Scientists at CERN, the European nuclear research center, today announced the discovery with "near-certainty" of the Higgs particle (or, more technically, boson). I provided a layperson introduction to the Higgs particle in 2007, for researchers seeking background information on the subject. In short, the Higgs provides a mechanism for all other types of particles to have different masses.
Further, more massive objects have stronger gravitational pull than less massive ones, thus allowing objects with larger mass to attract surrounding matter more strongly than could smaller objects and produce a physically differentiated universe. As noted in this tutorial document, "The gravitational force between the Earth and the molecules of gas in
the atmosphere is strong enough to hold the atmosphere close to our
surface. Smaller planets, that have less mass, may not be able to hold
an atmosphere."
Hence, according to a Reuters article announcing today's discovery, "The Higgs theory explains how particles clumped
together to form stars, planets and life itself. Without the Higgs
boson, the universe would have remained a formless soup of particles
shooting around at the speed of light, the theory goes."
Physicists apparently still differ, to some degree, on the interpretation of today's discovery, some pronouncing the newly announced particle definitely a Higgs boson, but others characterizing the new particle as being "consistent with the Higgs boson" and requiring further testing.
The human-interest element of today's discovery is also compelling. The Reuters article provided the reaction of 83-year-old Peter Higgs, who theorized the existence of the mass-giving particle nearly a half-century ago:
"It is very satisfying," Higgs told Reuters. "For me personally it's just the confirmation of something I did 48 years ago," he said of the achievement of the thousands who labored on the practical experimental work which had, finally, confirmed what he and others had described with mathematics.
"I had no expectation that I would still be alive when it happened," he said of the speed with which they found evidence.