Spacetime

evolving in time

  1. Can spacetime evolve in time?
  2. According to ChatGPT:

In essence, the Hamiltonian formulation of general relativity rewrites Einstein’s field equations in a way that highlights the time evolution of spacetime providing powerful tools for both theoretical and numerical work in gravitationl physics.

Strassler

  1. This is absurd right? Spacetime already include time.
  2. Matt Strassler says as much:

The word “expanding” means “growing over time”, which is something that spacetime cannot do, since time is contained inside it.

Notes

from cards

  1. Einstein’s theory is based on a monolithic spacetime where space and time are inseperably meshed. But this is not the case in practice.
  2. An indivisible spacetime does not exist
  3. Spacetime is an academic concept anyway
  4. Spacetime is an absurd academic concept that was rejected by nature
  5. But in physics Einstein’s authority is kacred so physicists use mathematicals tricks to get rid of the spacetime as a unit while at the same time saving Einstein’s authority
  6. Physicists emasculated Einstein’s spacetime by dividing into space and time
  7. Can we call a spacetim divided into space and time Einstein’s spacetime.
  8. Don’t forget physics is equivocation. Physicists can name spacetime not-spacetime and still call it spacetime. This is the power of equvocation, the oldest trick in the book of rhetorical tricks of scholasticism.
  9. Analogy: Electricity and magnetism are unified. Is there a similarity with the unification of space and time?
  10. The problem is that “space” and “time” are not “physical” quantities. They are not observed.
  11. Space and time are not unified but they are welded.
  12. Anyway the whole thing is a play on mathematical dimensions
  13. Not welded but maybe meshed so that space and time do not exist separately
  14. So, let them correct me. No Einsteinian faithful will agree on anything I say.
  15. There seems to some truth about seeing the space as slices of moments. But not slices of spacetime
  16. Also space is not space but length. We measure length.

Is there General Relativity without spacetime

  1. Can we say that if there is no spacetime there is no special and general relativity theories?
  2. There is no general relativity if there is no spacetime
  3. Because spacetime is general relativity

Equations of motion

  1. They have equations of motion but their equation of motion does not conform to Kepler’s Rule so they must be useless

What is curved?

  1. They say spacetime is curved
  2. Maybe. But what is curved? Being curved requires a substance. Is spacetime a substance?
  3. I need to understand. It looks like they are reifying the grid they use to indicate positions
  4. They use tensors as a grid then they reify this grid. But this is a guess I don’t understand what’s going on
  5. On the other hand spacetime is an academic furniture so it is really irrelevant

Is being 4 dimensional an inherent property of spacetime

  1. In physics we can simplify the study of motion by studying in one dimension or in two dimensions.
  2. For instance we can study simple harmonic motion in two dimensions (in one dimension?)
  3. Can we investigate spacetime in two dimensions?
  4. One time dimension and one space dimension

Space dimension is not space dimension but length

  1. Yes this is anothar problem
  2. The coordinates are not space coordinates they are length coordinates
  3. We measure length on the coordinates
  4. same with the so-called time coordinate. In time coordinate we measure length too
  5. coordinate axex are just line and we meausure intervals of length on these lines
  6. So we measure length and call it time or space
  7. There is a problem for me here
  8. This is called the reification of names
  9. Reification of labels

Created: 2024-10-27 Sun 10:50

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