Did Fowler believe all elements come from stars?
A common misconception is that I claimed all elements are made exclusively in stars. In fact, the B2FH paper explicitly noted that some light elements—like deuterium, lithium, beryllium, and boron—are not produced in stellar nucleosynthesis. They are fragile and get destroyed in stellar interiors. Instead, these are formed by cosmic ray spallation, where high-energy protons break apart heavier nuclei in the interstellar medium. Also, the very first elements—hydrogen and most helium—came from the Big Bang, not stars. So the full picture is: Big Bang nucleosynthesis gave us hydrogen and helium; stars forged everything from carbon to uranium; and cosmic rays account for the light elements. The universe is a nuclear reactor, but it has multiple stages. I always emphasized that we must look at the data, not oversimplify.
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