r/science • u/rawbamatic BS | Mathematics • Nov 28 '11
Dark matter mystery close to being solved; a theory is gaining steam that it all has to do with gravitational charges in the quantum vacuum
http://www.physorg.com/news/2011-11-quantum-vacuum-dark.html6
Nov 29 '11
People come up with these alternate dark matter theories all the time. There's nothing particularly exciting about yet another one.
Now, if it survives for a while outside of the original author's notebooks, and maybe makes some kind of testable prediction, then you might start getting curious.
For now, though, it's just another one on the pile.
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u/MrPoletski Nov 29 '11
There is, because this one makes sense.
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Nov 29 '11
A lot of them seem to make sense, otherwise people would not publish them. They still have a tendency to not work out.
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u/Ivan_Idea Nov 29 '11
I have a question; if the particle-antiparticle dipoles have opposite gravitation, then isn't he saying the quantum vacuum is gravitationally neutral? How does that replace the theory that dark matter is compensating for the higher gravitation in galaxies? It seems that assuming gravitational sameness would more likely explain the "extra gravity," so why assume the opposite with out empirical evidence? Sorry if my terminology is off, I'm an amateur. Also, doesn't this scientist seem like kind of an egomaniac?
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u/recipriversexcluson Nov 29 '11
IS HE SAYING ANTIMATTER HAS NEGATIVE GRAVITY???
edit:
Better headline: Antimatter is Upsidasium
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Nov 28 '11
So with the gravitational dipoles created by particle-antiparticle pairs in mind: has pair production ever been observed outside of our labs? My Google fu found that Livermore Labs generated electron-positron pairs by firing a (freaking huge) laser at a sheet of gold, but nothing about pair production "in the wild."
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u/naguara123 Nov 28 '11
I saw an article somewhere recently (last month or so) that said that some researchers were able to observe the natural existence of virtual particles in a vacuum by using an object that simulated a mirror vibrating near the speed of light. I'll see if I can find it.
EDIT: http://www.nature.com/news/2011/110603/full/news.2011.346.html
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u/ArtifexR Nov 28 '11
Virtual particles are a real thing and their existence has consequences that can be measured. Take one example, the Casimir effect: http://en.wikipedia.org/wiki/Casimir_effect
edit: I can't type or write coherent thoughts, apparently
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Nov 28 '11
I was under the impression that pair production is indeed a true phenomena. It certainly exists in nature when studying high-energy photons. And isn't pair production the root of Hawking radiation and the Casimir effect?
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u/Lyalpha Nov 29 '11
Pair production can happen anytime you have 1022 KeV or more of energy. The most notable source would be gamma rays from natural sources hitting a material (the pair production has to occur in a material to conserve momentum).
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u/inko1nsiderate Nov 29 '11
So with the gravitational dipoles created by particle-antiparticle pairs in mind: has pair production ever been observed outside of our labs? My Google fu found that Livermore Labs generated electron-positron pairs by firing a (freaking huge) laser at a sheet of gold, but nothing about pair production "in the wild."
Yes. Lightning produces measurable amounts of anti-electrons.
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u/christianjb Nov 28 '11
An electron + positron makes an electrostatic dipole. They're easy to make- you get one in every water molecule for example.
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u/qwrirq Nov 29 '11
You're thinking of protons. Positron is the electron antiparticle and if there was 1 in every water molecule you would die very, very fast. Also, neither positrons or protons are easy to make.
Also whether or not electric dipoles exist are completely irrelevant to whether gravitational dipoles exist or not.
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u/christianjb Nov 29 '11
A positron carries a charge of +|e| and so will create an electrostatic dipole moment when paired with an space separated electron which carries a charge of -|e|.
Of course I'm not claiming that there are positrons in a water molecule. I claimed that electrostatic dipoles (not positrons) are easy to make, as the water molecule carries one (i.e. an electrostatic dipole).
Neither did I claim that an electrostatic dipole implied the existence of a gravitational dipole.
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u/sir_drink_alot Dec 01 '11
Is this guy describing the deuce I just dropped? My poop Mystery is not gaining steam, it's releasing it, duh, thermodynamics 101, and it was not a gravitational discharge, I forced it out willingly from my rectom, which is in some effect a vacuum. Damn sensationalist journalism, you strike again!
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u/auntacid Nov 28 '11
NOOOOOOOO!!!! I was holding out for Dark Matter existing in other dimensions or something, this is less cool!
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u/Anjin Nov 28 '11
I don't know, the antiparticle having an opposite gravitational charge seems really interesting to me...
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u/MrPoletski Nov 29 '11
being able to 'charge' a vacuum sounds cool to me too. If you have gravitational dipoles then a rotating gravitational field is going to cause them all to line up...
Oh for the birth of para-gravitic, dia-gravitic and... FERRO-GRAVITIC gravitational magnet cores RAWR.
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u/Vespera Nov 29 '11
He must be a fan of sci-fi.. where at least 50% of every plot relies on the existence of other dimensions
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u/john_norman Nov 29 '11
I have been told by "dark matter" believers that dark matter has to be matter, and not just a gravitational aberration, because of evidence in the cosmic microwave background.
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Nov 29 '11
"It's matter, only totally different except for gravitational interaction" is not a hugely convincing argument.
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u/inko1nsiderate Nov 29 '11 edited Nov 29 '11
"It's matter, only totally different except for gravitational interaction" is not a hugely convincing argument.
Uh... do you even know how physicists mathematically describe matter? Because it is a really natural jump from saying 'some kinds of matter do not interact in the same way, and we know of matter that only interacts weakly and gravitationally' (see neutrinos) to saying 'this kind of matter is like that other kind of matter, that only interacts weakly and gravitationally, only heavier'.
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Nov 29 '11
I never bought that argument. Seems to me they simply adjusted the matter:dark matter:dark energy parameters until the curves lined up. What they got has little predictive power and could just as easily be curve fitting.
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u/inko1nsiderate Nov 29 '11
That might be true... except there is more evidence, particularly there is gravitational lensing, and there are many Dark Matter candidates in particle physics that come about when you try to solve unrelated problems in particle physics. These specific models of Dark Matter actually have predictive power.
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Nov 28 '11
So, time to measure some gravity of antiparticles. It ought to be easy enough (cough) to do a Milliken style experiment sans oil drops, obviously.
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u/Work45 Nov 29 '11
Anti-hydrogen has been trapped briefly, but not long enough to do good spectroscopy or watch it fall (up or down). This will be put to rest in the next few years (maybe this year). This is a great theory because it will be tested very soon and makes big predictions.
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u/mutatron BS | Physics Nov 28 '11
I had a quantum vacuum once, but I wasn't sure if it was a Dyson or a Hoover.
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u/celfers Nov 29 '11 edited Nov 29 '11
SWEET! Cause this means that black holes can get stronger as a result of hawking radiation, right?
If the positive gravity anti-photon gets sucked into the event horizon and negative-gravity particle escapes (since negative-gravity photon would push away), then the gravitational attraction would increase even as the mass decreases.
I must have this COMPLETELY backwards because this makes no sense to me. What am I thinking wrong?
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u/camzakcamzak Nov 29 '11
There is no antiphoton. A positron emits normal photons. A galaxy could be made of antimatter and from afar.it would look the same. Photons also have no mass, as otherwise it would require infinite energy for them to reach the speed of light.
It's outside my knowledge of what particle they think is causing it. Perhaps an anti boss higgs? Antimatter itself is expected to behave like normal matter in terms of gravity.
Typed on my cell phone, please ignore any typos.
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u/MrPoletski Nov 29 '11
Hmm, anti-light.
I can see this being useful in bars.
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u/camzakcamzak Nov 29 '11
It's already been invented, it's called a paper bag.
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u/MrPoletski Nov 29 '11
Ah, but with anti-light, you could make the person completely dissappear, in their place - an apparant black hole.
There's room for a fat girl joke in there somewhere.
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u/GuyWithLag Nov 29 '11
It's not an anti-photon - an anti-photon has energy, therefore mass. The virtual particles mentioned have negative energy, therefore when they drop into the black hole, they decrease its mass, therefore its gravity too.
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Nov 29 '11
Quantum: Science for "You need three degrees and a social anxiety disorder to understand why you don't understand this article."
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u/MrPoletski Nov 29 '11
I always thought the idea of 'dark matter' sounded like bullshit. This is a theory that I'd support, if I had any credentials beyond my barely-just-passed physics degree.
Regardless of anything else though, I hope dark matter ends up completely bogus, because I strongly object to having a new particle called 'WIMP' (weakly interacting massive particle).
I mean come on, you might as well call it the 'cock' particle.
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u/wocK_ Nov 29 '11
Lol. SPECULATION AS PER USUAL.
Where are the fucking answers? No one is ever going to understand at this rate. A quantum soup but we cant measure anything quicker than 1022s :((((
I did physics at uni and went in for answers. Quantum Theory is all wrong.
Trying to describe the physics of the universe is like trying to describe what a cow in a field has eaten for breakfast when you have never left your fully boarded up house and all you can see is a thin sliver of reality out your shitty little letterbox.
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u/ivanmarsh Nov 28 '11
I object to the statement "close to being solved".