There is no theory of everything - Democratic Underground

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Thu Apr-29-10 02:08 AM
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There is no theory of everything

A couple of unrelated articles.

http://arstechnica.com/science/news/2010/03/setting-the-record-straight-no-simple-theory-of-everything.ars

Setting the record straight: no simple theory of everything
By Matt Ford | Last updated March 31, 2010 9:39 PM

A bit over two years ago, news sources and science blogs lit up when a pre-print paper from Dr. A. Garrett Lisi came to light that proposed a novel theory of everything—one theory that accurately describes all four of the universes fundamental forces. Current theories have demonstrated that three of the four fundamental forces and their associated particles can all be obtained from different symmetry operations (think rotations and reflections) of an algebraic group called a Lie group The pre-print, hosted by the on-line repository arXiv, proposed that, within the complicated symmetry group E8, all four forces of nature could be described and united.

The hype that ensued ensured that a search for the term "surfer physicist" now leads to press stories about Lisi's ideas, and spawned an entire Wikipedia entry for the paper alone. As an engineer who specializes in theoretical work, it seemed to me to be a case of "give me enough parameters and I can fit a horse." Our in-Orbiting Headquarters physicist, Dr. Chris Lee, described it as solid, but noted it had some serious shortcomings.

In the intervening years, the paper—to the best of my knowledge and research ability—has not made it through peer-review to publication. A new paper, set to be published in an upcoming edition of Communications in Mathematical Physics, formally addresses the idea, and not only finds that Lisi's specific theory falls short, but that no theory based on the E8 symmetry group can possibly be a "Theory of Everything."

The new paper, which is also freely available as a preprint through the arXiv, is highly technical and lays out its case as a proof to a mathematical problem that attempts to define the criteria for a valid theory of everything. The authors begin by laying out three key criteria that a pair of subgroups on a Lie group must have in order to be a 'Theory of Everything.' The first is a trivial, yet purely mathematical, restriction that must hold true between the chosen sub-groups. The second is that the model cannot contain any "'exotic' higher-order spin particles." The final issue is that the gauge theory employed in our group must be chiral—a limitation dictated by the existing Standard Model.

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http://thedartmouth.com/2010/04/16/news/Gleiser

‘Theory of Everything’ cannot be found, professor says
Marcelo Gleiser, whose book, “A Tear at the Edge of Creation,” was recently published, spoke on Thursday.
Ashley Mitchell / The Dartmouth Staff
By Grace Afsari Mamagani, The Dartmouth Staff
Published on Friday, April 16, 2010

The age-old scientific and philosophical search for a unifying theory of nature fails to acknowledge the limitations of the scientific process and the asymmetry of natural phenomena, physics and astronomy professor Marcelo Gleiser writes in his new book, “A Tear at the Edge of Creation: A Radical New Vision for Life in an Imperfect Universe.” Beginning with the foundations of philosophy, Western culture has attempted to identify the fundamental substance of the universe and a single explanation for all that exists, Gleiser said during a public lecture in Wilder Hall Thursday evening.

The patriarchs of modern science — including Galileo, Kepler and Newton — adopted the Pythagorean ideal of a geometrical explanation for universal phenomena, according to Gleiser. In the 20th century, scientists such as Schrodinger and Heisenberg continued the search for this “theory of everything,” which is pursued today by superstring theorists, he said.

The research aiming to discover this “final theory” is misguided, Gleiser said, because such a theory can never be verified. Although scientists can develop a theory that incorporates all presently known phenomena, their scope of knowledge is limited by the range of current instruments and observations. Other phenomena that are not yet detectable may disprove the theory, Gleiser said.

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“The main theme of the book is that science and philosophy have been looking or courting the wrong muse,” Gleiser said in the interview. “Instead of looking for this perfect, old-fashioned aesthetic of science called beauty, why not look at the imperfect?”

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The rarity of intelligent life and the “beauty” of asymmetry — already glorified in modern and postmodern art and literature — supports a new kind of anthropocentrism, according to Gleiser.

“We have a new mission to be the guardians of life, and not the destroyers,” Gleiser said. “It’s definitely empowering. If there is hope for humanity, it is for finding a common goal.”