FREE ESSAY ON CHANGE THE GAME

CHANGE THE GAME

COOKING UP A COSMOS
Will our descendants create a universe in a laboratory?
YOU DON'T HAVE TO BE A MASTER CHEF TO MAKE meringue. Simply combine egg whites and sugar
in a large bowl and beat vigorously until the mixture is light and fluffy. Spread in a
pan and put in an oven preheated to 300 degrees F. Bake for 40 to 45 minutes and voile!
Could it be just as easy to make a universe? 
Since the big bang theory implies that the entire observed universe can evolve from a
tiny speck, it's tempting to ask whether a universe can in principle be created in a
laboratory. Given what we know of the laws of physics, would it be possible for an
extraordinarily advanced civilization to create new universes at will? 
The first thing to think about is the list of necessary ingredients. Curiously,
scientific theories continue to offer an enormous range of answers to the question of
what the universe was made from. One of the most dramatic differences between the
standard big bang theory (without inflation) and the inflationary universe theory is the
answer that each gives to this fundamental question. 
If the recipe for the standard big bang universe were written in a Cosmic Cookbook, how
would it read? To begin the universe at an age of one second, the ingredient list would
include 10[sup 89] photons, 10[sup 89] electrons, 10[sup 89] positrons, 10[sup 89]
neutrinos, 10[sup 89] antineutrinos, 10[sup 79] protons, and 10[sup 79] neutrons. The
ingredients should be stirred vigorously to produce a uniform batter, which should then
be heated to a temperature of 10[sup 10] kelvins. After heating, the total mass/energy of
the mix would be about 10[sup 65] grams, or 10[sup 32] solar masses. This number, by the
way, is about 10 billion times larger than the total mass in the visible universe today.
So, to produce a universe by the standard big-bang description, one must start with the
energy of 10 billion universes! Since a chefs first task is to assemble the ingredients,
this recipe looks formidable enough to discourage anybody. 
The Cosmic Cookbook entry for an inflationary universe, on the other hand, looks as
simple as meringue. In this case, the natural starting time would be the onset of
inflation -- just a fraction of a second after the Big Bang. In contrast to the standard
big bang recipe, the inflationary version calls for only a single ingredient: a region of
false vacuum (see The False Vacuum, page 56). And the region need not be very large. A
patch of false vacuum 10-26 centimeter across might be all the recipe demands. While the
mass required for the previous recipe was 1032 solar masses, the mass in this case is
only an ounce: about the mass of a slice of bread. So, in the inflationary theory the
universe evolves from essentially nothing at all, which is why I frequently refer to it
as the ultimate free lunch. 
Does this mean that the laws of physics truly enable us to create a new universe at will?
If we tried to carry out this recipe, unfortunately, we would immediately encounter an
annoying snag: Because a sphere of false vacuum 10[sup -26] centimeter across has a mass
of one ounce, its density is a phenomenal 10[sup 80] grams per cubic centimeter. For
comparison, the density of water is 1 gram per cubic centimeter, and even the density of
an atomic nucleus is only 10[sup 15] grams per cubic centimeter. If the mass of the
entire observed universe were compressed to false-vacuum density, it would fit in a
volume smaller than an atom. 
The mass density of a false vacuum is not only beyond the range of present technology, it
is beyond the range of any conceivable technology. As a practical matter, therefore, I
would not recommend buying stock in a company that intends to market do-it-yourself
universe kits. Nevertheless, I will dismiss the gargantuan mass density of the false
vacuum as a mere engineering problem, boldly assuming that some civilization in the
distant, unforeseeable future will be capable of creating such densities. Is it possible,
given what we know of the laws of physics, that someday our descendants might produce new
universes by slicing pieces of false vacuum? On the darker side, does the physics of the
false vacuum create the possibility of an ultimate doomsday machine? Is our universe
imperiled by the threat that a super-advanced civilization in some remote galaxy might
create a cancerous patch of false vacuum that would engulf us all? 
The first step in trying to fabricate a laboratory universe is to create a patch of false
vacuum. How exactly this can be achieved depends on the details of physics at extremely
high levels of energy (more than a trillion times higher than modern particle
accelerators), which at present we have no way of knowing. This part of the problem,
therefore, will be left for our descendants to solve. At present, we can say that our
current theories offer several possibilities. In many theories, the desired false vacuum
can be created by heating a region of space to enormous temperatures (perhaps 10[sup 29]
kelvins), and then rapidly cooling it. The region would then supercool into the false
vacuum, exactly as we imagine that the early universe may have done. 
Once a patch of false vacuum is created, its evolution does not depend on how it was
created. The false vacuum is characterized by having a huge energy density and a huge but
negative pressure. Through the equations of general relativity, these properties alone
determine how space-time is distorted by a region of false vacuum. 
Because the false vacuum creates a strong gravitational repulsion, we expect that the
region of false vacuum will grow. However, if the false vacuum bubble wall is to move
outward, there must be a force pushing it that way. The pressure outside the bubble is
zero, and the pressure inside is negative. The pressure is therefore higher outside than
inside, so the pressure difference will push inward on the bubble wall. 
One might guess that the gravitational repulsion of the false vacuum would push outward
on the bubble wall, so if this repulsion were strong enough, the bubble would start to
grow. Not so, however, say the equations of general relativity. The gravitational
repulsion causes the false vacuum to swell, but the repulsion does not extend beyond the
false vacuum. Objects outside the bubble wall are attracted toward the bubble, and the
gravitational force on the bubble wall is inward. 
Because both pressure and gravity pull inward on the bubble wall, a bubble that is
started from rest will start to contract. With nothing to halt the contraction, it will
collapse to a black hole. While a black hole is interesting, it would certainly be viewed
as a disappointment by our would-be universe creator. 
Suppose, however, that the bubble was not started from rest, but instead was given an
outward push. If the initial outward velocity is large enough, then the bubble will
follow the sequence shown in the figure on the facing page. As the bubble grows, the
indentation will become deeper, as shown at the top. The indentation will continue to
deepen, developing a neck, or wormhole, as shown in the middle. Once the wormhole
develops, a dramatic change takes place -- the bubble has turned inside out. Now the
region of false vacuum can grow larger and larger without encroaching on the original
space. It creates new space as it expands, resembling an inflating balloon. The climax of
the evolution is shown at the bottom: The region of false vacuum, with a region of true
vacuum attached, disconnects from the parent space, forming a new, completely isolated
closed universe. It will then continue to enlarge, going through the usual evolution of
an inflationary universe. A new universe has been created, and the parent universe is
unharmed -- universe creation is not a doomsday machine. From the point of view of the
parent universe, the umbilical cord of the child universe is indistinguishable from a
black hole. The umbilical connection in the child universe would similarly look like a
black hole. 
If we assume that the false vacuum driving the inflation has a mass density of about
10[sup 80] grams per cubic centimeter, then the time that it takes the child universe to
disconnect is roughly 10[sup -37] second. After this time there will be no contact
between the parent universe and child. A false-vacuum-bubble universe creator would watch
helplessly as his new universe slipped inexorably through the wormhole and severed all
contact. Once the new universe has separated, the black hole that remains in the parent
universe would evaporate. It would disappear in roughly 10[sup -23] second, releasing the
energy equivalent of a 500-kiloton nuclear explosion. While the parent universe would be
in no danger of annihilation, the safety of the experimenters would require precautions
similar to those used in hydrogen bomb tests. 
The story of inflationary universe creation sounds complete at this point, but there is
an important and surprising twist: It is not clear whether it is possible, even in
principle, to attain the expansion velocity needed for the false vacuum bubble to evolve
into a new universe. 
One hope for evading this problem involves a peculiar consequence of quantum theory, the
process of quantum tunneling. A quantum system can make a discontinuous transition from
one configuration to another, even when the system would not normally have enough energy
to exist in the intermediate configurations. This quantum leap is the origin of a
frequently used metaphor (and a successful American television series), and it also plays
a crucial role in the decay of the false vacuum. 
But calculations show that each time a false vacuum bubble is set into expansion, the
probability that it will tunnel to become a new universe is extraordinarily small. To
write out the number in decimal notation would require a decimal point, followed by
approximately 10[sup 13] zeros, followed by a one. So even if some super-advanced
civilization develops the capacity to produce and manipulate regions of false vacuum,
they would still require a fantastic amount of patience to produce a new universe. 
It may be premature, however, for us to bemoan the difficulties that our super-advanced
descendants will face. Calculations show that the probability becomes higher as the mass
density of the false vacuum increases. If there exists a false-vacuum state associated
with the unification of gravity and the other three forces of nature, then the mass
density would be about 10[sup 93] grams per cubic centimeter. For this density, the
answer to our probability calculation would be approximately one -- a new universe would
be created with just about every attempt. 
While advanced civilizations can conceivably create multiple universes, inflation itself
can have the same effect. Most versions of the inflationary universe theory imply that
the false vacuum does not decay all at once, but instead decays a fragment at a time.
Each fragment produces a universe, while the bulk of the false vacuum continues eternally
to double and redouble in size. Each doubling in size might occur in as little as 10[sup
-37] second. Because the time needed for the development of a super-advanced civilization
is measured in billions of years or more, there appears to be no chance that laboratory
production of universes could compete with the natural process of eternal inflation. 
On the other hand, a child universe created in a laboratory by a super-advanced
civilization would set into motion its own progression of eternal inflation. Could the
super-advanced civilization find a way to enhance its efficiency? We may have to wait a
few billion years to find out. 
THE FALSE VACUUM
The false vacuum is a peculiar form of matter predicted to exist by modern theories of
elementary particles. If inflationary cosmology is correct, it was the driving force
behind the Big Bang. The false vacuum has an extraordinarily high density, perhaps 10[sup
80] grams per cubic centimeter, and also a pressure that is extraordinarily large, but
negative -- it acts like a suction. The huge negative pressure turns gravity on its head,
producing a repulsive gravitational force that can launch a region of false vacuum into
explosive expansion. 
Why does the false vacuum have such a peculiar name? While the word vacuum is often
defined as a state devoid of matter, this definition is not precise enough for
physicists, since it is not clear exactly what matter means. The physicist defines vacuum
as the state with the lowest possible density of energy. The false vacuum is not really a
vacuum, but its energy density can be lowered only by a very slow process, called the
decay of the false vacuum. So, while the false vacuum is waiting to decay, it behaves as
if its energy density cannot be lowered -- as if it were a temporary vacuum.