here is one of his claims:"According to Popper's "Logic of Scientific Discovery" Einstein's reasoning is not only very strong, but in fact too strong. For it is, of course, true that the ray of light falling into the accelerating box will form a parabolic curve. But this is true not only for light, but also for any other ray travelling at constant speed, and entering the box at an angle of . The shape of the parabolic curve will, of course, vary depending on the velocity of the ray and the acceleration of the box, but if one of two intersecting systems of coordinates is moving at constant velocity while the other is being accelerated the function of the intersection must necessarily be a parabolic curve. This is not only true for rays of light; it is even true for rays, or lines, that exist only in our imagination, or for a box without top or bottom, and therefore without gravitational field. It is independent of any physical properties of those rays, and has nothing to do with gravitation, but simply consists of a geometrical description of two bodies, or systems of coordinates, moving at speeds relative to each other, when one of them is being accelerated and the other is not. It is the result of a valid mathematical inference which can therefore never be refuted. It is a simple truism of analytical geometry and therefore belongs to mathematics, but not to physics. So it falls victim to Einstein's own criterion: because it is certain it does not refer to reality. And if it does not refer to reality, then it does not describe a physical property of light, or of space. And in Popper's terminology the theory of curved space is non-empirical because it cannot be refuted by any conceivable experiment, or physical property of light. Therefore we may not infer from this theory that space is curved in reality, and that light will be deflected in the gravitational field. "
I reread this piece with more patience*. I reckon it is not so bad a critique as I first though.
This might be a good topic.
First of all, it may inspire a close look of Einstein's review of his theory from 1916, and whether it leaves some loose ends.
Secondly, it invites an explanation of the Hafele-Keating experiment. How do they control for expected differences in flight paths, allowing for the difference wrt rotation of the earth to stand out in the interpretation of the final clock values?
There are better GRT people here than I, who might explain these things clearly. I don't feel comfortable with my own understanding yet. But I think I understand one thing. The accelerating box (, lift or rocket) with the deflection of a transverse beam of light is not the reason for curved spacetime. It is just a deflection, just as it would be in a classical gravitation problem, without invoking a curved space concept. What does bring out the need for curvature is the desire for an envelope of spacetime relations that interconnect those tiny, throwaway, momentary accelerating boxes.
Thanks again for posting this topic.
*Lord, grant me the gift of patience--right now, damn it!!
An accelerating box is only useful for equivalence to an everywhere uniform constant gravitational field. In order to apply the idea to a more interesting case, say the spherically-symmetric concentrated gravitating mass of the Sun, then the box would need to have sloping sides that meet (when extended) at the center of the Sun, and it would need to have spherical segments for the top and bottom. Furthurmore, it would need to expand with time, as it gets farther away from the center of the Sun. Furthurmore, it would need to have a decreasing acceleration with time, since gravitation is known to decrease with distance from the center of the Sun. That all gets complicated. But simpler, one just assumes the gravitational/acceleration equivalence holds only differentially for a vanishingly-small volume of space and for a vanishingly-small duration of time. The box becomes just an artifice. For example, in analyzing the trajectory of a ray of light from another star that is grazing the Sun, it runs through a continuum of conceptual tiny boxes where the equivalence can be momentarily applied. The boxes themselves have no permanent significance outside the infinitesmal time the ray crosses them.
Having a plausible field law avoids this complication.
Acc. to TCR the experiment of Hafele & Keating the planes of which one flew eastward around the earth and the other westward around the earth, should have shown the same difference in time dillatations.
The eastward moving plane however gained time (aged more slowly), the westward moving plane however lost time (aged faster).
Both relative to a stationary clock on earth.
It is of course true that the stationary clock itself is in circular motion when compared to "an inertial observer looking down on the North Pole from a great distance".
If we however would look at the experiment from that point of view, we would have three moving frames of reference.
1. The eastward moving plane
2. The "stationary" point
3. The westward moving plane
Since we know the sun comes up from the east, we know the "stationary" point moves eastward too.
So, the eastward plane (as viewed from "inertial point above the earth" moves fastest, then the "stationary point", and then the westward moving plane.
So, from that point of view we have three points, that revolve with different speeds in a circular orbit in easward direction (see note below), and this explains the relative time dillations for the planes, since the time dillitations are: dT1, dT2, dT3 respectivly for the three points, now relative to the "inertial point" above the North Pole, and in which:
dT1 > dT2 > dT3
dT1 - dT2 > 0
dT3 - dT2 < 0
Quite simple, I would think.
I think the rest of the argument of TCR don't hold any water too.
The "speed" of the earth at the equator is 1666.67 Kilometer per Hour (equator length = 40.000 km, which rotates once every 24 hour around it's axis). Since most commercial airliners have speeds less then that, a westward flying plane, would not "catch up" the earth's rotation speed, and therefore would revolve in eastward direction also.
And some nice feature of the theory of Popper of falsification.
This theory says that if a scientific theory (T) is to be a valid scientific theory, it must be falsifiable.
This theory of falsification however is itself a theory. So this means if there is ANY scientific theory that is true, but which can not be falsified, then the theory of falsification itself is false.
There are however scientific theories that are not falsifiable, but which are nevertheless true.
For instance the scientific theory that says that time did not have a begin, is not falsifiable. We can never measure an infinite amount of time, and in that sense it is not falsifiable. But on other accounts (matter-energy conservation) we know this to be true.
here's a paper by Domina Eberle Spencer that argues that time is universal, i read the paper and the title of this paper is misleading because they dont even say that there isnt a time dilation, what she actually does is giving a postulate that i think was first proposed by newton and others here it is:"In a coordinate system that is not moving with respect to the source and which is not in rotation, the velocity of light in free space is a constant c." and she backs it up by an experiment she has done that this postulate confirms while einstein's postulate doesnt (i.e:"The velocity of light in free space is a constant c irrespective of the velocity of source or receiver in any coordinate system which is not in rotation."):"It was not until Spencer and Shama11 analyzed stellar aberration in 1996 that they found an experiment which discriminated between Postulates I* and III*. In a coordinate system in which the star is stationary, both Postulate I* and Postulate III* predict the correct stellar aberration first observed by Bradley in 1728. But in a coordinate system in which the star is moving and the telescope is stationary, Postulate I* predicts no stellar aberration while Postulate III* predicts the correct result. This is the first proof of the validity of Postulate III* and the failure of Postulate I*."
does someone have any information about this analyses?
she gives this reffrence:D.E. Spencer and U.Y. Shama “Stellar Aberration and the Postulates on
the Velocity of Light”, Physics Essays, Sept. 1996.
I'm on my way out right now, so I don't have much time to read through the article, but I can tell you that I only have heard of Physics Essays through a couple of crackpots in the forums. I wouldn't try to publish there.
Originally posted by matt grime Has no one told this lawyer about gravitational lensing?
as einstein said a theory must have at least one experiment that disproove it.
the idea that there are some verifications of the theory doesnt say that there couldnt be an experiment which shows it invalidity.
anyway i believe we finished to talk about the lawyer, now it's spencer