Observations: Garrett Lisi Responds to Criticism of his Proposed Unified Theory of Physics

Observations: Garrett Lisi Responds to Criticism of his Proposed Unified Theory of Physics:  Distler's colleagues also wrote a letter to the editor of Scientific American decrying the lack of parity violation. This fact would seem very damning for E8 Theory, but it is simply not true. The structure of gravity and the Standard Model along with one generation of fermions (including their parity-violating interactions) does fit in E8, as I described explicitly in a recent paper. In their misleading argument, Distler and Garibaldi make unnecessary assumptions about how the embedding needs to happen, and then prove it can't happen that way -- a "straw man" argument.

New particle at Fermilab?

"Would be great if this possible new particle is a Z' boson with interesting lepton and quark interactions." Garrett Lisi via facebook

A Geometric Theory of Everything: Scientific American

A Geometric Theory of Everything: Scientific American

Rummaging for a Final Theory: Can a 1960s Approach Unify Gravity with the Rest of Physics?: Scientific American

Rummaging for a Final Theory: Can a 1960s Approach Unify Gravity with the Rest of Physics?: Scientific American: "Not everyone shares this optimism. Skip Garibaldi, a mathematician at Emory University, says that E8-inspired nostalgia is misguided. Working with physicist Jacques Distler of the University of Texas at Austin, Garibaldi has shown that Lisi’s theory predicts the existence of unwanted particles, whose interactions are the mirror image of regular fermions. Such particles would most likely have already exerted a noticeable effect on known particles, Garibaldi argues. “There is no way to shove gravity inside E8 without also predicting something that has nearly been ruled out by experiment,” he says.

Lisi, who posted the latest version of his theory on the Internet in June and presented it at the meeting, concedes that mirror fermions are an issue but adds that E8 theory is a work in progress and that mirror fermions could have evaded notice if they are heavier than commonly thought. They could even show up in the Large Hadron Collider, he says."

E8 "theory of everything" looking rocky

E8 "theory of everything" looking rocky: "Using linear algebra and proving theorems to translate the physics into math, Garibaldi and Distler not only showed that the formulas proposed in Lisi's paper do not work, they also demonstrated the flaws in a whole class of related theories."

Grand designs: Symmetry's hidden depths

http://www.newscientist.com/article/mg19826601.800-grand-designs-symmetrys-hidden-depths.html

Mapping the 248-Fold Way

The Atlas Project to map the structure E8

http://www.sciencemag.org/cgi/content/summary/315/5819/1647