Smolin talks in London and Paris this month (June 2006)

[Martin]

Lee Smolin will be giving public lectures June 14 and 19.

 

I expect the talks to be controversial and relevant to the current debate surrounding unification issues and the status of string theory as science. But the description of the London talk does not explicitly make that connection.

 

That talk is "The Annual Public Lecture" at the London School of Economics CPNSS

http://www.lse.ac.uk/collections/CPNSS/events/Conferences/AnnualPublicLecture.htm

 

Anyone who happens to be in London around that time, if interested in science issues, might wish to attend. Prof. Smolin will be introduced by Jeremy Butterfield of All Soul's College-Oxford.

 

From the description, I would guess that the talk will be based on a book which Smolin is writing (I heard that it is scheduled for release this year by Houghton Mifflin) and also partly on a paper called Scientific Alternatives to the Anthropic Principle. The background to this paper is a crisis in string predictability and controversy surrounding appeals to the Anthropic Principle. Another source might be an essay by Smolin

A Crisis in Fundamental Physics

http://www.nyas.org/publications/UpdateUnbound.asp?UpdateID=41

published in the New York Academy of Sciences monthly.

=======

 

The other talk is titled Against Symmetry and appears to be based on Smolin's recent paper The Case for Background Independence.

http://arxiv.org/abs/hep-th/0507235

It will be given in Paris on June 14 at the Ecole Polytechnique (good venue: a French version of MIT)

 

This talk is explicitly controversial and presents two diametrically opposed views of physics leading to differing concepts of unification. Here is a short advance summary of the talk copied in Christine Dantas' blog:

http://christinedantas.blogspot.com/2006/05/lee-smolin-against-symmetry.html

 

===from the announcement of the Paris talk===

 

From the Leibniz-Newton debates to the present debates between string theorists and loop quantum gravity theorists two notions of fundamental physics have stood opposed. On the one hand is the Newtonian vision, which is based on a belief in a fixed absolute space and time and which holds symmetry to be fundamental and its breaking to be contingent. Leibniz's conception of space and time is an ever evolving network of relationships in which complexity is fundamental and symmetry is unnatural and accidental. This distinction characterizes the divide between background dependent theories like string theory and relational, background independent theories such as loop quantum gravity.

 

In this talk I analyze the present status of the two traditions and the plausibility of their contemporary incarnations. I show that the crisis of predictability facing string theory is a direct consequence of a conception of unification that is opposed to the principles that underlie the successful modern unifications such as general relativity and gauge theories. I close by describing a new kind of unification which emerges from background independent theories.

 

Amphithéâtre A, entrée par le 25 rue de la Montagne Sainte-Geneviève, Paris 5ème

Contact : Alexei Grinbaum (alexei.grinbaum@polytechnique.edu)

===end quote===

 

Any comment?

[Martin]

forgot to mention: Smolin's new book deals with science policy issues such as the conduct and funding of research. A foretaste of what he has to say on that score can be found in his article in the June 2005 issue of "Physics Today" titled

Why No 'New Einstein'?

http://www.everythingimportant.org/relativity/no-new-einstein.pdf

 

Smolin is critical of how physics theory research is currently organized.

He believes the system doesnt support mental independence particularly in young researchers.

This article ruffled some feathers last year, when it came out, which I suppose is why it is now available online outside the American Physical Society's Physics Today archives.

[bascule]

Leibniz's conception of space and time is instead of an ever evolving network of relationships

 

Wow, where have I heard that before...

[Martin]

Hi Bascule, you caught a typo. I will correct it.

 

...Leibniz's conception of space and time is an ever evolving network of relationship...

 

Wow, where have I heard that before...

 

Yeah, I know.

 

Oddly enough Leibniz didn't originate the idea either. Prior to Newton it was a fairly standard view of space in Western thinking.

 

aristotle apparently says something like: Space isn't anything separate (in and of itself). It is merely the relations between things.

 

i.e. some things are next to other things-----this is between that---etc etc.

and space is just the sum total of all those relations

 

there is a book about the history of the idea of space. I forget who by. It is a philosophy book, not written to go over on the mass market, just to appeal to Philosophy of Science specialists. The author might be Isham.

 

All that stuff is PRIOR and more basic in a way than the strangely similar notion of space you get in some non-string QG (and you have surely heard me trying to explain:-) )

 

I dont know if you know of the Newton Leibniz debates. Apparently they were very fierce and somewhat destructive---as scholars are wont to be at times.

 

the fact is Leibniz was basically defending the traditional view (Aristotal, Pascal etc) of space as relation

 

and Newton had a NEW idea of absolute space (he called it the Sensorium of God). It was God's REFERENCE FRAME and it had its own independent existence, separate from things.

 

With newton, space was not CONTINGENT on having things around that could have spatial relationships.

 

Well Newton was bound to win the argument because the trump card was that HE COULD CALCULATE GRAVITY AND MOTIONS AND poor Leibniz with his "relational" space could NOT calculate worth a damn.

 

in the end, some philosophical issues just come down to practical matters.

 

however in 1915 an ironical thing happened and The Sublime Albert found a way to calculate at least some gravity and some motions using RELATIONAL SPACE. In GR spacetime points dont have an absolute existence, events can only be defined relative to something---some matter, some real event, some field. The continuum is used to define fields and paths on, but then in the end they are what's real and the continuum is more of a conventional device (if you began with a different map of a different continuum you would get an equivalent picture).

 

I know that is vague and not well explained. But in fact what Newton did to poor Leibniz came back and bit him in the ass, because in 1915 a long process began of sort of "disestablishing" newton's absolute space and going back to a more relational-type view of space.

 

the kicker is always WHAT CAN YOU CALCULATE and many branches of physics still use absolute space (either newton or the 1905 version SR absolute space) because it is easier to calculate with.

 

they havent all gone over and reconstituted their theories on the space of General Relativity, and for good practical reasons. Only SOME have, because they couldnt avoid it------hard to make black holes in absolute flat space, etc.

 

Bascule, i forget if we have talked about this before. I may be just telling you stuff that you already know from somewhere or that we even had a thread about. But that is all right, because it is explicating what Smolin is talking about in Paris. So it does seem to belong in this thread.

 

For whatever reason, you are right on, saying you heard that about relational space before. You get it in SPIN NETWORK gravity, and also in other stuff like Seth Lloyd-like (crazy?) theories of space as cellular automata, and a bunch of places.

[bascule]

Most of what I know of the Leibniz/Newton debate came from Brian Greene's Fabric of the Cosmos. Thanks for the refresher though.

 

When it comes down to it though, I'm still going to side with the Platonic/Aristotelian view, which I suppose means I side with Smolin here... but yes, in the end all the philosophical pontificating is useless in the wake of empirical fact.