23 Jul 2019 08:07 AM PDT

In Network Theory is their any simple way to be able to tell if you can create the network without having links overlapping each other?

Posted: 24 Jul 2019 01:46 AM PDT

basically i was wondering if it would be possible to recreate this network https://i.imgur.com/pOIwe3L.png without having the branches over lapping (as it is kind of annoying my OCD)

PS: as someone who doesnt spend to much time in this subreddit (and thus doesnt have alot of karma) having to wait 8 minutes to repost my question because the 1st time i forgot a question mark, is kind of annoying

submitted by /u/D-Spark
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Do all brain cells contain microtubules​?

Posted: 23 Jul 2019 03:43 PM PDT

Why is the work done during expansion greater in adiabatic process than polytropic process, but it is vice versa in case of compression?

Posted: 23 Jul 2019 11:32 PM PDT

Is the Earth's speed of rotation always constant ? What would happen if it accelerated / decelerated randomly ? Also, if the speed went up / down, what would be some of the short and long term impacts on life ?

Posted: 23 Jul 2019 03:33 PM PDT

Where will the "new" highest mountain-top be once Everest stops growing and eventually erodes?

Posted: 23 Jul 2019 06:19 PM PDT

How is military-grade napalm made? How does it compare to the homemade version with styrofoam and gasoline?

Posted: 24 Jul 2019 01:25 AM PDT

Why aren’t there more triangular shaped molecules if it is the strongest shape?

Posted: 23 Jul 2019 07:31 AM PDT

Is there any scientific reason why the magnetic north/south has to correspond with extreme temperature?

Posted: 23 Jul 2019 03:45 PM PDT

I suppose what I'm asking is if the rotation of a planet is always aligned with its magnetic field. For example, would it be possible for the equator to run north to south?

submitted by /u/Pandemic589
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What are the differences between properties of cis and trans unsaturated fatty acids?

Posted: 23 Jul 2019 07:50 AM PDT

From what I understand cis configurations are when the two hydrogens bonded to the carbons forming the C=C double bond are facing the same direction, while trans configurations are when they face opposite directions. Is this correct?

What are the differences in properties that lead to the food industry creating trans fat products? Why are trans fatty acids more unhealthy than cis fatty acids?

Thanks in advance.

submitted by /u/_OblateEllipsoid
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