Baryon asymmetry

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Main article: baryogenesis

The baryon asymmetry problem in physics refers to the apparent fact that the baryons in the universe which have been observed are overwhelmingly matter as opposed to anti-matter. Neither the standard model of particle physics, nor the theory of general relativity provide an obvious explanation for why this should be so. There are competing theories to explain this aspect of the phenomena of baryogenesis, but there is no one consensus theory to explain the phenomenon at this time.

One possible explanation of baryon asymmetry is that there are regions of the universe in which matter is dominant, and other regions of the universe in which anti-matter is dominant, which are widely separated and thus do not interact. Approximately 30 years of scientific research have placed boundaries on how far away, at a minimum, any such region would have to be, and hence, this explanation is now considered rather unlikely, as matter seems to be not spaced that dilutely. At least one more major scientific study called the Alpha Magnetic Spectrometer (AMS) is planned to further refine that limit. [1] But, the AMS has faced funding problems.[2].

As of May, 2007, no helium atom (or larger atom) made of anti-matter, either in nature, or created synthetically, has ever been scientifically observed.[3] As a result, scientific limits on the possible quantity of such anti-matter atoms in existence in nature, and hence, of the extent of baryon asymmetry, are essentially a function of the accuracy of the scientific instruments used to detect them. While anti-matter atoms of any type are theoretically possible given existing scientific understanding, the failure of scientists to scientifically observe any helium or larger sized anti-matter atoms supports both the theory that anti-matter is very rare in our cosmic vicinity, and the theory that there are no helium or larger sized anti-matter atoms anywhere in nature.