Big Bang – Echoes in Space
Music; Ambience: timelapse sounds of creation of universe, from Big Bang forward 500,000 years
JM: Billions of years ago, an explosive flash of light marked the creation of the universe. The residual energy of this event permeates the universe even today – and it tells us that the young universe was filled with sound. I ‘m Jim Metzner, and this is the Pulse of the Planet.
MW: “Although the flash was brilliant light, that light has traveled to us across the universe, which is expanding. Those waves have been stretched by a large amount, by a factor of 1,000. So the light waves have been stretched, and they become microwaves.”
JM: Mark Whittle is a Professor of Astronomy at the University of Virginia. He tells us that since this pervasive microwave radiation was first detected 40 years ago, scientists have been able to observe it in great detail
MW: “And what was seen were patches, very slight patches, slightly brighter, slightly dimmer. What that is, it transpires, it’s like looking down on the ocean’s surface. You’re actually seeing the peaks and troughs of waves. And so, the microwave background is showing us an image of sound waves, peaks and troughs.”
JM: But sound waves in space?
MW: “What the microwaves telescopes see is gas which is glowing. It’s glowing because it’s hot. And where the gas is perhaps a little denser it glows a little brighter, and where the gas is a little less dense, it glows with not quite so much brilliance. If you imagine for a moment this gas has sound waves in it, these are pressure waves. These are regions where gas bunches up and is a little denser and regions where gas is spreading apart, a little less dense. And so, when you’re looking at this with the telescope, you’re seeing the fact that the gas contains within it these pulsing sound waves moving.”
JM: We’ve been listening to a timelapse version of those sound waves. We’ll hear more about that in future programs. Pulse of the Planet is made possible by the National Science Foundation.