[00:03.38]1998

[00:06.71]They were, by far,

[00:07.93]the largest and most distant objects

[00:10.14]that scientists had ever detected:

[00:12.36]a strip of enormous cosmic clouds

[00:14.67]some 15 billion light-years from earth.

[00:17.40](1)

[00:18.81]it was the farthest that scientists

[00:20.83]had been able to look into the past,

[00:23.26]for what they were seeing were the patterns

[00:25.28]and structures that existed 15 billion years ago.>

[00:29.61]That was just about the moment

[00:31.11]that the universe was born.

[00:33.23]What the researchers found

[00:34.75]was at once both amazing and expected:

[00:37.47]the US National Aeronautics

[00:39.28]and Space Administration's Cosmic Background Explorer satellite

[00:43.33]--Cobe--had discovered landmark evidence

[00:46.26]that the universe did in fact begin with the primeval explosion

[00:50.20]that has become known as the Big Bang

[00:52.59](the theory that the universe originated

[00:54.71]in an explosion from a single mass of energy).

[00:58.04](2)

[01:00.06]was virtually required for the Big Bang,

[01:03.32]first put forward in the 1920s,

[01:05.43]to maintain its reign as the dominant explanation

[01:08.36]of the cosmos.>

[01:09.86]According to the theory,

[01:11.49]the universe burst into being as a submicroscopic,

[01:14.83]unimaginably dense knot of pure energy

[01:18.16]that flew outward in all directions,

[01:20.57]emitting radiation as it went,

[01:22.79]condensing into particles and then into atoms of gas.

[01:26.42]Over billions of years,

[01:28.44]the gas was compressed by gravity into galaxies,

[01:32.17]stars, plants and eventually, even humans.

[01:36.50]Cobe is designed to see just the biggest structures,

[01:40.23]but astronomers would like to see

[01:42.04]much smaller hot spots as well,

[01:44.16]the seeds of local objects like clusters

[01:46.28]and superclusters of galaxies.

[01:49.01]They shouldn't have long to wait.

[01:51.11](3)

[01:53.03]with ground based detectors at the South Pole

[01:55.76]and balloon-borne instruments

[01:57.57]are closing in on such structures,

[01:59.71]and may report their findings soon.>

[02:01.86](4)

[02:04.48]that will be a triumph for yet another scientific idea,

[02:08.20]a refinement of the Big Bang

[02:10.12]called the inflationary universe theory.>

[02:12.84]Inflation says that very early on,

[02:15.37]the universe expanded in size

[02:17.20]by more than a trillion trillion trillion trillionfold

[02:20.58]in much less than a second,

[02:23.17]propelled by a sort of antigravity.

[02:26.11](5)

[02:27.52]cosmic inflation is a scientifically plausible consequence

[02:31.65]of some respected ideas in elementary particle physics,

[02:35.38]and many astrophysicists have been convinced

[02:38.21]for the better part of a decade that it is true.>