radioactivity that

For example, one might quote a ten-day adjusted figure, that is, the amount of radioactivity that will still be present ten days in the future.

Steel from pre-nuclear age ships either mothballed or sunk and raised, called low-background steel, is used in experimental physics when the experiment requires shielding material which is itself only extremely weakly radioactive, emitting less than present-day background radiation ; materials which were manufactured after atmospheric nuclear explosions had taken place reflect the higher ambient level of radioactivity that fallout has caused.

It would take further advances in geology and the discovery of radioactivity that showed that the sun was in fact heated by nuclear fusion that demonstrated the present estimated 4. 567 billion years, or ~ 700, 000 times Ussher's value.

One way to demonstrate that nuclear fusion has occurred inside a fusor device is to use a Geiger counter to measure the radioactivity that is produced in a sheet of aluminum foil.