SCIENCE WATCH: How well do you understand the Higgs field!

WEDNESDAY, JULY 18, 2012

The New York Times gives it a try: If you want to punish yourself, watch Robert Wright conduct this discussion of the ballyhooed Higgs boson.

Within the dramatic production described as the press corps, Wright is cast in the role of one of the bright guys. We’ll only suggest that you watch.

The person Wright keeps interrupting is physicist Lawrence Krauss. Krauss knows the physics—but can he explain it?

The New York Times let him try.

We’re going to guess that this isn’t Krauss’ fault. If our puzzlement is well founded, we’re going to blame this on editing.

That said, do you think this passage makes sense? We’ve inserted the bracketed numbers:

KRAUSS (7/10/12): The prediction of the Higgs particle accompanied a remarkable revolution that completely changed our understanding of particle physics in the latter part of the 20th century.

Just 50 years ago, in spite of the great advances of physics in the previous half century, we understood only one of the four fundamental forces of nature—electromagnetism—as a fully consistent quantum theory. In just one subsequent decade, however, not only had three of the four known forces succumbed to our investigations, but a new elegant unity of nature had been uncovered.

It was found that all of the known forces could be described using a single mathematical framework—and that two of the forces, electromagnetism and the weak force (which governs the nuclear reactions that power the sun), were actually different manifestations of a single underlying theory.

How could two such different forces be related? After all, [1] the photon, the particle that conveys electromagnetism, has no mass, while the particles that convey the weak force are very massive—almost 100 times as heavy as the particles that make up atomic nuclei, a fact that explains why the weak force is weak.

What the British physicist Peter Higgs and several others showed is that if there exists an otherwise invisible background field permeating all of space, [2] then the particles that convey some force like electromagnetism can interact with this field and effectively encounter resistance to their motion and slow down, like a swimmer moving through molasses.

As a result, these particles can behave as if they are heavy, as if they have a mass. The physicist Steven Weinberg later applied this idea to a model of the weak and electromagnetic forces previously proposed by Sheldon L. Glashow, and everything fit together.

This idea can be extended to the rest of particles in nature, including the protons and neutrons and electrons that make up the atoms in our bodies. If some particle interacts more strongly with this background field, it ends up acting heavier. If it interacts more weakly, it acts lighter. [3] If it doesn't interact at all, like the photon, it remains massless.

Maybe we’re missing something here. But go ahead—give it a try:

In passage [1], we’re told that the photon is the particle that conveys electromagnetism. We’re told it has no mass.

In passage [2], we’re told that particles that convey some force like electromagnetism (presumably, this would include photons) can interact with that otherwise invisible background field. As a result, these particles behave as if they have mass.

But in passage [3], we are told that the photon doesn’t interact with the background field at all. For that reason, it remains massless.

No attempt is made to explain the difference between having mass and acting as if there is mass. But do photons interact with that background field? The story seems to change, almost like a particle blinking in and out of existence.

This appeared in the weekly Science Times section. We’ve puzzled over it for a week.

Do you think that passage makes sense? If not, we’re going to say that the Times, not Krauss, is at fault.