Has a surfer Ph.D. rewritten physics? Maybe.

http://outside.away.com/outside/culture/200805/garrett-lisi-1.html

by robg • 18 years ago

38 43 18 years ago

outside.away.com

donw2• 18 years ago

My knowledge of mathematics is dwarfed by anybody with a higher degree in the subject, and Algebra (the abstract kind, not the kind with lots of letters) was my worst subject, but part of me is a bit pleased that E8 might be related to an important bit of physics. It's a rather interesting structure, although not 'the largest' as the article claims, as there are some which (if I recall correctly), reach into million-dimensionality.

E8 also has some interesting properties relating to symmetry, so I'm not surprised that it gets used in physics. It's just a pity that the universe couldn't be related to A4, or A8, because I can actually grasp what's happening in those groups.

Even if he's wrong, it goes to show that stepping outside the mainstream can often times be the only way to starting out on a novel, and potentially revolutionary, approach.

ninguem12• 18 years ago

E8 is an exceptional Lie group (ie a group that is also a manifold, hence in particular infinite). You seem to be mixing it up with the exceptional finite simple groups. Wikipedia explains.

donw2• 18 years ago

Spoken like a man with a drastically better grasp of group theory than my own. :)

timothyandrew• 18 years ago

Complex stuff.

canoebuilder• 18 years ago

I'm not entirely keen on the hubbub refered to(the articles on Lisi from about this time last year?)

Here is another article I read the other day, probably pretty similar, but it wasn't bad

http://www.newyorker.com/reporting/2008/07/21/080721fa_fact_...

robg2• 18 years ago

Not surprising given the source, but that's a much better version. Thanks.

d0mine2• 18 years ago

No, he has not. http://golem.ph.utexas.edu/~distler/blog/archives/001505.htm...

whordeley• 18 years ago

Oh. That made perfect sense. Can you summarize?

gaika3• 18 years ago

From the link: "the overlap between the set of people who know some group theory and those who are (still) interested in giving Lisi’s “Theory of Everything” a passing thought is empty."

wheels2• 18 years ago

I find that blog post characteristic of what's wrong with academia. Lisi's obviously not a nutjob, and obviously not an idiot, and he's treated with contempt for proposing a big idea that might be wrong; might even be spectacularly wrong. Academia as a whole would usually rather see people get back in line and go on solving irrelevant problems. I found it encouraging that in the originally linked article that he at least did find some people in the scientific community that would treat him with a modicum of respect even if it was just in taking the time to explain why his theory doesn't fit the bill.

d0mine2• 18 years ago

There are "big ideas" which look interesting and fresh for a general public, but they are boring and plain wrong for any professional in the field.

I'm sure you can find such things in your area of expertise.

All that glisters is not gold.

gaika3• 18 years ago

Have a pleasure of knowing Garrett, his foot once helped bring traffic to my site: http://joe.jaanix.com/22679-nuke-cerenkov-glow :)

You might also soon hear about his friend mentioned in the article, Brandyn. He's working on a problem that is just as important as ToE. They had a running joke: who would find ToE first, Garrent by math and thinking or Brandyn by inventing AI that would do it for him.

bootload• 18 years ago

*"... Have a pleasure of knowing Garrett, his foot once helped bring traffic to my site: http://joe.jaanix.com/22679-nuke-cerenkov-glow :) ..."

Hey Joe thanks for reminding me of jaanix again. I seem to remember it being reviewed in HN a long while ago. Looking at it again the sig/noise is pretty good. Is the site pulling HackerNews from RSS?

rguzman2• 18 years ago

I really don't know enough to say one way or the other, but for those who care, here is some skepticism about Lisi's paper: http://motls.blogspot.com/2007/11/exceptionally-simple-theor...

vsingh• 18 years ago

This Lubos Motl guy seems to be a sort of Erik Naggum of physics. Yikes.

rguzman2• 18 years ago

This also an older post back from when Lisi's paper first came out: http://www.math.columbia.edu/~woit/wordpress/?p=617 Again, I don't really know too much about this stuff, but it should be interesting to anyone who'd like to get to the bottom of how credible the paper is.

brentr3• 18 years ago

I don't remember where I read it, nor the exact wording, but there is a quote that is perfect for this. It went something like this, "Godel proved incompleteness. Anyone who thinks there is a theory of everything laughs in the face of Godel."

My point is that physics does not exist in a vacuum. It is built up from observational data found in nature and taken from experiments. If mathematics can't come to complete truth (Godel has proven this), then there is no hope for a theory of everything in something that uses mathematics as its language.

DanielBMarkham4• 18 years ago

I'm with you about 80% of the way here.

Godel showed (and guys tell me if I mess this up) that formal self-consistent systems have both statements that are true that cannot be proven and false statements that cannot disproved. In other words, complete systems are incomplete.

This does not mean that complete systems cannot model reality to a high degree -- there's no reason why a ToE could pop out from some rotation or transmutation of mathematics. It just means there would be parts of it that would be incomplete -- the model itself could have a very high degree of fidelity.

When applied to higher math and physics, this is another way of saying "you don't know what you don't know" ie, the models can work perfectly across all observation space and still be true to Godel.

Asmodeus• 18 years ago

It will be incomplete in the sense that it will contain axioms with no formal proof. Technically speaking the TOE is this axiom.

However, you can even prune these axioms by selecting for the simplest one that conflicts with the least data.

sarehu3• 18 years ago

That's complete nonsense. There's nothing about Godel's theorem that says the physical rules of the universe can't be described. You're babbling religiously.

brentr3• 18 years ago

Check out the following entry on Wikipedia related to Godel's Incompleteness Theorem and the Theory of Everything

http://en.wikipedia.org/wiki/Theory_of_everything

DanielBMarkham4• 18 years ago

"A small number of scientists claim that Gödel's incompleteness theorem proves that any attempt to construct a TOE is bound to fail. Gödel's theorem states that any non-trivial mathematical theory that has a finite description is either inconsistent or incomplete."

That's from the Wiki, FWIW. I'm not big on using Wiki as a source.

"Babbling religiously" is right on the line in my opinion. It makes you sound like an arrogant jerk. If you have problems with the content of the comment, state your case in neutral terms.

Learn to live with other people's ambiguity and looseness in phrasing. Then perhaps they'll be more forgiving of yours. (Downmod)

gaika3• 18 years ago

One counterexample for you: Conway's game of life has finite number of rules but you can construct universal turing machine with it that will have formally undecidable behaviour.

ninguem12• 18 years ago

"Theory of Everything" is not a theory for everything, literally. It is just a catchphrase used by physicists to mean a theory that encompasses the "Standard Model" (which describes particle physics) with General Relativity and gravitation, thus describing the whole physical universe (which, in the physicists narrow mind, is everything). So Godel has nothing to do with this.

hhm2• 18 years ago

You can have a theory of everything that is incomplete. There are no problems with that. And that's what people is looking for... ToE doesn't mean "a complete theory of physics", in the logical meaning of complete.

senthil_rajasek• 18 years ago

Here is a nice observation from Lee Smolin about this theory,

"I don't see it as a finished theory," he says of Lisi's formulation. "I see it as some mathematical observations and then a proposal."

Allocator2008• 18 years ago

Well leaving aside Godel, I think one can have a theory of everything that has, as Rumsfeld would say, "known unknowns", i.e., a theory of everything which "manages" in some way unknown parameters. Like infinities in quantum field theory go away by the nature of string theory's elimination of arbitrarily small distances. Anyway. I think I'm keeping my money on string theory, but an interesting thought nonetheless!

maurycy• 18 years ago

What a brilliant observation about "known unknowns". Though, one could say that there are also unkown unkowns, and unkown knowns, yet.

DanielBMarkham4• 18 years ago

If you read a bit of Wolfram, he asks a provocative question: suppose the universe is, in fact, discrete and not continuous. If this is the case, and I think that's non-controversial now, then it may be that Sir Newton took us way down the wrong road with his discovery of the integral. We've been doing continuous math-type things with a universe that simply does not work that way. The integral was simply a cheat -- a numbers game that looked as true to reality as we could possibly verify at the time.

So we're working with known unknowns. That is, the integral works so well in most everything we do we're comfortable where it falls apart -- right around ToE, probably. But if we went belly-up as far back as Newton, where to start to fix it? I know I'm sounding like a shill for NKS now, but I _did_ find it had some really interesting ideas. In a computational universe, we could have really simple physics that lead to incredibly complex and non-intuitive results.

DaniFong2• 18 years ago

I didn't think the question of continuous versus discontinuous universes has ever really been resolved in a convincing way. Do you have any references?

dehowell• 18 years ago

No. Even though particle physics gets all the media attention, theories like this (and string theory for that matter), are shallow in comparison to statistical mechanics and thermodynamics.

It's exciting to find out what the smallest building blocks look like, but all the real structure in the universe arise from the interactions... and statistical mechanics addresses the interactions at all scales.

Modifications to our understanding of the smallest scales will trickle up to stat mech and thermo, but statistical mechanics is the true heart of physics.

Has a surfer Ph.D. rewritten physics? Maybe.

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