Big Bang - Silent Bang?: 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: Jul 04, 2008
Scientist: Dr. (David) Mark Whittle

Big Bang - Silent Bang?

Big Bang - Silent Bang?
The 'Big Bang' was really more of a Big Crescendo!

Transcript:
Big Bang - Silent Bang?

Music; Ambience: Time lapse sounds of expanding universe

JM: Scientists often refer to the creation of the universe as the Big Bang, but perhaps a better title would be the Big Crescendo. I'm Jim Metzner, and this is the Pulse of the Planet.

MW: "There's a paradox here, and that is that despite its title, "the Big Bang", it actually emerged totally silently. "

JM: Mark Whittle is a Professor of Astronomy at the University of Virginia. He tells us that over the past few decades, scientists have been studying cosmic microwave radiation, the residual energy of the Big Bang. A picture made with this radiation revealed enormous sound waves moving through the hot gas of the young universe. From these observations, Whittle simulated the crescendo of the Big Bang.

MW: "It took time for sound to grow. So, one of the things that you hear on these recordings is it's getting louder as time goes by. The reason for this is that what is driving the sound is not somebody's vocal cords. It's actually gravity pulling gas down into areas where there's more matter. The gas drops in, and it bounces out again. It overshoots, and it drops back in again, and it bounces out again. That is the beginning of the oscillation, and, as times goes by, the regions which can participate in this get larger and larger. And so, the pressure wave is a stronger pressure wave, and that means it's a louder sound."

JM: For more information on sound waves from the early years of our universe, please visit our website at pulseplanet.com. Pulse of the Planet is made possible by the National Science Foundation. I'm Jim Metzner.