Parallel Worlds (23 page)

But if electrons
can exist in parallel states hovering between existence and nonexistence, then
why can't the universe? After all, at one point the universe was smaller than
an electron. Once we introduce the possibility of applying the quantum
principle to the universe, we are forced to consider parallel universes.

It is exactly
this possibility that is explored in Philip K. Dick's disturbing science
fantasy tale
The Man in the High
Castle.
In the book, there is an alternate universe separated from
ours because of a single pivotal event. In 1933, in that universe, world
history is changed when an assassin's bullet kills President Roosevelt during
his first year in office. Vice President Garner takes over and establishes an
isolationist policy that weakens the United States militarily. Unprepared for
the attack on Pearl Harbor, and unable to recover from the destruction of the
entire U.S. fleet, by 1947 the United States is forced to surrender to the
Germans and the Japanese. The United States is eventually cut up into three
pieces, with the German Reich controlling the east coast, the Japanese
controlling the west coast, and an uneasy buffer, the Rocky Mountain states, in
between. In this parallel universe, a mysterious individual writes a book,
called
The Grasshopper Lies Heavy,
based on a line
in the Bible, which is banned by the Nazis. It talks about an alternate
universe in which Roosevelt was not assassinated, and the United States and
Britain defeated the Nazis. The mission of the heroine in the story is to see
if there is any truth in an alternate universe in which democracy and freedom
prevail, rather than tyranny and racism.

TWILIGHT ZONE

The world of
The Man in the High Castle
and our world
are separated by only the tiniest of accidents, a single assassin's bullet.
However, it is also possible that a parallel world may be separated from ours
by the smallest possible event: a single quantum event, a cosmic ray impact.

In one episode
of the
Twilight Zone
television
series, a man wakes up only to find that his wife does not recognize him. She
screams at him to leave before she calls the police. When he wanders around
town, he finds that his lifelong friends also fail to recognize him, as if he
never existed. Finally, he visits his parents' house and is shaken to the core.
His parents claim that they have never seen him before and that they never had
a son. Without friends, family, or a home, he drifts aimlessly around town,
eventually falling asleep on a park bench, like a homeless man. When he wakes
up the next day, he finds himself comfortably back in bed with his wife.
However, when his wife turns around, he is shocked to find that she is not his
wife at all, but a strange woman that he has never seen before.

Are such
preposterous stories possible? Perhaps. If the protagonist in
The Twilight Zone
had asked some revealing questions
of his mother, he might have found that she had a miscarriage and hence never
had a son. Sometimes a single cosmic ray, a single particle from outer space,
can strike deep in the DNA within an embryo and cause a mutation that will
eventually lead to a miscarriage. In such a case, a single quantum event can
separate two worlds, one in which you live as a normal, productive citizen, and
another that is exactly identical, except that you were never born.

To slip between
these worlds
is
within the laws
of physics. But it is extremely unlikely; the probability of it happening is
astronomically small. But as you can see, the quantum theory gives us a picture
of the universe much stranger than the one given to us by Einstein. In
relativity, the stage of life on which we perform may be made of rubber, with
the actors traveling in curved paths as they move across the set. As in
Newton's world, the actors in Einstein's world parrot their lines from a script
that was written beforehand. But in a quantum play, the actors suddenly throw
away the script and act on their own. The puppets cut their strings. Free will
has been established. The actors may disappear and reappear from the stage.
Even stranger, they may find themselves appearing in two places at the same
time. The actors, when delivering their lines, never know for sure whether or not
they are speaking to someone who might suddenly disappear and reappear in
another place.

MONSTER MIND: JOHN WHEELER

Except perhaps
for Einstein and Bohr, no man has wrestled more with the absurdities and
successes of the quantum theory than John Wheeler. Is all physical reality just
an illusion? Do parallel quantum universes exist? In the past, when he was not
mulling over these intractable quantum paradoxes, Wheeler was applying these
probabilities to build the atomic and hydrogen bombs and was pioneering the
study of black holes. John Wheeler is the last of the giants, or "monster
minds," as his student Richard Feynman once called them, who have grappled
with the insane conclusions of the quantum theory.

It was Wheeler
who coined the term "black hole" in 1967 at a conference at NASA's
Goddard Institute for Space Studies in New York City after the discovery of the
first pulsars.

Wheeler was born
in 1911 in Jacksonville, Florida. His father was a librarian, but engineering
was in his family's blood. Three of his uncles were mining engineers and often
used explosives in their work. The idea of using dynamite fascinated him, and
he loved to watch explosions. (One day, he was carelessly experimenting with a
piece of dynamite and it accidentally exploded in his hand, blowing off part of
his thumb and the end of one finger. Coincidentally, when Einstein was a
college student, a similar explosion took place in his hand due to
carelessness, requiring several stitches.)

Wheeler was a
precocious kid, mastering calculus and devouring every book he could find on
the new theory that his friends were buzzing about: quantum mechanics. Right
before his eyes, a new theory was being developed in Europe by Niels Bohr,
Werner Heisenberg, and Erwin Schrodinger that suddenly unlocked the secrets of
the atom. Only a few years before, followers of the philosopher Ernst Mach had
scoffed at the existence of atoms, stating that atoms had never been observed
in the laboratory and probably were a fiction. What couldn't be seen probably
did not exist, they claimed.

The great German
physicist Ludwig Boltzmann, who laid down the laws of thermodynamics, committed
suicide in 1906, in part because of the intense ridicule he faced while
promoting the concept of atoms.

Then, in few
momentous years, from 1925 to 1927, the secrets of the atom came tumbling out.
Never in modern history (except for the year 1905, with the work of Einstein)
had breakthroughs of this magnitude been accomplished in so short a time.
Wheeler wanted to be part of this revolution. But he realized that the United
States was in the backwash of physics; there was not a single world-class physicist
among its ranks. Like J. Robert Oppenheimer before him, Wheeler left the United
States and journeyed to Copenhagen to learn from the master himself, Niels
Bohr.

Previous
experiments on electrons demonstrated that they acted both as a particle and as
a wave. This strange duality between particles and waves was finally unraveled
by the quantum physicists: the electron, in its dance around the atom, was
shown to be a particle, but it was accompanied by a mysterious wave. In 1925,
Austrian physicist Erwin Schrodinger proposed an equation (the celebrated
Schrodinger wave equation) that accurately described the motion of the wave
that accompanies the electron. This wave, represented by the Greek letter
psi,
gave breathtakingly precise predictions for the behavior of
atoms which sparked a revolution in physics. Suddenly, almost from first
principles, one could peer inside the atom itself to calculate how electrons
danced in their orbits, making transitions and bonding atoms together in
molecules.

As quantum
physicist Paul Dirac boasted, physics would soon reduce all of chemistry to
mere engineering. He proclaimed, "The underlying physical laws necessary
for the mathematical theory of a larger part of physics and the whole of
chemistry are thus completely known, and the difficulty is only that the
application of these laws leads to equations much too complicated to be
soluble." As spectacular as this
psi
function was, it was still a mystery as to what it really represented.

Finally, in
1928, physicist Max Born proposed the idea that this wave function represented
the probability of finding the electron at any given point. In other words, you
could never know for sure precisely where an electron was; all you could do
was calculate its wave function, which told you the probability of it being
there. So, if atomic physics could be reduced to waves of probability of an electron
being here or there, and if an electron could seemingly be in two places at the
same time, how do we finally determine where the electron really is?

Bohr and
Heisenberg eventually formulated the complete set of recipes in a quantum
cookbook that has worked beautifully in atomic experiments with magnificent
precision. The wave function only tells you the probability that the electron
is located here or there. If the wave function is large at a certain point, it
means that there is a high likelihood that the electron is located there. (If
it is small there, then it is unlikely that the electron can be found there.)
For example, if we could "see" the wave function of a person, it
would look remarkably like the person himself. However, the wave function also
gently seeps out into space, meaning that there is a small probability that the
person can be found on the moon. (In fact, the person's wave function actually
spreads out throughout the universe.)

This also means
that the wave function of a tree can tell you the probability that it is either
standing or falling, but it cannot definitively tell you in which state it
actually is. But common sense tells us that objects are in definite states.
When you look at a tree, the tree is definitely in front of you—it is either
standing or fallen, but not both.

To resolve the
discrepancy between waves of probability and our commonsense notion of
existence, Bohr and Heisenberg assumed that after a measurement is made by an
outside observer, the wave function magically "collapses," and the
electron falls into a definite state—that is, after looking at the tree, we see
that it is truly standing.
In other words, the process of observation determines the final
state
of the electron.
Observation is vital to existence. After we look at the electron,
its wave function collapses, so the electron is now in a definite state and
there is no more need for wave functions.

So the postulates of Bohr's Copenhagen school, loosely
speaking, can be summarized as follows:

a.
     
All energy occurs in discrete packets, called quanta. (The
quantum of light, for example, is the photon. The quanta of the weak force are
called the W- and Z-boson, the quantum for the strong force is called the
gluon, and the quantum for gravity is called the graviton, which has yet to be
seen in the laboratory.)

b.
    
Matter is represented by point particles, but the probability
of finding the particle is given by a wave. The wave, in turn, obeys a specific
wave equation (such as Schrodinger's wave equation).

c.
     
Before an observation is made, an object exists in all
possible states simultaneously. To determine which state the object is in, we
have to make an observation, which "collapses" the wave function, and
the object goes into a definite state. The act of observation destroys the
wave function, and the object now assumes a definite reality. The wave
function as served its purpose: it has given us the precise probability of
finding the object in that particular state.

DETERMINISM OR UNCERTAINTY?

The quantum theory
is the most successful physical theory of all time. The highest formulation of
the quantum theory is the Standard Model, which represents the fruit of decades
of experiments with particle accelerators. Parts of this theory have been
tested to 1 part in 10 billion. If one includes the mass of the neutrino, then
the Standard Model is consistent with all experiments on subatomic particles,
without exception.

But no matter
how successful the quantum theory is, experimentally it is based on postulates
that have unleashed storms of philosophical and theological controversy for
the past eighty years. The second postulate, in particular, has raised the ire
of religions because it asks who decides our fate. Throughout the ages,
philosophers, theologians, and scientists have been fascinated by the future
and whether somehow our destinies are knowable. In Shakespeare's
Macbeth,
Banquo, desperate to lift the veil that clouds our destiny,
delivers the memorable lines:

If you can look into the seeds of time