Long before we feared the Large Hadron Collider would kill us all, the US boasted the world’s leading particle collider—and now, after 25 years, Fermilab’s Tevatron is being shut down. The machine’s biggest achievement was the discovery of the top quark, a subatomic particle that was the last-discovered “building block of matter,” the Washington Post notes. The Tevatron found three of 17 particles considered to be the fabric of the universe.
Tevatron technology was key to the development of MRI machines—and the Large Hadron Collider. “There’s no way the LHC exists without the Tevatron,” says a physicist. So why shut it down? The LHC is now the most powerful machine of its kind, and the Tevatron “has discovered what it could discover within its reach,” says another physicist. Not all scientists agree. Either way, however, the closing of the machine this afternoon points to a transition in physics from US soil to European. (Read more physics stories.)