Peter Higgs, the theoretical physicist and Nobel Laureate, who died April 8, 2024, was known for predicting the existence of a very special, fundamental element of the known universe: The God Particle. Or "Higgs boson." 

In 2013, Higgs and Francois Englert won the Physcis Nobel Prize for their work on the particle which was thought to be a key to explaining the universe.

"After graduating from King's College London in 1950, Peter was interested in doing a PhD in elementary particle physics," recalled Sir David Wallace, who did his own PhD under Higgs in Edinburgh in the 1960s. "But Peter was advised against it by the theoretical chemist Charles Coulson. Coulson told him it was very difficult to make any impact in that area." 

Higgs started his own PhD under Coulson and was later supervised by Christopher Longuet-Higgins. And, luckily, this route led him to eventually make an incredible impact. And as Wallace said at the time, Higgs managed to remain modest about it all

"He didn't self-promote," Wallace wrote in an email to DW. "He was probably one of the last people in the physics community to refer to his predicted particle as 'the Higgs boson.'"   

A 'capstone' boson

You got the sense Higgs knew he's been lucky, too.

Other theoretical physicists, such as German-born Nobel Laureate, Albert Einstein, were not so lucky.

Einstein's theories of relativity gave us ideas about the warping of spacetime, black holes and gravitational waves. But he died long before those fundamental propositions about the universe could be proved or disproved.

But Higgs lived to see his theory proved.

The Higgs boson — or God Particle — is described as an elementary particle in the Standard Model of particle physics. 

"Its discovery was the 'capstone' for the standard model of particle physics," wrote Sir Martin Rees, British astrophysicist and Astronomer Royal, to DW.

The Standard Model describes some of the basic forces that hold the universe together. In that sense, it is anything but basic. It is quite fundamental.

And, alas, a little too complicated to explain here.

What's 50 years in science?

It was in the 1960s that Higgs, and his colleagues Robert Brout and François Englert first started work on a theory known as the Brout-Englert-Higgs mechanism, and later the "Higgs field." Out of that came the Higgs boson. 

They wanted to explain why some particles have mass and why others do not — and for those that do, how they get their mass. It's complicated. Physics can be a real rabbit warren of ideas when you get started.

 

So, we'll focus on only one aspect of the problem for the purpose of this piece: It took decades for scientists to observe the Higgs boson in an experiment. 

It was dubbed the "elusive" particle.

Until one day when, long after Higgs' retirement from active teaching in 1996, scientists at CERN shouted "Oh, my God, it's the God Particle!" 

Or words to that effect. 

"The fact it took nearly 50 years has a lesson for the future," said Rees. "Even if current speculative ideas about dark matter, strings, etcetera, are correct, it may be many decades before experiments and instrumentalists have the capability to test those ideas."

When physicists and their ideas collide

There's no doubting that the entire scientific community felt the excitement at CERN when its then-Director General, Professor Rolf-Dieter Heuer, revealed that they had detected a new particle "consistent" with a Higgs boson.

Having waited so many years, it was understandable that they were cautious until they confirmed its existence, which they did in 2013.

"It was undoubtedly one of the highlights of my career, and it was fantastic that we had Peter Higgs and François Englert with us that day," Heuer told DW when Higgs turned 90 years.

Carl Hagan and Gerry Guralnik were also there. Hagan and Guralnik, along with Tom Kibble, had reached similar conclusions to Brout, Englert and Higgs in the 1960s. So that was a coming together of its own kind.

But back to July 4, 2012.

"It was a day full of emotion," said Heuer. "Who can forget the image of Peter wiping a tear from his eye and declaring that he felt privileged to have lived to see the day?"

It was what Higgs said next, however, that was a true indicator of the kind of person Higgs was, said Heuer.

"When pressed by the media, he declined to comment, saying that this was a day to celebrate the experiments rather than the theory."

But he did accept his Nobel Prize in 2013. Higgs shared the Prize in Physics with Englert. Robert Brout had died a year before the Higgs boson discovery was revealed.

This article was originally published August 10, 2013, and updated April 10, 2024.