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HOW TO BUILD A UNIVERSE

NO MATTER HOW hard you try you will never be able to grasp just how
tiny, how spatially unassuming, is a proton. It is just way too
small.

A proton is an infinitesimal part of an atom, which is itself of
course an insubstantial thing. Protons are so small that a little
dib of ink like the dot on this i can hold something in the region
of 500,000,000,000 of them, rather more than the number of seconds
contained in half a million years. So protons are exceedingly
microscopic, to say the very least.

Now imagine if you can (and of course you can't) shrinking one of
those protons down to a billionth of its normal size into a space
so small that it would make a proton look enormous. Now pack into
that tiny, tiny space about an ounce of matter. Excellent. You are
ready to start a universe.

I'm assuming of course that you wish to build an inflationary
universe. If you'd prefer instead to build a more old-fashioned,
standard Big Bang universe, you'll need additional materials. In
fact, you will need to gather up everything there is--every last
mote and particle of matter between here and the edge of
creation--and squeeze it into a spot so infinitesimally compact
that it has no dimensions at all. It is known as a
singularity.

In either case, get ready for a really big bang. Naturally, you
will wish to retire to a safe place to observe the spectacle.
Unfortunately, there is nowhere to retire to because outside the
singularity there is no where. When the universe begins to expand,
it won't be spreading out to fill a larger emptiness. The only
space that exists is the space it creates as it goes.

It is natural but wrong to visualize the singularity as a kind of
pregnant dot hanging in a dark, boundless void. But there is no
space, no darkness. The singularity has no "around" around it.
There is no space for it to occupy, no place for it to be. We can't
even ask how long it has been there--whether it has just lately
popped into being, like a good idea, or whether it has been there
forever, quietly awaiting the right moment. Time doesn't exist.
There is no past for it to emerge from.

And so, from nothing, our universe begins.

In a single blinding pulse, a moment of glory much too swift and
expansive for any form of words, the singularity assumes heavenly
dimensions, space beyond conception. In the first lively second (a
second that many cosmologists will devote careers to shaving into
ever-finer wafers) is produced gravity and the other forces that
govern physics. In less than a minute the universe is a million
billion miles across and growing fast. There is a lot of heat now,
ten billion degrees of it, enough to begin the nuclear reactions
that create the lighter elements--principally hydrogen and helium,
with a dash (about one atom in a hundred million) of lithium. In
three minutes, 98 percent of all the matter there is or will ever
be has been produced. We have a universe. It is a place of the most
wondrous and gratifying possibility, and beautiful, too. And it was
all done in about the time it takes to make a sandwich.

When this moment happened is a matter of some debate. Cosmologists
have long argued over whether the moment of creation was 10 billion
years ago or twice that or something in between. The consensus
seems to be heading for a figure of about 13.7 billion years, but
these things are notoriously difficult to measure, as we shall see
further on. All that can really be said is that at some
indeterminate point in the very distant past, for reasons unknown,
there came the moment known to science as t = 0. We were on our
way.

There is of course a great deal we don't know, and much of what we
think we know we haven't known, or thought we've known, for long.
Even the notion of the Big Bang is quite a recent one. The idea had
been kicking around since the 1920s, when Georges Lem tre, a
Belgian priest-scholar, first tentatively proposed it, but it
didn't really become an active notion in cosmology until the
mid-1960s when two young radio astronomers made an extraordinary
and inadvertent discovery.

Their names were Arno Penzias and Robert Wilson. In 1965, they were
trying to make use of a large communications antenna owned by Bell
Laboratories at Holmdel, New Jersey, but they were troubled by a
persistent background noise--a steady, steamy hiss that made any
experimental work impossible. The noise was unrelenting and
unfocused. It came from every point in the sky, day and night,
through every season. For a year the young astronomers did
everything they could think of to track down and eliminate the
noise. They tested every electrical system. They rebuilt
instruments, checked circuits, wiggled wires, dusted plugs. They
climbed into the dish and placed duct tape over every seam and
rivet. They climbed back into the dish with brooms and scrubbing
brushes and carefully swept it clean of what they referred to in a
later paper as "white dielectric material," or what is known more
commonly as bird shit. Nothing they tried worked.

Unknown to them, just thirty miles away at Princeton University, a
team of scientists led by Robert Dicke was working on how to find
the very thing they were trying so diligently to get rid of. The
Princeton researchers were pursuing an idea that had been suggested
in the 1940s by the Russian-born astrophysicist George Gamow that
if you looked deep enough into space you should find some cosmic
background radiation left over from the Big Bang. Gamow calculated
that by the time it crossed the vastness of the cosmos, the
radiation would reach Earth in the form of microwaves. In a more
recent paper he had even suggested an instrument that might do the
job: the Bell antenna at Holmdel. Unfortunately, neither Penzias
and Wilson, nor any of the Princeton team, had read Gamow's
paper.

The noise that Penzias and Wilson were hearing was, of course, the
noise that Gamow had postulated. They had found the edge of the
universe, or at least the visible part of it, 90 billion trillion
miles away. They were "seeing" the first photons--the most ancient
light in the universe--though time and distance had converted them
to microwaves, just as Gamow had predicted. In his book The
Inflationary Universe, Alan Guth provides an analogy that helps to
put this finding in perspective. If you think of peering into the
depths of the universe as like looking down from the hundredth
floor of the Empire State Building (with the hundredth floor
representing now and street level representing the moment of the
Big Bang), at the time of Wilson and Penzias's discovery the most
distant galaxies anyone had ever detected were on about the
sixtieth floor, and the most distant things--quasars--were on about
the twentieth. Penzias and Wilson's finding pushed our acquaintance
with the visible universe to within half an inch of the
sidewalk.

Still unaware of what caused the noise, Wilson and Penzias phoned
Dicke at Princeton and described their problem to him in the hope
that he might suggest a solution. Dicke realized at once what the
two young men had found. "Well, boys, we've just been scooped," he
told his colleagues as he hung up the phone.

Soon afterward the Astrophysical Journal published two articles:
one by Penzias and Wilson describing their experience with the
hiss, the other by Dicke's team explaining its nature. Although
Penzias and Wilson had not been looking for cosmic background
radiation, didn't know what it was when they had found it, and
hadn't described or interpreted its character in any paper, they
received the 1978 Nobel Prize in physics. The Princeton researchers
got only sympathy. According to Dennis Overbye in Lonely Hearts of
the Cosmos, neither Penzias nor Wilson altogether understood the
significance of what they had found until they read about it in the
New York Times.

Incidentally, disturbance from cosmic background radiation is
something we have all experienced. Tune your television to any
channel it doesn't receive, and about 1 percent of the dancing
static you see is accounted for by this ancient remnant of the Big
Bang. The next time you complain that there is nothing on, remember
that you can always watch the birth of the universe.

Although everyone calls it the Big Bang, many books caution us not
to think of it as an explosion in the conventional sense. It was,
rather, a vast, sudden expansion on a whopping scale. So what
caused it?

One notion is that perhaps the singularity was the relic of an
earlier, collapsed universe--that we're just one of an eternal
cycle of expanding and collapsing universes, like the bladder on an
oxygen machine. Others attribute the Big Bang to what they call "a
false vacuum" or "a scalar field" or "vacuum energy"--some quality
or thing, at any rate, that introduced a measure of instability
into the nothingness that was. It seems impossible that you could
get something from nothing, but the fact that once there was
nothing and now there is a universe is evident proof that you can.
It may be that our universe is merely part of many larger
universes, some in different dimensions, and that Big Bangs are
going on all the time all over the place. Or it may be that space
and time had some other forms altogether before the Big Bang--forms
too alien for us to imagine--and that the Big Bang represents some
sort of transition phase, where the universe went from a form we
can't understand to one we almost can. "These are very close to
religious questions," Dr. Andrei Linde, a cosmologist at Stanford,
told the New York Times in 2001.

The Big Bang theory isn't about the bang itself but about what
happened after the bang. Not long after, mind you. By doing a lot
of math and watching carefully what goes on in particle
accelerators, scientists believe they can look back to 10-43
seconds after the moment of creation, when the universe was still
so small that you would have needed a microscope to find it. We
mustn't swoon over every extraordinary number that comes before us,
but it is perhaps worth latching on to one from time to time just
to be reminded of their ungraspable and amazing breadth. Thus 10-43
is 0.0000000000000000000000000000000000000000001, or one 10 million
trillion trillion trillionths of a second.

Most of what we know, or believe we know, about the early moments
of the universe is thanks to an idea called inflation theory first
propounded in 1979 by a junior particle physicist, then at
Stanford, now at MIT, named Alan Guth. He was thirty-two years old
and, by his own admission, had never done anything much before. He
would probably never have had his great theory except that he
happened to attend a lecture on the Big Bang given by none other
than Robert Dicke. The lecture inspired Guth to take an interest in
cosmology, and in particular in the birth of the universe.

The eventual result was the inflation theory, which holds that a
fraction of a moment after the dawn of creation, the universe
underwent a sudden dramatic expansion. It inflated--in effect ran
away with itself, doubling in size every 10-34 seconds. The whole
episode may have lasted no more than 10-30 seconds--that's one
million million million million millionths of a second--but it
changed the universe from something you could hold in your hand to
something at least 10,000,000,000,000,000,000,000,000 times bigger.
Inflation theory explains the ripples and eddies that make our
universe possible. Without it, there would be no clumps of matter
and thus no stars, just drifting gas and everlasting
darkness.

According to Guth's theory, at one ten-millionth of a trillionth of
a trillionth of a trillionth of a second, gravity emerged. After
another ludicrously brief interval it was joined by
electromagnetism and the strong and weak nuclear forces--the stuff
of physics. These were joined an instant later by swarms of
elementary particles--the stuff of stuff. From nothing at all,
suddenly there were swarms of photons, protons, electrons,
neutrons, and much else--between 1079 and 1089 of each, according
to the standard Big Bang theory.

Such quantities are of course ungraspable. It is enough to know
that in a single cracking instant we were endowed with a universe
that was vast--at least a hundred billion light-years across,
according to the theory, but possibly any size up to infinite--and
perfectly arrayed for the creation of stars, galaxies, and other
complex systems.

What is extraordinary from our point of view is how well it turned
out for us. If the universe had formed just a tiny bit
differently--if gravity were fractionally stronger or weaker, if
the expansion had proceeded just a little more slowly or
swiftly--then there might never have been stable elements to make
you and me and the ground we stand on. Had gravity been a trifle
stronger, the universe itself might have collapsed like a badly
erected tent, without precisely the right values to give it the
right dimensions and density and component parts. Had it been
weaker, however, nothing would have coalesced. The universe would
have remained forever a dull, scattered void.

This is one reason that some experts believe there may have been
many other big bangs, perhaps trillions and trillions of them,
spread through the mighty span of eternity, and that the reason we
exist in this particular one is that this is one we could exist in.
As Edward P. Tryon of Columbia University once put it: "In answer
to the question of why it happened, I offer the modest proposal
that our Universe is simply one of those things which happen from
time to time." To which adds Guth: "Although the creation of a
universe might be very unlikely, Tryon emphasized that no one had
counted the failed attempts."

Martin Rees, Britain's astronomer royal, believes that there are
many universes, possibly an infinite number, each with different
attributes, in different combinations, and that we simply live in
one that combines things in the way that allows us to exist. He
makes an analogy with a very large clothing store: "If there is a
large stock of clothing, you're not surprised to find a suit that
fits. If there are many universes, each governed by a differing set
of numbers, there will be one where there is a particular set of
numbers suitable to life. We are in that one."

Rees maintains that six numbers in particular govern our universe,
and that if any of these values were changed even very slightly
things could not be as they are. For example, for the universe to
exist as it does requires that hydrogen be converted to helium in a
precise but comparatively stately manner--specifically, in a way
that converts seven one-thousandths of its mass to energy. Lower
that value very slightly--from 0.007 percent to 0.006 percent,
say--and no transformation could take place: the universe would
consist of hydrogen and nothing else. Raise the value very
slightly--to 0.008 percent--and bonding would be so wildly prolific
that the hydrogen would long since have been exhausted. In either
case, with the slightest tweaking of the numbers the universe as we
know and need it would not be here.

Excerpted from A SHORT HISTORY OF NEARLY EVERYTHING ©
Copyright 2011 by Bill Bryson. Reprinted with permission by
Broadway Books. All rights reserved.