Free Parallel Worlds by Michio Kaku Page A

Later, at the University of Copenhagen, he met many of the giants of
physics, like Niels Bohr. (In 1932, he and his wife tried unsuccessfully to
defect from the Soviet Union by sailing on a raft from the Crimean to Turkey.
Later, he succeeded in defecting while attending a physics conference in
Brussels, which earned him a death sentence from the Soviets.)
    Gamow was famous
for sending limericks to his friends. Most are unprintable, but one limerick
captures the anxieties cosmologists feel when they face the enormity of
astronomical numbers and stare infinity in the face:
    There was a young fellow from Trinity
    Who took the square root of infinity
    But the number of digits
    Gave him the fidgits;
    He dropped Math and took up Divinity.
    In the 1920s in
Russia, Gamow scored his first big success when he solved the mystery of why
radioactive decay was possible. Thanks to the work of Madame Curie and others,
scientists knew that the uranium atom was unstable and emitted radiation in
the form of an alpha ray (the nucleus of a helium atom). But according to
Newtonian mechanics, the mysterious nuclear force that held the nucleus together
should have been a barrier that prevented this leakage. How was this possible?
    Gamow (and R. W.
Gurney and E. U. Condon) realized that radioactive decay was possible because
in the quantum theory, the uncertainty principle meant that one never knew
precisely the location and velocity of a particle; hence there was a small
probability that it might "tunnel" or penetrate right through a
barrier. (Today, this idea of tunneling is central to all of physics and is used
to explain the properties of electronic devices, black holes, and the big
bang. The universe itself might have been created via tunneling.)
    By analogy,
Gamow envisioned a prisoner sealed in a jail, surrounded by huge prison walls.
In a classical Newtonian world, escape is impossible. But in the strange world
of the quantum theory, you don't know precisely where the prisoner is at any
point or his velocity. If the prisoner bangs against the prison walls often
enough, you can calculate the chances that one day he will pass right through
them, in direct violation of common sense and Newtonian mechanics. There is a
finite, calculable probability that he will be found outside the gates of the
prison walls. For large objects like prisoners, you would have to wait longer
than the lifetime of the universe for this miraculous event to happen. But for
alpha particles and subatomic particles, it happens all the time, because
these particles hit against the walls of the nucleus repeatedly with vast
amounts of energy. Many feel that Gamow should have been given the Nobel Prize
for this vitally important work.
    In the 1940s,
Gamow's interests began to shift from relativity to cosmology, which he viewed
as a rich, undiscovered country. All that was known about the universe at that
time was that the sky was black and that the universe was expanding. Gamow was
guided by a single idea: to find any evidence or "fossils" proving
that there was a big bang billions of years ago. This was frustrating, because
cosmology is not an experimental science in the true sense of the word. There
are no experiments one can conduct on the big bang. Cosmology is more like a
detective story, an observational science where you look for "relics"
or evidence at the scene of the crime, rather than an experimental science
where you can perform precise experiments.
     
    NUCLEAR KITCHEN
OF THE UNIVERSE
    Gamow's next
great contribution to science was his discovery of the nuclear reactions that
gave birth to the lightest elements that we see in the universe. He liked to
call it the "prehistoric kitchen of the universe," where all the
elements of the universe were originally cooked by the intense heat of the big
bang. Today, this process is called "nucleosynthesis," or calculating
the relative abundances of the elements in the universe. Gamow's idea was that
there was an unbroken