## Tuesday, May 01, 2007

### Strings in Two Minutes or Less

The eight finalists for the Discover Magazine "String Theory in Two Minutes of Less" contest have been selected and can be found at discovermagazine.com. Even though Brian Greene is the official contest judge, there is a viewer's choice award that net surfers can participate in. I casted my vote for the 'String Ducky' entry, as it is pretty accurate and easy to follow. Which is your choice?

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## 12 comments:

Well, I'm not going to vote, but I quite liked

The New Revolutionwith the history of dimensional visualisation. Accuracy was not one of my criteria!Oops, I meant

The Next Revolution.OK, I voted just to see the poll. My choice is unpopular, but yours is clearly leading!

Kea has threads on 'M-Theory Lesson 47 and 48' stating that S-duality relates to electromagnetism, but there is no discussion of U-duality.

Considering the title of your blog, perhaps you can clarify for me if U-duality may relate to trajectories?

I ask this because of seemingly different discussions of U-duality:

1 - from the arxive; but I have difficulty visualizing:

a - Lu and Pope, 'T-duality and U-duality in toroidially-compacted strings', 1997

http://arxiv.org/PS_cache/hep-th/pdf/9701/9701177v2.pdf

b - Obers and Pioline, 'U-duality and M-Theory', 1999

http://xxx.lanl.gov/PS_cache/hep-th/pdf/9809/9809039v4.pdf

2 - from an unknown canadian source; I can easily visualize

Figure 09 U Duality

http://universe-review.ca/I15-51-11D.jpg

next to text within 'Superstring Theory - M-Theory - U Duality abd 11 Dimensions' with "... In the IIA case the eleventh dimension is a tube, whereas in the HE case it is a cylinder ..."

http://universe-review.ca/R15-18-string.htm

These Wolfram illustrations of tubes might be perturbed trajectories from my perspective.

http://mathworld.wolfram.com/Tube.html

Hi doug,

There is evidence that the perturbative and non-perturbative string dualities are all encoded in a global symmetry group of the low energy supergravity effective action, called the U-duality group. The U-duality group combines both the S and T dualities. An excellent reference is Hull and Townsend's Unity of Superstring Dualities paper.

In the study of extremal black holes, the U-duality groups enter as symmetry groups of electric and magnetic charges on the horizon. From the lens of loop quantum gravity, the charges are associated with spin network punctures of the horizon surface. See Baez's picture for visualization of this.

As far as trajectories go, take a look at my 3D dynamical system plots. The trajectories were plotted via iterated triples of the form (q1^k,q2^k,q3^k), where q1, q2 and q3 are electric extremal black hole charges.

Well I provided the 18th vote for "A Better Way: String Theory!".

In addition to being considerably better than the 8 others, it was filmed by the physics club at New Mexico Tech, where I took a BS and MS in mathematics.

wow, discover magazine chooses the lowest common denominators!

Not a good showing for string theorists to have small children petting animals or physics students hanging upside down from monkey bars, America's funniest home video style.

Is this a three ring circus and the Discover magazine folks are the ringleaders deciding what science should be to the average working Joe or Jane?

There were better videos posted on Brightcove than some of the finalists.

I'm so depressed with the common level of intelligence, I've got a pain in all the diodes down my left side.

I'm spending my morning doing nothing but finding physics sites and reading them and going wherever I go from there.

It's a shame that wasn't one of the choices in the poll.

Welcome Hank!

Hi Kneemo,

1 - Thanks for the Hull and Townsend reference.

The Baez picture reminds me of this NASA solar magnetic field

http://observe.arc.nasa.gov/nasa/ootw/1997/ootw_971217/ob971217.html

2 - RE: Bergman and Lifschytz 'When D-branes Break' referecnce in Kea blog 'Tetractys':

Maybe D-branes can undergo electromagnetic field reconnection?

See figues 4 and 5 from AIP article

http://www.aip.org/tip/INPHFA/vol-9/iss-6/p18.html

3 - RE: 'Twistors and Black Holes' arciv reference on Kea blog 'Updates II':

Maybe "twistfoam" might replace 'spinfoam' of LQG?

4 - Your refernce to a dynamic Linde multiverse on Kea blog may have a cosmic counterpart, but in the stellar factory scale?

Goddard-12 -> Chandra-3 -> Spitzer-5 picture -> The Spacecraft-10

Spitzer section

Captures Cosmic Mountains Of Creation [34s movie]

and

Size Comparison to Hubble’s “Pillars of Creation” [9s movie]

http://www.nasa.gov/centers/goddard/news/topstory/2006/2005seu_resource_prt.htm

Maybe "twistfoam" might replace 'spinfoam' of LQG?Twistfoam, ah, I like the sound of that.

Hi Kneemo,

1 - I accidentally stumbled across this wiki page on "algebra over a field K, or a K-algebra" which more properly should be in a previous thread.

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

Specifically discussed are Lie and Jordan algebras among others. There are links to:

Clifford algebra

Differential algebra

Geometric algebra

Max-plus algebra.

The last is a form of mathematical game theory algebra used in applied mathematics by both economists and engineers who apply physical mathematics.

2 - This is an informative site on the power of Petri Nets also used in applied mathematics as a graph form of Max-plus algebra.

In ‘Frequently Asked Questions’:

Petri Nets is a formal and graphical appealing language which is appropriate for modelling systems with concurrency and resource sharing. Petri Nets has been under development since the beginning of the 60'ies, where Carl Adam Petri defined the language. It was the first time a general theory for discrete parallel systems was formulated. The language is a generalisation of automata theory such that the concept of concurrently occurring events can be expressed.

http://www.informatik.uni-hamburg.de/TGI/PetriNets/

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