Dark Matter? Speculation about virtual particles

[phil_newby]

Hi All

I've been wondering about dark matter...

I understand that most of the mass of a proton or neutron is not the 3 quarks that make each one up but the plethora of virtual quarks that seem to hang about inside them.

 

So couldn't the seething mass of virtual particles that fill the vacuum of space make up a significant proportion of the so called dark matter that appears to be missing from our universal accounting of matter?

 

I assume someone has already thought of this and knows why it can not be the case

I'd love to know

 

phil

[Strange]

I haven't heard the mass of protons and neutrons described that way before. It is normally described as the binding energy (in the gluon field). But I guess that might be an equivalent way of looking at it.

 

The problem with just taking virtual particles as being the extra mass is that these just represent the vacuum energy which (I am fairly sure) is not enough to account for dark matter. It is also not distributed in the way that dark matter is (greatest density at the centre of galaxies, etc).

 

However,there is at least one attempt to explain dark matter in this way: http://phys.org/news/2011-08-dark-illusion-quantum-vacuum.html

 

But this assumes that matter and anti-matter have opposite gravitational "charge" and, currently, there is no reason to think that is the case. (This is being tested by the ALPHA project at CERN.)

[phil_newby]

Thanks, very interesting!

[ajb]

So couldn't the seething mass of virtual particles that fill the vacuum of space make up a significant proportion of the so called dark matter that appears to be missing from our universal accounting of matter?

This sounds more like the cosmological constant. For example, why would such an energy density be 'lumpy', presumably it would be rather uniform. Now, calculations of the effects of virtual particles on the vacuum energy are well off what we observe, something like 100 orders of magnitude. This is one of the big open problems in modern physics.

 

 

I haven't heard the mass of protons and neutrons described that way before. It is normally described as the binding energy (in the gluon field). But I guess that might be an equivalent way of looking at it.

It is the correct way to think of it when trying to calculate such masses, say via lattice QED.