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imported_ROB
2003-Sep-19, 12:47 PM
hi
can any one explain to me what anti matter is it the same as dark matter?
:blink:

Josh
2003-Sep-19, 01:34 PM
Hi Rob, how's it going?

Firstly, Dark matter and anti matter aren't the same thing.

Antimatter
When the big bang happened it is hypothesised that both matter and antimatter were created. When matter and antimatter come into contact they anihilate one another. Therefore there had to be a little bit more matter created than antimatter during the big bang and that is what we live in, see and feel today - matter. So we pretty much know what matter is. Matter is made up of three types of particles: protons, electrons and neutrons. These are the basic building blocks of pretty much everything. Until pretty recently very little was known about the electron, for example, and when it finally became a predictable "thing" it was found that the predictablity could only work if there was a twin electron out there ... an anti-electron or positron. Just as protons have antiprotons and neutrons have antineutrons. This was all done by Paul Dirac. Based on his work other physicists set about trying to create antimatter and succeeded by creating an electron-positron pair followed by the other particles and antiparticles. So possibly there is an anti-universe out there. but that is yet to be found or even remotely proven. There are places around the world with particle accelerators (like CERN) where antimatter studies are being carried out.

Dark Matter
Dark matter (as is the current thinking) is what most of the universe seems to be made out of. Dark matter can be detected by the amount of light that it DOESN'T emit and the way it interacts with the matter we can see like stars and galaxies (and galaxy clusters etc...). The way or amount of gravity measured to be acting on these visible things can only be correct if there is dark matter in the area acting on them too.

I hope that made sense ...

Deep_Eye
2003-Sep-20, 01:36 AM
I'd always thought they were the same thing. Does anyone have an idea as to what dark matter is made of?

Josh
2003-Sep-20, 02:16 AM
The verdict is still out on that Deep Eye. Some people have tried to suggest that the bulk of dark matter is made up of neutrinos. but this has found to be impossible. Others think thatdark matter is made of sub-luminous stars called 'brown dwarfs'. I think there may have been positive findings on a brown dwarf but am not sure. i certainly didn't see it through my telescope. Still others think that dark matter is a "new" material that we've not thought of or discovered.

The reason dark matter was hypothesised in the first place was to allow for the inflation theory of the universe to hold ... so essentially it's a fudge factor! Sometimes however, fudge factors turn out to be something very real.

kashi
2003-Sep-20, 02:40 AM
The interesting thing is, that theoretically, anti-matter and matter are made of the same tiny particles called quarks, just different combinations of them. Recently new theories have a emerged suggesting that when anti-matter and matter annihilate to produce energy, that matter actually "wins the battle" by a small margin. These theories are based on experiments in particle accelerators, and could explain why the universe appears to be dominated by matter.

Kashi

imported_ROB
2003-Sep-23, 11:23 AM
HI ALL

THANKS THAT CLEARS IT FOR ME A LITTLE

BUT HAS EITHER ACTUALLY BEEN PROVED TO BE OUT THERE OR ARE THEY JUST AGREED THEORIES?

:huh:

Josh
2003-Sep-23, 01:24 PM
There are quite a few places around the world that do experiments with antimatter particles. They are very real and have been observed in particle accelerators for eg.

Dark matter on the other hand is ... a little less observed.

Josh
2003-Sep-24, 05:03 AM
For a more in depth discussion on dark matter, its existence and its make up go here...

http://www.universetoday.com/forum/index.p...owtopic=367&hl= (http://www.universetoday.com/forum/index.php?showtopic=367&hl=)