273
See also: The birth of the universe 168–71 ■ The primeval atom 196–97 ■
Searching for the Big Bang 222–27 ■ Gravitational waves 328–31THE TRIUMPH OF TECHNOLOGY
had time to shine to the opposite
edge of the universe. So if no light,
energy, or matter has ever passed
between the edges of the universe,
this leaves a puzzle as to why space
appears so similar in every direction.The solution
Guth’s theoretical solution to
these problems was to inflate the
early universe using a quantum
effect called a false vacuum, where
positive matter energy was created
as space expanded, equally
balanced by an increase in gravity
(a form of negative energy). In the
fi rst 10–35 seconds after the Big
Bang, space doubled in size 100
times over, going from a billionth
of the size of a subatomic particle
to the size of a marble. This means
that, at the very beginning, the
edges were close enough to mix
and become uniform, thus solving
the horizon problem. During
inflation, space expanded faster
than the speed of light. (The
speed of light is only a speed
limit through space.) The inflationThe recent developments in
cosmology strongly suggest
that the universe may be
the ultimate free lunch.
Alan GuthAlan Guth
Born in New Jersey, Alan
Guth received his doctorate
in 1972 and specialized in
particle physics, pursuing
research into quarks
(elementary particles). By
the late 1970s, he had worked
at MIT, Princeton, Columbia,
Cornell, and Stanford, as he
searched the country for a
long-term academic position.
While at Columbia, Guth
became interested in the
Grand Unified Theory (GUT),
which had been proposed in- He began developing
his inflation theory in 1978
while at Cornell, after hearing
about the problem of the
flatness of the universe,
and shortly afterward, the
problems associated with
GUT. While at Stanford,
he then came across the
horizon problem, and went
on to publish his famous
theory in 1981. He is now
a professor at MIT, where
he helps with the search for
evidence of cosmic inflation.
Key works1997 The Inflationary
Universe: The Quest for a
New Theory of Cosmic Origins
2002 Inflation and the New Era
of High-Precision Cosmologycooled the universe rapidly, thus
solving the GUT problem, and
locked in the uniformity seen today.
Finally, the inflation ended as the
density of the universe evened out
at a value needed for a flat universe.
In 2014, BICEP2, an experiment
at the South Pole, reported ripples
in space consistent with cosmic
inflation. However, the claim was
soon withdrawn. Cosmic inflation
remains unproven, but it is the best
current theory for the Big Bang. ■It is not possible to visualize
warped three-dimensional space,
but if one dimension were removed,
the geometry of space could be
shown as curved (where the internal
angles of a triangle would add to more
than 180°); saddle-shaped (where the
angles would be less than 180°); and
flat (Euclidean), where a triangle with
angles of 180° would be drawn.CurvedSaddle-shaped
Flat