Wednesday, February 22, 2006
Tuesday, February 07, 2006
The Properties of Dark Matter (Latest News)
Not long ago, my professor told me Physicists and Astronomers have no idea what is dark matter. But now, a team from Institute of Astronomy, Cambridge has been able to place limits on how dark matter is pack in space and measured its temperature.
The team used the VLT, Very Large Telescope (You know, astronomers really not fancy to name things, there is another telescope coming soon called OWL, guess what does that mean? Overwhelmingly Large......), made a 3D maps of the galaxies, using the movements of their stars to trace the impression of the dark matter aming them and weigh it. (Of course, it involved a lot of Physics here...)
Ok, about the properties:
"It comes in a 'magic volume' which happens to correspond to an amount which is 30 million times the mass of the Sun."
"It looks like you cannot ever pack it smaller than about 300 parsecs - 1,000 light-years; this stuff will not let you. That tells you a speed actually - about 9km/s - at which the dark matter particles are moving because they are moving too fast to be compressed into a smaller scale."
"These are the first properties other than existence that we've been able determine."
"If this temperature for the dark matter is correct, then it has huge implications for direct searches for these mysterious particles (it seems [science] may be looking in the wrong place for them) and for how we thought the galaxies and clusters of galaxies evolve in the Universe."
"Having 'hotter' dark matter makes it harder to form the smallest galaxies, but does help to make the largest structures. This result will generate a lot of new research."
"It turns out the Milky Way is more massive than we thought,"
"It now looks as though the Milky Way is the biggest galaxy in the local Universe, bigger even than Andromeda. It was thought until just a few months ago that it was the other way around."
Human beings are one step forward again to understand our universe! This is exciting!!!