Major Contribution
Maria Goeppert-Mayer’s most notable contribution to the field of physics
was her discovery of the nuclear shell model, for which she and J. Jenson
were awarded the Nobel Prize in Physics. Goeppert-Mayer was part of the
Institute of Nuclear studies at the University of Chicago. One of
the topics of debate at the institute concerned the origin of the chemical
elements. Maria began to investigate this topic with Edward Teller.
While investigating this topic, she noticed similarities between
abundant elements with certain numbers of protons or neutrons in their
nuclei. These certain numbers were 2, 8, 20, 28, 50, 82, 126.
They are collectively called, “Magic Numbers”, a term coined by Eugene
Wigner. (Wigner was also awarded the Nobel Prize in Physics with Goeppert-Mayer
and Jenson for his discovery of “Magic Numbers”.) Maria noticed that
these magic numbers indicated very stable shells in the nuclei of the atom,
similar to electron shells. After further research, Maria developed
the spin-orbit coupling shell model of nuclei. Maria described the
nucleus as a “pattern of the circling protons and neutrons as spin orbiting
one pair going clockwise the other pair going counter clockwise”.
She also recognized that the seven magic numbers represented the most abundant
elements because these elements had tightly fitting nuclei, and would not
change properties or react with other elements.
Maria once wrote:
"Think of a roomful of waltzers. Suppose they go round the room in
circles, each circle
enclosed within another. Then imagine that in each circle, you can
fit twice as many dancers
by having one pair go clockwise and another pair go counterclockwise.
Then add one more
variation; all the dancers are spinning-twirling round and round like
tops as they circle the
room, each pair both twirling and circling. But only some of those
that go counterclockwise
are twirling counterclockwise; the others are twirling clockwise while
circling
counterclockwise. The same is true of those that are dancing around
clockwise; some twirl
clockwise, others twirl counterclockwise."