While some physicists used these discoveries for applications ranging from nuclear weapons to nuclear medicine, others applied them to understanding the natural world.The sun was once thought to burn like a coal fire, but physicists showed that it actually generates energy by slamming atoms together and creating new elements.He was employed at Caltech's Division of Geological & Planetary Sciences at the time of writing the first edition.
The great physicist Lord Kelvin had countered that the planet was actually relatively young perhaps 20 million years old.
Radiometric dating--the process of determining the age of rocks from the decay of their radioactive elements--has been in widespread use for over half a century.
There are over forty such techniques, each using a different radioactive element or a different way of measuring them.
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