Parallel Worlds (53 page)

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Authors: Michio Kaku

Tags: #Mathematics, #Science, #Superstring theories, #Universe, #Supergravity, #gravity, #Cosmology, #Big bang theory, #Astrophysics & Space Science, #Quantum Theory, #Astronomy, #Physics

BOOK: Parallel Worlds
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But at the other
extreme, we have the anthropic principle, which makes us realize that a
miraculous set of "accidents" makes consciousness possible in this
three-dimensional universe of ours. There is a ridiculously narrow band of
parameters that makes intelligent life a reality, and we happen to thrive in
this band. The stability of the proton, the size of the stars, the existence of
higher elements, and so on, all seem to be finely tuned to allow for complex
forms of life and consciousness. One can debate whether this fortuitous circumstance
is one of design or accident, but no one can dispute the intricate tuning
necessary to make us possible.

Stephen Hawking
remarks, "If the rate of expansion one second after the big bang had been
smaller by even one part in a hundred thousand million, [the universe] would
have recollapsed before it reached its present size . . . The odds against a
universe like ours emerging out of something like the big bang are enormous. I
think there are clearly religious implications."

We often fail to
appreciate how precious life and consciousness really are. We forget that
something as simple as liquid water is one of the most precious substances in
the universe, that only Earth (and perhaps Europa, a moon of Jupiter) has
liquid water in any quantity in the solar system, perhaps even in this sector
of the galaxy. It is also likely that the human brain is the most complex
object nature has created in the solar system, perhaps out to the nearest star.
When we view the vivid pictures of the lifeless terrain of Mars or Venus, we
are struck by the fact that those surfaces are totally barren of cities and
lights or even the complex organic chemicals of life. Countless worlds exist in
deep space devoid of life, much less of intelligence. It should make us
appreciate how delicate life is, and what a miracle it is that it flourishes on
Earth.

The Copernican
principle and the anthropic principle are in some sense opposite perspectives
which bracket the extremes of our existence and help us to understand our true
role in the universe. While the Copernican principle forces us to confront the
sheer enormity of the universe, and perhaps the multiverse, the anthropic
principle forces us to realize how rare life and consciousness really are.

But ultimately,
the debate between the Copernican principle and the anthropic principle cannot
determine our role in the universe unless we view this question from an even
larger perspective, from the point of view of the quantum theory.

QUANTUM MEANING

The world of
quantum science sheds much light on the question of our role in the universe,
but from a different point of view. If one subscribes to the Wigner
interpretation of the Schrodinger cat problem, then we necessarily see the
hand of consciousness everywhere. The infinite chain of observers, each one
viewing the previous observer, ultimately leads to a cosmic observer, perhaps
God himself. In this picture, the universe exists because there is a deity to
observe it. And if Wheeler's interpretation is correct, then the entire
universe is dominated by consciousness and information. In this picture, consciousness
is the dominant force that determines the nature of existence.

Wigner's viewpoint, in turn, led Ronnie Knox to pen the
following poem about an encounter between a skeptic and God, pondering if a
tree exists in the courtyard when there is no one there to observe it:

There was once a man who said, "God Must think
it
exceedingly odd If he finds that
this tree Continues to be

When there's no
one about in the Quad."

An
anonymous wag then penned the following reply:

Dear sir, Your astonishment's odd I am always about in the
Quad And that's why the tree Will continue to be,

Since observed
by
Yours
faithfully—God

In other words,
trees exist in the courtyard because a quantum observer is always there to
collapse the wave function—God himself.

Wigner's
interpretation puts the question of consciousness at the very center of the
foundation of physics. He echoes the words of the great astronomer James Jeans,
who once wrote, "Fifty years ago, the universe was generally looked on as
a machine . . . When we pass to extremes of size in either direction—whether to
the cosmos as a whole, or to the inner recesses of the atom—the mechanical interpretation
of Nature fails. We come to entities and phenomena which are in no sense mechanical.
To me they seem less suggestive of mechanical than of mental processes; the
universe seems to be nearer to a great thought than to a great machine."

This
interpretation takes perhaps its most ambitious form in Wheeler's theory of it
from bit. "It is not only that we are adapted to the universe. The
universe is also adapted to us." In other words, in some sense we create
our own reality by making observations. He calls this "Genesis by
observership." Wheeler claims that we live in a "participatory universe."

These same words
are echoed by Nobel laureate biologist George Wald, who wrote, "It would
be a poor thing to be an atom in a universe without physicists. And physicists
are made of atoms. A physicist is the atom's way of knowing about atoms."
Unitarian minister Gary Kowalski summarizes this belief by saying, "The
universe, it could be said, exists to celebrate itself and revel in its own
beauty. And if the human race is one facet of the cosmos growing toward
awareness of itself, our purpose must surely be to preserve and perpetuate our
world as well as to study it, not to despoil or destroy what has taken so long
to produce."

In this line of
reasoning, the universe does have a point:
to
produce sentient creatures like
us who can observe
it so
that it exists.
According to
this perspective, the very existence of the universe depends on its ability to
create intelligent creatures who can observe it and hence collapse its wave
function.

One may take
comfort in the Wigner interpretation of the quantum theory. However, there is
the alternate interpretation, the many-worlds interpretation, which gives us an
entirely different conception of the role of humanity in the universe. In the
many- worlds interpretations, Schrodinger's cat can be both dead and alive
simultaneously, simply because the universe itself has split into two separate
universes.

MEANING IN THE MULTIVERSE

It is easy to
get lost in the infinite multitude of universes in the many-worlds theory. The
moral implications of these parallel quantum universes are explored in a short
story by Larry Niven, "All the Myriad Ways." In the story,
Detective-Lieutenant Gene Trimble investigates a rash of mysterious suicides.
Suddenly, all over town, people with no previous history of mental problems are
jumping off bridges, blowing their brains out, or even committing mass murder.
The mystery deepens when Ambrose Harmon, the billionaire founder of the
Crosstime Corporation, jumps off the thirty-sixth floor of his luxury apartment
after winning five hundred dollars at a poker table. Rich, powerful, and
well-connected, he had everything to live for; his suicide makes no sense. But
Trimble eventually discovers a pattern. Twenty percent of the pilots of the
Crosstime Corporation have committed suicide; indeed, the suicides started a
month after the founding of Crosstime.

Digging deeper,
he finds that Harmon had inherited his vast fortune from his grandparents and
squandered it backing harebrained causes. He might have lost his entire
fortune, but for one gamble that paid off. He had assembled a handful of
physicists, engineers, and philosophers to investigate the possibility of
parallel time tracks. Eventually, they devised a vehicle that could enter a new
time line, and the pilot promptly brought back a new invention from the
Confederate States of America. Crosstime then bankrolled hundreds of missions
to parallel time lines, where they would discover new inventions that could be
brought back and patented. Soon, Crosstime became a billion-dollar corporation,
holding the patents to the most important world-class inventions of our time.
It looked as if Crosstime would be the most successful corporation of its age,
with Harmon in charge.

Each time line,
they found, was different. They found the Catholic Empire, Amerindian America,
Imperial Russia, and scores of dead, radioactive worlds that had ended in
nuclear war. But eventually, they find something deeply disturbing: carbon
copies of themselves, living lives almost identical to their own, but with a
bizarre twist. In these worlds, no matter what they do, anything can happen: no
matter how hard they work, they might realize their most fantastic dreams or
live through their most wrenching nightmare. Whatever they do, in some
universes they are successful and in others they are complete failures. No
matter what they do, there are an infinite number of copies of themselves who
make the opposite decision and reap all possible consequences. Why not become a
bank robber if, in some universe, you will walk away scot-free?

Trimble thinks,
"There was no luck anywhere. Every decision was made both ways. For every
wise choice you bled your heart out over, you made all the other choices too.
And so it went, all through history." Profound despair overwhelms Trimble
as he reaches a soul- wrenching realization: In a universe where everything is
possible, nothing makes any moral sense. He falls victim to despair, realizing
that we ultimately have no control over our fates, that no matter what decision
we make, the outcome does not matter.

Eventually, he
decides to follow Harmon's lead. He pulls out a gun and points it at his head.
But even as he pulls the trigger, there are an infinite number of universes in
which the gun misfires, the bullet hits the ceiling, the bullet kills the
detective, and so on. Trimble's ultimate decision is played out in an infinite
number of ways in an infinite number of universes.

When we imagine
the quantum multiverse, we are faced, as Trimble is in the story, with the
possibility that, although our parallel selves living in different quantum
universes may have precisely the same genetic code, at crucial junctures of
life, our opportunities, our mentors, and our dreams may lead us down different
paths, leading to different life histories and different destinies.

One form of this
dilemma is actually almost upon us. It's only a matter of time, perhaps a few
decades, before the genetic cloning of humans becomes an ordinary fact of life.
Although cloning a human being is extremely difficult (in fact, no one has yet
fully cloned a primate, let alone a human) and the ethical questions are
profoundly disturbing, it is inevitable that at some point it will happen. And
when it does, the question arises: do our clones have a soul? Are
we
responsible for our clone's actions? In a quantum universe,
we would have an infinite number of quantum clones. Since some of our quantum
clones might perform acts of evil, are we then responsible for them? Does our
soul suffer for the transgressions of our quantum clones?

There is a
resolution to this quantum existential crisis. If we glance across the
multiverse of infinite worlds, we may be overwhelmed by the dizzying
randomness of fate, but within each world the commonsense rules of causality
still hold in the main. In the multiverse theory proposed by physicists, each
distinct universe obeys Newtonian-like laws on the macroscopic scale, so we can
live our lives comfortably, knowing that our actions have largely predictable
consequences. Within each universe, the laws of causality, on average, rigidly
apply. In each universe, if we commit a crime, then most likely we will go to
jail. We can conduct our affairs blissfully unaware of all the parallel
realities that coexist with us.

It reminds me of
the apocryphal story that physicists sometimes tell each other. One day, a
physicist from Russia was brought to Las Vegas. He was dazzled by all the
capitalist opulence and debauchery that sin city had to offer. He went
immediately to the gaming tables and placed all his money on the first bet.
When he was told that this was a silly gambling strategy, that his strategy
flew in the face of the laws of mathematics and probability, he replied,
"Yes, all that is true, but in one quantum universe, I shall be rich!"
The Russian physicist may have been correct and in some parallel world may be
enjoying wealth beyond his imagination. But in this particular universe he lost
and left dead broke. And he must suffer the consequences.

WHAT PHYSICISTS THINK ABOUT THE MEANING OF
THE UNIVERSE

The debate on
the meaning of life was stirred even more by Steven Weinberg's provocative
statements in his book
The First Three
Minutes.
He writes, "The more the universe seems comprehensible,
the more it also seems pointless . . . The effort to understand the universe is
one of the very few things that lifts human life a little above the level of
farce, and gives it some of the grace of tragedy." Weinberg has confessed
that of all the sentences he has written, this one elicited the most heated
response. He later created another controversy with his comment, "With or
without religion, good people can behave well and bad people can do evil; but
for good people to do evil—that takes religion."

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