swansont

Newtonian gravity depends on mass, and distance from that mass. There is no antigravity. “Artificial” gravity is some other force (i.e. it’s not mass attracting mass)

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You’re asking for me to prove a negative. I didn’t say there was evidence it wasn’t an explosion, I said the evidence doesn’t support that hypothesis. You own the burden of proof here, if you want to claim that it was. What does an explosion look like, and what evidence exists? An explosion in a vacuum would have matter expanding from the point of the explosion. There’s no evidence of that. What’s the temperature profile of an explosion? Is it a predominantly uniform temperature everywhere you look? No.

As with all science, what we know is based on data and theory. The data are what we observe in nature and as the result of experiment, and the theory is the models we have that’s based on the data and has allowed us to make predictions. It’s provisional, since new data could require a modification of theory. But that’s what it means to know things in science. We know the big bang was not an explosion in space because the evidence does not support that hypothesis. If you want to consider other hypotheses, you’d need evidence for them before we can consider them as something we “know” Large numbers are beyond the average person, but not to scientists who deal with them in the course of their work

The issue is that we can’t investigate what’s happening at the level of detail you seem to be asking about. We have classical and quantum models about how radiation interacts, but it doesn’t tell us what’s happening at very small scales. We can’t probe what the photon is doing, because the photon is the probe. The temperature manifests itself both in terms of the CoM kinetic energy and the excitation of the electrons; for the latter the number of excited electrons varies as e^-(E/kT) where E is the excitation energy i.e. more electrons will be excited at higher temperature, or if the system has a smaller excitation energy

I think a classical model works better for a metal. The varying EM field causes the electrons in the conduction band to oscillate; the field transfers its energy and momentum to the metal (mostly to the electrons) The increased KE of the electrons manifests as an increase in temperature

Banned, as the spam continued

Not even that long, I suspect. Dense-packing the trees seems to stimulate growth for the few years observed, but what happens as the trees (literally) branch out? Will the proximity impede growth? What happens as their root systems start interfering with each other - will you run into issues if water is scarce?

Such as the timing of peak cherry blossoms in Tokyo https://ourworldindata.org/grapher/date-of-the-peak-cherry-tree-blossom-in-kyoto?facet=none

How does one walk without some material object upon which you place your feet?

True for a single magnet, because you induce a magnetic field in the material, but your system would induce opposite fields which would tend to cancel. i.e. the field halfway between the magnets is small, so the induced field is also small.

So it depends on M and r. Which means one could say that mass causes gravity.

Only because of the objects. If you didn’t have visual cues, you could not tell if you were moving relative to them. More than useful. Absolutely necessary. I wasn’t aware that this a requirement for it to be a dimension. This does not differentiate it from the spatial dimensions.

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?