July 24, 1999
Stephen Hawking is, all in all, one of the greatest thinkers of the twentieth century. Dr. Hawking is a theoretical physicist. In his own words, "A theoretical physicistÃ¢â‚¬Â¦[tries] to construct mathematical models which represent the universe." Sadly, though, his triumphs are often overshadowed by his illness. Dr. Hawking suffers from amyotrophic lateral sclerosis, and generally his successes are viewed "even though" or "despite" his illness. Viewing his achievements in this light minimizes what he has done for the scientific community and how he has changed and contributed to scientific thought.
Dr. Hawking was born in London in 1942, and received his doctorate from the University of Cambridge. He proved in the late sixties that if general relativity is true and the universe is expanding, then the universe did arise from a big bang and a singularity most likely caused the big bang to occur. In 1974, he discovered that black holes could radiate energy as particles are created in their vicinity. He became the Lucasian Professor of Mathematics at the University of Cambridge in 1979, a post once held by Sir Isaac Newton. He wrote A Brief History of Time in 1988 to put his theories into the hands of the general public. His book stayed on the London Sunday Times bestseller list for more than four years - the longest run for any book in history. He is well known for his attempts to unite general relativity and quantum mechanics. He has made countless other contributions to cosmology.
Dr. Hawking has redefined time, and changed the way it is thought of forever. Dr. Hawking has dedicated much energy to following up Einstein's research into time travel. To travel through time, one needs to exceed the speed of light; the problem is that one needs an infinite amount of power to exceed the speed of light. However, Dr. Hawking has proposed that throughout the universe, there are cosmic strings; similar to rubber bands, under tremendous pressure that move at extraordinary speeds. Theoretically, one could harness the power in a cosmic string to move a spaceship quickly enough to travel through time.
To travel from one end of the galaxy to the other would take over 160,000 years. Since it would take an infinite amount of power to reach the speed of light, it would appear that we couldn't travel that far in a reasonable amount of time. Dr. Hawking suggests wormholes as a way to travel such great distances in reasonable amounts of time. Wormholes act as short cuts that connect distant parts of space-time. To create a wormhole, one needs to warp space-time until it is concave, rather than convex as it normally is. To warp space-time that much, one needs matter with negative mass and negative energy density. Such matter is called exotic matter. Quantum theory says it is possible to have exotic matter. Dr. Hawking suggests that more time and energy should be dedicated to researching these ideas to see if time travel can be made possible. If we don't research what superficially appears to be frivolous, we will never find out if time travel or traversing great distances, such as the breadth of the galaxy, are within the realm of possibility.
Dr. Hawking uses mathematics when he draws all of these conclusions, and others. For example, he has done much research into the birth of the universe and the Big Bang Theory. In his attempts to unify general relativity and quantum mechanics, Dr. Hawking measured time with imaginary numbers instead of real numbers. Imaginary numbers are used to take square roots of negative numbers. For example, the square root of 4 is 2 or -2, but what is the square root of -4? By using i to represent the square root of -1, we can set the square root of -4 to 2i. In describing the curve of space-time, Dr. Hawking refers back to geometry. In Euclidian geometry, the angles of a triangle always add up to 180 degrees. Now, imagine a triangle on a sphere. If you draw a triangle on a convex surface, the angles will add up to more than 180 degrees; on a concave surface, the angles will add up to less than 180 degrees.
For all he has given us, Dr. Hawking has received very little recognition when compared to some of his companion physicists. When Time magazine did their compilation of the greatest contributors to the twentieth century, Dr. Hawking was not included in their selection of great physicists. Even when Dr. Hawking's incredible feats are given credit, they are looked at not as amazing accomplishments made by a brilliant man, but as things that he did even though he's sick. Dr. Hawking's illness overshadows his genius more often than not.