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Friday, March 24, 2017

Why is it advised to keep using the same antiseptic to treat an open wound?

Why is it advised to keep using the same antiseptic to treat an open wound?

Why is it advised to keep using the same antiseptic to treat an open wound?

Posted: 24 Mar 2017 03:14 AM PDT

Lots of different antiseptics exist with different active ingredients, but why is it bad to mix them?

submitted by /u/anonymous_coward
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How does brushing your teeth clean your mouth, and has the invention of toothbrushes affected bacterial evolution?

Posted: 23 Mar 2017 07:41 AM PDT

How are atoms aranged?

Posted: 23 Mar 2017 11:01 PM PDT

I know that there are protons and neutrons in the core with electrons orbiting around them, but how are the protons and neutrons aranged? Is it completly random? Is there an order? Is there a difference if the atom just got created by fusion?

I'm currently making a project for school don't want to do anything wrong.

submitted by /u/VayuDev
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Do we observe the handful of stars orbiting the Milky Way's central black hole moving slower during their perigees due to the intense gravity?

Posted: 23 Mar 2017 11:55 PM PDT

Since a distant observer sees an object moving more and more slowly as it approaches an extremely massive object, do we see this manifested in the stars that orbit close to the central supermassive black hole? Or, do they​ just not get close enough to have the effect be measurable.

Basically...Do we observe on some level what happened in "Interstellar"?

submitted by /u/locomike1219
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Since radioactive elements have half lives, why do we still have an abundant amount of certain unstable elements?

Posted: 23 Mar 2017 01:37 PM PDT

Say you have a naturally occurring isotope with a half life of 100 years. There is a current estimate of 100 tons of it on Earth right now. Does that mean in 1,000 years there will be hardly any left unless created by humans? Why is there still any naturally occurring isotopes left on Earth if they have short half lives?

submitted by /u/17_snails
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What field arises when a charged particle is changing in acceleration?

Posted: 23 Mar 2017 10:23 PM PDT

To my understanding, static electric fields arise from stationary charges, magnetic fields from moving charges, and radiation fields from accelerating charges. But what is the resulting field when a charge jerks or more generally has higher order (non-zero) time-derivatives in position?

submitted by /u/CallMeDoc24
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Does downloading a podcast make my phone heavier?

Posted: 24 Mar 2017 01:29 AM PDT

[Plant Biology] Why do some nuts like pecans and walnuts have "grooves" that look like brains?

Posted: 23 Mar 2017 08:04 AM PDT

If gravity can bend light, is it possible for light emitted from the front of an object to strike the rear of an object if it is above a gravitationally significant object?

Posted: 23 Mar 2017 06:25 PM PDT

For example, if I had a flashlight and turned it on a certain distance from a black hole, could the light bend around the black hole and hit my back?

submitted by /u/Zak7062
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How are we able to detect antimatter?

Posted: 23 Mar 2017 04:04 PM PDT

Why does a toy boat in a bath-tub behave as sped up real-size version boat, and if we were shrunk down to same scale, would it appear to be normal again?

Posted: 23 Mar 2017 08:21 PM PDT

I'm really curious on the subject of scale, and forces acting upon objects with different sizes . Does anyone have any links or videos to see?

submitted by /u/5hadow
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When and how was the drift speed of an electron first measured?

Posted: 23 Mar 2017 02:16 PM PDT

What is a virtual state?

Posted: 23 Mar 2017 03:00 PM PDT

I am a chemistry major and when dealing with Raman Spectroscopy, my professor keeps mentioning excitation to a virtual state but cannot explain exactly what a virtual state is. I was under the impression that energy was quantized so that only certain energy levels were available. Feel free to use math in your explanation. I should (hopefully) be able to understand it.

submitted by /u/rscrenci
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Can someone explain causal fermion systems and the Dirac Sea to me in "smart layman's terms"?

Posted: 23 Mar 2017 10:20 AM PDT

Because Wikipedia's article on them are all grad student-level gobbledegook.

I need something more on the level of A Brief History of Time or Cosmos.

submitted by /u/WorldSpews217
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Is antigravity a thing?

Posted: 23 Mar 2017 04:56 PM PDT

I know this might be a stupid question, but I'm actually kind of curious. You know how there's antimatter that is a counterpart to matter, I'm wondering if anyone knows how that sort of thing behaves. Also is there any evidence to suggest other "anti-other-important-things-in-the-universe" like antigravity, or antimagnetism, or anything similar to that.

submitted by /u/fartboi88
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Can tendrils in nebulae form planets without a parent star?

Posted: 23 Mar 2017 09:31 AM PDT

For a given problem, is there a theoretical lower bound on how fast any algorithm can solve it?

Posted: 23 Mar 2017 11:29 AM PDT

For example, the best sorting algorithms run in O(nlogn) time. Is it possible that there are more efficient algorithms 'out there" that are not yet discovered, or is O(nlogn) the hard limit on how fast sorting problems can be solved? If it is the latter case, why is O(nlogn) the limit?

Extending this question to any general problem, is there some way to know the lower bound on how fast any algorithm can solve it? Does a lower bound have to exist at all?

submitted by /u/SteveBouId
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Is there any directional orientation (up, down, left, right) of the universe or have humans just kind of reconciled it with Earth's position because it's the only reference point that matters to us so far?

Posted: 23 Mar 2017 12:26 PM PDT

Why do unpaired electrons always align with an applied B field, but unpaired nucleons do not?

Posted: 23 Mar 2017 09:37 AM PDT

The usual explanation for paramagnetism is that an unpaired electron is torqued by an applied magnetic field to align with the field and to generate a magnetic field that adds with the applied field.

In NMR, for instance, we know that unpaired nucleons can align with OR against the applied B field.

So why do these unpaired electrons always tend to align with the field? In a collection of atoms, each with their own unpaired e-, shouldn't approximately half of them align with an applied field, and half against the field, summing together to provide no paramagnetic effect?

submitted by /u/hannawillneverfindme
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What astronomical force allows a repeller to push a galaxy?

Posted: 23 Mar 2017 07:47 PM PDT

Recently it was announced that the 'Dipole Repeller' is pushing the Milky Way Galaxy (see this article).

Gravity is a force working on all things in the Universe, but it pulls only.

What force repels galaxies?

submitted by /u/BambooRollin
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We can see yellow even though we do not have visual receptors for yellow. Why can't we see ultraviolet and infrared?

Posted: 23 Mar 2017 07:47 PM PDT
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Thursday, March 23, 2017

which of the four fundamental forces is responsible for degeneracy pressure?

which of the four fundamental forces is responsible for degeneracy pressure?

which of the four fundamental forces is responsible for degeneracy pressure?

Posted: 23 Mar 2017 03:16 AM PDT

Degeneracy pressure is supposedly a consequence of the pauli exclusion principle: if you try to push two electrons into the same state, degeneracy pressure pushes back. It's relevant in for example the r12 term in the Lennard Jones potential and it supposedly explains why solid objects "contact" eachother in every day life. Pauli also explains fucking magnets and how do they work, but I still have no idea what "force" is there to prevent electrons occupying the same state.

So what on earth is going on??

submitted by /u/usernumber36
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As the speed of two colliding particles increases, does the chance of quantum tunneling increase as well or remain consistent per head-on?

Posted: 23 Mar 2017 04:22 AM PDT

Why do we need to compile separate 32 and 64 bit versions?

Posted: 22 Mar 2017 05:23 PM PDT

Can't the CPU run 32 bit instructions and vice versa? Or at least simulate it?

submitted by /u/comphacker
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Is it possible to have planets with shapes other than spheres? e.g. a cube or two spheres combined?

Posted: 22 Mar 2017 08:05 PM PDT

How does the RSA cryptosystem work?

Posted: 22 Mar 2017 05:06 PM PDT

I don't understand why its hard to decrypt. I'm not a mathematician so bear with me. I thought the method would be: take the product (or whatever mathematical function) of your code and the public key, then the bank or whoever would use the prime factors to divide the number you sent. But a system like this wouldn't need the prime factors to decode. TIA

submitted by /u/vivioo9
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Could the Doppler effect cause light to become ionizing?

Posted: 22 Mar 2017 10:41 PM PDT

I read once that what scitzophrenics experience can vary based on cultural influences. Is there truth to this and if so what exactly would cause this to occur?

Posted: 22 Mar 2017 05:08 PM PDT

The specific article i read (I wouldn't know where to look for it to cite it now) claimed that in one particular culture the voices heard by scitzophrenics tended to be friendlier and more positive. They contrasted this to patients in western nations that tend to have hallucinations that are more negative or even sinister qualities.

submitted by /u/bcmonke
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Are there invariant constants other than the speed of Light?

Posted: 22 Mar 2017 09:35 PM PDT

I was thinking about this because it'd be nice to define units in terms that don't vary in relativistic situations, but it's interesting for a lot of stuff.

submitted by /u/ChironXII
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Is there more intergalactic matter than galactic matter?

Posted: 22 Mar 2017 09:23 AM PDT

Given the volume of all intergalactic space vs the volume of all galaxies, could the sheer weight of all intergalactic matter (which I assume is just dust and gas) possibly exceed the weight of galactic matter?

Would a galaxy composed of all intergalactic matter put together weigh more than a galaxy of all galaxies put together?

submitted by /u/pastaeater88
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Are genetic defects/diseases present in sperm/egg cells or do they develop while the embryo grows?

Posted: 22 Mar 2017 09:13 AM PDT

If we have been using and experiencing time and distance measurements our whole life, why can't we estimate time/distance super accurately?

Posted: 22 Mar 2017 08:37 AM PDT

If the radioactive particles coming from the sun get trapped in Earth's magnetic field and end up in both Poles as the Northern Lights when in contant with the ozone layer, does the ozone in the ecuator actually protect us?

Posted: 22 Mar 2017 04:00 PM PDT

What are magnetic fields?

Posted: 22 Mar 2017 07:22 PM PDT

I know what causes magnetic fields (certain electrons spinning the same way of an iron atom etc. ) but what is the actual effect of this to make a magnetic field line in space? Is it something like a gravitational field does it warp the fabric in a certain way?

submitted by /u/theguyfromerath
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Does the photoelectric effect work for non-visible wavelengths?

Posted: 22 Mar 2017 08:28 AM PDT

Furthermore, would it be possible to make a "solar" panel which could run without the sun by using these non-visible wavelengths instead of light?

submitted by /u/ThesaGamer
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Wednesday, March 22, 2017

If we observe a star X light years away, does that mean theres nothing inbetween here and there obstructing our view?

If we observe a star X light years away, does that mean theres nothing inbetween here and there obstructing our view?

If we observe a star X light years away, does that mean theres nothing inbetween here and there obstructing our view?

Posted: 22 Mar 2017 02:44 AM PDT

Why is the wheel damage on the Curiosity rover so bad compared to Opportunity?

Posted: 21 Mar 2017 04:58 PM PDT

Recently in the news curiosity's wheel damage has been a subject of worry. I have yet to see a concise explanation as to why exactly the wheel damage is so bad compared to the 13 year old curiosity rover. Why is that, whats different between the two rovers or the two terrains?

submitted by /u/wegener1880
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Was the cosmic microwave background once visible light?

Posted: 22 Mar 2017 04:00 AM PDT

From what I understand of the CMB it was initially very high energy and high frequency and as the universe cooled and expanded the light was shifted down to microwave radiation. Does that mean that at some point in the history of the universe the night sky was lit up in a specific color of light that we would be able to see?

And going further was that point in time a time when there were solid planets and the universe pretty much as we know it now?

submitted by /u/ZacharyCallahan
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What is the maximum heat of any known solid?

Posted: 21 Mar 2017 04:16 PM PDT

My son asked me tonight if it was possible for something to be as hot as the sun and still be a solid and I couldn't give him an answer. Help!

submitted by /u/FinnFerrall
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If neutrons only have a half life of 10 minutes, why don't neutron stars just disappear after this time?

Posted: 22 Mar 2017 02:06 AM PDT

I'm currently studying particle physics in my Physics A level and I found out yesterday that neutrons only have a mean half life of around 800 seconds. This made me wonder why neutron stars don't decay after 10 minutes because they are made purely of neutrons. I asked my Physics teacher the same question and he brushed the question off in an "I don't really know" kind of way.

submitted by /u/NachoftheMach
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How do electronic devices detect battery percentage?

Posted: 22 Mar 2017 04:48 AM PDT

Is it possible to send a powerplant worth of electricity through a small wire of superconducting material?

Posted: 22 Mar 2017 03:54 AM PDT

Hey

AFAIK the point of these big power lines for the high voltage is to minimize the resistance and through that the enegergy loss, but if we invent a high temperature superconductor, would we be able to replace the power grid of the world with cables of lets say the size of a normal household power cable?

submitted by /u/KippieDaoud
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Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology

Posted: 22 Mar 2017 08:04 AM PDT

Welcome to our weekly feature, Ask Anything Wednesday - this week we are focusing on Biology, Chemistry, Neuroscience, Medicine, Psychology

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 did Edward Witten unify the 5 different string theories into one M-theory?

Posted: 21 Mar 2017 06:08 PM PDT

Like most people I don't know much about string theory so I was wondering if someone could explain it as I'd really like to understand (at least in layman's term). Thank you.

submitted by /u/deeaxident
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Are electrons, protons and neutrons actually spherical?

Posted: 21 Mar 2017 07:55 AM PDT

Do we have any proof they are spherical or do we just assume such due to their motion or reactions or some other observation?

submitted by /u/ethanbird1
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What is the difference between the Particle Horizon (which, according to Wikipedia, is the "boundary between the Observable and Unobservable Universe) and the Cosmological Event Horizon (16 billion light years away)?

Posted: 21 Mar 2017 02:06 PM PDT

On Wikipedia, for the Cosmological Event Horizon, it says that: "This fact can be used to define a type of cosmic event horizon whose distance from the Earth changes over time. For example, the current distance to this horizon is about 16 billion light years, meaning that a signal from an event happening at present can eventually reach the Earth in the future if the event is less than 16 billion light years away, but the signal will never reach the Earth if the event is more than 16 billion light years away." https://en.wikipedia.org/wiki/Observable_universe So does this mean that any object past this limit of 16 billion light years away currently will be emitting light that is impossible for observers on Earth to ever see? Also, according to Wikipedia, the Particle Horizon: "represents the boundary between the observable and the unobservable regions of the universe." https://en.wikipedia.org/wiki/Particle_horizon But here's what I am confused about is this: "the particle horizon represents the largest comoving distance from which light could have reached the observer by a specific time, while the event horizon is the largest comoving distance from which light emitted now can ever reach the observer in the future." https://en.wikipedia.org/wiki/List_of_cosmological_horizons This sentence just makes no sense to me. Could someone please explain it? It's really making my brain hurt cuz they both just sound the same to me.

submitted by /u/123td1234
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Is it possible to magnetically levitate an object with total freedom of rotation?

Posted: 22 Mar 2017 01:44 AM PDT

hi, i was wondering if it is possible to simulate how rigid objects rotate around their three axis in microgravity by using magnetic levitation. In this video the rotation seems to be constrained to one axis, while here the rotation is more freely.

submitted by /u/flurrux
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How can we be sure that planets light years away will still be there when we get there?

Posted: 21 Mar 2017 03:29 PM PDT

Can earphones/speakers be "overloaded" if I played, say, 1,000 songs through them at the same time? Is there a max? How can speakers/earphones handle several unique songs seemingly all at once?

Posted: 21 Mar 2017 02:05 PM PDT

How can you justify multiplying a wavefunction with a spin vector?

Posted: 21 Mar 2017 01:40 PM PDT

Since the wavefunction and spin live in different Hilbert spaces, what allows you to multiply them with each other? Also, the total symmetry of the function is the same, as if you would multiply 2 functions of the same space with each other, how can this be?

submitted by /u/digitalmus
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Can plants get cancer?

Posted: 21 Mar 2017 11:46 AM PDT

If we were to reduce a particle's mass to zero continuously, would its worldline smoothly go from a timelike to a null geodesic?

Posted: 21 Mar 2017 12:17 PM PDT

In relativity, the trajectories of particles follow worldlines. Massless particles (like photons) follow null worldlines, whose norm is zero, but massive particles' worldlines have a norm of 1. Is the zero-norm null geodesic just the low-mass limit of a massive particle's trajectory?

submitted by /u/eebootwo
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Will the Cosmic Microwave Background Radiation turn to Radiowaves as the universe further expands?

Posted: 21 Mar 2017 01:05 PM PDT

I always wondered why the light of the CMBR, that has been increasing in wavelength since it's formation, hasn't moved even farther to the low energy part of the EM spectrum in the last 14 billion years. As the universe is still expanding this eventually has to happen, right? How long would it take until we classified the radiation as radiowaves?

submitted by /u/powerpaddy
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What determines if a white dwarf goes nova or supernova?

Posted: 21 Mar 2017 10:09 AM PDT

A white dwarf accumulating mass from a companion can either blow off the mass in a nova at a regular interval or when it reaches 1.44 solar masses (Chandrasekhar limit) it will turn into a type Ia supernova. Both of these processes start the same way, so what factor determines if the mass being siphoned off will turn into a nova or create a supernova?

Also, if a white dwarf is periodically going nova, will it hit a point where it will siphon off enough matter to create a supernova, or are the conditions never right for that?

submitted by /u/vizard0
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When are Bremsstrahlung photons created?

Posted: 21 Mar 2017 09:06 PM PDT

Currently studying 2nd year physics at university.

When exactly are bremsstrahlung photons created when an electron curves around a nucleus? I understand how they are produced, but the photon has to be ejected at a certain time right? When exactly in the interaction are the created?

submitted by /u/Palanator
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How has the core of the earth been able to retain its heat for so long?

Posted: 21 Mar 2017 11:09 AM PDT

How far can radio signals sent into space travel while still remaining "readable?"

Posted: 21 Mar 2017 09:30 AM PDT

If we sent out a radio broadcast into space and could hypothetically travel faster than light to get in front of it, is there a limit to the distance we could go and still be able to read the signal? Do radio waves degrade over time or would it be theoretically possible to travel 80 light years away and watch an original airing of "I Love Lucy?"

submitted by /u/LaserRed
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