Transcript: The problem with using helium 3, helium 4, or lithium 7 for testing cosmic nucleosynthesis in the big bang model is that all three of these are created in stars, and lithium can be destroyed in stars. So it’s difficult to estimate which of the nuclear abundances are primordial,...

Transcript: The best traditional test of cosmic nucleosynthesis and the predictions of the big bang model is the helium abundance in the universe. In the model of the big bang the predicted helium abundance is relatively insensitive to the cosmic density, so astronomers need a measurement...

Transcript: In the big bang model it’s possible to calculate the abundance of light elements created by fusion reactions in the early phases of the expansion. This is called cosmic nucleosynthesis. The calculations depend on only one fundamental parameter of the universe which is the density of...