The theory called "particle physics" says the universe is a vacuum full of particles, including protons and electrons. The big mystery is why the particles have mass. The search for the so-called "God Particle" has led to "the biggest manhunt in the history of physics," with two competing groups composed of thousands of scientists each. They've been sifting data from the Large Hadron Collider, near Geneva. This morning, thousands of other scientists around the world were waiting for word of what they've been able to find, according to Dennis Overbye, who writes about science for the New York Times.