I certainly learnt a couple things about general relativity from that article (e.g. the "modern view" (meaning largely, the view from string theory) that "we understand Einstein's equations just as the equations of an "effective field theory""), although it was way over my head.<p>That blog (Luboš Motl's) has an amazingly large number of long and technical or topical articles on physics. I found this one on Boltzmann and thermodynamics especially insightful and relatively non-technical:<p><a href="http://motls.blogspot.co.nz/2013/02/ludwig-boltzmann-birthday.html?m=1" rel="nofollow">http://motls.blogspot.co.nz/2013/02/ludwig-boltzmann-birthda...</a>
When I took the basic physics sequence at MIT 40 years ago Special Relativity was a first semester elective and General Relativity in the seventh semester. You can derive much of SR with high school algebra and additional integration. But the GR field equations were rather hairy.
I admire the general theory of relativity, the theory of gravitation and the field equations. Einstein proofed this way equality of inertial and gravitational mass, in my view his biggest merit. - But I can't understand why still today physicists allow to mess the beauty of the field equations by applying it to the universe as a whole. - It's wrong to apply the field equations cosmologically, as I have shown here: <a href="http://ow.ly/MrQgy#einstein_was_wrong" rel="nofollow">http://ow.ly/MrQgy#einstein_was_wrong</a>