Origins of the Universe - Cosmic Background Radiation: The Pulse of the Planet daily radio program offers free legal online mp3 downloads, exploring the world of sound in nature, culture and science, with audio adventures, world music, extraordinary sound portraits, science diaries, and nature ring-tones; an amazing sonic experience.

Airdate: Sep 15, 2006
Scientist: Dr. John E. Carlstrom

Origins of the Universe - Cosmic Background Radiation

Origins of the Universe - Cosmic Background Radiation
Astronomers are observing cosmic radiation to test theories about the creation of the universe.

Origins of the Universe - Cosmic Background Radiation

Music; Ambience: Cosmic Background Radiation

We're listening to an echo of the creation of the universe. I'm Jim Metzner, and this is the Pulse of the Planet. Approximately seven percent of the hiss that we're hearing is cosmic background radiation - residual energy released from the so-called "Big Bang." It was picked up by an antenna and translated into sound by an amplifier. Professor John Carlstrom is an astronomer at the University of Chicago who studies the origins of the universe.

"We know the universe is expanding, and if you think about what was the universe like a long, long time ago, well it must have been much much denser, the energy was in a much much smaller volume - it was hotter. And if you go back far enough, something like fourteen billion years ago, it was so hot and dense that galaxies, structure, stars - none of that existed. In fact, atoms, hydrogen atoms, if they formed at all from a proton, electron, would very quickly be broken apart by radiation. We know the universe is expanding, and as it expands, it cools. You get to a point where the radiation - it's cooling too, it's wavelengths are stretching out - no longer has enough energy to break up hydrogen, and in fact then no longer interacts much with the universe. Today we see it as microwave radiation. So, we wanted to study what the early universe looked like and this cosmic microwave background gives us a direct view of the universe. Essentially you can take a snapshot of the universe by building instruments to look at that radiation. And why we want to do that is we want to test theories of the origin of the universe. We want to find out what the universe is made out of."

Although the radiation is uniform, and comes from every direction, there are slight fluctuations that recent technology has been able to detect. We'll hear more about that in future programs. Pulse of the Planet is presented by the National Science Foundation. I'm Jim Metzner.