Stephen Hawking Essay, Research Paper

Many people think of science as a collection of facts and ideas about the world around us. But science is more than of how human beings have brought their individual strengths and weaknesses to the ever going struggle to learn more about our world. Stephen Hawking is one of the best-known and most admired scientists in the world today. His life and work have been featured in numerous newspaper and magazine articles, television documentaries, and even a movie. Part of Hawking s fame comes from his ability to use his imagination or intuition to see connections between seemingly unrelated ideas. He has combined the physical laws governing suns and galaxies with those governing the particles inside the atom. He has created a chain of thought that links events inside collapsing stars with the almost unimaginable explosion that, most scientists believe, began our universe about fifteen billion years ago (Boslough).

In early 1942, Great Britain was in the third year of a bitter struggle for survival. England had been spared from invasion, but night after night, German bombers continued to pound London. Frank and Isobel Hawking were expecting their first child. The Hawkings were well-educated and talented. Both had attended the university at Oxford. The couple realized that London was an unsafe place to raise a child, and decided to move to Oxford which Germany had agreed not to bomb in return for the British not bombing Heidelberg and G*ttingen. Stephen Hawking once noted that he was born on January the 8th, 1942, exactly three hundred years after the death of Galileo.

World War Two changed the way people looked at scientists and their theories. Suddenly the incomprehensible ideas of physics had become very important. The laws of gravity and motion, discovered centuries earlier by Sir Isaac Newton, now enabled warring nations to aim and launch rockets and new jet airplanes that would soon break the sound barrier. Science became a more important part of the school curriculum, especially after the Soviets launched Sputnik, the first artificial earth satellite, in 1957. Children of Hawking s generation had a greater opportunity than ever before to be exposed to the exciting and swiftly changing world of Science.

Stephen did well enough in high school to be accepted at the prestigious Oxford University in 1959. He loved the freedom that accompanied College, but had a hard time applying himself to his studies. Hawking later calculated that he had studied an average of only an hour a day during his three years at Oxford. Stephen wanted to go to graduate school at Cambridge, But to be accepted he would have to pass his finals with the highest possible honors. His test scores were borderline, and Hawking managed to talk his way into Cambridge and entered in 1962 (Boslough).

One year later, Hawking s life took a drastic turn. His coordination had been off for a while, and he noticed that he had a hard time controlling his hands and fell quite often. He went to his family doctor and after extensive tests, was diagnosed with amyotrophic lateral sclerosis, or motor neurone disease. Hawking recalls:

The realization that I had an incurable disease that was likely to kill me in a few years was a bit of a shock. How could something like that happen to me? I was going to lose the use of my body. And they told me that eventually I would essentially have the body of a cabbage but my mind would still be in perfect working order, and I would be unable to communicate with the rest of the world. They said that at the end, only my heart, lungs, and mind would still be in working. After that, either my heart or lungs would give up. Then I will die. (Hawking)

But something new was about to come into Hawking s life.

Once at Cambridge, Hawking was required to pick a subject to research for a doctoral degree. He decided on Cosmology, the study of the nature and origin of the universe. It focused on some fascinating questions about which new theories could be applied. How big was the universe? Why was it growing bigger all the time? How did he universe begin? Would the universe die someday or go on existing forever? Besides questions of the origin of the universe, cosmology also offered Hawking another puzzle. What happens to stars when they die? (Susskind)

Hawking became fascinated by the idea of singularity. As a physical body, a singularity, or black hole, was expected to have some very strange properties (Gribbin). A black hole would still have most of the mass that it had when it was a full-sized star, but its surface would now be very close to the body s center of mass (Susskind).

As a result the surface would be immense– so powerful, in fact, that anything that entered the black hole would be trapped inside, and nothing, not even light, could ever come out. Put another was a black hole would bend space so completely around itself that it would, in effect, disappear into a private universe of its own (Susskind).

In his book A Brief History of Time, Hawking gives his opinion of black holes.

The best explanation for this phenomenon is that matter has been blown off the surface of the visible star. As it falls toward the unseen companion, it develops a spiral motion (rather like water running out of a bath), and it gets very hot, emitting X-rays. For this mechanism to work, the unseen object has to be very small, like a white dwarf, neutron star, or black hole. From the observed orbit of the visible star, one can determine the lowest possible mass of the unseen object. In the case of Cygnus X-1 [a likely candidate for a black hole is this star system], this is about six times the mass of the sun, which according to Chandrasekhar s result, is too great… to be a white dwarf. It is also too large a mass to be a neutron star. It seems, therefore, that it must be a black hole… (Hawking)

Hawking continued to make progress in following up his insights into black holes. Unfortunately, His condition was worsening and he began getting around in a wheelchair. The future seemed uncertain, and he and his wife, Jane, whom he married in 1965, felt they could lose no time in starting a family. Their first child, Robert, was born in 1967.

Robert was followed by a daughter, Lucy, in 1970, and another son, Timothy, in 1979 (Boslough).

Hawking continued to work on black holes. He struggled with these problems. Then he had an important realization

One evening, shortly after the birth of my daughter, Lucy, I started to think about black holes as I was getting into bed. My disability made this rather a slow process, so I had plenty of time. Suddenly I realized that the area of the event horizon always increases with time. I was so excited with my discovery that I didn t get much sleep that night. (Hawking)

Why was it important that the area covered by a black hole s event horizon could only get bigger, never smaller? For one thing, it suggested for the first time that there was something about black holes that did change over time. Hawking then asked himself if this property of black holes was like anything else in the more familiar realms of physics. He found that there was a principle called entropy in the laws of thermodynamics that could be compared to the behavior of a black hole s event horizon. Entropy is a measure of how disordered or disorganized something is (Boslough). The principle of entropy expresses our common experience that everything tends to wear out, run down, or get jumbled over time. For example, even mountains that have stood for millions of years eventually erode or crumble away. In physics entropy usually refers to the amount of heat energy in a system (Susskind).

At first the existence of black holes seemed to violate the idea that the entropy of the universe as a whole was always increasing. Since nothing can come out of a black hole, you have seemingly cheated the law of entropy. The amount of entropy in the universe would not, it seems, increase in this situation, because the inside of the black hole is sealed off from our ordinary universe. Hawking also pointed out that a black hole, since it could not emit any form of radiation, could not have a temperature. Since entropy is measured by temperature, Hawking hypothesized that a black hole couldn t have entropy in any meaningful way (Gribbin).

Thus far Hawking had been applying Einstein s theory of general relativity along with a bit of thermodynamics to black holes. Einstein s theory was one of the two powerful theories that had given twentieth-century physics the unprecedented ability to explain the behavior of matter and energy. The other breakthrough theory was that of quantum mechanics, first formulated in the 1920s, which explained how things worked in the world within the atom– a world of tiny particles, minuscule distance, and incredibly brief intervals of time. When Hawking began to apply the equations of quantum mechanics to black holes, the results startled and distressed him. According to the equations black holes appeared to emit radiation, just as the Russian Physicist Zel dovich had suggested. This meant that a black hole had a temperature and, therefore, could have entropy. Hawking confirmed the results of the Soviet research and extended it to apply to all black holes, not just spinning ones (Susskind).

Only a few weeks after announcing his discovery of the radiation (named Hawking Radiation after the discoverer), Stephen Hawking received an invitation to join the Royal Society, Britain s most prestigious scientific body, founded in 1660. Having just turned thirty-two years old, he was one of the youngest scientists to receive this honor (Gribbin).

If black holes were slowly turning their mass into radiation, might a black hole eventually evaporate into space? Hawking published a paper entitled Black Hole Explosions? . The paper looked at this possibility. Hawking believed that the ordinary kind of black hole, made from a massive star, pulled in matter from surrounding space much faster than it could lose it through emitting radiation (Susskind). Starting in 1971, however, Hawking started to think about another kind of black hole. Anything can create enough pressure on some matter can create a black hole– not just the collapsing mass of a huge star (Boslough). In particular, Hawking began looking back at the Big Bang.

In the mid-1970s, Hawking had another one of the great leaps of intuition that seemed to mark each new stage in his career. What would happen, he thought, if the sum of histories technique (A technique that involves calculating and mapping all of a particle s possible paths and assigning them probabilities. The result is a kind of map of the particle s possible presence in space-time.) was applied not to a single particle but to the evolution of the entire universe out of the Big Bang? Hawking constructed a model based on a single particle moving in the kind of curved space-time that Einstein had described. When he determined the most probable path for such an ideal particle, the result was a space-time that was curved and boundless (Wagner).

According to this model of the universe, if you move for enough in time from the Big Bang, the universe expands to a very large size. After reaching a maximum size, i begins to collapse until it is compressed to a very high density. This state, the opposite of the Big Bang,

has been dubbed the Big Crunch. A Big Crunch is just a Big Bang approached from the other side (Wagner).

By the early 1980s Hawking realized that he needed greater financial security. He had to have money both to pay for his full-time nursing care and to put his daughter through college. Around the end of 1982 Hawking decided that writing a popular science book might go a long way toward solving his money problems (Boslough). Hawking also felt that writing a popular science book would give him a chance to explain things in his own words and correct what he thought were the distortions that had crept into popular accounts of his work.

Hawking decided to call his book A Brief History of Time. In it Hawking describes how scientists have, step by step, uncovered the secrets of the universe and of the atoms from which all matter is made. The result is challenging reading, but Hawking had taken the advice about not having sums in his book: the only equation that appears is Einstein s classic E=mc^2. Instead of equations, Hawking relies on analogies and diagrams to show relationships and movement in space and time (Gribbin).

By the summer of 1988 A Brief History of Time had been on the American best-seller lists for four months and had sold half a million copies.

Hawking told one interviewer:

I am pleased a book on science competes with the memoirs of pop stars. Maybe there is still hope for the human race. I am very pleased for it to reach the general public, not just academics. It is important that we all have some idea of what science is about because it plays such a big role in modern society. (Wagner)

The popularity of A Brief History of Time encouraged Bantam Books in 1993 to publish a collection of Hawking s earlier writings– essays, talks, and interviews– with the title Black Holes and Baby Universes. While A Brief History of Time focused on scientific matters, the new book includes autobiography and even a discussion of Hawking s favorite music in addition to the exploration of scientific questions (Wagner).

Superstardom and personal problems overshadowed Hawking s scientific work for a while, but they did not bring it to an end. As the 1990 s began, Hawking continues to play a part in the finding of a theory of everything that might explaining how the forces we find in the universe today had arisen, and how they might be covered by a single, comprehensive explanation (Gribbin).

What has the work of Stephen Hawking added to twentieth-century science? Hawking s key discoveries about singularities, black holes, and the Big Bang did more than explain puzzling cosmic phenomena. By bringing together the very different worlds of relativity and quantum mechanics, Hawking created a new way to look at the shape of space and time and the history and possible future of the universe. He also did valuable work in making the discoveries of the new physics accessible to a wide range of readers.

The fact that these achievements came despite a crippling disease that would have devastated most people has, in my opinion, made Hawking a genuine hero and role model, not only for the disabled people, but for all of us. Whatever else he may achieve, Stephen Hawking has already advanced the amount of human understanding.

Hawking sees the goal of the future and calls us all to it:

If we do discover a complete theory, it should in time be understandable in broad principle by everyone, not just a few scientists. Then we shall all, Philosophers, scientists, and just ordinary people, 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 would know the mind of God.

(Hawking)