Re: Newton's 3rd law is wrong

Tom Roberts il 12/12/2024 09:20:30 ha scritto:

With my animation https://www.geogebra.org/m/v33hu4en I show what
Newton said.

>
I never click on such links.

My Geogebra works are the heart of my proofs and thought experiments.

And you make your judgments without even looking at them.

[...]
Instead, Einstein argues that there is no force between the particles
of the Earth and those of the Moon, and that the action between the two
bodies is due to the space-time curvature of one in contrast to the
different space-time curvature of the other.

>
That is not correct. Using the spacetime curvature interpretation of GR,
it is the curvature due to ALL components of the solar system that
determines all of their orbits.

What do the curvatures due to all the other components of the solar
system have to do with it?

And while you're at it, why don't you add all the other galaxies in the
universe?

But the two curvatures are not equal!

>
Of course not! Granting your separation, their effects are not equal,
either. The effect of earth on moon is huge and causes the moon to orbit
around the earth. The effect of moon on earth is MUCH smaller, and
merely makes it wiggle a little bit as it orbits the sun.

The Earth's effect on the Moon is *much* larger than the Moon's effect
on the Earth because Earth's spacetime (which is more curved than the
Moon's) acts on the Moon *more* than the Moon's reacts on the Earth.

Consider a solar system with just sun, earth, and moon (i.e. ignore
everything else). The earth does not orbit around an ellipse, not even
approximately -- it is the earth-moon barycenter that orbits around the
(approximate) ellipse you are thinking of. The earth wiggles around that
(approximate) ellipse. The wiggles have period ~ 29.5 days,
corresponding to the moon's orbit. (This is exact in Newtonian
mechanics, but only approximate in GR -- NM is linear while GR is not.)

This is beside the point: the motion of the Earth-Moon barycenter
depends on forces *external* to the Earth and the Moon, while the third
law talks about forces *internal* to the Earth-Moon system.

And therefore, even for Einstein, the gravitational equality between
the two opposing bodies no longer exists, ]...]

>
Hmmm. Newton's third law discusses FORCES, not "gravitational equality".

No, Newton's third law talks about "action and reaction" and not just
forces.

In Newtonian mechanics, because earth and moon have such different
masses, the effects of equal forces on them are most definitely NOT
equal. In the spacetime curvature interpretation of GR there are no
gravitational forces, and one simply cannot apply any of Newton's laws.

The third law can (and should) be applied in General Relativity because
it does not speak of forces but of action and reaction.

The spacetime of General Relativity (with its curvature) acts between
the Earth and the Moon as the tension in Newton's string acts between
the horse and the stone.

(But one can apply the Newtonian approximation to GR, and all three of
Newton's laws apply within that approximation.)
>
Hint: it is outrageously arrogant to think you alone can see an error in
a theory that has stood the test of time for hundreds of years and
inspection by tens of thousands of physicists. There is a reason that no
journal articles have been published on this....

I don't think I can see a mistake, I *prove* that the mistake is there
(for those who watch my animations).

An error that neither you nor anyone else have been able to detect.

Luigi Fortunati.