Sunday, January 29, 2012

Brief Summary of "A Brief History of Time"

Stephen Hawking wrote "A Brief History of Time" in order to explain to the ordinary people who populate society how science works. But Hawking did not do so in a complicated fashion in which he fills it up with scientist jargon that would scare off most non-scientists. He finds a way to teach it to the non-scientist community in a way that makes sense. This is what has made his book so popular and well-known. Explaining the most complicated things we know of in science today, he simplified several theories such as the Theory of Relativity, the models of the universe, and the mind-boggling Quantum Mechanics field.
For the general theory of relativity, I learned from him that an object can never move at the speed of light because Einstein's famous equation, E=MC^2, says that it would take an infinite amount of energy and infinite mass in order to propel it that fast. I also learned that gravity travels at an infinite speed, but not at the speed of light.
I learned about the three models of the universe that scientists have come up with over the years. One model says that gravity will expand the universe until it collapses on itself. Another model says that space is curved and not infinite and gravity cannot prevent the inevitable expansion of our universe. the third model states that space is flat and infinite and the expansion of the universe is going fast enough to not collapse. Through Hawking's calculations, he says that the universe will continue to expand for infinity.
Quantum Mechanics is a field that is not fully realized yet, but is still credible enough to put faith in. Einstein once said "God does not play dice" in disdain towards this field. He did not know that this theory would soon become generally accepted. Quantum Mechanics says that energy must be produced in particles called quanta. To predict the location of a particle, you need to know its position and velocity. But in order to view the particle, you need to use at least one quantum of light which changes the velocity of the particle. This is what makes it hard to observe particles because by observing the particle more properly, you will disrupt the particle more.
Hawking's book did what my physics teacher struggles to achieve in class everyday: Make me understand the concept of physics. It is a very foreign field to people who use their right brain a lot more often like me, and it takes some simplification in order to get these concepts understood correctly. This is a book that does a good job in compressing physics down into one understandable format.