Re: The Einstein Effect

On 10/01/2025 16:46, john larkin wrote:

On Fri, 10 Jan 2025 10:33:13 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:
 

On 1/10/25 01:41, john larkin wrote:

On Thu, 9 Jan 2025 23:54:46 +0100, Jeroen Belleman
<jeroen@nospam.please> wrote:
>

On 1/9/25 19:48, john larkin wrote:

On Wed, 8 Jan 2025 17:42:39 -0000 (UTC), "Don" <g@crcomp.net> wrote:
>

john larkin wrote:

>
https://www.inc.com/jessica-stillman/einstein-and-adam-grant-agree-the-puzzle-principle-will-make-you-instantly-smarter/91102339
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Cohen's book looks interesting, so I ordered it.
>
I'm now reading Gleick's short biography of Isaac Newton, who was a
very weird guy.

>
Einstein loved the sound of his own metaphysical bark and wasn't above
fudging the score:
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<https://pubs.aip.org/physicstoday/article/58/9/43/399405/Einstein-Versus-the-Physical-Review-A-great>
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Regardless, my followup isn't about this thread's titular Einstein.
It's about Newton.
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      "Did you know? It was AYABHATA & not Newton or (sic) Leibniz who
      first developed Calculus"
>
      <https://x.com/Aelthemplaer/status/1874573331330167032>
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Danke,

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Seems to me that if gravity has finite velocity, there have to be
gravitational waves.
>

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Yes, and if there are gravitational waves, there must be quantization
effects. Where waves and matter interact, quantization occurs. The
scale of the phenomena, both in time and in size, may make it hard
to recognize it as such though.
>
That said, there are plenty of examples of quantization effects in
the behaviour of objects in our solar system. Orbital resonances,
tidal locking, Trojans, what else?.

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But quantized?
>

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Well, yes! That's what orbital resonance is. It tends to make
moons orbit with periods related by simple rational numbers.
Their energy is then constrained to discrete levels. If that
isn't quantization, then what is?

 I don't think planetary orbital energies are constrained to discrete
levels, but you can define approximate periodicity to be quantization
if you like.

A single planet in orbit around a sun can have any orbital period it likes but once it becomes a 3 (or more) body problem it has to satisfy certain heuristic rules that in handwaving terms amount to that they stay out of each other's way as much as possible. That translates to having orbital periods that follow a simple ratio rule.
Bode's law is the heuristic one for our solar system. A slightly different rule applies to Jupiters Galilean moons and to Saturn's.

Come to think of it, when a star gets ejected at high speed from a
star cluster, as sometimes happens,  isn't that in some way similar
to the decay of a radioactive atom?
>
Jeroen Belleman

>
Suppose there was some gigantic mass drifting around. Everything else
in the universe would feel its gravitational attraction. Now blow it
up, convert all its mass to energy. The sudden loss of mass creates a
bubble of not-gravity that expands at the speed of light and everybody
will notice (maybe hear a click?) when it hits them, the same time as
the flash does.
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Since Al discovered E = MC^2, you'd think he would have thought about
that.

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Energy and mass are equivalent, so the field would not just vanish.

 But photons have no mass and are unaffected by gravity.

Photons have no *rest* mass, but they are not stationary either.
E = mc^2
Cuts both ways. The matter converted into photons still has mass just that mass is moving away from its start position at the speed of light. Expanding uniformly assuming it was symmetrical to begin with. Gauss's
They are just as much influenced by gravity in GR as anything else is. GR bends spacetime and photons travel the shortest time path or geodesic between any two points. Eddington measured the sun bending starlight to test Einstein's theory of GR.

I'll pass about the effects of converting a gigantic mass into energy.

 Or take two billiard balls that collide off-center. A velocity
differential is created orthogonal to the original path. That creates
a gravitational wave.

Not much of one. You really have to throw things about violently for any of the GR corrections to classical dynamics to come into play. Tightly bound pairs of neutron stars make excellent testbed for this.

If something moves really fast, does it make a gravitational wake?
Wouldn't that make it lose energy?

>
Yes and yes, as was recently confirmed by the detection of such waves.

 I was referring to uniform velocity motion there, not a giant event.
Seems like it would make a wake, and that might slow it down. In that
case, the entire universe is viscous.

Most of the slowdown would come from blue shifted microwave background photons and intergalactic medium hitting the leading edge of the object.
We see this actually happening in FR type II radio galaxies where the relativistic beam hits the intergalactic medium and lights it up.
Canonical example is the jet in Cygnus A which was first seen in 1983.
https://www.nrao.edu/archives/items/show/33384

Moving things must lose energy. They wiggle other things as they pass. >
The g-field around us must be very noisy. Must sound cool.

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Kind of hard to do. Ask the LIGO people, Except for some cataclysmic
events, the noise is really low frequency too, in the nHz domain and
below.

 Still there, and could be speeded up for listening.

It has to be multiple solar masses and near light speed before gravitational radiation is noticeable at any distance from the source.
--
Martin Brown