Who's better, Baez or Rovelli? (at explaining GR)

[marcus]

Baez explains GR in several online tutorial-things

Short Course Outline
http://math.ucr.edu/home/baez/gr/outline1.htm

Long Course Outline
http://math.ucr.edu/home/baez/gr/outline2.htm

Oz stories of General Relativity

The Meaning of Einstein's Equation
http://www.math.ucr.edu/home/baez/einstein/einstein.html

Baez approach is intuitive and needs very little *special* relativity background. At a point where he would like to have Minkowski metric from "special" he quickly explains it.
I think the need for "special" as a prerequisite is exaggerated. Certain things one needs to know, but there is a lot of excess baggage about astronauts that is not needed for an introductory course in General. I think Baez tutorial demonstrates that.

Baez intro to GR is good, but ROVELLI'S APPROACH IS ENTIRELY DIFFERENT

If you have looked at Baez, have a look at Chapter 2 of Rovelli's new book (1 August, 2003 draft) pages 21-71, which is his General Relativity chapter, and compare.

Rovelli's treatment is serious, modern, and difficult. Baez's is easy and comic and old-fashioned in the sense that he uses the metric g as the fundamental variable.

Rovelli does not introduce the subject by way of the metric. This impresses me as radically new.

Rovelli is a Relativist----GR is his professional field of specialization. He seems to be taking a new approach to introducing the subject...right away the development begins with Ashtekar's new variables, or so it seems to me.

Rather than beginning the development with the metric and going along the way textbooks have for 70 years and then
finally, if there is time, showing how to change over to the new variables.

So this looks like a ground-breaking thing pedagogically, to me.
Do you know anyone else who approaches the subject that way?

Rovelli's book is online
http://www.cpt.univ-mrs.fr/~rovelli/book.pdf
I mentioned the link in the "Theoretical" forum thread about it

 

[jeff]

Originally posted by marcus
Rovelli does not introduce the subject by way of the metric. This impresses me as radically new.

It's not. These are the most common formulations in high energy theory since they're needed to couple spinorial degrees of freedom to gravity, and are more natural from the point of view of supersymmetry, as I've explained in more detail in a number of previous posts.

 

[selfAdjoint]

Marcus means as in a textbook. All the GR textbooks I know start with Riemannian geometry. Metric, then connection.

 

[marcus]

Originally posted by selfAdjoint
Marcus means as in a textbook. All the GR textbooks I know start with Riemannian geometry. Metric, then connection.

Exactly! He begins with the connection (page 21)
and after a quick 9 page development
has a footnote where he translates things over
into terms of the metric.
So the connection comes first and metric only comes
on page 30 in small type
It is a pedagogical departure for a general textbook
on gravity, or so it seems to me

 

[jeff]

Originally posted by marcus
It is a pedagogical departure for a general textbook on gravity, or so it seems to me

If it were truly a text on GR, I might have agreed. But really, this is a text about quantum gravity in the same sense that text's on string theory are, and rovelli's formulation of GR suits the real subject which is LQG, just like the very same formulations found in string theory texts suit that subject.

However, none of this is important. What's really important is that you guys now have a document that will allow you to approach the subject in a more organized, integrated and systematic way.