posted
Well, I mean, "Everything" is kind of a grandiose way of saying, "particle physics only." I guess I have some reservations about that.
I mean, it doesn't even touch on the reasons why pirates are better than ninjas. Not to mention explaining cats.
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If I had to point to some potential trouble for the theory, it would seem to be contained in this admission from the conclusion:
quote:Currently, the symmetry breaking and action for the theory are chosen by hand to match the standard model -- this needs a mathematical justification.
posted
Not so much where we came from, but the geometry of what is.
I can only imagine that tucked into a curl of x million tons of water gives one a certain appreciation for the geometry of reality.
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posted
In all honesty, this is the first time I've seen opposition to this theory. Sadly I hadn't taken the time to look into what they have been calling a break-through, and was just willing to be mildly excited about it. However to now look and see that there is some - at least appearing - well thought out arguments, I'm really going to have to look into this.
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posted
I'm certainly not qualified to speak about what may be good and bad physics because I only have a knowledge of physics that isn't much above that of the general layman's.
But seriously, are we supposed to believe that a surfer dude can just wake up one morning and have the Theory of Everything, therefore besting the work of thousands of scientists and years of inquiry?
Oh, BTW, Chuck Norris IS the Theory of Everything.
Edit: So, it isn't testable. What a surprise.
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quote: The crucial test of Lisi's work will come only when he has made testable predictions. Lisi himself accepts this, saying that although his theory is beautiful to him, "nature may disagree".
So it's not as though he has found this and believes whole-heartedly that he is correct, but rather is taking it with a grain of salt.
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quote:Originally posted by adfectio: In all honesty, this is the first time I've seen opposition to this theory.
That's mostly because almost every major news outlet, and every scientific journal, has figuratively at this. They're not bothering to spend the time to be "opposition."
And it's not because he's a surfer, or because he's not an academic. I know of at least one well-known physicist who surfs, and certainly there have been quite a few important theories first devised by those who received a less than traditional education.
It's because it's utter nonsense.
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posted
I saw fugu's link on the other thread. Problem is, Motl has a history with Lee Smolin and the Perimeter Institute for Theoretical Physics arising from Smolin's book "The Trouble with Physics" and specific critiques that Smolin levels on Motl's martix string theory.
Much of Motl's critique in that blog was unabashedly ad hominen and association fallacy. For Motl, if Smolin endorses it, it must be crackpot.
Perhaps he is correct. You certainly seem convinced.
There are obvious problems with Lisi's theory. But then, there are obvious problems with Motl's matrix string theory. I guess what gives me pause is that Lisi does (at least potentially) offer testable predictions. Thirty years of string theory has yet to match that boast.
I don't know who is right. Neither do they and ultimately, neither do you. Maybe CERN will clear it up, maybe not. In the meantime, choosing one camp over the other will entail something other than the 'facts' because they just aren't in yet.
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posted
He may be a surfer dude, but he's a dude with a doctorate in theoretical physics. This at least makes him qualified to comment.
It's hardly as if some THC raddled beach-bum suddenly developed a grand unified theory from nothing, after a heavy night on the cider...
Cut the guy some slack. After all, the whole theory of relativity schtick came from an unknown patent clerk...
I for one hope he is on the right track - string thoery makes my head hurt, and at leasts his work is something you could hang on the wall.
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posted
He didn't actually design that. That picture was designed back in the 1800s, according to the first article. He just realized that his calculations on particles seemed to match up with calculations done to get that design...
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posted
Physics schmisics. Everyone already knows how the universe started. Chuck Norris Round-House kicked his way out of a Black Hole which resulted in the Big Bang.
Which leads us to:
Only a Chuck Norris Round-House kick can escape the Event horizon of a Black Hole. This is also the Force responsible for the so-called "Hawking Radiation". Chuck felt sorry for Mr. Hawking though, and hasn't demanded for the name to be changed.
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posted
Mmm. I'm not inclined to be completely dismissive (except as much as I'm required to be of weird new theoretical ramblings to maintain my lab cred, of course). The Standard Model can be expressed in group-theory terms, after all; it would hardly be surprising if the GUT could as well. And since he predicts new particles, well, great; that's how the Standard Model group-theoretic description came to be accepted, by pointing out that "Here are these particles corresponding to this group, and here is a hole in the group, so if you look around mass X, what do you find?" And lo and behold there were particles there with the predicted properties. So, sure, let him work out the masses of his predicted new particles and we'll let the LHC loose at it. This is good classic theory-experiment interaction. I wish the papers hadn't picked up so much on the surfer-dude aspect, though. Clearly that's not the important part of the guy, if he does good theoretical work.
The note about being unable to explain the symmetry breaking is a bit of a quibble; neither can any other candidate for a grand unified theory, as far as I'm aware. If there's a better way of introducing symmetry breaking than setting the values by hand, I don't know of it. (Which is not to say that one doesn't exist; I admit to a tendency towards eye-glazing when the theory guys really get going. I usually stick to the experimental literature.)
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quote:Currently, the symmetry breaking and action for the theory are chosen by hand to match the standard model -- this needs a mathematical justification.
Just wanted to point out that LOTS of particle physics happens like this. See "renormalization". Heck, even the Feynman path integral has some mathematical difficulties associated with it, but that doesn't stop physicists from using it- an coming up with really nice results.
Also, the quote "Lisi's inspiration lies in the most elegant and intricate shape known to mathematics, called E8 - a complex, eight-dimensional mathematical pattern with 248 points first found in 1887, but only fully understood by mathematicians this year after workings, that, if written out in tiny print, would cover an area the size of Manhattan." is VERY misleading.
E8 isn't 8 dimensional and it doesn't have 248 points.
It is the 8th in a family of objects (cleverly denoted E1, E2, E3, etc), which is 248 complex dimensional (or 496 real dimensions for us normal folk).
Anyway, I haven't yet read his paper, but I'm quite eager to do so....
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posted
Incidentally, just what makes E8 "the most elegant and intricate shape"? Unless you mathematician types have come up with some quantitative measure of elegance recently, of course. And as for intricacy, pff, from any given group I can generate a more intricate one by making the same group, with each of the elements being another instance of the group. Poof, squared intricacy. Damn these journalists, anyway.
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posted
Ah, ok - no predictions of masses without very difficult calculations. That makes it a bit of a meh. Let him come back when he knows a particle mass.
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quote:Originally posted by King of Men: Incidentally, just what makes E8 "the most elegant and intricate shape"? Unless you mathematician types have come up with some quantitative measure of elegance recently, of course. And as for intricacy, pff, from any given group I can generate a more intricate one by making the same group, with each of the elements being another instance of the group. Poof, squared intricacy. Damn these journalists, anyway.
(I'm gonna lose everyone who's not mathy or physicsy here).
E8 is a lie group corresponding to a lie algebra e8, which is simple (no nontrivial ideals).
It turns out, we have a classification of ALL simple lie algebras. They fit into 4 infinite families (denoted a1, a2, etc, b1, b2, etc, c1, c2, etc, and d1, d2, etc), and there a finite number (either 4 or 8, I forget) of simple lie algebras which don't fit into any of the 4 families. E8 is the largest simple lie algebra not fitting into 1 of the 4 families, making it quite "intricate"
Incidentally, while I've heard of proofs and techniques being described as "elegant", I've never heard of an object being described as elegant. I chalk that up to a journalist mix an matching a phrasing some physicist/mathematician used in an interview.
Also, you said you could take a group, replace each of its elements with a copy of the group. I agree that this would make it much more "intricate", but is there some way to make this object into a group?
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posted
Waving my hands here, but intuitively: if A and B are elements of the small group, then elements of the large object are denoted AA, AB, BA, BB, where the first letter is the subgroup and the second letter is the element within the subgroup. Now, we can define the operator for our big object in terms of the operator we already have which defines the group, so that
NM * UV = [NU][MV]
It is pretty obvious that this is closed, so let's check the other properties. Associativity:
and for each square bracket we already know that we have associativity, so check. Identity element; let A be the identity element for the small group, then
[AA][NM] = [AN][AM] = NM
check. Inverse; suppose elements X and Y to have inverses N and M, then
posted
I thought E8 was described by octonions, ie the algebra is non-associative and non-commutative.
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posted
Well, if it's not associative it's not a group. Anyway you can just drop that check and my expanded group will pass whatever tests the un-expanded one does.
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posted
And here I thought E8 was a group of 8 main European Countries (The G8 meets the EU). England, France, Spain, Portugal, Germany, Italy, Sweden, and Ireland.
And I would have to agree KOM, that's not a group, they try hard to be non-associative and non-communicative (you mispelled that Aspectre)and definately the leaders of those countries should XYZ.
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quote:Originally posted by aspectre: I thought E8 was described by octonions, ie the algebra is non-associative and non-commutative.
I THINK E8 is a subgroup automorphism group of the octonians. It MAY be all of the automorphisms, but I'm VERY not sure about this.
A friend of mine gave a talk on this a few weeks ago - I'll ask him about it tomorrow and report back.
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quote:Originally posted by King of Men: Waving my hands here, but intuitively: if A and B are elements of the small group, then elements of the large object are denoted AA, AB,....
As soon as I typed my question asking WHY it was a group, the multiplication you described popped in my head and I was just too lazy to work it out. Thanks for doing so for me!
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posted
It took me several paragraphs in the article to realize that I wasn't reading an Onion-esque article.
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posted
cool article. not sure i buy into the theory, but i enjoyed reading about it. i hope that new particle accelerator helps prove a lot of what scientist want to know. otherwise it might seem like a big waste of money.
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What a funny word. Like a good name for a Mario boss--Bad Breath and he makes you cry! And you have to peel off layers to beat him.
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quote:Originally posted by aspectre: I thought E8 was described by octonions, ie the algebra is non-associative and non-commutative.
I THINK E8 is a subgroup automorphism group of the octonians. It MAY be all of the automorphisms, but I'm VERY not sure about this.
A friend of mine gave a talk on this a few weeks ago - I'll ask him about it tomorrow and report back.
It's strange quoting oneself.
I asked my friend and it's G2 which is the automorphism group of the octonians. I still have virtually no clue what E8 is ;).
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quote:Garrett Lisi, 39, has a doctorate but no university affiliation and spends most of the year surfing in Hawaii, where he has also been a hiking guide and bridge builder (when he slept in a jungle yurt).
In winter, he heads to the mountains near Lake Tahoe, Nevada, where he snowboards. "Being poor sucks," Lisi says. "It's hard to figure out the secrets of the universe when you're trying to figure out where you and your girlfriend are going to sleep next month."
But, like, getting a job? Forget that noise, daddy-o.
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