SSS 2008-04-22

（单词翻译）

This is Scientific American's 60-Second Science, I'm Cynthia Graber. This will just take a minute.

Ben Franklin started it and it's hotter than ever: research on lightning. For the first time, a team of European scientists have used lasers to create electrical activity in thunderclouds. They published in Optics Express. Man-made lightning strikes help with a variety of research efforts including uncovering the mechanisms¹ of  lightning and finding the sensitivity of airplanes and power lines. Current methods of creating lightning are expensive and only work about half the time. Lasers could provide a more reliable and cost-effective method. Working atop a New Mexico mountain, scientists shot pulsed lasers into passing thunderclouds. This technique had been suggested 30 years ago. But lasers then weren't stronger enough to trigger any response. The new generation of lasers create plasma² filaments³, or ionized channels of molecules⁴ that act like wires. Researchers tested the electrical activity at the sites where they'd aimed the lasers, and they found that there was in fact an electrical discharge. But the channels didn't last long enough to bring a lightening strike to earth. So the team is now working to build stronger and more targeted laser bursts to create homemade lightning.

Thanks for the minute, for Scientific American's 60-Second Science, I'm Cynthia Graber.