Now that the point-particle has been extended into a one-dimensional string and expanded into a two-dimensional world sheet, why stop there? String theory is not only a theory of strings. It also has a series of objects with one to nine dimensions called p-branes. P is the number of dimensions of the object. For instance, a string is a 1-brane, and a world sheet is 2-brane. There are also D-branes which are like a collective excitation of strings.
String theory has energy equations created by Einstein. P-branes are the solutions to these equations (like how zeros are the solutions to a parabola, only this is a little more complicated). The solution tells how many dimensions the energy density of a field (like the electromagnetic field) are confined to. These branes took a long time to find because physicists had to first discover a T-duality, which is a mathematical transformation that makes one theory look like another. The p-branes were buried in these mathematics until recently. This duality, along with other dualities, allowed physicists to imagine a theory that connected all the string theories into one.
In 1995, Edward Witten started the Second Superstring Revolution by introducing the concept of M-theory. It is a combination of six theories (Type I, Type IIA, Type IIB, HO, HE, and 11D Supergravity). They are joined together by dualities, specifically T-duality, S-duality, and U-duality, which are ways of converting one theory into another.
Though the dualities have been discovered long before, Witten was the first to suggest that all the previous theories had only been approximations of a larger, more complex theory. Now the question remains: How will the discovery of a unifying theory that appears to have no direct influence on everyday life affect everyday life?
| Project Info | | |
The Conflict | | |
Past Endeavors | | |
Strings Attached | | |
Strings Squared |
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VSF |