Bill

13 Aug 06,, 16:08

Highsea, Dalem..Doh...

Enjoy. :biggrin:

Testing String Theory(page 4 of a 4 page article, it's DEFINITELY worth reading the whole thing IMO)

Advocates say vibrating strings underlie every particle and every force in the universe. But will anyone ever be able to prove that?

By Michio Kaku

Illustrations by Don Foley

DISCOVER Vol. 26 No. 08 | August 2005 | Space

PURE MATHEMATICS

Despite new ideas and experimental activity, it is possible that none of these tests will find any support for string theory. Perhaps the evidence emerges only at energies much greater than are possible with today’s technologies. Perhaps the only way to study strings directly is to run experiments at the so-called Planck energy, a level not seen since the first 10–43 second after the Big Bang.

For those of us who want to know the answers before we die, this is a discouraging possibility. In our impatience for results, however, we tend to forget that many of the greatest ideas in science have waited centuries for even indirect confirmation. In 1783 astronomer John Michell predicted the existence of a star so massive that even light could not escape its enormous gravity. His prediction was difficult to accept because the object would be impossible to observe. Two hundred years later the Hubble Space Telescope has amassed stunning evidence that black holes are real and common—not by seeing the black holes themselves but by detecting disks of hot gas spinning around them.

PURE MATHEMATICS

Codeveloped by the author, this equation describes strings in 10 dimensions. It cannot be the final equation, because it does not incorporate the 11th dimension that is central to M-theory. If physicists can find a master version of this formula that includes membranes and describes quantum reality, they will have the final version of string theory, and possibly the equation of the universe.

Atomic theory offers another example of delayed confirmation. The Greek philosopher Democritus predicted that matter is composed of atoms in the fourth century B.C. In 1906, more than two millennia later, physicist Ludwig Boltzmann committed suicide in part because he was mercilessly ridiculed for believing in atoms, for which there was no direct proof. Our ability to directly observe and manipulate atoms is less than 20 years old.

Some theorists, myself among them, believe that the final verdict on string theory will not come from experiments at all. Rather, the answer may come from pure mathematics. The principal reason predictions of string theory are not well defined is that the theory is not finished. The underlying mathematics of string theory was accidentally discovered by two physics postdocs, Gabriele Veneziano of Italy and Mahiko Suzuki of Japan, working independently in 1968. The theory has evolved in fits and starts ever since. Even its greatest proponents agree that the final version has not yet been determined. When it is, we may be able to put it to a mathematical test.

If string theory is sound, it should allow us, mathematically, to compute basic properties of the universe from first principles. For instance, it should explain all the properties of familiar subatomic particles, including their charges, mass, and other quantum properties. The periodic table of elements that students learn in chemistry class should emerge from the theory, with all the properties of the elements precisely correct. If the computed properties do not fit the known features of the universe, string theory will immediately become a theory of nothing. But if the predictions accurately match reality, that would represent the most significant discovery in the history of science.

Einstein once said that “the creative principle resides in mathematics. In a certain sense, therefore, I hold it true that pure thought can grasp reality, as the ancients dreamed.” If so, some enterprising physicist could vindicate string theory as early as tomorrow.

The remarkable proof of the theory might not cost years of effort and billions of dollars. It might come instead from the most basic tools of science: paper, pencil, and a human brain.

WHO’S PUSHING STRING THEORY

In its 37-year history, string theory has already experienced two major revolutions. The first showed that strings describe gravity and particles and are free of mathematical inconsistencies. The second unified the various versions of string theory by adding an 11th dimension. These are just a few of the many key researchers who have guided the theory’s development and continue to push it forward.

John Schwarz of Caltech showed that string theory could describe quantum gravity, launching the first superstring revolution in 1984.

Michael Green of Cambridge worked closely with Schwarz, establishing the viability of string theory as a theory of everything.

David Gross of U.C. Santa Barbara helped develop “heterotic string theory” in the mid-1980s. He shared the Nobel Prize in Physics in 2004.

Joseph Polchinski of U.C. Santa Barbara showed that multidimensional membranes can describe large objects as groups of open strings.

Edward Witten of Princeton was the driving force behind M-theory, which sparked the second superstring revolution, in the mid-1990s.

Paul Townsend of Cambridge, along with Witten, developed M-theory, an 11-dimensional model that unified various forms of string theory.

Cumrun Vafa of Harvard put string theory on firmer theoretical ground in 1996 when he helped use it to calculate the entropy of black holes.

Juan Maldacena of Princeton found a link between string theory and field theory in 1997, bridging two branches of quantum physics.

(Follow link above to continue article)

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Mathematical perfection: Unified 11 dimensional string equation

Enjoy. :biggrin:

Testing String Theory(page 4 of a 4 page article, it's DEFINITELY worth reading the whole thing IMO)

Advocates say vibrating strings underlie every particle and every force in the universe. But will anyone ever be able to prove that?

By Michio Kaku

Illustrations by Don Foley

DISCOVER Vol. 26 No. 08 | August 2005 | Space

PURE MATHEMATICS

Despite new ideas and experimental activity, it is possible that none of these tests will find any support for string theory. Perhaps the evidence emerges only at energies much greater than are possible with today’s technologies. Perhaps the only way to study strings directly is to run experiments at the so-called Planck energy, a level not seen since the first 10–43 second after the Big Bang.

For those of us who want to know the answers before we die, this is a discouraging possibility. In our impatience for results, however, we tend to forget that many of the greatest ideas in science have waited centuries for even indirect confirmation. In 1783 astronomer John Michell predicted the existence of a star so massive that even light could not escape its enormous gravity. His prediction was difficult to accept because the object would be impossible to observe. Two hundred years later the Hubble Space Telescope has amassed stunning evidence that black holes are real and common—not by seeing the black holes themselves but by detecting disks of hot gas spinning around them.

PURE MATHEMATICS

Codeveloped by the author, this equation describes strings in 10 dimensions. It cannot be the final equation, because it does not incorporate the 11th dimension that is central to M-theory. If physicists can find a master version of this formula that includes membranes and describes quantum reality, they will have the final version of string theory, and possibly the equation of the universe.

Atomic theory offers another example of delayed confirmation. The Greek philosopher Democritus predicted that matter is composed of atoms in the fourth century B.C. In 1906, more than two millennia later, physicist Ludwig Boltzmann committed suicide in part because he was mercilessly ridiculed for believing in atoms, for which there was no direct proof. Our ability to directly observe and manipulate atoms is less than 20 years old.

Some theorists, myself among them, believe that the final verdict on string theory will not come from experiments at all. Rather, the answer may come from pure mathematics. The principal reason predictions of string theory are not well defined is that the theory is not finished. The underlying mathematics of string theory was accidentally discovered by two physics postdocs, Gabriele Veneziano of Italy and Mahiko Suzuki of Japan, working independently in 1968. The theory has evolved in fits and starts ever since. Even its greatest proponents agree that the final version has not yet been determined. When it is, we may be able to put it to a mathematical test.

If string theory is sound, it should allow us, mathematically, to compute basic properties of the universe from first principles. For instance, it should explain all the properties of familiar subatomic particles, including their charges, mass, and other quantum properties. The periodic table of elements that students learn in chemistry class should emerge from the theory, with all the properties of the elements precisely correct. If the computed properties do not fit the known features of the universe, string theory will immediately become a theory of nothing. But if the predictions accurately match reality, that would represent the most significant discovery in the history of science.

Einstein once said that “the creative principle resides in mathematics. In a certain sense, therefore, I hold it true that pure thought can grasp reality, as the ancients dreamed.” If so, some enterprising physicist could vindicate string theory as early as tomorrow.

The remarkable proof of the theory might not cost years of effort and billions of dollars. It might come instead from the most basic tools of science: paper, pencil, and a human brain.

WHO’S PUSHING STRING THEORY

In its 37-year history, string theory has already experienced two major revolutions. The first showed that strings describe gravity and particles and are free of mathematical inconsistencies. The second unified the various versions of string theory by adding an 11th dimension. These are just a few of the many key researchers who have guided the theory’s development and continue to push it forward.

John Schwarz of Caltech showed that string theory could describe quantum gravity, launching the first superstring revolution in 1984.

Michael Green of Cambridge worked closely with Schwarz, establishing the viability of string theory as a theory of everything.

David Gross of U.C. Santa Barbara helped develop “heterotic string theory” in the mid-1980s. He shared the Nobel Prize in Physics in 2004.

Joseph Polchinski of U.C. Santa Barbara showed that multidimensional membranes can describe large objects as groups of open strings.

Edward Witten of Princeton was the driving force behind M-theory, which sparked the second superstring revolution, in the mid-1990s.

Paul Townsend of Cambridge, along with Witten, developed M-theory, an 11-dimensional model that unified various forms of string theory.

Cumrun Vafa of Harvard put string theory on firmer theoretical ground in 1996 when he helped use it to calculate the entropy of black holes.

Juan Maldacena of Princeton found a link between string theory and field theory in 1997, bridging two branches of quantum physics.

(Follow link above to continue article)

----

Mathematical perfection: Unified 11 dimensional string equation