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Name: Dan
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Question:
What percentage of the universe is made of ordinary matter?



Replies:
Dan,

I am not exactly sure what you are trying to ask, so I will take a couple stabs.

Are you asking what percentage of the volume of the universe contains matter?

The answer to that question is not well understood by scientists. The rate of expansion of the universe indicates there should be more mass than we observe through telescopes. Thus, some scientists have predicted 'dark matter' that we cannot see, or other solutions, to explain this apparent contradiction. So, we are not really sure how much matter there is, and if this dark matter exists, where it is or how much space it takes up. However, there is a lot more 'empty space' (it is not really empty, but ...) where we do not see stars and galaxies than where we do see them.

Are you asking what is the ratio between the matter we can see and the matter we think should be there (e.g. dark matter)?

If this is your question, estimates range up to 95% of the matter in the universe being 'dark' matter. There is also 'dark energy' which could be three times more than that as well. Scientists do not have a great grasp on this yet -- they are working on it though.

I hope these are helpful. If you're asking something else, reply back and let me know what you meant.

Thanks,

Burr Zimmerman



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