Non-standard Cosmology - Nucleosynthesis Objections To Non-standard Cosmologies

Nucleosynthesis Objections To Non-standard Cosmologies

One of the major successes of the Big Bang theory has been to provide a prediction that corresponds to the observations of the abundance of light elements in the universe. Along with the explanation provided for the Hubble's law and for the cosmic microwave background, this observation has proved very difficult for alternative theories to explain.

Theories which assert that the universe has an infinite age, including many of the theories described above, fail to account for the abundance of deuterium in the cosmos, because deuterium easily undergoes nuclear fusion in stars and there are no known astrophysical processes other than the Big Bang itself that can produce it in large quantities. Hence the fact that deuterium is not an extremely rare component of the universe suggests that the universe has a finite age.

Theories which assert that the universe has a finite life, but that the Big Bang did not happen, have problems with the abundance of helium-4. The observed amount of 4He is far larger than the amount that should have been created via stars or any other known process. By contrast, the abundance of 4He in Big Bang models is very insensitive to assumptions about baryon density, changing only a few percent as the baryon density changes by several orders of magnitude. The observed value of 4He is within the range calculated.