Science from the Sky

If you're American, chances are you'll be looking up this weekend for a spectacle of physics. But you also can look down from above -- way, way above -- to see the homes of some of the greatest physics experiments on Earth.

Brookhaven's Relativistic Heavy Ion Collider (RHIC) is probably one of the most visible particle accelerators from space.

Check out this satellite shot from 1982, when construction was underway for RHIC's predecessor, ISABELLE:

And this more recent aerial shot, taken in May:

RHIC is the first machine in the world capable of colliding heavy ions, which are atoms that have had their outer cloud of electrons removed. RHIC primarily uses ions of gold, one of the heaviest common elements, because its nucleus is densely packed with particles.

The massive machine collides two beams of gold ions head-on when they're traveling at nearly the speed of light (what physicists call relativistic speeds). The beams zip in opposite directions around RHIC's 2.4-mile, two-lane ring. At six intersections, the lanes cross, leading to a collision.

If conditions are right, the collision "melts" the protons and neutrons and, for a brief instant, liberates their constituent quarks and gluons. Just after the collision, thousands more particles form as the area cools off. Each of these particles provides a clue as to what occurred inside the collision zone. Physicists sift through those clues for information about the most fundamental forces and properties of matter and the early universe.

But RHIC isn't the only particle accelerator you can spy from an omnipotent perch; take a look at these other famous atom smashers (thanks to Google Maps).

Of course, many accelerators are kept hundreds of feet underground, and, thus, out of view. But some clever Google Mappers still found a way to mark the position of the world's largest and most powerful collider, the LHC.

Happy 4th!

(Fermilab, SLAC, and LHC map images are Copyright Google)