Fra said:
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Does anyone know if Smolin and Rovelli had differing opinions in 1997?
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I don't know. I will try to make sense of this and reply soon. But right now I want to say that the second lecture is available online. It was given 16 january but it takes a while for them to get it ready for download and put it out, so it showed up the next morning.
http://pirsa.org/08010034
In general if you want to look for PIRSA video lectures here's the link
http://www.perimeterinstitute.ca/Scientific/Seminars/PIRSA/
About Smolin and Rovelli they have different and in a sense complementary personalities. I have never noticed them to be in CONFLICT where one say A and one says NOT-A. But I have always seen them to be interested in different things and contributing differenty to the research effort.
I don't know how much anyone can say about the opinions of a creative researcher, a stranger cannot look inside the mind. Unless it is in the special case where someone writes a review paper that survey's the field, like Rovelli's 1997, or his book.
If it is not impolite of me, i will make a kind of cartoon sketch or caricature of their two personalities. I think Smolin likes to take risks and to foster creative young people who will take risks. If some program he sees is going along all right with lots of people helping, then he will go off in wild unexplored territory and SCOUT some new idea. I think Rovelli is more with the main body of the research, like a conventional leader. He always keeps a strategic picture in mind. He plans logically. If he sees a small gap, he tries to fill it. If he sees a major objective for the program he gathers people and attacks that goal. He is somewhat more orderly and predictable. This does not mean any less creative.
So one can make a cartoon picture of these two ways of behaving that recalls the covered wagons of the Old West in North America where you have one kind of leader who stays with the wagons and is more central, and you have another person who is a scout and explorer. sometimes he is in advance, other times he may be trying some new path that might not work.
I wouldn't say that the two have different opinions, because I don't know their opinions except as shown in survey papers. they behave differently, they have different kinds of vision. they emphasize different stuff and work on different stuff, but all this seems complementary in the sense of fitting together rather well.
Look at what Starodubtsev did. In 2004 he was at Perimeter collaborating on one or more papers with Smolin, then he continues at perimeter and collaborates with Freidel, then in 2006 he goes to postdoc in LOLL's group at Utrecht. Now he is in Rovelli's group at Marseille.
Now Staro is giving seminar talks on a way to LINK UP the Triangulations approach with LQG.
In some sense the work of somebody in Rovelli or Smolin's position is to build up a research community that is innovative and focused on the important problems. Part of the output is people. This is another form of collaboration.
I'm sorry I can't say much definite about differences of opinion. Of course Smolin's main work since 2005 has been on incorporatiing MATTER as topological aspects of the spinnetwork quantum state of geometry. This is avant guard and high risk. Rovelli is focused on the main problem of perfecting the LQG dynamics, working out the classical limit, just for pure gravity. He is more deliberate and gradual, doing things in logical order instead of jumping ahead.
But it would be very nice if, by the time Rovelli et al are finished getting the LQG spinnetwork dynamics and the classical limit, that already some progress has been made of realizing different particles as the braids and twists in the spinnetwork. So I do not see a conflict, but more a kind of division of labor.
