SCI/TECH: Astronomers find Dark matter Galaxy

Astronomers have found what they believe to be an invisible galaxy made up entirely of dark matter. They believe it is the first to ever be detected. This is a when a large area in the Universe contains a large amount of mass and rotates like a galaxy, but contains no stars. It was found 50 million light years away using radio telescopes.



As a result of the scientists finding no trace of stars, and no galaxies nearby that would suggest a collision this looks to be the first find of its kind and very exciting. Very little is still known about dark matter, and maybe with this discovery more can be learned about it...maybe even one day know how to use it as an energy source.


[edit on 23-2-2005 by John Nada]

what if its another dimension ?

[edit on 23-2-2005 by leejones]

Is this the only way dark matter can be observed, through the detection of invisible matter?

Originally posted by leejones
what if its another dimension ?

I think you've been watching too much Star Trek
you never know though right?

More info on the discovery here

dark matter is effectively some exotic form of matter that does not react with light, ie its literally invisible.

An invisible galaxy. Incredible.

Isn't 50 light years a bit too close? Aren't galaxies seperated by thousands of light years?

50 light years is damned closed. You coudl send a ship there an back in a century at light speed.

You can have moderately reasonable radio communications with it.

Hydrogen gas releases radiation that can be detected at radio wavelengths.

In the Virgo cluster of galaxies, they found a mass of hydrogen atoms a hundred million times the mass of the Sun

This is just weird. Its a galactic mass with no burning stars but its detectale because of these radio emissions. Its filled with hydrogen, so its regular matter, not 'dark matter'?

Yes it is incredible! Astronomers and Cosmologists have theorized such galaxies may exist but to detect one is something alltogether different. To the people who discovered this! This could be Cosmological find of the decade! And it isn't 50 light years away, try 50 million light years away as the bbc article stated.

Well here would be my question.

If a light year is the distance light can travel through space within a 365 day cycle, would that sort of measurement even mean anything in a dark matter galaxy?

If dark matter does not react with light, would it be governed by our ideas of space and time? Would its laws of physics be completely different?

Dark matter, very fickin cool.

SPiderj

If a light year is the distance light can travel through space within a 365 day cycle, would that sort of measurement even mean anything in a dark matter galaxy?

Gravity travels at the speed of light, so I assum they detected the dark matter by its gravitic interactions with normal matter.

If dark matter does not react with light, would it be governed by our ideas of space and time? Would its laws of physics be completely different?

Yes it would, it's just we do not know the whole picture yet, so it could quite literally re-write the books if it were found that Dark Matter operated on different laws then everything else, not very plausible IMO.

Indeed, the only evidence we have for dark matter is from the observation of rotation curves in galaxies... as far as we can tell galaxies are rotating far too fast, they should in theory be flinging their outer parts out into space, yes somehow there's enough gravity there to hold them together, hence there must be some sort of "invisible" matter that only affects other matter through gravity. So, as far as I can tell, this is basically a galaxy without stars, as all galaxies have far more mass than we can see and are built up mainly of Hydrogen. Pity we can't go visit really, one of those niggling problems my Astronomy lecturers keep complaining about.