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Thursday, March 15, 2018

We’ve now discovered that spending a year in space can change your DNA - What does this change about what we thought we knew about DNA?

We’ve now discovered that spending a year in space can change your DNA - What does this change about what we thought we knew about DNA?

We’ve now discovered that spending a year in space can change your DNA - What does this change about what we thought we knew about DNA?

Posted: 14 Mar 2018 09:43 PM PDT

At what point in human evolution did we develop a dominant hand? Is this a trait found in other primates as well?

Posted: 14 Mar 2018 03:06 PM PDT

If someone is paralyzed from the neck down, how can they still breathe or have a heartbeat?

Posted: 15 Mar 2018 07:14 AM PDT

If the spinal cord is damaged to the point where a person cannot use their arms or legs, why can their heart an lungs still function? Are they connected to the brain in a different way?

submitted by /u/dandashem
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What is the hiccup actually doing? Is the function trying to accomplish something, or is it just an alert to drink water? Or is it something entirely different?

Posted: 14 Mar 2018 07:53 PM PDT

In quantum physics if an particle and an anti-particle pair is created, what does energy of each particle equal to? Is it same for both or is energy of normal particle equal to n and the energy of anti-particle equal to -n?

Posted: 15 Mar 2018 01:57 AM PDT

We recently discovered 'all galaxies rotate once every billion years'. Is this expected, and if not what are the implications?

Posted: 14 Mar 2018 08:48 AM PDT

PDF here

Article here

So it seems that there is a direct correlation between angular velocity and size. I assume this is expected, but I can't wrap my head around how this always yields a near billion year rotation.

Is this due to 'dark matter' distribution? Or something else? And was this expected of dark matter?

submitted by /u/iam_we
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How do we know if a particle is elementary?

Posted: 15 Mar 2018 06:38 AM PDT

How are scientists able to determine if a particle cannot be broken down any further?

submitted by /u/EarthsFlatYo
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If a plant was unable to build a proton gradient in the chloroplast, I know it wouldn't be able to produce ATP. Would it still be able to produce NADPH?

Posted: 15 Mar 2018 06:34 AM PDT

Why don't the protons in the nucleus repel each other like positive magnets?

Posted: 15 Mar 2018 05:40 AM PDT

Since particles increase in mass as they approach c, does that mean that mass is relative? Is mass therefore dependent on your frame of reference?

Posted: 15 Mar 2018 05:12 AM PDT

I recently started reading A Brief History of Time and the chapter on space and time.

It's (somewhat) common knowledge that time is relative - time moves slower for someone in orbit than for someone on the surface of the earth.

It's hard for me to articulate exactly, but it seems that mass, energy and velocity are all interlinked because of space-time and e=mc2 - does this mean that the mass of an object is dependent on your frame of reference as well?

If a particle is accelerated to a velocity where it's mass is increased tenfold, would the rest of planet earth, from the particle's frame of reference, also be increased tenfold?

If this is true, it seems strange that if you pick a specific frame of reference, you can accelerate the entire planet earth to near-c velocities, and also increase it's mass tenfold, without spending much energy at all.

submitted by /u/Pwntheon
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If an electron is a "elementary" particle, how can it combine with a proton in electron capture during radioactive decay and turn into something else?

Posted: 14 Mar 2018 01:09 PM PDT

If electrons and quarks are elementary particles, how can they combine to form a different type of quark, e.g. in electron capture of a electron by a proton to form an neutron and an electron neutrino? Is 'elementary' a misnomer as far as irreducibility or unchangeability of so called elementary particles? How does this work in a QFT sense?

submitted by /u/danielchorley
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How fast does electricity travel? If I had an extremely long circuit, and turned it on at one end, how long would it take until the person at the other end would see the current flow?

Posted: 15 Mar 2018 07:05 AM PDT

Will the universe ever stop expanding?

Posted: 14 Mar 2018 09:12 PM PDT

I don't mean will it ever be so massive that its own gravity will stop it from growing, but rather will it ever run out of energy to create matter? Is there a finite amount of energy the expansion can create or will the universe continue growing forever (discounting apocalypse theories)?

submitted by /u/Bletcherino
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Have we ever observed an object (such as an asteroid or comet) from another solar system come into our solar system?

Posted: 14 Mar 2018 12:28 PM PDT

Does static testing of large rocket motors increase Earth's angular velocity, or affect its rotation in any way?

Posted: 14 Mar 2018 06:22 PM PDT

Is it possible to change the shape of a subatomic particle?

Posted: 14 Mar 2018 07:38 PM PDT

If you put enough of a certain type of force, could you deform an electron from a sphere into, say, a cube?

submitted by /u/B_Wilks
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Why do dispersion affects differents colours in different ways?

Posted: 14 Mar 2018 06:14 PM PDT

I'm aware that the speed of light on media (and it's refractive index) depends on wavelength, but I can't find any source on why that happens. Shouldn't change in wavelength be compensated by the frequency changing, in a way to keep the speed of light constant (in a same medium)?

submitted by /u/MonoTitty
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How can smoking cause cancer years after the smoker has quit?

Posted: 14 Mar 2018 03:36 PM PDT

I understand the risk of cancer caused by smoking decreases after cessation but never completely, how is this?

submitted by /u/whowaitwhat
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What's the difference between laser and light?

Posted: 14 Mar 2018 04:48 PM PDT
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Wednesday, March 14, 2018

Stephen Hawking megathread

Stephen Hawking megathread

Stephen Hawking megathread

Posted: 13 Mar 2018 10:03 PM PDT

We were sad to learn that noted physicist, cosmologist, and author Stephen Hawking has passed away. In the spirit of AskScience, we will try to answer questions about Stephen Hawking's work and life, so feel free to ask your questions below.

Links:

submitted by /u/AskScienceModerator
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What experiments are currently being conducted to discover what dark matter/dark energy is?

Posted: 13 Mar 2018 08:38 AM PDT

Einstein birthday megathread

Posted: 13 Mar 2018 10:03 PM PDT

Hi everyone! Today is Albert Einstein's birthday and we're here to answer all of your Einstein-related questions.

His most famous achievement is arguably the development of the general relativity in 1915. General relativity is an extremely well-tested theory of gravity, with implications for mechanics, astrophyiscs, cosmology, and more. It has been a hot topic lately with the direct detection of gravitational waves.

Besides his work in gravity, Einstein was known for a great many other things. In 1921 he received the Nobel Prize in Physics for the discovery of the photoelectric effect. He also worked on thermodynamic/statistical physics (such as Brownian motion and Bose-Einstein statistics), the famous mass-energy equivalence, atomic physics, quantum mechaincs, and more.

Feel free to ask all of your Einstein-related questions!

submitted by /u/AskScienceModerator
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How does gravity effect time?

Posted: 14 Mar 2018 07:11 AM PDT

I once heard that if aliens were looking at the Earth due to how gravity bends time they would be seeing the Earth ruled by dinosaurs, is this true? If it is isnt any planet we view possibly at a totally different place in its own history?

submitted by /u/Witherdrake
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Is the water used to cool spent nuclear fuel rods radioactively contaminated? If yes, what is happening with it after it gets exchanged with fresh water?

Posted: 13 Mar 2018 10:36 AM PDT

I was not able to find any useful resource on this topic, thought someone here could help me :)

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

Posted: 14 Mar 2018 08:07 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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Why do sperm cells turn white/clear when they die?

Posted: 14 Mar 2018 01:54 AM PDT

I was looking at my semen under a microscope and for a couple minutes it was really cool watching all the sperm cells move around like black squiggles. It wasn't long after that when they started dying and when they did, they would gradually slow down and also gradually fade from black to either white or transparent (or translucent really not sure). Why did they change/lose color as they died?

submitted by /u/2scared
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On this the anniversary of its discovery, why is the axis of Uranus rotation tilted sideways, and have there been any exoplanets discovered with the same feature?

Posted: 13 Mar 2018 07:55 PM PDT

Do shark teeth contain DNA and could Megalodon DNA be recovered?

Posted: 13 Mar 2018 10:03 PM PDT

It's Said That Fusion Power is Always 30 Years Away, But How Close Have We Actually Come to Fusion Power, and Have There Been any Recent Advances?

Posted: 13 Mar 2018 07:23 AM PDT

As a followup, what are the biggest hurdles currently in the way of fusion power, and what's being done about them?

submitted by /u/ZeroBitsRBX
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Would passing the speed of light have an “event” like the sonic boom passing the speed of sound?

Posted: 13 Mar 2018 05:25 PM PDT

Congratulations, /r/AskScience! You are subreddit of the day!

Posted: 14 Mar 2018 05:01 AM PDT

How do remote car starters and keyless entry work, in terms of sending their signals?

Posted: 13 Mar 2018 05:27 PM PDT

Is it some sort of infrared beam? What's the normal range?

submitted by /u/Jay_B_
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Why can't we extinguish the Centralia mine fire in Pennsylvania?

Posted: 13 Mar 2018 02:29 PM PDT

It's been burning for 55 years. It has to be a large contributor to current climate change, or is that not true?

submitted by /u/Ohm_eye_God
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Are phonons a type of electromagnetic wave?

Posted: 13 Mar 2018 09:26 AM PDT

My chem prof keeps referring to sound waves/phonons as electromagnetic waves but I always thought they were purely kinetic/due to pressure differential and not electromagnetic.

If they are electromagnetic how come they don't travel at the speed of light?

If they aren't electromagnetic what are they?

submitted by /u/GIAway
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Is it possible to create a light emitting zener diode (LEZD)? [Engineering]

Posted: 13 Mar 2018 08:49 AM PDT

If so, would it be able to create visible light and then during an avalanche breakdown emit another non-visible wavelength (or maybe vice versa)?

submitted by /u/ryanadanderson
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Is it possible to create an LC oscillator circuit that emits gamma waves?

Posted: 13 Mar 2018 09:21 AM PDT

E.g. If a straight wire has am inductance, albeit a low one, and a capacitance, also low, and you cut a current to it very suddenly, wouldn't it form a LC oscillating circuit for a split second, with a frequency near the range of gamma rays?

submitted by /u/arzthaus
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Tuesday, March 13, 2018

If you cut entirely through the base of a tree but somehow managed to keep the tree itself perfectly balanced on the stump, would the tree “re-bond” to the stump or is this a tree death penalty?

If you cut entirely through the base of a tree but somehow managed to keep the tree itself perfectly balanced on the stump, would the tree “re-bond” to the stump or is this a tree death penalty?

If you cut entirely through the base of a tree but somehow managed to keep the tree itself perfectly balanced on the stump, would the tree “re-bond” to the stump or is this a tree death penalty?

Posted: 12 Mar 2018 12:32 PM PDT

Wikipedia and other sources say adult nuerogenesis (creation of new neurons in the brain) continues throughout life. But this new study in Nature says this is not true. What gives?

Posted: 12 Mar 2018 08:23 AM PDT

so we have many sources out there which state that since the 1970's its been well established that adult neurogenesis is an ongoing phenomenon.

Neurogenesis is the process of birth of neurons wherein neurons are generated from neural stem cells. Contrary to popular belief, neurogenesis continuously occurs in specific regions in the adult brain

but this recent study says the opposite. So what gives?

https://www.nature.com/articles/nature25975

We conclude that recruitment of young neurons to the primate hippocampus decreases rapidly during the first years of life, and that neurogenesis in the dentate gyrus does not continue, or is extremely rare, in adult humans.

submitted by /u/Bluest_waters
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How do solar panels work?

Posted: 13 Mar 2018 06:16 AM PDT

Does salt used for snowstorms actually damage my asphalt driveway, and if so why?

Posted: 13 Mar 2018 06:19 AM PDT

How can phytoestrogen consumption reduce menopausal symptoms in women but not alter blood androgen levels in men?

Posted: 13 Mar 2018 08:04 AM PDT

In this review there are two statements:

On the other hand, exposition of women to phytoestrogens (isoflavones, lignans, coumestans of different botanical sources) in pre- and postmenopausal period may prevent the menopausal symptoms induced by declined endogenous estrogen production – hot flashes, vasomotor symptoms, vaginal atrophy a.o., whilst no negative side-effect of these phytoestrogens on breast and endometrial health have been observed (Kronenberg and Fugh-Berman, 2002; Branca and Lorenzetti, 2005; Bedell et al., 2012).

Meta-analyses indicated no statistically significant association between soy isoflavones consummation and men plasma estrogen and androgen level (van Die et al., 2013).

And as noted earlier in the review:

Phytoestrogens are strikingly similar in chemical structure to the mammalian estrogen, estradiol, and bind to estrogen receptors alpha and beta with a preference for the more recently described estrogen receptor beta (Younes and Honma, 2011; Rietjens et al., 2013; Paterni et al., 2014).

[...]

Phytoestrogens besides their ability to bind to estrogen receptors, have other biological effects, which are not mediated with these receptors

I am hoping someone better acquainted with the literature and reproductive science could help connect all these dots for me. It sounds like phytoestrogens can exert some effects similar to that of estrogens, but in some cases don't exert those effects at all, or exert other unrelated effects.

Some males express concern over the consumption of phytoestrogen-containing foods, e.g. soy, due to perceived risk of 'feminization' through increased 'estrogen' intake. To what extent does phytoestrogen act like an estrogen-analog in men? To what extent does it act like one in women?

submitted by /u/alphaMHC
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Does the temperature of water have an effect on being able to put out fire?

Posted: 12 Mar 2018 01:33 PM PDT

How do we know that the inverse square laws are not inverse "2 + epsilon" laws, where epsilon is too small to be detected by current detectors?

Posted: 12 Mar 2018 10:31 PM PDT

How is the frequency in the european electric grid dropping to 49.996hz?

Posted: 12 Mar 2018 02:39 PM PDT

Tom Scot tells in his new video that its happening, stated in this this press release The statement doesn't answers mine and my SO's question how its happening.

submitted by /u/Go3tt3rbot3
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Why does it take more effort to only close one eye than it does to close both eyes?

Posted: 12 Mar 2018 01:26 PM PDT

How sure are we that our understanding of the fossil record of ancient megafauna (eg dinosaurs) is a result of their actual abundance vs sampling/survivorship bias?

Posted: 12 Mar 2018 06:33 PM PDT

Do we have any controls that we can use to determine if a particular ancient megafauna was actually common? Is it possible the dinosuars we have fossil records of were more a result of them living in situations that lead to increased rates of fossil creation rather than them being common? Might dinosaurs have lived alongside vastly different kinds of animals that we just have no record of?

submitted by /u/random-dent
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Would it be possible to measure the angular momentum of Sag A* by observing a frame dragging effect on the stars orbiting it?

Posted: 12 Mar 2018 05:32 PM PDT

Or are the orbits of the closest stars still too far, or is there too much complex interaction to make such a measurement? I found some abstract that mention other methods like hydrodynamic flow of stellar wind or something else that I don't understand.

submitted by /u/-Tesserex-
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How do multi-drug-resistant bacteria maintain their resistance genes in the absence of selective pressure?

Posted: 12 Mar 2018 04:36 PM PDT

As a bioengineering grad student, I was taught early on that E. coli transformed with an Ampicillin-resistance plasmid would only maintain that plasmid in the presence of ampicillin; that in the absence of the antibiotic, maintaining the plasmid would cost too much energy and put them at an evolutionary disadvantage. How is it then that certain pathogens can maintain resistance to almost all types of antibiotics while not being exposed to them?

submitted by /u/PiousBlasphemer
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Assuming the theory is true that a Mars-sized body collided with Earth causing the ejection of matter that would latter form the moon. How did the ejected matter circularize its orbit? Wouldn't the matter have fallen down to Earth?

Posted: 12 Mar 2018 01:15 PM PDT

Is there a difference between receiving O negative blood vs your original blood type?

Posted: 12 Mar 2018 03:56 PM PDT

Essentially wondering if there are any up or downsides to receiving O negative when you are not O negative yourself.

submitted by /u/DudeInCorner1
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Is there a reason why most electrical appliances with analog knobs (ovens and fans, for example) when turned on default to the highest intensity, and you need to keep turning the knob to reduce it?

Posted: 12 Mar 2018 07:17 PM PDT

What causes Ball Lightning, and have we made any recent discoveries on it?

Posted: 12 Mar 2018 10:06 AM PDT

Have we been able to reproduce it? From the footage I have seen, it looks to phase in and out instead of strike like typical lightning.

submitted by /u/eblackham
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Why does the color of a sunset look more orangish than the sunlight at midday?

Posted: 12 Mar 2018 05:49 PM PDT

Axial precession and fixed stars?

Posted: 12 Mar 2018 11:43 PM PDT

How does the north star remain at a fixed spot in the sky, in regard to the earths axial recession?

submitted by /u/Mr8sen
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Does dark matter lose energy via gravitational wave emission?

Posted: 12 Mar 2018 04:05 PM PDT

If so, when dropped around a gravity well (like a galaxy or a star) would it behave like a pendulum that eventually loses energy and settles down in the center? If not, is it just going to keep swirling around the center forever and never decay?

submitted by /u/lucaspon
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How much does your diet actually effect the healing of broken bones?

Posted: 12 Mar 2018 12:30 PM PDT

What is the maximum temperature water will reach in a microwave? Can it exceed boiling on a stove?

Posted: 12 Mar 2018 01:33 PM PDT

I was just microwaving my coffee for 30 seconds and suddenly wondered what's stopping water/liquid from reaching extremely high temperatures in a microwave? Thanks for any help!

submitted by /u/balleyhooey
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When opening an encrypted file/partition, how does the software know that I entered the correct password?

Posted: 12 Mar 2018 11:04 AM PDT

I figure that using a wrong password would return jibberish. How does the software determine that it's not the jibberish I wanted?

submitted by /u/AidsPeeLovecraft
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