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Tuesday, September 27, 2016

What is the temperature of the plasma inside a plasma globe?

What is the temperature of the plasma inside a plasma globe?


What is the temperature of the plasma inside a plasma globe?

Posted: 26 Sep 2016 08:05 PM PDT

I understand that the total thermal energy is low because the density of the gas is low. Does it make sense to talk about the temperature of the plasma in the same way as the temperature of the glass?

submitted by /u/HypnoJoad
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Is it possible to shrink plastic, then bring it back to original size?

Posted: 26 Sep 2016 06:24 PM PDT

Very interested to know this

submitted by /u/lazyboyah
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How are the values for electro-negativity determined?

Posted: 26 Sep 2016 08:35 AM PDT

For example: the Pauling scale. How did Pauling find the values of the electronegativities of each element?

submitted by /u/hmpher
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How does radiation or proton therapy get rid of cancer cells?

Posted: 26 Sep 2016 09:18 AM PDT

I've received radiation, along side chemotherapy, for a tumor I had in my head. It was one of the main reasons why the tumor went away and never came back in that area. Unfortunately, it spread to a different part of my brain and now we are looking at proton therapy, as it's more precise, for treatment. I'm curious as to how radiation and proton therapy work and how they help kill cancer cells. Thanks in advance.

submitted by /u/ViscousFluid
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Why do some welders use diffrent "fillers"?

Posted: 26 Sep 2016 08:23 PM PDT

Why do some projects require diffrent types of metals when welding? What is the benifit of using diffrent metals for the "filler"? Does it have something to do with the metallic bonds or somthing similar?

submitted by /u/dankpizzarolls
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Why _exactly_ does my microwave "kill" my internet?

Posted: 27 Sep 2016 04:10 AM PDT

I know that it has to do with my microwave and router having the same radio frequency, but why would it cause that?

submitted by /u/adamthedog
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[Physics] Is my teacher wrong about plasma?

Posted: 27 Sep 2016 03:45 AM PDT

My teacher says that plasma is a stage between solid and liquid form. That dosen't seem right to me since I thought it was: Solid -> Liquid -> Gas -> Plasma.

Am I confusing things or is my teacher wrong? Is there something he could have confused it with?

submitted by /u/zzappe
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How many Kilograms all the DNA inside a medium human body weight on the whole?

Posted: 27 Sep 2016 06:02 AM PDT

How does a nuclear fission bomb's chain reaction work?

Posted: 26 Sep 2016 05:43 PM PDT

Hello! I'm confused about how a nuclear fission reaction perpetuates itself.

It is my understanding that a fission reaction starts when the nucleus of an unstable element is bombarded with a neutron and splits, giving off additional neutrons which then go on to hit other nuclei and causing fission again.

However I am also of the understanding that the nucleus of an atom is very very small in comparison to the overall size of the atom when you include the electron cloud. Wouldn't that make it unlikely the released neutrons would collide with another nucleus?

Also would love a brief explanation of why fission weapons are so powerful compared to conventional weapons. Thanks! I tried to search to no avail, if you know of a post that already provides an explanation on this topic, a link would be much appreciated.

submitted by /u/saabek
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How much more difficult is it to send a rover on Europa compared to Mars?

Posted: 26 Sep 2016 11:43 PM PDT

I ask this, because :
- Europa looks more and more intereting.
- Europa is a moon (is it more difficult to go on a moon than going on a planet ?)
- Europa is far way (do you need more fuel ?)
- We don't know much where to land on the surface of Europa, do we know ?

submitted by /u/sphks
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How can chemicals like CO2 acidify water if they don't contain H+?

Posted: 26 Sep 2016 08:08 PM PDT

Tetanus can apparently develop due to contamination of minor/superficial injuries. How would that work with an obligate anaerobic germ?

Posted: 27 Sep 2016 07:29 AM PDT

While C. tetani can occur anywhere, it should be only present in the form of spores, which would require anaerobic conditions to germinate, reproduce, and release tetanospasmin.

It seems to me that any of those steps would require necrotic tissue, rather than healthy, properly oxygenated tissue, to occur.

Yet according to CDC, it may also happen in "Wounds caused by an object puncturing the skin, like a nail or needle", and " clean superficial wounds (when only the topmost layer of skin is scraped off)".

This doesn't seem to add up, does it?

submitted by /u/buuun
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What is the maximum size for a particle to be able to do simple diffusion into a cell?

Posted: 26 Sep 2016 08:45 PM PDT

So I understand that small non-charged molecules such as H2O and O2 can pass through the plasma membrane with just simple diffusion, whereas bigger molecules such as glucose cannot and need facilitation. My question is what is the "cut-off" for a molecule being too big, and needs to be facilitated through?

submitted by /u/ethansmith123
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How do scientist determine where and how many samples of an element to take to determine it's isotope composition?

Posted: 26 Sep 2016 09:11 PM PDT

Does the Sun's gravity have a significant impact on the plate tectonics of the planet Mercury?

Posted: 26 Sep 2016 05:13 PM PDT

I saw this post that Mercury apparently has active plate movement, and was curious if the Sun's gravitational pull has a significant effect, being in such close proximity.

submitted by /u/MattTheFlash
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How long can muscle tissue go without oxygen?

Posted: 26 Sep 2016 04:44 PM PDT

What is the difference between congestion and nasal inflammation?

Posted: 26 Sep 2016 03:46 PM PDT

I am a student studying the effects of phenylephrine on decongestion, and NSAIDs on inflammation. My understanding is that phenylephrine constricts blood vessels, thereby avoiding nasal edema (congestion). This sounds pretty identical to the fluid retention associated with the migration of WBCs to an infected area in inflammation. Can anyone make the distinction clearer to me? What causes congestion if not an inflammatory response?

submitted by /u/lilsebastian0101
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Why are some elements more electro-negative than others?

Posted: 26 Sep 2016 07:43 PM PDT

If it has to do with filling up the final shell (valence electrons), then why is Oxygen more electro-negative than Chlorine?

submitted by /u/MrMineHeads
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Could frozen fish be lying around on the surface of Europa?

Posted: 26 Sep 2016 02:42 PM PDT

Well, I mean frozen life. If the water plumes on Europa suck up life from the water underneath and blow it out over the surface, would the life get destroyed and be unidentifiable or could a probe tell us that this was once a living thing? Would bones or scales or horn or even soft tissue, like singe-cell creatures survive, dead but intact, frozen on the surface? I've read about concern that drilling probes might contaminate the seas under the ice. Maybe all we have to do is look at the surface.

submitted by /u/Algernon_Moncrieff
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What makes the australian black bean - castanospermum australe - poisonous?

Posted: 26 Sep 2016 03:56 PM PDT

Wikipedia didn't specify what chemical actually made it poisonous, and several other links also didn't specify it.

submitted by /u/MILKB0T
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Monday, September 26, 2016

Why is it not possible to simply add protons, electrons, and neutrons together to make whatever element we want?

Why is it not possible to simply add protons, electrons, and neutrons together to make whatever element we want?


Why is it not possible to simply add protons, electrons, and neutrons together to make whatever element we want?

Posted: 25 Sep 2016 12:06 PM PDT

I cannot grasp the concept of the 4th dimension can someone explain the concept of dimensions higher than 3 in simple terms?

Posted: 25 Sep 2016 12:40 PM PDT

Question about basis in infinite dimensional vector spaces?

Posted: 25 Sep 2016 11:47 AM PDT

I read that in infinite dimensional vector spaces, a countable ortonormal system is considered a basis if the set of finite linear combiantions of elements of such system is everywhere dense in the vector space. For example, the set {ei / i in N} is a basis for l2 (oo) (where ei is the sequence with a 1 in the i-th location and 0 everywhere else). I was wondering if there was a way of considering a set a basis if every element in the space is a finite linear combination of the elements of the set and this set is linearly independent. I guess the vector space itself generates the vector space, but it's elements are not linearly independent. Is there a way to remove some of the elements of the vector space in such a way that the set that remains is linearly independent and it generates all the space only with finite combinations?

submitted by /u/Paul-Lubanski
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Simple question, is anybody able to give me a scientific journal or any verifiable source, for whether or not the refilling of plastic bottles, over a continuous amount of time. Will the bottle degrade and you consume a chemicals from said bottles?

Posted: 25 Sep 2016 05:04 PM PDT

Why can't we use capacitor as batteries?

Posted: 25 Sep 2016 12:09 PM PDT

Instead of chemical batteries?

submitted by /u/ucefkh
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What is the total volume of the sky?

Posted: 26 Sep 2016 06:35 AM PDT

So my sister had some silly quote on her facebook about "The Endless Sky" which got me thinking that there was no way it could be endless. Is there a "point x" so many meters above ground that starts the sky and then a "point y" that marks the end of the sky and the start of outer space. If so could you measure the volume and/or mass of the sky?

submitted by /u/communistcrashdummy
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When we look into the night sky, the light we're seeing from those stars is millions of years old. How do we know how many of those haven't already died?

Posted: 25 Sep 2016 11:57 PM PDT

Is there an empirical method to calculate the surface area of an irregular solid?

Posted: 25 Sep 2016 09:38 PM PDT

Archimedes (apocryphally, at least) provided us with an empirical method of calculating the volume of an irregular solid using water displacement.

Is there any analogue for surface area? It would be nice if there were a method that doesn't rely too much on technology (I kinda want something that could've been produced by the Greeks), but I'm interested in any solution that doesn't use any kind of calculus / convergence of approximations arguments.

If there is no analogue for surface area, is there some kind of proof or heuristic argument that there can be no such method?

submitted by /u/riemannia
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How can light have momentum if the formula for momentum is p=mv? If light has no mass doesn't that mean it has no momentum?

Posted: 25 Sep 2016 10:48 PM PDT

p=mv where p is momentum, m is mass, and v is velocity.

submitted by /u/Dusicyon
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Do particle accelerators produce dark matter?

Posted: 25 Sep 2016 08:15 PM PDT

In a particle accelerator, how is speed of a particle measured?

Posted: 26 Sep 2016 04:00 AM PDT

I've seen speeds quoted as "99% the speed of light" or similar, but how is that measured? I assume it's linked to energy decay somehow as there's no way it could be sampled that fast.

submitted by /u/mrpurplez
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Why are there spiral galaxies?

Posted: 25 Sep 2016 12:25 PM PDT

Shouldn't they all be elliptical because objects orbiting closer to the center of the galaxy move faster and pass up the stars on the end of an arm.

submitted by /u/Zexer_Alphius
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Why didn't natural selection eliminate poor eyesight before glasses were invented?

Posted: 25 Sep 2016 04:51 PM PDT

My train of thought with this is that poor eyesight seems like it would've been a big enough hindrance to things like hunting and gathering and generally not running into stuff and dying back in those times that eventually people with poor eyesight wouldn't have been able to reproduce. Am I just confused on how poor eyesight works?

submitted by /u/buttmunch3
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What is the point of using specific gravity?

Posted: 25 Sep 2016 05:37 PM PDT

In my pharmaceutics course/lab I see a lot of density measurements expressed in "specific gravity". I understand that Specific Gravity is the density of a substance in reference to a "benchmark" substance, but that "benchmark" substance is normally water, which is 1 g/mL. So my question is, why bother having a unit of measurement that is, for intents and purposes, equal to density? Are there instances where the reference substance isn't water and specific gravity would be preferable to use?

Edit: I'm flairing this as "Medicine" just because I've only encountered Specific Gravity in my pharmaceutics course. If there is a more appropriate flair I'll change it accordingly.

submitted by /u/joe_jon
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What's the name of the property that ∫u+v dx = ∫u dx + ∫v dx?

Posted: 26 Sep 2016 01:17 AM PDT

I believe the phrase I'm looking for is "integration is [adjective] [preposition] addition". (I'm specifically not looking for "[operation] rule".) For instance, "integration is distributive over addition". But you know that thing where you say a phrase, and it doesn't sound like it's actually a thing?

submitted by /u/Piquan
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[Mathematics] Are there vector spaces where no discrete set of vectors form a basis?

Posted: 25 Sep 2016 09:53 PM PDT

The question is regarding infinite dimensional vector spaces.

In quantum mechanics you usually bump into infinite dimensional Hilbert spaces, but I've always noticed that you can find a basis with cardinality = Aleph_0 (the cardinality of the natural numbers). A question I've had since learning QM is wether there exist vector spaces V where the dimension is 'larger than Aleph_0', in the following sense:

Let S be a subset of V, a necessary condition for S to form a basis is that |S| > Aleph_0 .

Thanks!

submitted by /u/fuckwatergivemewine
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If there was no dark matter in the vaccum of space would light travel faster? Or does light get slowed down occasionally because of this?

Posted: 25 Sep 2016 05:03 PM PDT

Have Mental illnesses been around since the dawn of humanity?

Posted: 25 Sep 2016 05:52 PM PDT

How did crazy mental illnesses develop? And how did old civilations deal with them?

submitted by /u/R_af_ael
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Is there a connection between Bernalism (the communist philosophy of science) and the current reproducibility crisis in science?

Posted: 25 Sep 2016 03:34 PM PDT

Don't now if this is the right place, but I am interested in literature to answer the above.

submitted by /u/AMatterofTrust
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How does radiation effect precious metals?

Posted: 25 Sep 2016 03:34 PM PDT

This is a multi part question and I'm not really sure how to ask it. Please forgive me if I ask a question in a stupid way

How do metals like gold, silver and copper become radioactive (irradiated (if somebody could clear up the semantic, that'd be nice)) and what happens to these metals when that happens?

Does simple proximity to radiation render metals radioactive, eg: if a gold vein and deposit of uranium ore hypothetically shared the same mine, would the gold be useless? why?

Would the same radioactive source have the same effect on the same metals, that is to say: would the same thing that reacts with gold react with silver or any other metal left or right of the metals' respective column on the periodic table?

Bonus question: Just how harmful is non-enriched uranium ore?

submitted by /u/ereg
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Are all metal elements able to be detected by a metal detector?

Posted: 25 Sep 2016 07:07 PM PDT

Simple question I've been wondering, since how the elements are grouped, I have a few questions:

Will ALL transition metal be detected? (If not which ones will/won't)

Will any Metalloids be detected?

Will any alkali metals be detected?

Will any basic metals be detected?

Will any earth metals be detected!

( by the way, when I'm talking about metal detector, I mean the security-type used in airports and such)

Thank you

submitted by /u/The2xfire
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Do biologists/neuroscientists agree with the suggestion that there are 58 genders?

Posted: 25 Sep 2016 04:16 PM PDT

Just curious what people in the actual field believe.

submitted by /u/Oh_hamburgers_
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Sunday, September 25, 2016

How do ancient languages compare to modern ones in terms of complexity? Roughly the same?

How do ancient languages compare to modern ones in terms of complexity? Roughly the same?


How do ancient languages compare to modern ones in terms of complexity? Roughly the same?

Posted: 24 Sep 2016 05:02 PM PDT

Is IQ a predictor of personality traits, such as empathy or antisocial behavior?

Posted: 24 Sep 2016 04:54 PM PDT

Fairly simple question with, I'm sure, a fairly complicated answer. Is the measurable intelligence of a person in any way related to their likelihood of being a functionally integrated, relatable member of society? Are those with high IQs more likely to be sociopaths, or have higher emotional intelligence? Are those with low IQs more likely to be aggressive and antisocial, or are they more likely to be empathetic?

submitted by /u/CursedLemon
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Would it be possible for a star to have planets that orbited it both horizontally and vertically?

Posted: 24 Sep 2016 02:02 PM PDT

Could that happen? If not could it be possible for a planet to be orbiting the star on a more diagonal plane compared to the rest of the planets? Or do orbiting bodies always more or less sync up how they orbit the host star?

submitted by /u/BlueDreamWidow
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How do mirrors reflect light from a quantum perspective?

Posted: 24 Sep 2016 02:04 PM PDT

In particular, if a photon hits a flat mirror, it is reflected at the same angle, correct? If photons are absorbed then re emitted by the mirror, how is the angle preserved? Also, is it reflected by the surface only or also by atoms deeper inside?

submitted by /u/andrebis
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Do particles from the solar wind cause any outward velocity pressure on the planets in their orbits?

Posted: 25 Sep 2016 06:06 AM PDT

In other words, if the solar wind were to suddenly cease, would planetary orbits gradually decay due to not being bombarded and "pushed outwards" by these particles?

submitted by /u/canadave_nyc
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Would a supernova produce an audible sound due to the gas cloud formed during the explosion?

Posted: 24 Sep 2016 11:14 AM PDT

How do you calculate kinetic energy in outer space?

Posted: 25 Sep 2016 12:31 AM PDT

If ke = 0.5 mv2 (squared) what is v relative too?

Furthermore, a given rocket rocket has a fixed delta-v, and it's total energy is fixed so this implies that kinetic energy would be linear.

Can someone enlighten me.

P.s I have a level physics and degree level maths if that helps.

submitted by /u/Stevetrov
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Why this water stream seems frozen?

Posted: 25 Sep 2016 12:11 AM PDT

https://gfycat.com/DeepCheapKronosaurus

Is it because of some strange hydrodynamic or is it a similar phenomenon to car wheels in videos?

submitted by /u/Handsome_Claptrap
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Is it possible to design a lens that has no spherical aberration?

Posted: 25 Sep 2016 04:55 AM PDT

A parabolic mirror can reflect all incoming rays parallel to the optical axis to a single focus. Is there an analogous geometry for a lens that can do the same, at least for a single wavelength of light, so that spherical aberration is not a concern?

submitted by /u/fzztr
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Is there any true scientific evidence for the simulation hypothesis?

Posted: 24 Sep 2016 11:01 PM PDT

It's becoming fairly common to see articles claiming certain chances that the reality we live in is not a "base" reality. Elon musk claims it's one in a billion that this isn't a simulation. Bank of America says it's 50%. I've been unable to find true science behind these claims. They seem to originate from anecdotal evidence, such as looking at Moore's and saying it will eventually be impossible to tell simulation from reality. What, if any, actual evidence or tests have been done?

The Wikipedia page goes into a little bit about testing by trying to prove that the universe is a finite lattice, but how could this actually be done? And if even points out that it wouldn't even be proof of a simulated reality.

One additional thought I've had is about the Moore's law idea. Technology as we know is made of finite values, binary is 0 or 1, Trinary is 0, 1, or 2, etc. But there really isn't any room for probabilistic outcomes. Quantum mechanics as we know it is based on probability. My thought here is that our current technology couldn't even be the predecessor to something that could be a new universe. That coupled with the fact that Moore's law is an observation and not a rule, seems to provide an anecdotal argument to the anecdotal evidence that I've seen used. Am I missing something here?

submitted by /u/holy_halo_man
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Why can you detect radio waves using a bare wire antenna but special sensors like photodiodes are required for detecting shorter wavelengths like visible light?

Posted: 24 Sep 2016 02:26 PM PDT

Car and handheld radios are capable of detecting low wavelength electromagnetic frequencies using only a wire antenna. Why is it that we cannot detect frequencies of visible/other light in this way? Would it simply require a shorter length of wire than would be practical?

submitted by /u/PartPangolin
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[Biology] Are there any other life forms that practise traditions like humans do?

Posted: 24 Sep 2016 03:16 PM PDT

When I type on my computer, where does the actual electricity from my keystroke travel to and what physical changes does it cause?

Posted: 24 Sep 2016 04:01 PM PDT

I'm so curious about where the actual rubber meets the road when it comes to instructions I send to my CPU.

submitted by /u/SkincareQuestions10
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Do wave functions stay collapsed after an initial measurement, or so they return to a superposition of states?

Posted: 24 Sep 2016 06:30 PM PDT

For instance, if I were to measure the system a second time, would there be a 100% chance that the system is in the same configuration observed upon the initial measurement/collapse? Or does the wave function return to a superposition of states and collapse again every time the system is measured?

submitted by /u/creamulum
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Why is the international date line not a straight line?

Posted: 24 Sep 2016 03:56 PM PDT

Can gravity be so strong that it forces water to become ice?

Posted: 24 Sep 2016 02:08 PM PDT

Are there plans to search for Life on Europa?

Posted: 24 Sep 2016 11:07 AM PDT

Can Brownian motion be considered an application of chaos theory ?

Posted: 24 Sep 2016 10:42 AM PDT

Chaos theory applies to systems highly sensitive to initial conditions. In the (highly unlikely) situation where we know everything about every particle (for exemple, in the case of a computer simulation), can Brownian motion, a typical stochastic process, be considered an application of chaos theory ?

submitted by /u/Slaaneshou
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Does acceleration affect density?

Posted: 24 Sep 2016 01:44 PM PDT

Ladder Paradox Shutting the garage door, is there a solution for this.

For this to be possible the volume of the ladder should decrease because of slowing down. If this is the case is it true for all accelerations?

For example:
- Increasing acceleration (speeding up) will decrease your density. (Less volume)
- Increasing your acceleration in negative sign (slowing down) will increase your density. (More volume)

Is this true?

submitted by /u/schlinglebop
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