9 ms·

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

38 points by robg 18y ago

donw 18y 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.
- ninguem1 18y 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.
  - donw 18y ago
    Spoken like a man with a drastically better grasp of group theory than my own. :)
timothyandrew 18y ago
Complex stuff.
canoebuilder 18y 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_wallacewells?currentPage=all http://www.newyorker.com/reporting/2008/07/21/080721fa_fact_...
- robg 18y ago
  Not surprising given the source, but that's a much better version. Thanks.
d0mine 18y ago
No, he has not. http://golem.ph.utexas.edu/~distler/blog/archives/001505.html http://golem.ph.utexas.edu/~distler/blog/archives/001505.htm...
- whordeley 18y ago
  Oh. That made perfect sense. Can you summarize?
  - gaika 18y 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."
    - robg 18y ago
      From the article, Lee Smolin (http://www.leesmolin.com/ http://www.leesmolin.com/) has already put out a paper building on Lisi's approach.
    - hhm 18y ago
      Lisi replies to the article too...
- wheels 18y 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.
  - d0mine 18y 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.
gaika 18y ago
Have a pleasure of knowing Garrett, his foot once helped bring traffic to my site: http://joe.jaanix.com/22679-nuke-cerenkov-glow 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 18y ago
  *"... Have a pleasure of knowing Garrett, his foot once helped bring traffic to my site: http://joe.jaanix.com/22679-nuke-cerenkov-glow 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?
  - deleted 18y ago
    [deleted]
rguzman 18y 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-theory-of.html http://motls.blogspot.com/2007/11/exceptionally-simple-theor...
- vsingh 18y ago
  This Lubos Motl guy seems to be a sort of Erik Naggum of physics. Yikes.
- rguzman 18y ago
  This also an older post back from when Lisi's paper first came out: http://www.math.columbia.edu/~woit/wordpress/?p=617 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.
brentr 18y 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.
- DanielBMarkham 18y 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 18y 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.
- sarehu 18y 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.
  - brentr 18y 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 http://en.wikipedia.org/wiki/Theory_of_everything
senthil_rajasek 18y 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 18y 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 18y ago
  What a brilliant observation about "known unknowns". Though, one could say that there are also unkown unkowns, and unkown knowns, yet.
- DanielBMarkham 18y 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.
  - DaniFong 18y 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?
    - aswanson 18y ago
      No references and I may be going down the wrong path here, but wasn't there some relatively recent activity with respect to the quantization of space, with the Planck length being the minimal quantum?: http://www.scienceandresearchdevelopmentinstitute.com/planck.pdf http://www.scienceandresearchdevelopmentinstitute.com/planck...
dehowell 18y 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.

38 points by robg 18y ago

donw 18y 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.

ninguem1 18y 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.
- donw 18y ago
  Spoken like a man with a drastically better grasp of group theory than my own. :)

timothyandrew 18y ago

Complex stuff.

canoebuilder 18y 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_wallacewells?currentPage=all http://www.newyorker.com/reporting/2008/07/21/080721fa_fact_...

robg 18y ago
Not surprising given the source, but that's a much better version. Thanks.

d0mine 18y ago

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

whordeley 18y ago
Oh. That made perfect sense. Can you summarize?
- gaika 18y 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."
  - robg 18y ago
    From the article, Lee Smolin (http://www.leesmolin.com/ http://www.leesmolin.com/) has already put out a paper building on Lisi's approach.
  - hhm 18y ago
    Lisi replies to the article too...
wheels 18y 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.
- d0mine 18y 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.

gaika 18y ago

Have a pleasure of knowing Garrett, his foot once helped bring traffic to my site: http://joe.jaanix.com/22679-nuke-cerenkov-glow 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 18y ago
*"... Have a pleasure of knowing Garrett, his foot once helped bring traffic to my site: http://joe.jaanix.com/22679-nuke-cerenkov-glow 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?
- deleted 18y ago
  [deleted]

rguzman 18y 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-theory-of.html http://motls.blogspot.com/2007/11/exceptionally-simple-theor...

vsingh 18y ago
This Lubos Motl guy seems to be a sort of Erik Naggum of physics. Yikes.
rguzman 18y ago
This also an older post back from when Lisi's paper first came out: http://www.math.columbia.edu/~woit/wordpress/?p=617 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.

brentr 18y 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.

DanielBMarkham 18y 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 18y 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.
sarehu 18y 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.
- brentr 18y 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 http://en.wikipedia.org/wiki/Theory_of_everything

senthil_rajasek 18y 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 18y 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 18y ago
What a brilliant observation about "known unknowns". Though, one could say that there are also unkown unkowns, and unkown knowns, yet.
DanielBMarkham 18y 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.
- DaniFong 18y 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?
  - aswanson 18y ago
    No references and I may be going down the wrong path here, but wasn't there some relatively recent activity with respect to the quantization of space, with the Planck length being the minimal quantum?: http://www.scienceandresearchdevelopmentinstitute.com/planck.pdf http://www.scienceandresearchdevelopmentinstitute.com/planck...

dehowell 18y 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.