Dark Matter, What is it?

[tcthomas4]

Hey all,

Just throwing an idea I had out there for you all to dissect and discuss. What if dark matter is not WIMP's or MACHO's or any particle we havent discovered yet? What if it is actually all the "virtual particle" pairs that exist for periods of time less than the Plank time (10^-43 seconds)? Think about it... they are being created everywhere all the time but exist for times periods to short to detect: but who is to say that the Universe didnt detect them? How long does a particle have to exist before its gravitational influence can be experienced? And since the dark matter seems so homogeneous it makes sense that whatever it is exists everywhere, like virtual particles.

I am no physicist but think that it is strange that I have never heard anybody discuss this option. At least to debunk it. Any ideas or theories about this idea from the scientific community would be appreciated.

 

[DrRocket]

Hey all,

Just throwing an idea I had out there for you all to dissect and discuss. What if dark matter is not WIMP's or MACHO's or any particle we havent discovered yet? What if it is actually all the "virtual particle" pairs that exist for periods of time less than the Plank time (10^-43 seconds)? Think about it... they are being created everywhere all the time but exist for times periods to short to detect: but who is to say that the Universe didnt detect them? How long does a particle have to exist before its gravitational influence can be experienced? And since the dark matter seems so homogeneous it makes sense that whatever it is exists everywhere, like virtual particles.

I am no physicist but think that it is strange that I have never heard anybody discuss this option. At least to debunk it. Any ideas or theories about this idea from the scientific community would be appreciated.

The quantum vacuum, which is what "spawns" virtual particles, has been considered. It is really more germane to the question of dark energy than to dark matter.

The effect of the quantum vacuum and the virtual particles is to provide a negative pressure term in the field equations that govern general reltivity. That results in an effective repulsive force, as described by dark energy or a cosmological constant. Dark matter requires an attractive effect, so virtual particles are in the wrong direction for that phenomena.

Virtual particles don't solve the dark energy problem either. The calculations result in a repulsive effectd that is about 120 orders of magnitude too large -- and that is a HUGE error.

 

[tcthomas4]

Thanks for your answer. You sure do get around here! Questions: If the net repulsive effect due to virtual particles should be on the order of 120 times larger than what we perceive as "dark energy" then wouldn't this be causing the Universe to accelerate its expansion on the order of 120 times more than what we are currently witnessing? What do you believe is the most likely source of "dark matter" and "dark energy"? I know you probably don't like to go out on a limb like this, but what does your gut tell you?

And I realize that virtual particles were inserted by hand in order to balanace some quantum field equations and have never been witnessed, but I don't understand why they wouldnt have some gravity during their brief existence. Obviously, I am no quantum physicist but am trying to wrap my mind around some of the nonsense these guys come up with to expalin what they see in particle accelerators. I would say Einstiens work is intuitive and you can actually do "mind experiments" and see the truth of relativity. Not so with the quantum world, you just have to believe it. I am not saying I don't believe it because have performed double slit experments myself, just that it goes against all common sense. And so if you tell me that virtual particles result in a net repulsive force and not attractive force due to gravity, well, once again I say quantum theory is more strange than I thought before. At least its consistent in this respect.

 

[DrRocket]

Thanks for your answer. You sure do get around here! Questions: If the net repulsive effect due to virtual particles should be on the order of 120 times larger than what we perceive as "dark energy" then wouldn't this be causing the Universe to accelerate its expansion on the order of 120 times more than what we are currently witnessing? What do you believe is the most likely source of "dark matter" and "dark energy"? I know you probably don't like to go out on a limb like this, but what does your gut tell you?

I did not say that the repulsive effect shold be 120 times larger that we is observed. Is said it should be 120 orders of magnitude greater. As a factor that is

1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.

That is a bit more than 120.

I would be quite willing to go out on a limb. But I have no idea what the real answer is.

It MIGHT be that the quantum field theories the predict the effect of the vacuum and that are off by 120 orders of magnitude, when unified with general relativity in some future theory can provide and answer. I don't know how to do that. Neither does anyone else.

 

[tcthomas4]

I did not say that the repulsive effect shold be 120 times larger that we is observed. Is said it should be 120 orders of magnitude greater. As a factor that is

1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.

That is a bit more than 120.

I would be quite willing to go out on a limb. But I have no idea what the real answer is.

It MIGHT be that the quantum field theories the predict the effect of the vacuum and that are off by 120 orders of magnitude, when unified with general relativity in some future theory can provide and answer. I don't know how to do that. Neither does anyone else.

Oh wow! I misread your initial response but it is quite clear to me now. Clearly, there is nothing that can make up for a discrepancy this large.

But this once again confirms that there is a problem with quantum theory, or perhaps there is a problem with relativity. I prefer to think that quantum theory is wrong because I can do relativity in my head. It makes sense, logically. Then again, with the addition of a cosmological constant, it is suddenly reduced a theory that explains observation... like quantum theory. I wish I could understand all of the math of quantum theory, string theory, and M-theory... but it is beyond me. Relativity at least is simple, like Einstein believed a grand unified theory would be. I am not so convinced that it will be simple and elegant because clearly God does play dice. But with discrepancies on the order of magnitude ^google20, anybody knows that there is a fundamental lack of understanding. I love this stuff! Keep it coming!