Exploring fundamentals of matter and life in the giant cosmic puzzle

When Indian media was busy deciphering Rahul Gandhi’s scientific-sounding metaphor of “escape velocity”, the world of physics was agog with the news of this year’s Nobel Prize in physics going to the theoretical discovery of a mechanism that explains the origin of fundamental building blocks of all material things in this world. The theoretical assumptions on sub-atomic particle mass were made half a century ago by Peter W Higgs and Francois Englert and were proven only recently through experiments using the world’s largest particle collider called Large Hadron Collider (LHC) at the European Organization for Nuclear Research, known by its popular acronym CERN.

It was a poignant moment in the history of modern physics, despite murmurs about exclusion of other scientists or groups from the coveted recognition. The subject matter of the Nobel given to theorists of the Higgs particle may sound esoteric to most of us, but the fact is that the science behind it is crucial for an understanding of the existence of the physical world and the universe.

As kids most of us have played a game while watching a starlit sky by asking our elders ‘what’s beyond stars, the Milky Way, the Sun, planets’ and so on. What will be there in this universe if there was no earth, no humans, no planets, no moons, no stars? Our elders would have told us ‘there would be darkness, vacuum and perhaps empty space’. What will remain if there was no dark space or vacuum? Our elders had no convincing answers to such mind-boggling questions.

This is where theists enter the scene and tell us that the creation of this Brahmand or the universe is all divine, an act of God. However, scientists tell us that the universe is filled with dark matter which is defined as something which can’t be detected by the light it emits or the light which falls on it. All celestial bodies like stars and galaxies can be detected because of the light they emit or when light falls on them. The existence of dark energy —  which makes up about 70 per cent of the universe and appears to be associated with the vacuum in space — is also a scientific fact.

Scientists have also hypothesized something called Higgs field — an invisible field that exists throughout the universe and is responsible for the proper functioning of this universe. Englert and Higgs had proposed that particles acquire mass when they come in contact with this invisible field that fills up all space. Higgs field is part of the theoretical framework that explains the functioning of the universe. Whatever we see in the physical world is made up of matter or a few fundamental particles, governed by fundamental forces. The theory that explains these fundamental particles and the forces that keep them going is known as the Standard Model of physics. Over the past few decades, physicists have been conducting experiments to test different aspects of the Standard Model. It is like a grand puzzle which scientists are solving piece by piece. The discovery of the Higgs particle is a crucial piece of this cosmic puzzle.

For centuries, we believed that the atom is the building block of all matter in this world. The very meaning of atom — in Greek — is indivisible.  But now we know that an atom is divisible. It consists of electrons that circle around a nucleus consisting of protons and neutrons.  Not just this, neutrons and protons are made up of smaller particles called quarks. Then there are leptons — a class of particles like electrons. Broadly, leptons and quarks are elementary particles which are at the base of all matter that we can see in this universe. The Standard Model unites these building blocks through forces of nature to make sure that everything works.

The discovery of the Higgs particle is not the end of the road for particle physics. The next step, according to scientists at the LHC, is to determine the precise nature of the particle and its significance for our understanding of the universe. They will continue searching for yet unknown particles and, of course, the elusive dark matter. After all, the matter we can see constitutes just four per cent of the universe with the rest 96 per cent remaining obscure. There are many such unanswered questions.

Science is about believing what you see. Multi-billion dollar mega experiments such as those underway or planned at LHC are meant to prove theories of physics through experimentation.

Elsewhere, too,  scientists are engaged in such endeavours. A couple of years back, NASA proved Einstein’s theory of general relativity by generating data in a $760 million satellite-based experiment. Billions of dollars are being invested in setting up powerful radio telescopes so that astronomers can ‘see’ birth of galaxies that took place billions of years ago, in what is called the cosmic dawn. It is hoped that these radio telescopes would be able to accelerate the search for the elusive ET or extra terrestrial beings, if any.

Such Big Science projects, which find it difficult to attract funding in a cash-strapped world, are fascinating for the world of physics. The goal of such projects is scientific, but they do have a larger societal fallout. After all, it was the CERN which is the birthplace of the Worldwide Web and many computing technologies widely used globally. The space programme in the past 50 years has spun off many a technology ranging from improved pacemakers to digital cameras. The fundamental work on antimatter done at the European Organization for Nuclear Research as part of experiments like Low Energy Antiproton Ring and Antiproton Decelerator has led to development of new cancer therapies. An exciting journey in experimental physics has just begun.

The author is a science journalist based in New Delhi.