What is the Higgs Field?

Peter Higgs awaits the July 4, 2012, official announcement that CERN has found evidence consistent with the Higgs boson that he predicted in the 1960's. CERN, copyright 2012

Question: What is the Higgs Field?

Answer: The Higgs field is the theoretical field of energy that permeates the universe, according to the theory put forth in 1964 by Scottish theoretical physicist Peter Higgs. Higgs suggested the field as a possible explanation for how the fundamental particles of the universe came to have mass, because in the 1960s the Standard Model of quantum physics actually couldn't explain the reason for mass itself.

He proposed that this field existed throughout all of space and that particles gained their mass by interacting with it.

Discovery of the Higgs Field

Though there was initially no experimental confirmation for the theory, over time it came to be seen as the only explanation for mass that was widely viewed as consistent with the rest of the Standard Model. As strange as it seemed, the Higgs mechanism (as the Higgs field was sometimes called) was generally accepted widely among physicists, along with the rest of the Standard Model.

One consequence of the theory was that the Higgs field could manifest as a particle, much in the way that other fields in quantum physics manifest as particles. This particle is called the Higgs boson. Detecting the Higgs boson became a major goal of experimental physics, but the problem is that the theory didn't actually predict the mass of the Higgs boson. If you caused particle collisions in a particle accelerator with enough energy, the Higgs boson should manifest ...

but without knowing the mass that they were looking for, physicists weren't sure how much energy would need to go into the collisions.

One of the driving hopes was that the Large Hadron Collider (LHC) would have sufficient energy to generate Higgs bosons experimentally, since it was more powerful than any other particle accelerators that had been built before.

On July 4, 2012, physicists from the LHC announced that they found experimental results consistent with the Higgs boson, though further observations are needed to confirm this and to determine the various physical properties of the Higgs boson. The evidence in support of this has grown, to the extent that the 2013 Nobel Prize in Physics was awarded to Peter Higgs and Francois Englert. As physicists determine the properties of the Higgs boson, it will help them more fully understand the physical properties of the Higgs field itself.

Brian Greene on the Higgs Field

One of the best explanations of the Higgs field that I've run across is this one from Brian Greene, presented on the July 9 episode of PBS' Charlie Rose show, when he appeared on the program with experimental physicist Michael Tufts to discuss the announced discovery of the Higgs boson:

Mass is the resistance an object offers to having its speed changed. You take a baseball. When you throw it, your arm feels resistance. A shotput, you feel that resistance. The same way for particles. Where does the resistance come from? And the theory was put forward that perhaps space was filled with an invisible "stuff," an invisible molasses-like "stuff," and when the particles try to move through the molasses, they feel a resistance, a stickiness. It's that stickiness which is where their mass comes from.... That creates the mass....

... it's an elusive invisible stuff. You don't see it. You have to find some way to access it. And the proposal, which now seems to bear fruit, is if you slam protons together, other particles, at very, very high speeds, which is what happens at the Large Hadron Collider... you slam the particles together at very high speeds, you can sometimes jiggle the molasses and sometimes flick out a little speck of the molasses, which would be a Higgs particle. So people have looked for that little speck of a particle and now it looks like it's been found.

The Future of the Higgs Field

If the results from the LHC pan out, then as we determine the nature of the Higgs field, we'll get a more complete picture of how quantum physics manifests in our universe. Specifically, we'll gain a better understanding of mass, which may in turn give us a better understanding of gravity. Currently, the Standard Model of quantum physics does not account for gravity (though it fully explains the other fundamental forces of physics). This experimental guidance may help theoretical physicists hone in on a theory of quantum gravity that applies to our universe.

It may even help physicists understand the mysterious matter in our universe, called dark matter, that cannot be observed except through gravitational influence. Or, potentially, a greater understanding of the Higgs field may provide some insights into the repulsive gravity demonstrated by the dark energy that seems to permeate our observable universe.