1

Flat Earth Theory / Re: Something odd about magnets

« on: August 29, 2021, 12:59:05 AM »

The major one we are discussing, however, is the acute lack of mechanism/description/definition of WHAT gravitation is and how it accomplishes its many miracles.

Just repeating that there is no mechanism or description of what gravitation s and how it works doesn’t make it true.  GR describes both the mechanism and how it works.

If by "solved" you mean "ignored" and "showing", you mean "assuming" - then yes, that's correct.

I have no idea what you mean by that. Newton assumed that gravity acted instantaneously.  GR shows that gravity doesn’t, nor does it have to. I Nobody is ignoring anything.

Relativity is an aether theory (though I doubt you were taught this).  It mathematically presumes a physical substrate to "empty" reality which contorts with the presence of mass.  The contorting of this aether is the presumed cause of gravity in relativity.  Empiricism demands that we provide observational and experimental support for the theoretical entity itself (aether/spacetime) as well as the mechanism responsible for matters contortion of it from a distance.  Because we excised aether from the schools, and physics is so poorly taught generally, there was believed to be nothing to go looking for (in part because many that tried found nothing)

This is where you ignorance shines the brightest.  There is no shame in ignorance, it can easily be cured by a little education.

Einstein didn’t assume a physical substrate at all.  In fact, he started out trying to prove the exact opposite.  He was an admirer of Mach and like him opposed to the idea of absolute space, to which all motion is relative. If there was any philosophy guiding Einstein’s science it was that space wasn’t a “substrate” or a physical reality.

In 1918, Einstein defined three fundamental principles of GR
"(a) Principle of relativity. The laws of nature are only assertions of timespace coincidences; therefore they find their unique, natural expression in generally covariant equations.
(b) Principle of equivalence. Inertia and weight are identical in essence. From this and from the results of the special theory of relativity, it follows necessarily that the symmetric ‘fundamental tensor’ (gμν) determines the metric properties of space, the inertial relations of bodies in it, as well as gravitational effects. We will call the condition of space, described by the fundamental tensor, the ‘G-field.’
(c) Mach’s principle. The G-field is determined without residue by the masses of bodies. Since mass and energy are equivalent according to the results of the special theory of relativity and since energy is described formally by the symmetric energy tensor (Tμν), this means that the G-field is conditioned and determined by the energy tensor.

That last sentence means that the gravitational field is determined by what is in it.  All motion within the g field is relative to other matter within the field, not the field itself.

Ultimately, he was unable to incorporate Mach’s principle into GR and later disavowed Mach.  The tl:dr is that over the course of 10 years, Albert realized that even if the universe was completely void of any matter, the g field would still exist.

This is a really good account of that process if you are interested.  Like I said there is no shame in ignorance.  But there is shame (or should be) in spouting off things “you know” without any knowledge or education on the matter.

http://philsci-archive.pitt.edu/4377/1/LoveMinusZero.pdf

The first couple of chapters of Brian Greene’s “Fabric of the Cosmos” is also a good account.  I think you can download a pdf of that for free. And it’s easier to read. Anyway, we seemed to have strayed from the OP’s original intent, so if you want to start another thread, I’m happy to discuss further.

2

Flat Earth Theory / Re: Something odd about magnets

« on: August 28, 2021, 06:35:20 PM »

Perhaps.  And perhaps how you learned it was!  History is an extremely subjective field, and requires reading multiple sources and between the lines to understand

Luckily, we have a comprehensive record of nearly everything Einstein ever wrote or published including his own autobiography, so we don’t have to rely on third party subjectivity. 
https://www.amazon.com/dp/B081J1DV8J/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1
https://einsteinpapers.press.princeton.edu/

Maybe you can show me where in any of the things he wrote he says anything like what you claim. 

Almost.  The problem, known for centuries by competent physicists since newton, is that instantaneous "spooky action at a distance" conflicted with REALITY and was anathema to physics writ-large.  It was (and still is) a MAJOR problem in physics that relativity aimed (and failed) to address.

How can something that appears to happen in nature conflict with nature?  And it wasn’t  the “action at a distance” that conflicted with relativity.  It was the instantaneous action at a distance of Newton’s gravity. SR showed that nothing can propagate through space faster than the speed of light, including gravity. Newton assumed gravity acted instantaneously, so relativity was incompatible with that.  Relativity solved that by showing that gravity doesn't act instantaneously. 

There is a MAJOR difference between describing what something does/causes and describing what it is (and how it does/causes it)!

That’s true.  The challenge is coming up with a theory of cause is that it is consistent with the effects we perceive.  The effects of gravity that we see are that inertial and gravitational mass are the same and that neglecting air resistance, all bodies fall with the same acceleration.  Taking relativity into account and that nothing can move faster than the speed of light, the spacetime curvature theory meets all the criteria for explaining how bodies (and light) move.  That’s the mark of a viable theory, if it explains observed phenomenon as well as make accurate predictions for what we may not have yet observed. GR hits all the marks on that, at least so far.
If GR works the way we think it does, then there should be a measurable differences in how light and bodies move through space and those differences should be consistent with the field equations.  So far so far good on that point.  GR predicts motion of bodies and light perfectly, at least so far.

Also, if GR works the way we think it does., we should be able to measure the physical differences in the space itself, that determine how light and bodies move  GR is a geometric interpretation of gravity, so we should be able to find evidence of geometric differences or changes in spacetime that are consistent with what we would expect according tot he field equations.  Again, we have been able to measure those geometric differences and they are consistent with the field equations.

http://www.thephysicsmill.com/2015/12/27/measuring-the-curvature-of-spacetime-with-the-geodetic-effect/

Here’s a cool animation of the same thing.

https://einstein.stanford.edu/Media/Rel_gyro_expt-anima-flash.html

Spacetime curvature can also be measured by testing how the gravitational field changes as over distance.  Kind of the same way you can determine the shape of any physical object by measuring it at different points.  If all sides are equal and perpendicular you know you are dealing with a square.  If the gravitation field is weaker at higher elevations and stronger at lower, you know that the shape of the field is curved downwards.  The difference in the measurements can tell you how much it curves.

https://www.forbes.com/sites/startswithabang/2019/02/16/ask-ethan-how-can-we-measure-the-curvature-of-gravity/?sh=54095661134f
 

3

Flat Earth Theory / Re: Something odd about magnets

« on: August 27, 2021, 07:15:30 PM »

You seem to be a little confused.  Newton came long before einstein, and is the one generally credited for inventing gravitation.

What I meant was that Einstein didn’t set out to explain Newton’s theory or come up with some new theory.  His goal was to make what was already observed about gravity consistent with relativity.

I don't see it this way.  Einstein came up with relativity, in part, specifically to try and make gravitation an actual part of physics (for the first time)

How you see it is irrelevant.  The historical record says otherwise. There is all kinds of source material out there.  You might try reading some of it.

Newton’s gravity was already an established part of physics.  GR was Einstein’s effort to merge the theory of relativity with what was already understood about gravity...that inertial and gravitational mass were equal and that all objects fall with the same acceleration. The problem, as I mentioned before, was that instantaneous action at a distance of Newton gravity conflicted with relativity.  Remember that one of the postulates of SR is that all of the laws of physics take the same form in inertial frames.  He had already shown how thermodynamics, electrodynamics and the mechanical motion of bodies could be incorporated into relativity. GR was his effort to incorporate gravity.

You are conflating things. We are talking about gravitation, not relativity.

You can’t separate the two.  The way that Einstein incorporated gravity into relativity was to generalize special relativity, aka “general relativity”.

 

There is no experimental evidence to support gravitation, nor is an experiment possible to contrive should we want to (due to the lack of rigorous definition of what, if anything, gravitation is in physical reality).

There is a rigorous definition of what gravitation is.  It is the movement of bodies consistent with spacetime curvature.  Spacetime curvature has been measured, predicted and observed to be consistent with the field equations dozens of times.

4

Flat Earth Theory / Re: Something odd about magnets

« on: August 27, 2021, 01:54:59 AM »

Gravitation is perhaps the quintessential example of something that was theorized to exist without evidence for it.  Rather than allow the study of the natural world to lead US to answers, an answer was mathematically contrived and then forced upon reality.

You have the sequence of events backwards.  Einstein didn’t start with a theory of gravitation and work backwards. Special relativity contradicted Newton’s “instant action at a distance”. He developed GR as a way of reconciling that problem.  It was exactly the study of the natural world that led to GR.  And since then, all kinds of experimental evidence supports it.

5

Flat Earth Theory / Re: Gravity experiment

« on: August 23, 2021, 12:24:17 PM »

No worries, but the idea of everything moving through spacetime at c is fundamental to relativity.  The Thorne quote didn’t address it directly, but its accepted as axiomatic.

“Special relativity declares a similar law for all motion: the combined speed of any object’s motion through space and its motion through time is always precisely equal to the speed of light. At first, you may instinctively recoil from this statement since we are all used to the idea that noting but light can travel at light speed.  But that familiar idea refers solely to motion through space.  We are now talking about something related, yet richer, an object’s combined motion through space and time.  The key fact, Einstein discovered, is that these two kinds of motion are always complementary.  When the parked car you were looking at speeds away, what really happens is that some of its light-speed motion is diverted from motion through time into motion through space, keeping their combined total unchanged.  Such diversion unassailably means that the car’s motion through time slows down.”

That’s from Greene’s “The Fabric of the Cosmos” (sorry can’t cite the page #, its on my Kindle location 1131, if that helps, lol). It doesn’t get anymore mainstream than Brian Greene.  He’s the Nickleback of physics.

 That’s the essence of time dilation and why it causes things to fall.  When an object goes from stationary to moving through space (without any outside forces) the only path it can take is its geodesic because there is no “extra energy” to move it and the geodesic is the path of least resistance. Because of the way time dilation curves spacetime, that geodesic will always be down.  And because it moves down in space, its motion through time is slowed and the balance of c is preserved.

Its really very elegant when you think about it.

6

Flat Earth Theory / Re: Gravity experiment

« on: August 23, 2021, 04:01:51 AM »

 If you want to push your pet theory, go study for a few years, work in the field for more, get some credentials, and publish in actual scientific forums (of which this is NOT one).

A guy named Albert Einstein already did that.

“If we restrict ourselves to the case which almost exclusively offers itself to our experience,  of v being small as compared with the velocity of light...…What is remarkable in this result is that the component g₄₄ [the time component of spacetime curvature ] of the fundamental tensor alone defines, to a first approximation, the motion of a material point.

That’s from p. 158-9 of The Foundation of the General Theory of Relativity in a section titled Newton’s Theory as a First Approximation

Kip Thorne (https://en.wikipedia.org/wiki/Kip_Thorne) explains what Einstein meant in Chapter 4 of his book The Science of Interstellar

Warped Time and Space, and Tidal Gravity
Einstein's Law of Time Warps
Einstein struggled to understand gravity on and off from 1907 onward. Finally in 1912 he had a brilliant inspiration.Time, he realized,must be warpedby the masses of heavy bodies such as the Earth or a black hole,and that warping is responsible for gravity. He embodied this insight in what I like to call "Einstein's law of time warps," a precise mathematical formula1 that I describe qualitatively this way: Everything likes to live where it will age the most slowly, and gravity pulls it there.
The greater the slowing of time, the stronger gravity's pull.

This is a really good distillation of the subject if you are more of a visual learner.


 Any physicist will tell you that there is very little (relatively speaking) warping of the space component of spacetime near the earth. It isn’t massive enough.  For practical purposes, it is flat and what we experience as gravity on earth is due to the warping of the time component. Of course you are free to disagree with the idea, but it is hardly my pet theory. Its pretty mainstream.  At the beginning of the video I linked, the host references numerous other videos that explain the same thing in different ways.  You might try doing some research before making snide comments

7

Flat Earth Theory / Re: Gravity experiment

« on: August 22, 2021, 10:38:03 PM »

Gravity is very well defined as part of general relativity as the warping of space due to mass.

This is incorrect, but commonly taught.  Gravity is actually a natural law millennia old. Often when speaking of gravity colloquially, we are actually talking about gravitation.  Gravity is purely the observation of the phenomenon.  Gravitation is a theoretical cause of the completely real phenomenon.  Handwaving "mass does it" is not a rigorous definition - obviously.

Gravitation is neither rigorously defined nor understood.  It is important to recognize this fact.

Time dilation is rigorously defined, understood and experimentally verified.  Even the FE wiki recognizes that.  And time dilation is, ultimately. the "cause of gravity".

Everything, at all times, is moving through spacetime at c.  Velocity through time + velocity through space=c.  Time dilation means that things move through time faster at higher elevations relative to things at lower elevations.  A stationary object moves through the time dimension at c and through space dimension at 0.  If it begins to move through the space dimension, then its motion through the time dimension must decrease.

This is accomplished as objects follow geodesics created by the warping of space time.  The geodesics will always curve downwards (where time moves more slowly).  Forward motion in time results in downward motion in space in order to maintain equilibrium at c.


Its  really a bit more complicated than that, but the bottom line is that time dilation, which even, FET acknowledges exists, is what causes things to fall.