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Scientists Expand Knowledge of Dark Matter
nife00 writes "BBC News is reporting that British scientists at Cambridge have expanded the current understanding of the mysterious particles known as dark matter." According to the article: "[The Cambridge Team] has at last been able to place limits on how it is packed in space and measure its "temperature". "It's the first clue of what this stuff might be," said Professor Gerry Gilmore. "For the first time ever, we're actually dealing with its physics," he told the BBC News website."
Nothing for you to see here. Please move along.
Beware: In C++, your friends can see your privates!
Doesn't the name "Very Large Telescope facility" sound like it is out of a Monty Python sketch, sort of like the "Ministry of Silly Walks"?
Further, I am struck with the thought that dark matter is "Silly Putty" which has gone off a bit.
Harpo Tunnel Syndrome--my wrist feels funny.
"For the first time ever, we're actually dealing with its physics,"
Thats because we've secretly replaced the regular dark matter with Folger's Crystals!
British scientists at Cambridge have also placed limitations on the possible properties of the luminiferous aether. "We're pretty sure it's not yellow," says one researcher, "and we've also ruled out blue and pink. It's nice to know that we'll soon have figured out both this dark matter stuff and the luminiferous aether. Then we can start puzzling out those epicycles again."
What the findings suggest is that dark matter isn't exotic matter but a different kind of matter all together. The hierarchy of forces according to interaction goes gravity -> electroweak -> strong. This means all matter we know of interacts with gravity, all matter (until recently) interacts with the electroweak force and a subset of matter, quarks, interacts with the strong force. Note, quarks also interact with the electroweak force since protons and neutrons have electric charge and these particles are made of quarks. However leptons, like the electron do not interact with the strong force.
Now it was possible that dark matter could interact with the electroweak force but very weakly and therefore undetectable at large scales. It was assumed that this meant they were very cold and at very low energy states. However if they are moving at 9km/s that would mean they have high energy states. Therefore if they did interact with the electroweak force, they would be absorbing or emitting photons. But they aren't.
So we have a new type of matter with that only interacts with standard matter(leptons, quarks) via the gravitational force.
The best education consists in immunizing people against systematic attempts at education. - Paul Feyerabend
Here's what makes me unhappy:
The Cambridge University team expects to submit the first of its results to a leading astrophysics journal in the next few weeks.
I don't like this "press release before publication" mode of doing science. It's all about making sure that you get the attention and public recognition, and not about propery distributing the results so that others can understand and evaluate what you've done. Alas, it seems that Marketing Is All in the modern world, and not just in the USA any more. You can be sure that the institutions who house these scientists love to get the attention and so forth.
I'd be happier if the paper had already been accepted by some real journal, with a preprint available on www.arxiv.org. As it is... we have a press release and a pop-sci article about an intersting result that's hard to truly evaluate. The article is mostly good and sounds reliable, but in my experience these pop-sci articles usually get something wrong. (For instance, even though 10,000 degrees sounds "hot", given the likely mass of the Dark Matter particle, it still is "cold" in the cosmological sense of "cold dark matter", which really means "nonrelativistic dark matter". I'm not sure how much of a surprise that temperature is, but it's probably not enough to make CDM wrong.)
-Rob