## Elementary Particles

Why do humans do science? Why do they do arts? The things that are least important for our survival are the very things that make us human.

— Savas Dimopoulos, in Particle Fever

On July 4th 2012, a catchy headline in New York Times captured the imagination of the world: “Physicists Find Elusive Particle Seen as Key to Universe”. The article described an event—the discovery of the Higgs boson, often known by its nickname: the “God particle.” Washington Post described the July 4 discovery as one which “marked a new chapter in scientific knowledge also reignited debate over the universe’s origins — and the validity of religious faith as scientific knowledge expands.”

Rarely does a scientific discovery cause such an uproar. In Geneva, the auditorium at the European Organization of Nuclear Research (CERN) was packed with people—many even stood in line all night to get into the auditorium to witness the announcement of the discovery of the Higgs. The atmosphere had a rock-concert ambience. The spokespersons of the two big experiments, ATLAS and CMS, who announced the discovery, were repeatedly interrupted during their presentations by applause as they showed their slides of data. The Higgs boson manifested as unmistakable bumps rising like mountains from the sea of data. It was a triumphant moment for science.

The story began nearly 50 years ago, in the 1960s, when a group of six theoretical physicists came up with a theory that later led to the discovery of the Higgs boson. Peter Higgs, for whom the particle is named after, and the other surviving founders of the theory entered the auditorium on the announcement day to a huge ovation. And all the excitement for minuscule subatomic particle! The discovery came with a very hefty price tag though. The search for the Higgs boson led to the construction of the Large Hadron Collider (LHC) at CERN, the world’s biggest machine. LHC is a particle accelerator that needed \$9 billion to build.

Experiments like this have been done in the past, but not to this scale. The basic idea is to accelerate streams of protons to nearly the speed of light, and crash them into each other. According to Einstein’s famous formula, $E=mc^2$ , i.e., energy equals mass multiplied by the square of the speed of light, the enormous energy of the collision will create new forms of matter in the form of particles that no one has actually seen before. The Higgs boson is expected to be one of them.

Interestingly, the Higgs could have been discovered about a decade ago in the United States rather than in Europe. In the 1980s, American physicists were developing the concept of a particle accelerator, the Superconducting Super Collider (SSC), which was designed to be three times as powerful as the LHC. But Congress eventually cut the funding for the ambitious project, deeming it a waste of money as the potential discoveries were not going to produce anything of immediate practical importance. In other words, the money could be better spent elsewhere.

The demise of the Super Collider was not just because of its price tag, but because of a nagging suspicion that scientific research is sometimes a wild goose chase. Sometimes science seems too mind-bending to follow, too esoteric for public consumption, particularly particle physics. This poses a question which physicists often have to face: what is the financial gain or economic return of running an experiment like this? How is the astronomical cost justified?

These are fair questions and deserve authentic answers.

Physicist and Noble Prize winner Steven Weinberg in his essay, The Crisis of Big Science, writes:

What really motivates elementary particle physicists is a sense of how the world is ordered—it is, they believe, a world governed by simple universal principles that we are capable of discovering. But not everyone feels the importance of this.

Consider the LHC: It is often hard for physicists to explain why we build such huge machines to find such miniscule particles. The purpose of the machine is neither for any military application nor for any commercial purpose. The idea is to help scientists understand something about the basic laws of physics.

Mark Levinson’s celebrated documentary film, Particle Fever, shows a scene where physicist David Kaplan brilliantly explains this in front of a packed audience in a forum at the Aspen Institute of Physics:

When the radio waves were discovered, they weren’t called radio waves, because there were no radios. They were discovered as some sort of radiation. Basic science for big breakthroughs needs to occur at a level where you’re not asking “What is the economic gain?” You are asking “What do we not know, and where can we make progress?” So what is the LHC good for? Could be nothing other than just understanding everything.

There are numerous such examples. The World Wide Web (WWW) was originally conceived by Sir Tim Berners-Lee in 1989 at CERN to automatically share information between scientists in various universities and institutes around the world. Today it is effortlessly used by hundreds of millions of people around the world. Similarly, electricity is the quintessence of everything from computers to phones to microwaves. Sir J.J. Thomson initially thought his “corpuscles” (later identified as electrons) were much too small to be of interest to anyone outside a science lab. But it was quickly realized that electric current was in fact made of moving electrons. The rest is history.

There are many similar examples in every branch of science. Basic discoveries are hardly made with profitability in mind. The benefits, if at all, are often gained much later. So, why do we humans do scientific research? Simply stated, we do it to understand how the universe works, to know the unknown, to document our awareness for the benefit of the future generations—no different than the way ancient cave dwellers created the magnificent cave paintings of the wild animals they saw every day, between 30,000 and 33,000 years ago in present day France. Our prehistoric ancestors most definitely did not have to think about commercial success—their actions were driven by ritualistic traditions, but their art-form transcended thousands of years to inspire us even today.

 Figure 1-1: THE CAVE PAINTINGS OF CHAUVET REPRESENT A PRACTICE THAT EXISTED FOR AN EXTREMELY LONG PERIOD OF TIME, BUT IT IS AN ART-FORM THAT CAN NEVER BE RECREATED. Credit: Wikimedia Commons. Figure 1-2: PANEL OF THE LIONS FROM THE CHAUVET CAVE. Credit: BRADSHAW FOUNDATION.
Nobel Laureate Jerome Friedman has this to say about human innovations:

The development of humankind has been strongly linked to the innovations arising from human creativity, from the earliest crude tools to the modern technological society of today. In the modern era, science and technology have provided innovations that have enhanced our standard of living, improved our health and driven the economies of nations.