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Friday, August 31, 2018

Is washing your hands with warm water really better than with cold water?

Is washing your hands with warm water really better than with cold water?


Is washing your hands with warm water really better than with cold water?

Posted: 30 Aug 2018 01:10 PM PDT

I get that boiling water will kill plenty of germs, but I'm not sold on warm water. What's the deal?

submitted by /u/mitchade
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In Layman's terms, how do the new RTX graphics cards calculate the path of light rays?

Posted: 31 Aug 2018 01:28 AM PDT

Why does our brains tend to recall bad memories and make us in a bad mood rather than recall good memories and make us in a good mood more often?

Posted: 31 Aug 2018 05:50 AM PDT

What happens to a material's heat capacity as it approaches the speed of light?

Posted: 31 Aug 2018 01:47 AM PDT

As an object's velocity increases close to the speed of light so does it's apparent mass which makes continual acceleration to c essentially impossible. My question is does this apparent increase in mass effect the thermal properties of the material involved? Would it be harder to melt a block of ice going 99.9% the speed of light than an identical block of ice going at 0.01c?

submitted by /u/AlistairStarbuck
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How do ants find even the smallest piece of food far away from their nests?

Posted: 31 Aug 2018 07:27 AM PDT

What causes the soft tissues to expand when humans grow?

Posted: 31 Aug 2018 06:05 AM PDT

Say someone grows a foot over three years. For example, what makes sure that his intestines grow at the same rate so he doesn't have disproportionately small intestines bouncing around in him whenever he walks? Or what makes sure that our muscles grow longer when we grow so that we're not stuck with the arms of a two-year old?

submitted by /u/SatOhShe_KnockAMoto
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Is there any difference in the water that forms the rings of Saturn and the water we have on earth?

Posted: 31 Aug 2018 06:18 AM PDT

So I recently read that the icy rings that orbit Saturn are made up of 99.9% pure water. Is the water there more purified than the water we have on Earth?

Once we filter or purify water here on Earth, does it match the purity of the water that can be found in the rings of Saturn?

submitted by /u/TrooperNI
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How does our brain wake itself up?

Posted: 31 Aug 2018 12:17 AM PDT

Why do we get older?

Posted: 31 Aug 2018 04:02 AM PDT

We are made of cells, and these cells are bunch of atoms connecting to each other. But atoms can't be drained out of energy, so why do we get older and die when the atoms keep vibrating?

(Not a native English speaker, sorry if I was unclear.)

submitted by /u/ronkandelker512
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Why Don’t we have fusion power yet?

Posted: 30 Aug 2018 08:25 PM PDT

I was just wondering why we don't have fusion power yet. I know that right now the reactors are highly inefficient but I was wondering if there was a specific reason? Is it the material that the reactors are made of or the amount of hydrogen and deuterium and tritium needed.

submitted by /u/Allseeingeye49
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Why do different oral magnesium salts (supplements) have different bioavailability measures?

Posted: 31 Aug 2018 02:10 AM PDT

Hi all.

I have always wondered why Mg salts are reported to have different oral absorption rates and bioavailability in studies.

Isn't Mg in all oral salts paired with acids that are weaker than hydrochloric acid? Wouldn't all Mg then turn into MgCl2 and whatever acid made the salt in solution inside the stomach? I must admit that my chemistry knowledge is limited, so I would love a clear answer to this.

Thanks!

submitted by /u/4f14-5d4-6s2
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Is rust AKA iron oxide potentially toxic or harmful to humans?

Posted: 31 Aug 2018 01:29 AM PDT

If you want detail about why I'm asking this question, see below. Otherwise, the title should suffice as the pithiest version of this question.

This is really a question about rust developing on coffee grinder burrs, specifically the burrs on a popular hand grinder known as the Aergrind.

I've been having an very anxious week and the weirdest shit is getting to me, so I gotta' ask. Some wet/damp beans went into my new Aergrind earlier today, which has only grinded about 12oz of beans over a week and a half (so, I'm not sure how much of that oily "protective coating" has developed on the burrs, which apparently protects against some water).

Since then, I've become obsessed with the idea of rust developing on the burrs. Can't even see the Aergrind's burrs clearly, so I can't confirm one way or the other.

Then I found this from Baratza's website: "Rusty Burrs - Really?". Noted in that article is the following:

"you may find some rust when you receive your burrs. Yes, this is normal and it will not harm you, nor does it make for an inferior burr."

I'm assuming this applies to other grinders, including the Aergrind.

If this is true, why are many coffee connoisseurs (i.e., not me; I'm an utter amateur) so fastidious about not getting water on the burrs like it'll be the end of the equipment or something terrible will happen?

The same article also cites the following:

The National Institute of Occupational Safety and Health (NIOSH) indicates that rust is not toxic…… If eaten, the acid in the digestive processes will convert rust to iron needed for blood formation or excrete the excess."

Then again, rust is an iron oxide, and you can get sick from iron overdose, but does that also apply to iron oxide? Correct me if I'm wrong, that would be pretty nearly impossible just from rusty burrs regardless of how many beans you're grinding, right?

So, as far as ingesting coffee that's been ground up via a rusty burr, are there any actual -- and significant/meaningful -- downsides?

submitted by /u/signs_unbreakable
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If you kept a person in a room in which nothing ever emitted light at wavelengths below 550 nm, would their blue-sensitive cone cells atrophy?

Posted: 30 Aug 2018 11:08 PM PDT

How do far away space probes like New Horizon account for the motion of the Earth and the probe during communications transmission and reception?

Posted: 30 Aug 2018 09:56 AM PDT

At over 4 billion miles away, the signal would take 6 hours to reach Earth which would have moved about 389 thousand miles. Does the probe account for this motion and realign its transmission antennas?

Edit: Apparently, there would not be too much precise calculations due to the frontal lobe of the signal spreading out enough that as long as the transmission antenna was pointed in the direction of Earth, the signal could be received. Also once a probe is far enough above or below the ecliptic, obstruction would not be a major issue. As for the displacement of the Earth during transmission, it would be minimal given the distance of the probe.

Conclusion: I leaned a lot about probe signal transmission and reception. Which was the intent of this post. Thanks /r/askscience ! :)

submitted by /u/Skwurls4brkfst
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Whats the deal with Asteroid 2002 NT7?

Posted: 30 Aug 2018 09:58 PM PDT

I remember when NASA predicted that this asteroid would likely hit Earth and calculated the accuracy of that statement down to the time it would hit. 11:47 am, February 1st, 2019. Then four days later they changed their prediction and said its collision is unlikely.

So the questions are: How did they go about changing their minds? Is four days really enough time? How unlikely is it that said asteroid hits Earth?

submitted by /u/FrenchSnail
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Why does Hypocalcemia cause Tetany?

Posted: 30 Aug 2018 09:01 PM PDT

The textbook just says hypocalcemia increases neuronal excitability. But what about how calcium is needed to release ACh from synaptic knobs? How are the muscles stimulated without ACh in that case?

Or does anyone have one of those ".edu" or ".html" links that have very simple explanations (similar to like this) which explains Calcium's role in the action potential?

Thanks for any help

submitted by /u/kuhataparunks
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How do nautiluses stay upright while swimming?

Posted: 30 Aug 2018 01:29 PM PDT

I'm interested in nautilus locomotion. Apparently they rise and sink by osmosis, and suck water in and out to move forward. How do they remain upright? Are they passively stable based on their anatomy, or do they have to actively try to remain upright?

submitted by /u/notadoctor123
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How do you predict the way a reation is going to take?

Posted: 30 Aug 2018 10:52 PM PDT

Does Fire Extinguish Easier in Cold Weather?

Posted: 30 Aug 2018 10:52 PM PDT

How much of earths mass is due to its spin?

Posted: 30 Aug 2018 03:16 PM PDT

Does a top have more energy when it is spinning than when it is stationary? Does a ball have more energy when spinning? Does a planet?

Since we know that energy is equivalent to mass, how much of Earth's mass is due to it's spin?

submitted by /u/dani1235a
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How do we know the surface temperature, chemical makeup, ages of rock formations, and other details of other planets? How can images and other data tell us these things? A lot of it seems like a stretch. How much of it is conjecture?

Posted: 30 Aug 2018 06:54 PM PDT

Thursday, August 30, 2018

AskScience AMA Series: We're compression experts from Stanford University working on genomic compression. We've also consulted for the HBO show "Silicon Valley." AUA!

AskScience AMA Series: We're compression experts from Stanford University working on genomic compression. We've also consulted for the HBO show "Silicon Valley." AUA!


AskScience AMA Series: We're compression experts from Stanford University working on genomic compression. We've also consulted for the HBO show "Silicon Valley." AUA!

Posted: 30 Aug 2018 04:00 AM PDT

Hi, we are Dmitri Pavlichin (postdoc fellow) and Tsachy Weissman (professor of electrical engineering) from Stanford University. The two of us study data compression algorithms, and we think it's time to come up with a new compression scheme-one that's vastly more efficient, faster, and better tailored to work with the unique characteristics of genomic data.

Typically, a DNA sequencing machine that's processing the entire genome of a human will generate tens to hundreds of gigabytes of data. When stored, the cumulative data of millions of genomes will occupy dozens of exabytes.

Researchers are now developing special-purpose tools to compress all of this genomic data. One approach is what's called reference-based compression, which starts with one human genome sequence and describes all other sequences in terms of that original one. While a lot of genomic compression options are emerging, none has yet become a standard.

You can read more in this article we wrote for IEEE Spectrum: https://spectrum.ieee.org/computing/software/the-desperate-quest-for-genomic-compression-algorithms

In a strange twist of fate, Tsachy also created the fictional Weismann score for the HBO show "Silicon Valley." Dmitri took over Tsachy's consulting duties for season 4 and contributed whiteboards, sketches, and technical documents to the show.

For more on that experience, see this 2014 article: https://spectrum.ieee.org/view-from-the-valley/computing/software/a-madefortv-compression-algorithm

We'll be here at 2 PM PT (5 PM ET, 22 UT)!

submitted by /u/AskScienceModerator
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Do geese belong to individual flocks, or can they just join up with whatever flock is headed in the right direction?

Posted: 29 Aug 2018 07:37 AM PDT

I just watched a large V of geese go overhead, then split apart into two groups and head to different directions. There were also a couple of stragglers rushing to catch up, one of whom seemed to have missed the boat completely and just kept going straight, blazing his own path.

Will that goose be looking around at some point for his family / friends? Will they just be looking around for any flock of geese to join up with? I assume that there are only a few main flyways, and they can catch up with their own flock "on the road", as it were, but does that matter to them?

submitted by /u/ProLicks
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How can a phone tell the exact percentage of the battery?

Posted: 30 Aug 2018 03:39 AM PDT

When someone receives a heart transplant as a child, does the heart grow with the child?

Posted: 29 Aug 2018 06:44 PM PDT

I don't know much about this stuff but I'm really curious. If someone receives a heart transplant or another transplant as a child, does the received organ grow with the child? Or does it stay the same size as it's a foreign body and they need to receive and adult one later on? Or is it the same size anyway?

submitted by /u/frankierabbit
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What happens to air that escapes the ISS?

Posted: 30 Aug 2018 06:24 AM PDT

Generally, what happens to air that escapes the ISS? Does it eventually get reabsorbed into Earth's atmosphere? Or is it stuck up in orbit or escape our planet?

submitted by /u/lquigley6
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How will the ISS 'land'?

Posted: 30 Aug 2018 02:25 AM PDT

Keeping the ISS at 400km height and delivering food for the astronauts is really expensive and as much as I know ISS will run out of funding in the next 10ish years. So what will happen with the station? Making it leave orbit will be impossible so how will it come back to earth?

submitted by /u/chogawin
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How do we know that the concept of dark matter isn't just the observed gravitational effect of undetected black holes on their surrounding stars and galaxies?

Posted: 29 Aug 2018 10:17 PM PDT

How is a bionic arm controlled?

Posted: 30 Aug 2018 07:26 AM PDT

I have seen videos where people just but the bionic arm on there body and it suddenly works.

submitted by /u/Redhonu
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What causes the symptoms of motion sickness and why do medications such as scopolamine in a transdermal patch alleviate these effects?

Posted: 29 Aug 2018 09:21 PM PDT

What happens to proteins over time? Do they degrade, are they broken down in by the cell, do they just hang around? How long will a protein stay viable?

Posted: 29 Aug 2018 08:58 PM PDT

In the last 50 years, ten volcanic-made islands were formed. Is this a consistent and predictable rate? If so, can/will the earth over millions of years eventually become solid volcanic rock? Why or why not?

Posted: 29 Aug 2018 07:52 PM PDT

Can a particle accelerator beam be referred to as a Laser?

Posted: 29 Aug 2018 11:20 PM PDT

I read an article about Anatoli Burgorksi, the Russian scientist who survived after being struck by a particle accelerator beam to the head.

The article uses the term" High-Powered Laser" in the headline. Is this just a sensationalised headline or is it acceptable to use the terms, Laser and Particle Beam interchangeably?

Article

submitted by /u/bushknifebob
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What's stopping us from creating smaller than ~5nm transistors and also makes it difficcult to even reach there?

Posted: 29 Aug 2018 04:39 PM PDT

GloFo just shut down its 7nm fab amd intel isnt doing very well with 10nm so this question came in mind

submitted by /u/geonik72
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Can you make a nuclear bomb with any element?

Posted: 29 Aug 2018 07:58 PM PDT

Could you use an element like gold, or sodium, instead of uranium?

submitted by /u/superhareball
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Did all written language originate from a single early language?

Posted: 29 Aug 2018 02:57 PM PDT

or have different writing systems been created completely separately with no influence or knowledge of the existence of other written language?

submitted by /u/DalvaMozzerX
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Neurologically speaking, what makes a child's brain better at learning new skills and languages than that of an adult?

Posted: 29 Aug 2018 03:44 PM PDT

How does an electron multiplier release upwards of a million electrons from just one? Where do those electrons come from?

Posted: 29 Aug 2018 02:48 PM PDT

Does animals of same species understand each other irrespective of the country they came from? Not talking about human beings..!

Posted: 29 Aug 2018 08:01 PM PDT

For instance, a cow from USA speak the same language(or understand) another from a different continent?

submitted by /u/raja777m
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How much does the change in climate affect the spread of cold and flu viruses In places that experience the change in seasons more rapidly?

Posted: 29 Aug 2018 07:59 PM PDT

Thanks for any informed answers/comments!

submitted by /u/DutchNugget
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If Andromeda is going to hit us but we are actually seeing that galaxy in the past, does that mean that Andromeda might have already hit us?

Posted: 30 Aug 2018 03:30 AM PDT

Water vapor is Earth's primary greenhouse gas both in quantity and effect. What prevents the cycle of the atmosphere heating, thus able to hold more water, thus heating the atmosphere even more, and so on?

Posted: 29 Aug 2018 07:25 AM PDT

Wednesday, August 29, 2018

What are the technological hurdles that need to be overcome in order to create a rotating space station that simulates gravity?

What are the technological hurdles that need to be overcome in order to create a rotating space station that simulates gravity?


What are the technological hurdles that need to be overcome in order to create a rotating space station that simulates gravity?

Posted: 29 Aug 2018 03:10 AM PDT

I understand that our launch systems can only put so much mass into orbit, and it has to fit into the payload fairing. And looking side-to-side could be disorientating if you're standing on the inside of a spinning ring. But why hasn't any space agency even tried to do this?

submitted by /u/PhyrexianOilLobbyist
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Why isn't atmospheric CO immediately oxidised to CO2 by oxygen in the air?

Posted: 29 Aug 2018 05:50 AM PDT

Is oxygen just not a powerful enough oxidising agent?

submitted by /u/SpaceSpheres108
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If you were traveling forward as fast as a bullet, what would happen if you shot a bullet towards the direction you were heading?

Posted: 28 Aug 2018 11:01 PM PDT

Does Hawking Radiation violate Baryon Number conservation?

Posted: 28 Aug 2018 08:17 AM PDT

Since Hawking Radiation doesn't consider the types of particles that entered the black holes, doesn't that mean at some point baryon number conservation is violated?

Since Hawking Radiation is an explanation of quantum effects, shouldn't it be in agreement with current quantum theory?

As far as I know Hawking Radiation and Baryon Number Conservation are both generally accepted, but how can they be reconciled?

submitted by /u/Anaklusmos
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Ask Anything Wednesday - Engineering, Mathematics, Computer Science

Posted: 29 Aug 2018 08:12 AM PDT

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Engineering, Mathematics, Computer 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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How can the speed of light be constant?

Posted: 29 Aug 2018 06:57 AM PDT

Sorry, this is just a collection of thought, and I dont have any hard facts to back me up, but I have thought a lot about it.

The speed of light is constant and is used in a few equations such as E=MC2. My ultimate question is that if speed is relative then would physics change at near light speed?

If you are in a car moving 10 m/s north, and you pass another car moving at 9 m/s then relative to you the car is moving at 1m/s south. So by the same logic if you are standing on earth looking at a star, and rocket were to speed towards that star at 1000 m/s then to the person on earth the light is moving at the speed of light. However to space ship moving directly towards the star the light would be moving at the speed of light plus 1000 m/s, the speed of the ship.

If there is something in there that is logically unsound then here is another example.

Speed is defined as distance traveled over time. However, as you approach the speed of light time and distance dilate. Due to this dilation we can assume that time and space are relative, and as such speed (which time and space make up) is also relative.

Do I have some form of a misunderstanding? If speed is relative then we can assume that the speed of light is relative. If that universal constant isn't constant relative to another position then would physics act differently where that speed is different?

Again, sorry about how this might have not made much sense. I am not sure how to explain it better.

submitted by /u/sontath
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Alternatives to the Linde-Process for producing nitrogen?

Posted: 28 Aug 2018 02:33 PM PDT

I know about the Linde-Process but are there any other (cheeper) processes to get pure nitrogen out of the air and how do they work (industrial not lab. scale)?

I can't find much in the internet about the membran-process. How does it work and do you know good sources?

Thanks for your answer!

submitted by /u/druef99
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Do the Strong and Weak Forces have a field like Gravitation and EM?

Posted: 28 Aug 2018 09:43 AM PDT

Can anyone point me to an explanation of the greenhouse effect written by a physicist?

Posted: 28 Aug 2018 09:28 AM PDT

This is a crosspost from askphysics, but since they're a fairly small sub, I was hoping it would be ok to share it here.

https://www.reddit.com/r/AskPhysics/comments/9b06wd/physics_of_greenhouse_effect/

I'm having difficulty understanding how greenhouse gases (GG) "trap" infrared radiation (IR). As I understand it, carbon dioxide (CO2) absorbs IR in a few narrow bands of wavelengths (4.3 and 15 micrometers). A CO2 molecule that absorbs a photon will vibrate until it can emit a photon of its own.

A few questions for those of you who've studied thermodynamics;

  • do GG's increase global temps via vibration, or emission?

  • if vibration, how long is the time between absorption and emission?

  • if emission, do emitted photons leave a molecule in a consistent direction, or are their vectors completely random?

  • do the absorbed and emitted photons have identical wavelengths?

Thanks to all who take the time to help explain...

submitted by /u/adoomedman
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What actually happens to a Guitar string on a physical level that results in a different note playing after being tightened?

Posted: 28 Aug 2018 09:23 PM PDT

How many vertebrates are there on earth?

Posted: 28 Aug 2018 09:04 AM PDT

I'm trying to find an estimate of the total number of vertebrate animals on earth--not species, but population of individual vertebrates.

I can only find various sources (1,2) that estimate subsets of vertebrates (for instance, livestock chickens is estimated to be 19.6 billion alone)3, and many more that get into individual subsets, but I'm hoping to find something that estimates all vertebrates from lower chordates to primates.

Sources:

1 https://en.wikipedia.org/wiki/Lists_of_organisms_by_population

2 https://www.npr.org/sections/thetwo-way/2011/11/03/141946751/along-with-humans-who-else-is-in-the-7-billion-club

3 https://www.fastcompany.com/3031945/a-massive-global-map-of-where-all-the-cattle-pigs-and-other-livestock-live

submitted by /u/fidler
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As gamma waves became CMB, at what rough time in the Universe's history did they red shift through visible light?

Posted: 28 Aug 2018 07:40 AM PDT

This has bugged me for years. I am perfectly content with CMB as evidence for the big bang and all that, but, given that gamma waves were simply shifted down into longer wavelengths, this raises the implication that at some point, everywhere you looked, it would have been violet. Then indigo, then blue, etc.

Do we have any idea when this might have happened in the Universe's history? Even approximately?

submitted by /u/Perigeesus
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How does airplanes and helicopters behave with respect of Earth once they take off?

Posted: 28 Aug 2018 01:10 PM PDT

I can't wrap my head around how a flying object, like an airplane or helicopter, behave once in flight with respect of the Earth. Let me explain: consider a flight from Frankfurt to Capetown, almost straight north-south route: does the plane flight in a straight north-south line or does it need to "correct" because the earth is actually "escaping" under it, thus flying in an oblique line from the initial point of view? Does it "feel" earth rotation? Does it need to point towards the position of Capetown at the time of take-off or at the time of landing?

Similarly, if an helicopter simply takes off and stays up indefinitely, does it stays over the same point? I expect the answer being yes; in this case, is it due to some sort of drag from the atmosphere or because helicopter and earth are actually in the same system and are tied together?

Sorry for: question being eventually stupid, me being a little drunk and English not being my language.

submitted by /u/tekanet
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Why was the transistor such an important breakthrough?

Posted: 28 Aug 2018 02:20 PM PDT

What makes it a necessary part of computers and how does it work?

submitted by /u/DefaultPlayer99
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What is healthier for the phone battery?

Posted: 28 Aug 2018 10:33 AM PDT

Don't know where to ask it, so might as well put it here.

Lets say my smartphone needs to be constantly connected for a long period of time to the computer, even though the battery is already full. In this case what would be better in preserving the battery in the long run, leaving the screen turned on or off? Is there even a difference?

submitted by /u/PinkiePieYay2707
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