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Does Dark Anti-Matter exist?

by WhiteKnights
Tags: antimatter, dark, exist
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Chronos
#37
Apr2-12, 08:04 AM
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There is so much dark matter in the universe it is unlikely much of it is 'anti' dark matter. We would otherwise expect to see an abundance of spurious gamma radiation in the cosmic background - which is not observed. It also appears probable dark matter is not a half spin particle meaning it has no anti particle equivalent.
StevenJParkes
#38
Apr2-12, 04:01 PM
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Quote Quote by Chronos View Post
There is so much dark matter in the universe it is unlikely much of it is 'anti' dark matter. We would otherwise expect to see an abundance of spurious gamma radiation in the cosmic background - which is not observed. It also appears probable dark matter is not a half spin particle meaning it has no anti particle equivalent.
Makes sense. So my line of questions meets a dead end. Still, I don't truly believe that the speed of photons is unaffected in a vacuum as we know it. This is because gravity would still exist in a vacuum should such a thing as a true vacuum exist. Perhaps the value of c would be different to what Einstein theorized in the absence of the effects of matter, dark or otherwise.
Drakkith
#39
Apr2-12, 04:07 PM
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Quote Quote by StevenJParkes View Post
Makes sense. So my line of questions meets a dead end. Still, I don't truly believe that the speed of photons is unaffected in a vacuum as we know it. This is because gravity would still exist in a vacuum should such a thing as a true vacuum exist. Perhaps the value of c would be different to what Einstein theorized in the absence of the effects of matter, dark or otherwise.
I fail to see what gravity has to do with the speed of light. Also, there is nowhere in the universe that is free of gravity. Even the voids between galaxy superclusters have gravity.
StevenJParkes
#40
Apr3-12, 02:48 AM
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I could be mistaken. If gravity could bend light it must be able to limit its velocity. Perhaps, outside our universe there is a void...a real vacuum and the universe is rushing off to form an equilibrium. It would be interesting though, if there were other universes rushing towards us, or something of that nature.
Drakkith
#41
Apr3-12, 06:03 AM
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Quote Quote by StevenJParkes View Post
I could be mistaken. If gravity could bend light it must be able to limit its velocity.
I don't believe this happens.

Perhaps, outside our universe there is a void...a real vacuum and the universe is rushing off to form an equilibrium. It would be interesting though, if there were other universes rushing towards us, or something of that nature.
Please, try to avoid speculation without references to back it up.
phinds
#42
Apr3-12, 06:13 AM
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Quote Quote by StevenJParkes View Post
I could be mistaken. If gravity could bend light it must be able to limit its velocity.
No, that does not follow. Gravity changes the geodesic that light follows but the photons still travel at c.

Even inside a black hole where light cannot escape, it is still traveling LOCALLY at c, because the black hole just warps the geodesic.

You say
I don't truly believe that the speed of photons is unaffected in a vacuum as we know it
You really need to get over this thought that it matters what you believe. You should study physics, not make stuff up.
StevenJParkes
#43
Apr6-12, 07:09 AM
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Please forgive me. I will stop this. I was under the impression that thinking outside the box may stimulate something useful.
phinds
#44
Apr6-12, 07:36 AM
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Quote Quote by StevenJParkes View Post
Please forgive me. I will stop this. I was under the impression that thinking outside the box may stimulate something useful.
Thinking outside the box is a GREAT thing to do, but ONLY after you understand what the box is.
Drakkith
#45
Apr6-12, 04:24 PM
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Quote Quote by StevenJParkes View Post
Please forgive me. I will stop this. I was under the impression that thinking outside the box may stimulate something useful.
Bouncing off what phinds said, thinking outside the box requires that you understand how current theories work. Not just in an informal "i read a book or two on it" way, but an actual understanding of the math that governs the theory. Otherwise, similar to what Phinds said, you don't know where the box is or where it ends.
Physgeek123
#46
Apr7-12, 07:49 AM
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Basically, there is no reason why anti dark matter cant exist. True, that it is not charged, but that can be perfectly explained by anti neutrons. Antineutrons have equal amounts of positrons and antiprotons.

A different explanation according to my theory:

Also on another note, since neutrinos have no charge and are not visible, could it be possible that neutrinos could be a new fundamental particle for dark matter? Maybe things like neutrinoprotons and neutrinoelectrons could exist. And since every particle has a anti matter part, nuetrinoparticles might as well have a antinuetrinoparticle counterpart? I'm confused about all this, but you tell me.
mfb
#47
Apr7-12, 08:20 AM
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Quote Quote by Physgeek123 View Post
True, that it is not charged, but that can be perfectly explained by anti neutrons.
Wait, what? Antineutrons decay (into charged antiparticles), and they would react with baryonic matter via the strong interaction. This would be really bad for life.

Also on another note, since neutrinos have no charge and are not visible, could it be possible that neutrinos could be a new fundamental particle for dark matter?
The energy density of neutrinos can be calculated. It is not negligible, but it is not large enough to explain the amount of dark matter present in the universe.

Maybe things like neutrinoprotons and neutrinoelectrons could exist
No. Unless you write a paper with a theory where they pop up as result of the theory.
It is bad that theoreticians invent so many particles with a mathematical foundation. We don't need even more particle names without any theory behind it.
Drakkith
#48
Apr7-12, 06:38 PM
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Quote Quote by Physgeek123 View Post
Basically, there is no reason why anti dark matter cant exist. True, that it is not charged, but that can be perfectly explained by anti neutrons. Antineutrons have equal amounts of positrons and antiprotons.
They do not. Antineutrons are composed of one up antiquark and two down antiquarks. An normal neutron is composed of one up quark and two down quarks. Protons and electrons, or their antimatter counterparts, do not make up neutrons and antineutrons.

A different explanation according to my theory:

Also on another note, since neutrinos have no charge and are not visible, could it be possible that neutrinos could be a new fundamental particle for dark matter? Maybe things like neutrinoprotons and neutrinoelectrons could exist. And since every particle has a anti matter part, nuetrinoparticles might as well have a antinuetrinoparticle counterpart? I'm confused about all this, but you tell me.
I suggest you read the following article.
http://en.wikipedia.org/wiki/Elementary_particle


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