onnihs
06-17-2004, 02:44 PM
I love it... super strings, 10 dimensional universe, it gets me excited and makes me THINK so hard.
I stumbled across this web page by Dr. Michio Kaku, Prof. of Theoretical Physics at the City College of New York, and it had me bedazzled. I've read it 4 or 5 times already, and have gotten 4 other people hooked on the topic. Now i share it with you! Below is a little excerpt of the things he talks about. The entire article can be found HERE (http://home.flash.net/~csmith0/theryall.htm).
10 Dimensional Hyperspace
The superstring theory represents perhaps the most radical departure from ordinary physics in decades. But its most controversial prediction is that the universe originally began in 10 dimensions. To its supporters, the prediction of a 10 dimensional universe has been a conceptual tour de force, introducing a startling, breath-taking mathematics into the world of physics.
To the critics, however, the introduction of 10 dimensional hyperspace borders on science fiction.
To understand these higher dimensions, we remember that it takes three number to locate every object in the universe, from the tip of your nose to the ends of the universe.
For example, if you want to meet some friends for lunch in Manhattan, you say that you will meet them at the building at the corner of 42nd and 5th Ave, on the 37th floor. It takes two numbers to locate your position on a map, and one number to specify the distance above the map. It thus takes three numbers to specify the location of your lunch.
However, the existence of the fourth spatial dimension has been a lively area of debate since the time of the Greeks, who dismissed the possibility of a fourth dimension. Ptolemy, in fact, even gave a "proof" that higher dimensions could not exist. Ptolemy reasoned that only three straight lines can be drawn which are mutually perpendicular to each other (for example, the three perpendicular lines making up a corner of a room.) Since a fourth straight line cannot be drawn which is mutually perpendicular to the other three axes, Ergo!, the fourth dimension cannot exist.
What Ptolemy actually proved was that it is impossible for us humans to visualize the fourth dimension. Although computers routinely manipulate equations in N-dimensional space, we humans are incapable of visualizing spatial dimensions beyond three.
The reason for this unfortunate accident has to do with biology, rather than physics. Human evolution put a premium on being able to visualize objects moving in three dimensions. There was a selection pressure placed on humans who could dodge lunging saber tooth tigers or hurl a spear at a charging mammoth.
Since tigers do not attack us in the fourth dimension, there simply was no advantage in developing a brain with the ability to visualize objects moving in four dimensions.
From a mathematical point of view, however, adding higher dimensions is a distinct advantage: it allows us to describe more and more forces. There is more "room" in higher dimensions to insert the electromagnetic force into the gravitational force. (In this picture, light becomes a vibration in the fourth dimension.) In other words, adding more dimensions to a theory always allows us to unify more laws of physics.
A simple analogy may help. The ancients were once puzzled by the weather. Why does it get colder as we go north? Why do the winds blow to the West? What is the origin of the seasons? To the ancients, these were mysteries that could not be solved. From their limited perspective, the ancients could never find the solution to these mysteries.
The key to these puzzles, of course, is to leap into the third dimension, to go up into outer space, to see that the earth is actually a sphere rotating around a tilted axis. In one stroke, these mysteries of the weather become transparent. The seasons, the winds, the temperature patterns, etc. all become obvious once we leap into the third dimension.
Likewise, the superstring is able to accommodate a large number of forces because it has more "room" in its equations to do so.
I stumbled across this web page by Dr. Michio Kaku, Prof. of Theoretical Physics at the City College of New York, and it had me bedazzled. I've read it 4 or 5 times already, and have gotten 4 other people hooked on the topic. Now i share it with you! Below is a little excerpt of the things he talks about. The entire article can be found HERE (http://home.flash.net/~csmith0/theryall.htm).
10 Dimensional Hyperspace
The superstring theory represents perhaps the most radical departure from ordinary physics in decades. But its most controversial prediction is that the universe originally began in 10 dimensions. To its supporters, the prediction of a 10 dimensional universe has been a conceptual tour de force, introducing a startling, breath-taking mathematics into the world of physics.
To the critics, however, the introduction of 10 dimensional hyperspace borders on science fiction.
To understand these higher dimensions, we remember that it takes three number to locate every object in the universe, from the tip of your nose to the ends of the universe.
For example, if you want to meet some friends for lunch in Manhattan, you say that you will meet them at the building at the corner of 42nd and 5th Ave, on the 37th floor. It takes two numbers to locate your position on a map, and one number to specify the distance above the map. It thus takes three numbers to specify the location of your lunch.
However, the existence of the fourth spatial dimension has been a lively area of debate since the time of the Greeks, who dismissed the possibility of a fourth dimension. Ptolemy, in fact, even gave a "proof" that higher dimensions could not exist. Ptolemy reasoned that only three straight lines can be drawn which are mutually perpendicular to each other (for example, the three perpendicular lines making up a corner of a room.) Since a fourth straight line cannot be drawn which is mutually perpendicular to the other three axes, Ergo!, the fourth dimension cannot exist.
What Ptolemy actually proved was that it is impossible for us humans to visualize the fourth dimension. Although computers routinely manipulate equations in N-dimensional space, we humans are incapable of visualizing spatial dimensions beyond three.
The reason for this unfortunate accident has to do with biology, rather than physics. Human evolution put a premium on being able to visualize objects moving in three dimensions. There was a selection pressure placed on humans who could dodge lunging saber tooth tigers or hurl a spear at a charging mammoth.
Since tigers do not attack us in the fourth dimension, there simply was no advantage in developing a brain with the ability to visualize objects moving in four dimensions.
From a mathematical point of view, however, adding higher dimensions is a distinct advantage: it allows us to describe more and more forces. There is more "room" in higher dimensions to insert the electromagnetic force into the gravitational force. (In this picture, light becomes a vibration in the fourth dimension.) In other words, adding more dimensions to a theory always allows us to unify more laws of physics.
A simple analogy may help. The ancients were once puzzled by the weather. Why does it get colder as we go north? Why do the winds blow to the West? What is the origin of the seasons? To the ancients, these were mysteries that could not be solved. From their limited perspective, the ancients could never find the solution to these mysteries.
The key to these puzzles, of course, is to leap into the third dimension, to go up into outer space, to see that the earth is actually a sphere rotating around a tilted axis. In one stroke, these mysteries of the weather become transparent. The seasons, the winds, the temperature patterns, etc. all become obvious once we leap into the third dimension.
Likewise, the superstring is able to accommodate a large number of forces because it has more "room" in its equations to do so.