When clouds build up extra electrons, they need to get rid of the charge somehow. A thunderous blast of lightning often results, but disruption of accelerator operations doesn't require a direct hit. "When lightning strikes, large currents flow through the ground," Johnson said. The Tevatron relies on a high-speed and delicate communication system, and strikes can cause power glitches and scramble the signals of underground cables. "A lot of the signals between Tevatron buildings say 'OK, here's a piece of data you need to keep running'," Johnson said. When significantly interrupted, the beam automatically terminates.

To avoid the threat of brewing storms, run coordinators sometimes call Jim Morgan, a Fermilab engineering physicist known as "the weatherman." "I was a weatherman for five years, so a few guys call me that around here," he said. Morgan feels predicting the weather to exacting detail is a dicey business, but he lends a hand when necessary. "A small number of times per year, having the right knowledge about this kind of thing can help quite a bit," he said.

Johnson says thunderstorms affect the Tevatron in other, far more annoying ways. When lightning strikes, fire alarms in any of the dozens of Tevatron buildings can trip. "I once spent an entire night shift doing nothing but driving to buildings where alarms were set off," he said. Although the Tevatron is sensitive to electrical storms, Johnson feels it is a surprisingly robust system. "But when we see a thunderstorm approaching," Johnson said, "we cross our fingers."
--Dave Mosher

I would consider Thursday quite an honor in the crossword world--it marks the first step into serious crossword territory: it sits respectfully on the cusp between Wednesday, designed for the knowledgeable enthusiast, and Saturday--a puzzle for the seriously intense, almost professional crossword worker. (And who has the time or energy to do Friday anyway?).
--Kelly Daley, University of Chicago

If you would like to submit a letter, write to us at today@fnal.gov.

As they opened separately like accordion window blinds, the solar wings looked like cosmic blankets of gold bars in the reflection of an orbital sunrise.

"Big day for space station. Congratulations," astronaut Pam Melroy in Mission Control radioed Atlantis commander Brent Jett. "We're all extremely happy."

The astronauts had adjusted the space station's position before starting, then halted each deployment midway for about 30 minutes so the solar panels could be heated by the sun to prevent them from sticking together, a problem astronauts have encountered before.

NASA engineers ran into one early glitch with the space station's new Ferris wheel-like rotating joint that allows the solar arrays to move with the sun to maximize the amount of power generated. They were able to fix the software problem, but it put the day's activities several hours behind schedule.
Read More