[puppypower (OP)]

Gravitational lens without accelerating


As known, in the theory GR the acceleration and gravity are mentioned at identical meaning.

And a light has a curved path in an accelerating elevator cabinet according to GR mentality; and this event is called "gravitational lens".

However if the cabinet has fixed speed (acceleration = 0) the light will has an inclined path instead of curved path in accordance with same GR mentality.

Please look at the figure.

There is another way to create a gravitational lens affect and apparent Doppler shifts, without acceleration or even motion. This can be done using frequency modulation. As an analogous example, say we had a train that was moving away from us and sounding its whistle. We would hear a pitch change, due to the Doppler shift and motion. Say the same train was now stationary, but the conductor turned the knob and tweaked the frequency of his whistle. It would sound the same as motion, but without motion. One could tweak the pitch and lower the volume to simulate the sound of a moving train whistle all while being stationary.

The question is, can frequency modulation be generated, without motion, to create what appear to be motion? The answer is yes. It can be done with gravitational pressure. Pressure can alter phase properties of materials and change the pitch.

GR does not deal wth pressure and phases changes of matter to any degree. it is not designed to deal with matter, but more with the energy output from matter. For example, space-time contracts in the center of a star, relative to the surface. The core is where time runs the slowest. Yet ,the pressure due to gravity causes matter to fuse resulting in the the fastest frequency transitions within the star; gamma. Time from GR and space-time and time induce by pressure run in the opposite directions. Acceleration is d/t/t or space-time plus pressure/phase frequency.

As an applied example, on earth's surface, at the temperature of the earth's core, iron would be a gas. This medium would result in the speed of sound being that of other gases. It was add the pressure of the earth's core, iron is a solid with a faster speed of sound. There will be a pitch change for any given sound wave passing through the two media.  This can be extrapolated to light and optics. 

[jeffreyH]

@puppypower So you haven't heard of the stress-energy-momentum tensor then?

[xersanozgen]

There is another way to create a gravitational lens affect and apparent Doppler shifts, without acceleration or even motion.

I agree that some fraction of Doppler shifts can be caused by gravitational forces; e.g.the sun light has some Doppler shift  although the distance between Sun-Earth has fixed value for measument moment.

[evan_au]

Doppler shifts can be caused by gravitational forces

The Doppler effect was first documented in 1842. It relates to velocity of the observer and source.
See: https://en.wikipedia.org/wiki/Doppler_effect

The fact that gravitation could cause a frequency shift was an implication of Einstein's General Theory of Relativity, published in 1915. Christian Doppler could not have known about this*.

This type of frequency shift is often called Einstein shift, to emphasise its similarities (and differences) from Doppler Shift.
See: https://en.wikipedia.org/wiki/Gravitational_redshift

If you have an observer traveling close to the speed of light, there is an additional frequency shift due to Einstein's Special Relativity. This is called Relativistic Doppler Shift, but it is really just a correction to Doppler shift that must be applied at very high speeds, and does not affect Doppler Shift at "normal" speeds (like for a supersonic fighter jet).

* The astronomer John Mitchell did predict black holes in the 1700s, well before General Relativity!