Wednesday, July 16, 2008

Not "normal" dark matter

Symmetry magazine has a news blog, as you might know. Today I read that next issue will discuss a dark matter controversy: the DAMA dark matter detector sees a signal, which cannot be seen in other experiments. It has pretty much been ruled out that it was dark matter causing the signal. What it is that they see is debated: something that has an annual modulation. Could it have something to do with cosmic rays? The number of cosmic ray particles vary with season because of the varying density of the atmosphere. This is just a speculation. We'll see if they sort it out.

What made me interested in this little news item is that they also mention COUPP, a detector i like. It's a bubble chamber!

Within a week or so I will post a little text about a dark matter detector. It was originally intended for first year physics students. There, now I have promised, so I have to do it!

1 comment:

Magnus said...

Bubble chamber! Cool! :-D

So dark matter has been ruled out as the cause of the DAMA signal? I'm not surprised, but I haven't been kept up to date on the issue. By what arguments can we now rule out dark matter?

And yes, it will be interesting to see what explanation people will finally come up with for the signal.