Trip like I do
Feb 07, 2005, 05:50 PM
We live in a three-dimensional world, right?
Physicists have traditionally described the universe using four dimensions: the familiar three spatial dimensions and a time dimension. This model has helped explain everything from the bending of starlight as it skirts the Sun to the formation of black holes.
Some physicists don't understand why gravity is vastly weaker than the other three fundamental forces of nature: the electromagnetic, strong, and weak forces.
One group, led by Lisa Randall of MIT in Cambridge, and Raman Sundrum of Johns Hopkins University in Baltimore, Maryland, recently proposed adding an extra dimension: we live in a four dimensional world, but graiton particles, which carry the gravitaional force, live in another. A small fifth-dimensional seperation between the two worlds greatly diminishes the force of gravity.
Evidence for the fifth-dimension could arrive soon. Randall and Sundrum predict that the Large Hadron Collider in Geneva, Switzerland, which is due to begin operations in 2007, could generate enough energy to let a graviton breifly leak into our world (I'm wondering if that would be a good thing to do).
Unknown
Feb 07, 2005, 08:01 PM
String Theorists are attempting to unify the four fundamental fources of physics in an eleven-dimensional universe model in which tiny loops and bits of string are the most fundamental particles. theory predicts that the strings are one hundred million billion times smaller than the smallest subatomic particle created in the most powerful particle accelerators.
Trip like I do
Feb 07, 2005, 08:03 PM
Briane Greene - String theory postulates that space has six or seven dimensions in addition to the three that we are familiar with.
-I like to say things more than one way. I just think when it comes to abstract ideas, you need many roads into them.
-If you stick to one road you really compromise your ability to make breakthroughs.
-Everybody is looking at a problem one way, and you come at it from the back. That different way of getting there somehow reveals things that the other approach didin't.
-The universe in a sense guides us towards truths, because those truths are the things that govern what we see. if we're all being governed by what we see, we're all being steered in the same direction. Therefor, the difference between making a breakthrough and not can often be just a small element of perception, either true perception or mathematical perception.
-General Relativity is such a leap, such a monumental rethinking of space, time, and gravity. It's not obvious how and when it would have happened without Einstein. We are still waiting for another leap of that magnitude.
-String Theory has been built up out of a lot of smaller ideas that alot of people have contributed and been slowly stitching together into an ever more impressive theoretical ediface.
-In Mirror Symmetry there can be two spacetimes and one physics. Space can evolve in ways that we wouldn't have thought possible before. It divorces spacetime geometry from physics but it doesn't divorce them completely.