Having only just learnt of the existance 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 aswell see what others think.(adsbygoogle = window.adsbygoogle || []).push({});

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 wont 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)

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# Gravitational Redshift

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