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All Things Great and Small

Glamour vs. Meat and Potatoes
The theory of relativity is probably the most glamorous result of twenti-
eth-century physics. It is both beautiful and profound, and it made Albert
Einstein an iconic figure. However, other than to show the equivalence of
matter and energy, which has led to extremely destructive weapons and
an energy technology which is widely used outside the United States but
has fallen into disrepute here, exactly what has the theory of relativity
done for the average person?
The short answer is “not much.” The theory of relativity also involves
gravity, but although gravity is used to turn dynamos much as gravity
was used to turn waterwheels in the past, it is the electricity produced by
the dynamos that powers our lives, not the gravity-induced fall of the wa-
ter that turns them. Unquestionably, the theory of relativity has had a
significant impact upon the world, but it pales in comparison with the
impact made by the study of the physics of the electron and the photon.
The deeper understanding of the electron and the photon is the domain of
quantum mechanics. Many great physicists have contributed to quantum