Comments on: A small step toward dark matter

By: Torbjörn Larsson, OM

Torbjörn Larsson, OM — Wed, 22 Oct 2008 22:01:07 +0000

dark matter is composed of charged

Dark matter doesn’t EM interact (measurably); try again.

inflation is never mentioned, even though it seems to be a really well supported theory.

AFAIK it isn’t well supported yet, say, by any single 3 sigma experiment predicted by theory. OTOH AFAIU it resolves many problems and fits naturally with sundry theories.

By: Jesper

Jesper — Wed, 22 Oct 2008 14:10:41 +0000

So you’re in a bar, and there is an alpha male shouting around, while you’re trying to listen to what the shy wimp is saying…

By: Gary Ansorge

Gary Ansorge — Wed, 22 Oct 2008 13:39:55 +0000

AARON:
The OORT cloud does in fact interact with normal electromagnetic radiation by absorbing/scattering it. It’s just far enough away and of such low density we don’t get to see much of that interaction. Over interstellar distances there’s enough dust/small masses for us to readily detect that interference. Over intergalactic distances, dust/normal matter displays its interference quite well but dark matter is detectable ONLY by its gravitational effects, not by absorption or scattering of EM.
We are looking for dark matter close to earth, but it’s estimated that there would only be a few particles/Cm^3, which makes detecting it really hard, especially since we can’t see it in the EM range however, we are working on it.
It’s a little like looking for a mirror in an unlit room. You’ll know it’s there when you trip over it,,,

GAry 7

By: madge

madge — Wed, 22 Oct 2008 05:16:15 +0000

Cool post BA. I studied the SNO during my particle physics course and am hoping to visit the Boulby mine, just up the coast from me where they are also looking for dark matter. I love this stuff!

By: Phy

Phy — Wed, 22 Oct 2008 04:29:13 +0000

You may have mentioned it before when talking about the Sudbury Neutrino Observatory, Phil, but I thought I’d bring it up: The mine in which SNO is situated was excavated to gain access to a great walloping nickel deposit, one which formed in the aftermath of a great walloping meteor impact. The crater that formed, known as the Sudbury Basin, seems to be one of the largest known on Earth.

So dark matter astronomy is taking place two kilometers underground in a facility that never directly sees the sky, sited knee-deep in the wreck of a monstrous and ancient meteor strike.

How cool is science again?

By: Davidlpf

Davidlpf — Wed, 22 Oct 2008 02:42:49 +0000

@Aaron
The other things probably are part of dark matter as well.
Part of the problem is you do know how gravity works and also how these particles interact with matter. That is why these experiments like this and LHC are done.

By: Aaron Gibbons

Aaron Gibbons — Wed, 22 Oct 2008 02:28:53 +0000

Davidlpf
I never implied that nuetrinos would of accouted for all of the dark matter. Also, “probably” implies to me that there has been to date, insufficient research into this area. Do we really know how many of these things are out there?

And what about all the other stuff I mentioned?

And how come dark matter is so exotic but everywhere, how come there is not gravitational footprint of it in our solar system? If stellar winds push gases/dust out of their systems thus putting this stuff between stars then to me there is a base arguement to suggest that dark matter is simply loose gas/dust between stars (and maybe event galaxies) that hasn’t yet been given the time and opportunity to consolidate.

Like I said, I’m not an astronomer or a physicist but I see so many questions pointing to the obvious which haven’t been fully explored.