New Book
Well I decided I wasn't quite versed enough in the general relativity realm, so got this very easy to read and informative book. The thing that bothers me of course is the tensor math. Yucky rules that must be remembered. In itself the book is a great tutorial of the rules and applications of general relativity.
Whether the general theory is true or not, it does predict:
Perihelion of Mercury: Measured very accurately and proven many times. This is due to the different flow of of time (relative to us) near the gravity of the Sun.
Bending of Light: Light according to relativity follows a "geodesic", which then can be measured by a star occulting the Sun. Again this angle has been verified to great precision. A similar and my favorite related effect though is "stellar aberration". This means a star's relative position will shift depending on our relative velocity about the Sun.
Black Holes: The math allows for a singularity in space, in the 80's and before a speculation, has effects now which are pretty much an accepted reality in the centers of most galaxys, measured by expected x-ray and gamma radiation.
GPS satellites: These reliable accurate position keepers of our life need to be continually updated because their clocks run at different speeds outside our ground level gravity field.
Gravity Waves: Pulsars orbiting each other have been discovered and their orbital period decreases enough to account for the gravitational wave energy.
This is all nice, so none of this "proves" anything, but certainly must be on the right track. I still think tensors are too cumbersome to work with. There are some alternatives like Hestene's geometric algebra which can reduce Maxwell's Lorentz covariant 4 equations into 1.
Well I decided I wasn't quite versed enough in the general relativity realm, so got this very easy to read and informative book. The thing that bothers me of course is the tensor math. Yucky rules that must be remembered. In itself the book is a great tutorial of the rules and applications of general relativity.
Whether the general theory is true or not, it does predict:
Perihelion of Mercury: Measured very accurately and proven many times. This is due to the different flow of of time (relative to us) near the gravity of the Sun.
Bending of Light: Light according to relativity follows a "geodesic", which then can be measured by a star occulting the Sun. Again this angle has been verified to great precision. A similar and my favorite related effect though is "stellar aberration". This means a star's relative position will shift depending on our relative velocity about the Sun.
Black Holes: The math allows for a singularity in space, in the 80's and before a speculation, has effects now which are pretty much an accepted reality in the centers of most galaxys, measured by expected x-ray and gamma radiation.
GPS satellites: These reliable accurate position keepers of our life need to be continually updated because their clocks run at different speeds outside our ground level gravity field.
Gravity Waves: Pulsars orbiting each other have been discovered and their orbital period decreases enough to account for the gravitational wave energy.
This is all nice, so none of this "proves" anything, but certainly must be on the right track. I still think tensors are too cumbersome to work with. There are some alternatives like Hestene's geometric algebra which can reduce Maxwell's Lorentz covariant 4 equations into 1.
posted by AlexanderTheGreat at 9:53 PM
1 Comments:
Just a little light reading...sounds good for the beach or pool this summer. (The potato recipe was right up my alley, though!)
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