swansont

I give up. GR can apparently only be explained using GR Every time i look into GR it’s like pulling teeth; I come away convinced that nobody does a numerical calculation because none of the math is ever presented in a way where that’s possible. I’ve read that GR reduces to Newtonian gravity, but have never been able to find a worked example of that, because nothing is ever presented but the tensor mathematics. Along the line of my frustration, I recall a seminar (on Lie algebra, IIRC) in grad school where the prof was asked what the difference was between contravariant and covariant, and the response was something like “contravariant means the indices are along the top” which is true but doesn’t do anything to advance anyone’s understanding.

And what are the boundary conditions of those sets?

The Coulomb field is static; that’s the 1/r^2 field. EMR intensity drops off as 1/r^2 from a point source, but intensity is the square of the field strength.

How? Usually there’s only one solution for a given set of boundary conditions.

You can only sense the expanse of space because of objects in it, i.e. the observables are objects, not length itself. Just like the fact that your location changes lets you sense the passage of time.

“Allows” doesn’t mean these exist. How would one get a gravitational wave absent energy-momentum? (Maxwell’s equations allow EM waves, but classically you aren’t going to get one in a situation where you don’t have a charge somewhere) The scenario has two parts, the earth influencing geometry and the location. You only addressed the latter. Does mass cause a particular geometry to exist? It’s my understanding that it does. The geometry you have depends on whatever mass (as a first-order approximation) you have.

That wasn’t the whole point, though. The geometry tells the mass how to move, but does it cause the mass to exist?

Excellent arguments for why it should not be recognized as a dimension; if it’s in your mind I can’t observe it or measure it.

How about ‘mental space’? Or ‘imagination’? Or ‘the twilight zone’? No. It’s not physical, so it doesn’t belong there. Such things are studied already. In neurology, psychology, and other fields.

How does your conclusion follow from the quote? What kind of radiation is it?

Local ≠ co-located

Isn’t the sun’s (or earth’s) field approximately a solution to the Schwarzschild geometry? They are equal, but isn’t that a static solution? And if you perturb the energy-momentum, don’t you get a lightlike fluctuation in the curvature? How is it not local? Gravitational waves are a dynamic effect, though. What if we limit ourselves to a static configuration?

Isn’t the separation of momentum-energy and curvature lightlike? The fluctuations (gravitational waves) propagate at c What’s the curvature of the Schwarzschild solution? I’m confused. “The Schwarzschild geometry describes the spacetime geometry of empty space surrounding any spherical mass” https://jila.colorado.edu/~ajsh/bh/schwp.html

This implies that lightlike separations are not causal.

Length is a concept, “observable” as an interval between objects. But you need the objects, like you need events to measure time.

Hmm. This post wasn't here a moment ago... By this metric, length isn't observable, either

How is this a dimension in a physics sense?

What is the algebraic form of that component?

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KJW responded to/quoted me, not the other way around, so if they were not engaging in the context of what I was talking about it’s on them, not me. To add to that, I had already written about some of the points raised. These were ignored.

My default is to take threads at face value and not read anything into them.

Natural? That’s rather subjective. Why does it have to? In the first case you’re explaining what causes the redshift. Nothing else. True gravity? The equivalence principle says you can’t distinguish it from other acceleration. But one can make that association. And that’s also an equality one can write down. I hardly think time dilation can be considered a phenomenon we all experience, considering the sophistication of the equipment necessary to detect it. Well, that’s rather convenient. The original suggestion was that time causes gravity, and that this was a consensus. What textbooks teach this, as apposed to energy-momentum and curvature? What’s the breakdown in the literature? Not liking an explanation is not really a consideration. And how does a clock “know” that its time dilation is gravitational?

All you’ve shown is an equality. That’s not causality. Are there any other equations for gravitational acceleration in GR? Also, please address my comments about kinematic dilation, which you’ve ignored.

Because science isn’t here to conform to your preferences. The world doesn’t revolve around you. The people who actually do science get to name things. Sometimes names provided by others stick, and inertia takes over. None of these avenues (or other possible ones) involves consulting you for approval. Perhaps a unit of hubris could be named for you.

Motors don’t always spin freely. The unconnected motors may be offering too much resistance for the car to move. Does the car roll very far if you just push it (no batteries)?