Science Interviews

Science Update - Planets

Bob - Hey, Naked Scientists! We were inspired by your last show to talk about planets this week. I’m going to tell you how scientists are using diamonds and lasers to simulate the intense pressures inside large planets. But first, Chelsea has this for us from the Acoustical Society of America meeting that just finished up in Salt Lake City, Utah.

Chelsea - Do you recognize this, Bob? [music]

Bob - Sure. It’s the opening riff from Smoke on the Water.

Chelsea - Yeah. And haven’t you wondered what it would sound like on Mars?

Bob - Yeah. In fact I wonder that on a daily basis.

Chelsea - Well, you have something in common with physicist Andi Petculescu of the University of Louisiana-Lafayette.

Andi Petculescu (University of Louisiana-Lafayette): It’s one of my all-time favorite songs.

Chelsea - He’s come up with a new way of simulating sound on different planetary bodies. Here’s Venus:

[Smoke on the Water riff on Venus]

Chelsea - It’s chock-full of carbon dioxide, which steals energy from the riff’s high-frequency tones. Here’s Saturn’s moon Titan:

[Smoke on the Water riff on Titan]

Chelsea - Titan’s atmosphere is a lot like Earth, but it’s colder and under more pressure, so the sound travels farther and the music sounds louder. But what about Mars?

Andi Petculescu: Mars would sound like this. [silence] So basically no sound.

Chelsea - Making it not such a great place for the next inter-planetary rock festival.

Bob - Yeah, I guess not. Thanks, Chelsea. Well, pairing gem-quality diamonds with lasers sounds like fashion design, but it’s actually a new scientific technique for simulating high-pressure environments. Geophysicist Raymond Jeanloz of the University of California-Berkeley says you first compress a small amount of the material you’re studying between two diamonds. Then you send shockwaves through the material using powerful new lasers.

Raymond Jeanloz (University of California-Berkeley):  With these very high-powered lasers, it’s possible to get to very, very high pressures that previously were effectively accessible only next to nuclear explosions.

Bob -   At these high pressures, chemicals behave completely differently; for instance, water becomes metallic. Jeanloz says that outside of labs, these conditions would be found at the cores of supergiant planets beyond our solar system.

Chelsea - Thanks, Bob. Next time, we’ll be back to tell you how television watching and moving in with a partner can affect your weight. Until then, I’m Chelsea Wald...

Bob - ...and I’m Bob Hirshon, for AAAS, The Science Society. Back to you, Naked Scientists!

June 2007