Well I am glad they listed a helpful analogy with a room and a bunch of chairs that cleared everything up for me.

As opposed to giving you a graduate education in math & physics and many years of research besides?

The problem with putting jokes on HN is that you always have to explain the damn joke afterwards.

So yes I think good analogies can be helpful, but this particular analogy made no sense whatsoever. I mean what does it mean that one has to put two chairs on top of each other? And why does that make the theory invalid. Theories do not have to look nice or symmetrical to be valid. In any event the analogy is completely baffling.

If you cannot come up with an analogy that actually makes sense you may as well resort to authority and just say this was published in a peer reviewed journal so until someone refutes it, it is probably right.

It made sense to me (although correct me if im wrong because i dont know anything about real math or e8): the room is a collection of furniture, the e8 is a collection of theories. if you rearrange all the furniture, it's still a room full of furniture, but now all the smaller pieces' intended purpose (sitting on them, putting books in them etc) no longer work. he still keeps e8 intact holistically, but he manages to do so only by invalidating the sub theories which make up the e8.

close?

Based on my reading of the first few pages of the paper (available here http://arxiv.org/abs/0905.2658 ), your description appears roughly correct.

E8 is a lie group, which is a set of matrices which is closed under inversion and multiplication. In fact, E8 is a very large group.

Particle physics is based on a set of smaller groups, but these groups are distinct. A "theory of everything" would embed these smaller groups into a single large group. Lisi showed that you can embed these smaller groups into E8, although he didn't show that all the important properties hold.

Garibaldi showed that there are only 6 ways of doing this embedding which don't create higher spin particles. He then showed that none of these 6 ways preserve chirality (the right-handedness of the universe).

So basically, while the relevant groups can be embedded into E8, they don't preserve the physics necessary for a theory of everything.

Good job figuring out the paper, but if you had to read the paper, that just proves my initial point that the analogy failed.

A gearbox with sufficient volume, but whose design prevents the gears from meshing as intended?

That's nothing, I understand that a paragliding philosopher has proven that both the original theory and the refutation are immaterial contributions to knowledge under his own theory of scientific progress, to be published soon.

Which would have all come to naught if a particle physicist stunt driver crack shot brain surgeon rockstar hadn't saved the world from alien annihilation in the early 80's.

http://www.youtube.com/watch?v=0gNJ1z-ulB4

Garrett Lisi: "Dear Skip, you're now the guy who "proved E8 Theory can't work." Good luck. In physics, the universe gets the last laugh."

I think I felt an optical illusion in the E8-inspired graph.

Wasn't this from about a year ago?

The original E8 theory of everything paper by Garret Lisi was written around 2 years ago. The paper mentioned in this article, published about a month ago, claims to prove that a theory of everything cannot be based on E8 http://www.springerlink.com/content/h3h4wh813606ggq8/?p=6d2b...

Yes. A preprint has been on the arxiv since May '09. Lisi has also responded to the criticism at length, and others have weighed in too.