Gravitational Redshift: Exploring a Theory with Physics

In summary, Owen's theory is that light behaves like a particle, and that the gravitational force caused by a body (such as the sun) on the photon affects the photon's mass and speed. He calculates the increased or decreased frequency of light due to gravity using data from the sun and Earth, and finds that the redshift is very small. If Owen chooses to pursue his idea, he'll need to find a way to derive unambiguous predictions and test his ideas using experiments.
  • #1
Owen
36
0
Having only just learned of the existence of this board I feel that I should make use of it as i spend most of my free time working on seemingly useless theories, might as well see what others think.

I have read a little on gravitational redshift but have never really understood the theory. My own theory does tend to break a few of the basic principals which I've been taught (for example light having zero mass). Firstly I model light as a photon which is moving away from a body (eg the sun) at the speed of light. Using Newtons third law (F= ma = d(mv)/dt) and the universal law of gravitation I come up with an equation (which I won't quote here as I'm only looking for opinions on my method at the moment) which relates the gravitational force provided by the body on the photon to the mass and speed of the photon. by setting the speed of the photon as the speed of light (which remains constant) an equation for the rate of change of mass is established, using E = mc^2 and E = hf this rate of change of mass becomes a rate of change of frequency (or wavelength). This can be used to calculate the increase (or decrease) in frequency due to gravity. Using data for the sun and the Earth the values of redshift are minute (which is to be expected).

I would appreciate any feedback on this, and I am fully prepared to accept that it is complete rubbish because although I enjoy physics my knowledge isn't too good (i'm only 17, so give me some credit, lol)
 
Physics news on Phys.org
  • #2
Originally posted by Owen
I would appreciate any feedback on this, and I am fully prepared to accept that it is complete rubbish because although I enjoy physics my knowledge isn't too good (i'm only 17, so give me some credit, lol)
Fair enough: 17 is a good age to be thinking about this stuff - old enough to understand it, young enough to question it.

Have you looked into Einstein's relativity (besides just the equation) yet? You can't combine those equations because the "E" isn't the same kind of "E."
 
  • #3
I haven't got a very good grasp of the equation but my understanding was that for low speeds the area under the momentum vs speed graph was that of a triangle (1/2 mv^2) but as you near the speed of light the line straightens out (to the area of a rectangle, mv^2). If anyone could explain why this is incorrect I would be greatful.


P.S. didn't de Broglie combine those 2 equation for something else?
 
  • #4
Match with observations?

Another aspect to consider is 'what are the results from experiments?' In your reading you will find that a) GR makes very precise, concrete, and testable predictions; and b) experiments have validated these predictions to a high level of accuracy (~1 in 10,000).

If you choose to develop your idea, please find a way to derive unambiguous predictions - e.g. the relationship between the observable redshift, and gravitational potential. You can then use the results of experiments conducted to test GR to test your own ideas.
 

1. What is gravitational redshift?

Gravitational redshift is a phenomenon in which light emitted from an object appears to be shifted towards the red end of the electromagnetic spectrum due to the effects of gravity.

2. How does gravitational redshift occur?

Gravitational redshift occurs when light travels from a region with a stronger gravitational field to a region with a weaker gravitational field. The gravity of the stronger field causes the light waves to lose energy and therefore appear shifted towards the red end of the spectrum.

3. What is the significance of gravitational redshift in physics?

Gravitational redshift is significant because it confirms the predictions of Einstein's theory of general relativity. It also allows scientists to measure the strength of gravitational fields and study the effects of gravity on light and other forms of energy.

4. How is gravitational redshift different from Doppler redshift?

Gravitational redshift is caused by the effects of gravity, while Doppler redshift is caused by the relative motion of the source of light and the observer. Gravitational redshift is a fundamental property of light, while Doppler redshift is a result of the motion of objects.

5. How do scientists study and measure gravitational redshift?

Scientists study gravitational redshift by observing the light emitted from objects with strong gravitational fields, such as black holes or neutron stars. They can measure the amount of redshift by analyzing the spectra of the light and comparing it to the expected values based on the strength of the gravitational field. Modern instruments, such as spectrometers and telescopes, have greatly improved our ability to study and measure gravitational redshift.

Similar threads

  • Special and General Relativity
Replies
11
Views
267
  • Special and General Relativity
Replies
21
Views
470
  • Other Physics Topics
Replies
27
Views
1K
  • Other Physics Topics
Replies
5
Views
2K
  • Special and General Relativity
Replies
11
Views
993
  • Other Physics Topics
Replies
11
Views
2K
  • Other Physics Topics
Replies
1
Views
1K
  • Special and General Relativity
Replies
4
Views
1K
  • Special and General Relativity
Replies
5
Views
770
  • Astronomy and Astrophysics
Replies
13
Views
1K
Back
Top