Exploring an Intriguing Perspective on General Relativity

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In summary, the conversation is about two interesting papers related to general relativity. One paper is a short paper with an angle on GR, while the other is a resource for learning relativity. The conversation also mentions a resource letter by R. M. Wald for teachers of general relativity, which discusses different approaches for teaching tensors in undergraduate and graduate courses. Overall, the conversation highlights the importance of finding a balance between teaching fundamental concepts and allowing for more time for in-depth discussions of physical applications.
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  • #2
http://arxiv.org/abs/gr-qc/0511074 was entertaining to read. I like the conlcution:
Therefore, if the Earth were flat, we could explain terrestrial
physics by saying: bodies fall downward because
there is a white wall 3 × 1015 meters away sitting over-
head in the heavens which is pushing off them. Moreover,
for example, we could test General Relativity by sending a
light signal upwards to the sky, and receiving it six months later.
:biggrin:
 
  • #3
Spin_Network said:
That has an interesting angle on GR.
http://arxiv.org/abs/hep-th/0511131
What you think it,s only a short paper?
http://arxiv.org/abs/gr-qc/0511074

Interesting papers.

this paper is agreat resource for relativity learning:http://arxiv.org/abs/gr-qc/0511073

This resource letter by R. M. Wald for teachers of general relativity is very interesting. Wald has come around to the point of view that it's OK to teach undergraduate general relativity courses that don't cover tensors or the Einstein fild equation. Undergraduate courses should concentrate on mining (via, e.g., Lagrange's equations) given (not derived as solutions to Einstein's equation) metrics for physical information. This way, much more time can be spent on quantitative aspects of interesting topics like black holes and cosmology.

Wald: "The philosophy on teaching general relativity to undergraduates expounded in this resource letter is adopted directly from the approach taken directly from Hartle in this (Hartle's) text."

For grad courses, Wald says that tensors must be taught, but that there is no satisfactory way of doing this.

Wald: "In 30 years of teaching general relativity at the graduate level, I have not found a satisfactory solution to this problem, and I have always found the discussion of tensors to be the 'low point' of this course,"

Wald say that there are 2 main options: 1) manifolds, and tensors as multilinear maps; 2) tensors strictly form a coordinate-based point of view.

1) is more fundamental, but requires more time, which leads to rushed presentations of physical applications of GR. 2) can be covered in half the time as 1), allowing for more leisurely and detailed presentations of physicall applications, but is not sufficient for treating things like global methods and singularity theorems.

Regards,
George
 

1. What is general relativity?

General relativity is a theory of gravity proposed by Albert Einstein in the early 20th century. It describes the relationship between space, time, and gravity, and how massive objects cause curvature in spacetime.

2. How is general relativity different from Newton's theory of gravity?

While Newton's theory of gravity described gravity as a force between masses, general relativity explains gravity as the curvature of spacetime caused by masses. General relativity also accounts for the effects of acceleration and the speed of light, while Newton's theory did not.

3. What is an intriguing perspective on general relativity?

An intriguing perspective on general relativity is the concept of time dilation, where time moves slower in the presence of a strong gravitational field. This has been demonstrated through experiments such as the Hafele-Keating experiment, where atomic clocks on airplanes showed a slight time difference compared to atomic clocks on the ground.

4. How does general relativity impact our daily lives?

General relativity has numerous practical applications, such as in GPS systems, where it is necessary to account for the slight time dilation caused by the Earth's gravity. It also helps us understand the behavior of massive objects in the universe, such as black holes and the expansion of the universe.

5. Is general relativity still a valid theory?

Yes, general relativity is still a valid theory and has been extensively tested and proven through experiments and observations. However, it may not be a complete theory as it does not account for the effects of quantum mechanics, and scientists are still working on finding a unified theory of gravity that can encompass both general relativity and quantum mechanics.

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