An Apparent Contradiction in General Relativity?

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SUMMARY

The discussion centers on the apparent contradiction between background independence in General Relativity (GR) and the concept of geodesics in curved spacetime. Participants argue that if all objects travel through spacetime, this implies a preferred direction, contradicting the principle of frame independence. The conversation highlights the need for precise definitions and references to mainstream scientific literature to clarify these concepts. Ultimately, the discussion emphasizes that the interpretation of "traveling" in GR does not inherently violate background independence, as spacetime itself is dynamic and does not require an external reference point.

PREREQUISITES
  • Understanding of General Relativity (GR) principles
  • Familiarity with the concept of geodesics in curved spacetime
  • Knowledge of background independence in physics
  • Basic grasp of frame independence and its implications
NEXT STEPS
  • Study the Einstein Field Equations to understand the dynamics of spacetime geometry
  • Explore the concept of geodesics in General Relativity through academic papers
  • Research background independence and its implications in theoretical physics
  • Examine the differences between General Relativity and Special Relativity regarding spacetime structure
USEFUL FOR

Students of physics, researchers in theoretical physics, and anyone interested in the foundational principles of General Relativity and its interpretations.

  • #31
maddog said:
In 1975 after an Astrophysics lecture, I asked the professor of my class, if the energy of a Quasar could be a galaxy with a Black Hole at its center - could that be enough energy release to create the energy speculated to be emitting from it. He thought that was ludicrous there is no way that a Black Hole could be so massive to swallow up a whole galaxy...

I would certainly agree that the professor was wrong to say that. But note carefully how you phrased your question: you didn't say "I think relativity is wrong because it doesn't agree with my new idea". You asked, in effect, "could my new idea be consistent with relativity?" And the correct answer, even in 1975, would have been "yes, it could". Nothing in GR prohibits the existence of supermassive black holes, or having them at the centers of galaxies, and this was known in 1975. The only difference then was that such black holes were not thought to be as common as we now know them to be.

maddog said:
Oh yah, in 1975 that was sure not original...

It wasn't. Misner, Thorne, and Wheeler was published in 1973, and it talks about supermassive black holes, and makes it perfectly clear that they are consistent with GR, and that they could be at the centers of galaxies, and that objects falling into them could release enormous energies in the process. Who was your Astrophysics professor? How in touch was he with the latest developments in black hole physics at that time? (I'm guessing "not very".)

maddog said:
My only understanding is if I make a conjecture (if original so be it), I want to be able to state it as it is, empirical as it is & not requiring proof, or corroboration or any nonexistent citation.

It makes a big difference how you state it. See my comments above.
 
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  • #32
As a clarification the patent review I was talking about, handled internal patents submitted by employees. It's purpose was to recommend potential candidates for due diligence in the Intellectual Property law department. Inventors would submit a brief description and come to present and defend it. Often we would find some web reference or product that already implemented the idea and squash it. Other times we would recommend it for publish so while we don't want we also don't want to be sued by someone filing it.

The chairman taught us to be very diplomatic but this was lost on some of our members who either invented everything there ever was or never invented anything but were experts in some field. It was a fun review board we got see how an idea that can't be patented could be transformed into one that could be.
 
  • #33
Suppose someone asks "Apparent nonsense in Newtonian mechanics? : Every force has an equal an opposite reaction. If this is true, then nothing can accelerate." Will he be asked for a reference, or will his understandable confusion be clarified?
 
  • #34
Please CLOSE this thread, it has veered way off course and the OP hasn't responded sine being rebuked for his lack of references.
 
  • #35
atyy said:
Suppose someone asks "Apparent nonsense in Newtonian mechanics? : Every force has an equal an opposite reaction. If this is true, then nothing can accelerate." Will he be asked for a reference, or will his understandable confusion be clarified?

If he claims that he read this somewhere then I for one would ask for a reference.
 
  • #36
jedishrfu said:
Please CLOSE this thread, it has veered way off course and the OP hasn't responded sine being rebuked for his lack of references.
OK..
 

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