Dark matter

[Sharapovaphan]

How can baryonic dark matter exist? Dark matter is nonbaryonic. Shouldn't baryonic dark matter be on the visible ("normal") matter side of the ledger thus subjected to a name change? Or at the very least be treated as something different than dark matter or visible matter. The name is driving me nuts!

[ajb]

Baryonic dark matter refers to things like neutron stars, white dwarfs and brown dwarfs. These objects are made up of normal matter i.e. protons and neutrons.

 

Big bang nucleosynthesis suggests that there is not enough baryons in the Universe for there to be sufficient baryonic matter to explain dark matter. This is backed up by careful observation of the CMBR.

[Sharapovaphan]

I understand. It was mostly semantics with me. In some circles the definition of dark matter is that it is exclusively nonbaryonic. More recently dark matter is described as the vast majority being nonbaryonic.

 

Thank you...

[Sharapovaphan]

At the top of the blackboard in my high school algebra class was a simple message: "Always go back to the definition." Probably the best advice ever.

[Sharapovaphan]

Baryonic dark matter refers to things like neutron stars, white dwarfs and brown dwarfs. These objects are made up of normal matter i.e. protons and neutrons.

 

Big bang nucleosynthesis suggests that there is not enough baryons in the Universe for there to be sufficient baryonic matter to explain dark matter. This is backed up by careful observation of the CMBR.

 

The correct or incorrect prediction concerning the density of neutrons and protons around the big bag is so important to everything in this discussion. From how much Helium was present, all the way to the Hubble Constant. Everything points to the required density of baryons (neutrons & protons) being a very low percentage. This indicates that not all dark matter is baryonic.

[ajb]

Everything points to the required density of baryons (neutrons & protons) being a very low percentage. This indicates that not all dark matter is baryonic.

 

That is my understanding.

[steevey]

what about this?

http://news.yahoo.com/s/afp/20110527/sc_afp/australiaastrophysicsscience

[IM Egdall]

what about this?

http://news.yahoo.co...ophysicsscience

 

 

The article refers to "ordinary" barionic matter, not dark matter.

[Moontanman]

what about this?

http://news.yahoo.com/s/afp/20110527/sc_afp/australiaastrophysicsscience

 

 

A cool link, i didn't know there was missing baryonic matter, cool to know for sure.