SCIENTISTS FIND THE "TOP QUARK"

Scientists have confirmed the existence of the so-called "top quark," a basic building block of nature dating from the time of the "big bang" that helped begin the formation of galaxies between 8 billion and 25 billion years ago. Physicists at Energy Department's Fermi National Laboratory near Chicago announced they verified evidence of the missing subatomic particle, without which scientists' theories of time and matter would simply fall apart. "This provides a sense of relief," says TIME senior science writer Michael Lemonick, who notes that the top quark completes a set of six oddly-named particles that account for the atom. But there's more: now scientists are free to chase the elusive "Higgs boson," to "answer the question most of us didn't think needed to be answered -- why all the other particles have any mass at all."