field switched on a trillionth of a second after the big bang blasted the universe into existence. Before this moment, all of the particles in the cosmos weighed nothing at all and zipped around chaotically at the speed of light. When the Higgs field switched on, some particles began to feel a "drag" as they moved around, as though caught in cosmic glue. By clinging to the particles, the field gave them mass, making them move around more slowly. This was a crucial moment in the formation of the universe, because it allowed particles to come together and form all the atoms and molecules around today. But the Higgs field is selective. Particles of light, or photons, move through the Higgs field as if it wasn't there. Because the field does not cling top them, they remain weightless and destined to move around at the speed of light forever. Other particles, like quarks and electrons -- the smallest constituents of atoms -- get caught in the field and gain mass in the process. The field has enormous implications. Without it, the smallest building blocks of matter, from which all else is made, would forever rush around at the speed of light. They would never come together to make stars, planets, or life as we know it. 12.58pm: The Higgs field is often said to give mass to everything. That is wrong. The Higgs field only gives mass to some very simple particles. The field accounts for only one or two