I find myself admiring Prof. Stephen Hawking, the genius in a wheel chair, for his intelligence, determination, courage, persistence and humour on many occasions. After hearing the news of his death, I felt sad and rather shocked as, like many, I had hoped that he might be able to unlock the mystery of the universe. The pioneering astrophysicist, who used a wheelchair and communicated through a computerized voice system because he lived with amyotrophic lateral sclerosis (ALS), was the first to demonstrate along with mathematician Sir Roger Penrose, that Einstein’s general theory of relativity implies space and time would have a beginning in the Big Bang and an end in black holes. With his mind, he almost roamed the whole cosmos, pondering the nature of gravity, without allowing his physical limitations to hinder his quest to answer the big question: Where did the universe come from? His book, ‘A Brief History of Time’ has sold more than 10 million copies and has entered the Guinness book of records, revealing to the world how an unlikely book can become a mainstream bestseller if it can inspire a sense of wonder within us. The 2014 film about his life and his relationship with his wife Jane, ‘The Theory of Everything’, has been nominated for several Academy Awards. His horizon expanding curiosity led him in a search for a theory of everything, the final theory or ultimate theory, a single, all-encompassing, coherent theoretical framework of physics that fully explains and links together all physical aspects of the universe, the major unsolved problems in physics. It is rewarding to know the secrets and the history behind this theory of everything.
For more than three centuries, there has been ongoing endeavor by scientists to unify the various phenomena of nature within a single theoretical framework or a single set of descriptive equations. During the 17th century, Sir Isaac Newton unified celestial and terrestrial phenomena, when he could explain the elliptical orbits of the planets through the same physical laws of motion that apply on earth – his law of universal gravitation. James Clerk Maxwell regarded as the greatest theoretical physicist of the 19th century, unified electricity, magnetism and optics. In the 1830s, Michael Faraday discovered that changing magnetic fields produced electric fields. Maxwell thought that the opposite should also be true, that a changing electric field would produce a magnetic field; and, in June 1865, he published his treatise on electricity and magnetism in the Philosophical Transactions of the Royal Society, which described how electricity and magnetism are closely connected to one another and how they propagate through space in the form of electromagnetic waves at the speed of light. Thus a set of four equations called Maxwell’s equations provided a unified theory of electricity, magnetism, and light, as well as all other types of electromagnetic radiation, including infrared and ultraviolet light, radio waves, microwaves, x-rays, and gamma rays.
The world’s most famous physicist, Albert Einstein, was awarded the 1921 Nobel Prize in Physics, for his discovery that light must consist of particles, known as photons. This paved the way for the understanding that light is both a particle (photon) and a wave (the flow of photons) and laid the early stepping-stones towards a fundamentally new type of physics which was to be known as quantum theory, the theory of elementary particles. However, the major contribution of Albert Einstein came on November 15th, 1915, when he used his imagination rather than mathematics to come up with his most famous and elegant equation that rules the universe, transforming our understanding of space and time – the general theory of relativity (GR). GR states that, in space-time, massive objects distort the geometry of the cosmos to produce the effect called gravity in the same way that a heavy sleeper distorts the geometry of a sagging mattress on which he sleeps. This causes all objects, from light beams (light gets bent around clusters of galaxies) to pebbles, to follow curved paths through space. Before this, Isaac Newton and other scientists thought that all matter strutted and paraded on the stage called space-time, but Einstein showed that that stage itself dances – folding and wrapping, stretching and growing or collapsing. It is mind-boggling to know that space-time wraps itself around a dead star and disappears into a black hole, which was later discovered by Hawking based on Einstein’s GR. The fascinating thing about General Relativity is that it correctly predicts and explains some weird phenomena like astronauts in space ships aging slower than people who stay on earth and solid objects changing their shapes at high speeds.
However, Einstein could not fulfill the dream of physicists to discover a theory of everything. The dual rise of Albert Einstein’s theory of general relativity and the theory of quantum mechanics, both of which have been robustly verified by experiments, could not fit together. This puzzle of reconciling the two incompatible descriptions of reality – Quantum Mechanics, which is wonderfully adept at describing small things, the behavior of matter and energy at subatomic scales, and General Relativity, that wonderfully accounts for gravity and hence the big things of the universe like the planets and galaxies seemed like working out a marriage relationship with two polar opposite people. For nearly 30 years Einstein pursued a quixotic goal – the creation of a unified field theory to describe all the forces of nature and to demystify the quantum world. Tim Folger, Einstein’s Grand Quest for a Unified Theory, He failed, of course, but he didn’t exactly waste his time, Discover Magazine, September 30, 2004. Tim Folger, writing for the September issue 2004 of Discover Magazine, recalls an incident when Einstein wrote to a self-taught physicist Muffat in this way, “Dear Mr. Moffat, Our situation is the following. We are standing in front of a closed box which we cannot open, and we try hard to discover about what is and is not in it.” That closed box is the universe, and Einstein tried his best to pry off the lid and it looked that he squandered his genius by chasing vainly after an ultimate theory.
Einstein’s lonely quest, later engaged thousands of physicists around the world, the most famous of whom was Stephen Hawking, who was pursuing that one question – what happened at the cosmological, singularity, a point with zero volume and infinite density, where space and time cease to exist. Such singularities, like the Big Bang singularity and the black holes, are zones where Einstein’s Relativity goes blind and Quantum Mechanics struggles to take over and there is no mathematical model to explain it. In such zones, when General Relativity demands an infinitely small point, quantum theory says there is no such thing as a point at that quantum level and it is more like a smear due to the wave-like nature of particles. Hawking believed that, if these two theories could be reconciled, it could solve questions like: What is inside a black hole? What happened at the beginning of the universe? and why is the universe accelerating?
Hawking spoke about God in his book, “A brief history of Time” and wrote that, “if we discover a complete theory…then we shall all be able to take part in the discussion of the question of why it is that we and the universe exist. If we find the answer to that, it would be the ultimate triumph of human reason – for then we should know the mind of God.” Hawking considered himself an atheist and spoke more plainly about his thoughts on God in an interview with Spanish publication El Mundo. “Before we understand science, it is natural to believe that God created the universe. But now science offers a more convincing explanation,” he said. “What I meant by ‘we would know the mind of God’ is, we would know everything that God would know, if there were a God, which there isn’t. I’m an atheist.” All his scientific interpretation was based on his atheistic worldview. He attributed the extraordinary fine-tuning required for a universe which would eventually be able to support human life, to chance as his mind was not able to perceive an intelligent design. He presents the same view in his book, ‘The Grand Design’, with Leonard Mlodinow, “Spontaneous Creation is the reason that there is something rather than nothing, why the universe exists and why we exist. It is not necessary to invoke God to light the blue touch paper and set the universe going.’ In an interview with The Guardian, he said: “I regard the brain as a computer which will stop working when its components fail. There is no heaven or afterlife for broken-down computers; that is a fairy story for people afraid of the dark.” Though he did not believe in God, he always remained anxious about what might lie ahead for humanity, issuing numerous warnings about aliens who can destroy us or artificial intelligence that could lie in wait or even about the Higgs Boson that could become unstable wiping out the whole universe.
September 2010 article in New Scientist says that Stephen Hawking finally gave up his quest for a “theory of everything” though three decades ago, he declared that such a theory was on the horizon, with a 50 per cent chance of its completion by 2000. It continues that now he can explain the riddles of the existence of universe without it because of superstring theory and M theory. However, these theories turned out to be untestable and instead of one theory, it ended with multiple theories and instead of a single description of reality, there are now multiple and overlapping way of representing reality. Why do these theories keep stumbling and why a theory of everything looks far from the reality? One possibility is that we simply don’t know enough yet of the major phenomena that can never ever be seen, and while understanding the big picture we might be missing the basic truths. The big question pops up in our minds – Does these theories warrant the postulation of God? Is there a missing ingredient? Carlo Rovelli, a theoretical physicist at the University of the Mediterranean in Marseille, France said regarding the theory of everything, “Einstein defined what later became a fundamental problem in physics; but he was missing an ingredient.”
The brilliant physicist, Stephen Hawking who died on March 14th, on the anniversary of Albert Einstein’s birth in 1879, also missed the same ingredient like Einstein in his search for a theory of Everything. Although Hawking did not, during his life, find the elusive theory of everything, and although he did not have confidence that there would be an afterlife, I cannot help wondering whether, having passed on, beyond the event horizon, he might now have been surprised, having found the answer he was looking for.