昂贵的研究：用激光轰击钻石

RENEE MONTAGNE, HOST: Physicists have used the world's most powerful laser to zap diamonds. Even by the standards of advanced science, this sounded like an unusually pricey prospect. So we asked NPR's Geoff Brumfiel to find out exactly what they were doing.

GEOFF BRUMFIEL, BYLINE: Diamonds? Giant lasers? Maybe a little world domination?

(SOUNDBITE OF FILM, "YOU ONLY LIVE TWICE")

DONALD PLEASENCE: (As Blofeld) James Bond, allow me to introduce myself.

BRUMFIEL: Yeah, that's what I thought too, until I met the real scientist behind this experiment.

RAYMOND SMITH: My name is Raymond Smith. I guess most people call me Ray.

BRUMFIEL: Not the world domination type. Smith is a physicist at Lawrence Livermore National Laboratory in California. When he looks at diamonds, he sees a scientific marvel.

SMITH: Well, you know, diamond has very special properties besides being expensive and used for jewelry, etcetera. It's the hardest substance known to man.

BRUMFIEL: And diamonds aren't just here on earth. Diamonds are made of carbon, and carbon is one of the most abundant elements in the universe.

SMITH: Potentially, there's a lot of diamonds elsewhere on other planets.

BRUMFIEL: Including the eighth planet in our solar system, Neptune.

SMITH: Yes, there's a study suggesting that Neptune has a diamond core.

BRUMFIEL: At least that's the theory. But the pressure at Neptune's center is enormous. Researchers weren't sure what that would do to a diamond core.

SMITH: Before these experiments, scientists just did not have the capabilities at hand to generate these high pressures.

BRUMFIEL: Livermore Lab has the world's most powerful laser. They let Smith use it to squeeze a tiny diamond target. He and his collaborators got up to 50 million atmospheres of pressure. That's about 10 times the density of Earth's core. As he reports in the journal Nature, they found that diamond can withstand these pressures. So what expensive thing can Smith target next? Champagne? Caviar?

SMITH: That would be interesting, yeah. We could compress caviar at the very high pressure, but probably the practical and planetary applications would be limited.

BRUMFIEL: Smith says boring, old iron is next. It is, after all, what's at the core of the earth. Geoff Brumfiel, NPR News.