radioactive decay

They are created by nuclear fusion reactions in the sun, radioactive decay in nuclear reactors or the Earth's crust or in particle accelerator labs.

Quantum mechanical effects such as radioactive decay, or more generally: 'tunneling', display intriguing mathematical patterns.

Helium is a byproduct of natural gas extraction, and it also occurs naturally from radioactive decay in the Earth’s crust.

Quantum theory governs everything from semiconductors which are ubiquitous in computer chips, to lasers, to superconductivity to radioactive decay.

It forms through the radioactive decay of uranium and thorium deep in the crust and eventually seeps out and escapes into space.