Wednesday, January 15, 2014

Loops vs Strings. Almost discovered for much longer.

I didn't attend this year's FQXi conference, but most of the talks will be uploaded sooner or later to the FQXi YouTube channel. The FQXi conferences always feature a mock debate with a role switch. I've never seen one with an actual exchange of arguments, but the debates have some amusement value. This year we have Carlo Rovelli defending String Theory ("You Loop people... insist that you cannot get any prediction from your theory. But we can't either.") and Raffael Bousso defending Loop Quantum Gravity ("What happened next was the string landscape. You've all heard of the string landscape. It's also known as 'The End of Science.'"). Enjoy.


Plato Hagel said...

Ya I posted this yesterday as well.

Seeing how you were speaking of relevancy, I could hear the people in the background laugh. This when something rang true to their ears, as if, we are walking in another persons shoes for a minute. Here, we are witness to this reverse debate. It really was quite funny to me too.

Your absence was duly noted as well, regarding your heretic freewill perspective. I believe you were being chided for your absence even though it is much appreciated. I kind like this humor over all, as it seems quite friendly.

I just wish FQXi would accept anonymity for comment accessibility, as I would like to retain this status.


Uncle Al said...

Claim quantum gravitation, dark matter, and the standard model? No quantum gravitation, no dark matter. The standard model is holes and patches (neutrino-antineutrino see-saw mechanism? Odious). Applied math must be empirically validated. Empirical falsification can leave useful but not truthful black boxes.

Empirical failure falsifies postulates. If boson photon vacuum symmetries are not exact for fermionic matter, failed theory is sourced and ab initio correctable. Bosons and fermions are not exactly interchangeable Physics' ever new potions all assume active ingredients. Chemical failure of a physics' postulate is Not Of Our Class, Dearie. Don't look. Revelation 22:7: Gauged, renormalized, perturbation theoried, dualed, promoted into higher dimensions, exhaustively peer reviewed and published. Wrong, Aristotle versus Galileo.

Dick Jones, "I had a guaranteed military sale with ED-209. Renovation program. Spare parts for 25 years. Who cares if it worked or not?" Robocop

Robert L. Oldershaw said...

Well, clearly the clowns have been sent in.

Where have you gone Albert? Our scientific nation turns its lonely and desperate eyes to you.

Zephir said...

/* You Loop people... insist that you cannot get any prediction from your theory. But we can't either ..*/

These two theories are essentially AdS/CFT dual. Inside of emergent environment the stringy density fluctuations would be the smallest and largest observable artifact. So that string theorists deals with strings in the role of particles and loop theorists deal with strings in the role of quantum loops forming the space-time. The stringy people are considering the extradimensions and Lorentz symmetry (which excludes the extradimensions), whereas the loopy people have similar consistence problem with equivalence principle and mass-energy equivalence.

Phillip Helbig said...

"I just wish FQXi would accept anonymity for comment accessibility, as I would like to retain this status."


Arun said...

I can't imagine dynamics without time, so how space emerges from whatever the quantum substrate is, and then entangles with time to form the classical space-time of general relativity is something I find very hard to imagine.

L. Edgar Otto said...

Discover magazine some years ago - since we do not know the ultimate substance of the universe it may just as well be "clown noses " .

"He just loved the name of Sarah while you lit for him your menorah near Christmas day, when I was your tragic fool and you played his clown."

Zephir said...

/* so how space emerges from whatever the quantum substrate is */

If you compress the gas, its density fluctuations will EMERGE: they will appear first like the fuzzy blobby spheres ("unparticles"), later they will get the stringy shape and they will connect itself into dynamic mesh or stringy network. This process can be simulated at computer rather easily with sufficient number of mutually colliding particles. The onset of HT superconductivity is based on the same phenomena with electrons in the role of particles.

The trick is, the condensing gas is rather poor conductor of energy waves in the same way, like the air or underwater. Once the continuous phase of stringy density fluctuations will be formed, the energy density will raise significantly. As you can probably imagine, most of energy spreads along water surface, not through underwater. During underwater nuclear explosions most of damage is made with surface tsunami, not the underwater shock wave.

So that most of energy in this foamy environment will be transferred in transverse waves along its density fluctuations after then, i.e. in similar way, like the ripples at the water surface. The resulting foam of strings will therefore represent the actual environment for absolute majority of energy spreading, i.e. the space-time.

IMO this model is quite trivial and easy to imagine - but the dismissal of aether model before one century has made a political problem from its acceptation.

Phil Warnell said...

Hi Bee,

They argue so convincingly against their own points of view I'm now more encouraged that there is still hope for physics after all :-)



Zephir said...

/*..Discover magazine some years ago - since we do not know the ultimate substance of the universe it may just as well be "clown noses "*/

This is actually quite correct insight. In dense aether model the geometry of particles is not important, only the geometry of their packing is. In addition, this model is inherently recursive: once the emergent less or more continuous space-time is formed in the above way, it may form a new generation of density fluctuations and so on. This repetitive process would wipe out the underlying nature of original environment quite well before observer.

IMO the emergent model of reality is so rich in its consequences, we could delay the questions about its underlying nature for the further next centuries quite comfortably.

L. Edgar Otto said...

I got your point some time ago. Why do you not get Sabine's who seems to me to have looked in depth under these issues of aether? She has not asserted alternative models are wrong just not good science.
Unclear and not forbidden possibilities makes it hard to have s nose for clowns.

Sorry my last post used confusing quotation marks. My song Outside My Window quoted myself if that is possible... it should read. Tragic tramp not tragic fool... it is about this Jewish friend of mine who worked as a clown at parties in New York and once played the part on the Bill Cosby show episode.
Put on the spot Googling my brain can have errors as in tests.

Georg said...

Loops, strings but no hooks to fasten
the ends of strings to (maybe using loops)

L. Edgar Otto said...

I find that a most relavant comment. As a chid I could draw a map of the earth then I discovered the celestial globe. So one night I asked the folks "what holds the moon up? " They said a long rope. I thought about where it was tied then one day looking at a celestial globe I asked myself how they got all the stars out there on a globe and something clicked!
We have only three color receptors, the birds four, turtles five. Bats none for the colors. But female guppies can see a males display of orange with up to eleven color receptors (which with a little imagination strikes me as a string theory approach. )
Now atoms, which at the time were hypothetical as we could not see them, for awhile were said to stick together by little hooks. I find it tragic and humorous that in the string and loop debate on a deeper level that is where we seem to be now. :-)

L. Edgar Otto said...

Science Daily just announced a new form of QM in three dimensional space analogous to 2D Diracian ideas on graphene. Now, is this an emergent property string theory by itself predicts, or approaching it from the loop ideas on space itself easy to make predictions for such quantization? Recall that playing. 2D chess in 3D is harder than ND into 2D quite besides what is curved spaces or
intelligibly discrete.
Can 4D and 5D new QM constructs be far behind this tech in coming?
This applies to alternative models too debating the independent axioms of choice and the continuum hypothesis. Can we not see our compact grey matter brain is at least three dimensional? Someone will whip off a paper saying this new QM applies to our brains even though in dimensionfree scales that QM at all applies is a matter of passionate debate. QED

muon said...

Hilarious! Great to see that people can retain their humanity and sense of humor. Thanks for the post.