Air Date: Week of November 7, 2003

Host Steve Curwood talks with John Cramer, a physicist at the University of Washington in Seattle. Prof. Cramer put together some NASA data and simulated the sound of the Big Bang.

Transcript

CURWOOD: Some thirteen billion years ago – okay, so maybe it was fourteen billion years ago – a tiny point rapidly expanded to make what became our universe. The Big Bang is how science today believes our universe came to be. A few years ago, John Cramer, a physicist at the University of Washington in Seattle wrote about a project that mapped radiation leftover from the Big Bang. That column got an eleven year old boy wondering what it all sounded like. So Professor Cramer set out to simulate the sounds of the Big Bang. Professor Cramer, how did you go about re-creating a sound that happened billions of years ago?

CRAMER: Well, there’ve been some recent measurements by NASA satellites of radiation that was released about 300,000 years after the Big Bang. And what one finds if you look very closely at this radiation on a small angle scale, is that it has a structure that represents temperature being high or low at certain places in the sky. And the people who measured this characterize it in terms of frequencies, essentially sound frequencies, that were present in the early Big Bang. And I took those and used them in a computer program to make the sound that you hear.

CURWOOD: Let’s give it a listen.

CRAMER: Okay.

[LOW BUZZING, LIKE A QUIET ENGINE]

CURWOOD: What are we actually hearing?

CRAMER: You’re hearing frequency-shifted sound waves from the Big Bang that were measured by a NASA satellite, moved very far up in frequency so that the human ear can hear them. You’re also hearing the sound waves dropping in frequency as the universe expands. And you’re hearing the sound get more intense as the cosmic microwave background becomes stronger and stronger, and then falling off as it becomes weaker and weaker over the first 700,000 years of the universe.

CURWOOD: Now, how possible is it to give us the sound of the actual moment of the Big Bang?

CRAMER: The instant of the Big Bang something rather spectacular was going on, namely a process called inflation where the universe was expanding much, much faster than the speed of light. That stopped, I don’t know, after picoseconds or less, and then the Big Bang proceeded to expand at a much more leisurely pace. We don’t have any data that represents that inflation period, when there must have been something that really sounded more like a bang.

CURWOOD: What’s next on you’re agenda?

CRAMER: Well, this is not what I do for a living. I do relativistic heavy ion physics at RHIC.

CURWOOD: RHIC?

CRAMER: Yeah, the Relativistic Heavy Ion Collider at Brookhaven. And we have some very interesting data coming out of our gold-gold collisions there that seem to have destroyed most of the theories that existed before the machine ran, and we’re trying to understand what’s going on.

CURWOOD: Sounds pretty physical to me.

CRAMER: Yeah, right. We bash gold nuclei together at nearly the speed of light and we make a fireball that looks something like the first microsecond of the Big Bang, so perhaps there’s some connection between this and the sound file.

CURWOOD: John Cramer is a physicist at the University of Washington in Seattle. Thanks for taking this time with me today.

CRAMER: Thank you.

[LOW BUZZING, LIKE A QUIET ENGINE]

 

Links

mp3 | RealAudio)
– Listen to a longer version of this interview - (mp3 | RealAudio)
– John Cramer’s “Analog” column

NASA mission on cosmic background radiation