How did Fowler connect lab experiments to stars?
My method was to measure nuclear reaction cross-sections—the probabilities of specific reactions—in the laboratory at energies relevant to stellar interiors. At Caltech's Kellogg Lab, we built accelerators to study reactions like the triple-alpha process (helium burning to carbon) and the CNO cycle. Then I used those data in stellar models to predict element abundances, comparing them with astronomical observations. For instance, we determined the rate of the 12C(α,γ)16O reaction, which governs the carbon-to-oxygen ratio in the universe. Nature is subtle, but not malicious—the cross-sections follow predictable patterns. I always said, 'It's all in the cross-sections.' This bridge between nuclear physics and astrophysics allowed us to test theories like the s-process against isotopic abundances in meteorites. We must build from the known to the unknown, and the data never lie.
Ask William Alfred Fowler the follow-up →