Where does mass come from?

That time, that place

In 1964 several researchers, Higgs among them, made much the same proposal at much the same time.

A particle has mass not because it is intrinsically heavy. A field pervades the universe, and how strongly a particle interacts with it as it moves determines how heavy it seems. Photons do not interact with it, and so have no mass.

Why this question

If such a field exists, then shaking it should produce a particle — as disturbing water produces a wave.

Find it and the theory holds. Fail and it must be rethought.

For forty-eight years it was not found.

What was found

What was built to find it was an accelerator twenty-seven kilometers around.

Protons are driven to near light speed and collided head-on. Very rarely a Higgs particle forms — and immediately breaks into other particles. So the only route is to collect the fragments and reconstruct backward.

The difficulty is that such fragments arise for many other reasons. So trillions of collisions had to be accumulated until a bump at one particular value stood out too sharply to be chance.

Nearly ten thousand people from a hundred countries took part. At the announcement on 4 July 2012, Higgs, eighty-three, sat in the audience wiping his eyes.