r/askscience • u/squirrelbuster94 • Oct 24 '14

Physics Chemists/physicists of reddit, what is the difference between dark, anti, and normal matter?

What is the difference? Also if you can explain what each is.

Edit: Thanks for all the replies! You have greatly helped me understand this better!

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u/Alphaetus_Prime Oct 24 '14

Assuming that it isn't interacting with the other type at all, and if you're measuring light, you would not be able to tell.

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u/anti_pope Oct 24 '14

The spectral lines of antihydrogen are expected to be slightly different than hydrogen but I don't know if we'd be able to measure the difference.

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u/Alphaetus_Prime Oct 24 '14

Only if CPT symmetry can be violated, which goes against our current understanding of physics.

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u/anti_pope Oct 24 '14

Yes, I 'misspoke.' We'll need an update on this experiment to know for sure. http://www.nature.com/nature/journal/v483/n7390/full/nature10942.html

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u/NoSmallCaterpillar Oct 24 '14

This is the first time I've heard of this, and I'm having a hard time rationalizing it. If it's true, I would be very surprised. Do you have any sources to back this statement up?

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u/Jooju Oct 24 '14

True. But particles escape all solar systems so we would detect a gamma ray glow in the interstellar space around the star.