Dismiss Notice
Join Physics Forums Today!

Light Speed and Gravity

  1. Jun 25, 2003 #1

    Les Sleeth

    User Avatar
    Gold Member

    I stumbled on an article entitled, “Crash of relativity after Lorenz-Einstein” at: www.worldspace.nm.ru/en/articles/pdf/lor_e.pdf It is written by A.V. Rykov, Ph.D., chief of lab. Of Seismometry at the Russian Academy of Science.

    What interested me was his assertion that the speed of light is dependent on gravity. I quote (you’ll have to interpret through his broken English):

    “The speed of light versus gravity acceleration is given.

    “At start of space vehicles speed of light on the Earth is one, and in a free space it is another and difference is visible only in the 8th mark. For the Sun at which the acceleration of a gravity in 28 times more terrestrial, the effect of reduction of speed of light on a surface of the Sun is more and the difference is already in 5-6 marks of value of speed. In the research experts result the formula of dependence of Doppler displacement of frequency of a radio communication with “Pioneer – 10” – [del]v = v(sub)0V/c

    “That abnormal part of Doppler displacement of frequency depends not only on reduction of speed of movement of device “V”” rushes to eyes, but also from speed of light “c”. It is enough to determine a difference of speed of light in a free space from speed of light in a gravitational field of the Earth and the riddle of abnormal acceleration of the device can be solved so: there is no abnormal acceleration, and there is a dependence of speed of light on gravitation. It is remarkable, the increase of speed of light in space just coincides with is the sign of Doppler abnormal displacement.”

    Does gravity slow the speed of light?
    Last edited: Jun 26, 2003
  2. jcsd
  3. Jun 25, 2003 #2
    Relativity doesn't say that all light beams will be percieved as moving at c. c is just the speed of light in vacuo.
  4. Jun 25, 2003 #3

    Les Sleeth

    User Avatar
    Gold Member

    Re: Re: Light Speed and Gravity

    That was helpful.
  5. Jun 26, 2003 #4

    Les Sleeth

    User Avatar
    Gold Member

    Anybody know?

    Can anyone evaluate Dr. Rykov's observation? Does it have an any merit? Or is the answer so obvious no one wants to embarass me by saying so? Don't worry, I can take it!

    But, I am very interested in the effects of gravity on light.
  6. Jun 26, 2003 #5
    The link is no good. Perhaps folks want to read that link for themselves, before responding to you. I know I would.

  7. Jun 26, 2003 #6

    Les Sleeth

    User Avatar
    Gold Member

    Sorry everyone, I had an extra period stuck at the end :frown:. The url is: www.worldspace.nm.ru/en/articles/pdf/lor_e.pdf
  8. Jun 26, 2003 #7
    Extra dot

    LW...hey no prob. Didn't even notice it myself. Will read over the file and go from there.

  9. Jun 27, 2003 #8


    User Avatar
    Staff Emeritus
    Science Advisor

    I have not read the article mentioned and will not comment on it. I just want to point out that the existence of black holes does NOT imply either that light "slows down" or that it "bounces around" inside.

    As light moves against a strong gravitational field, it's energy decreases just as it would for a massive body (by which I mean "a body that has mass"). The massive body would slow down. Light loses energy by it's frequency reducing. The frequency of light coming out of a black hole is reduced to 0 when it has lost all it's light.
  10. Jun 27, 2003 #9
    a thought or two


    I posted a response to this last night, but this goofy website apparently logs you off without warning after a scant 30 minutes. Pretty ridiculous, but anyway....here's essentially what I said:

    The content of the paper by the Russian 'scientist' is, in my opinion (imo) far from a thorough, insightful treatise on the subject matter. There is essentially no substance to what this man's claims are. I could be swayed away from the 'traditional' Einstein side of the issue if I was presented with unwavering evidence and not a lot of hand-waving as is done in that paper.

    Photons --- light....have zero rest mass, but have mass otherwise. As such, they are subject to gravitation the same as any other mass of that size and extent. It would take a body of extraordinary size and mass to deflect a photon from an otherwise straight-line path......[enter] the Sun. As was shown long ago, the sun's mass has the ability to bend light. In my own heart I don't believe it's much more complicated than that. Nature is not complicated....it is simple. Does it's speed change? It doesn't have to. So, if you take a large gravitational object and accelerate it and then pass a ray of light thru it will the speed of the ray change? I highly doubt that it will. It's direction will change, and it will therefore undergo an acceleration, but the magnitude of the velocity can remain constant....remember, velocity is a vector, and speed as we throw it around, is the *magnitude* of velocity.

    So....that's my 1.5 cents worth.

  11. Jun 27, 2003 #10

    Les Sleeth

    User Avatar
    Gold Member

    (I am going to assume in your last sentence you meant "The frequency of light coming out of a black hole is reduced to 0 when it has lost all it's energy.)

    Thank you for responding. I figured my black hole reasoning was not very clear, which is why I removed it from my post.

    What I was trying to do is use it as an example of how gravity might slow down light by imagining what would happen to the first light a black hole pulls in. In other words, say a huge star supernovas and its core begins to collapse under its own gravitational field. As it collapses it begins pulling surrounding gases and other matter, including light.

    Now if the light it catches had been traveling away from the core before it collapsed, then it seems light would first be "slowed" before it was captured. So in this way it seemed light speed might be affected by gravity (which is really my question). According to you, the only effect will be slowing of the frequency, but since light's energy and c are unrelated, you aren't saying are you that after light interacts with a black hole, some oscillitory-less ghost light, robbed of its energy, continues onward at light speed?

    But if light is trapped intact by a black hole, then I wonder what light is doing there. Is it absorbed into the matter there and if so, is it caught up in some furious dynamic or does it just sit there?
    Last edited: Jun 27, 2003
  12. Jun 27, 2003 #11

    Les Sleeth

    User Avatar
    Gold Member

    Re: a thought or two

    Thanks for answering. I wonder if you might read some of my reasoning to HallsofIvy and tell me what you think. I didn’t understand the Russian either, except for him implying some interdependence between light speed and gravity. I still can’t see how a black hole is supposed to "capture" light unless it is absorbed into whatever sort of matter is there.

    If you'll allow me, let me tell you what I am really wondering about. I want to understand the effects of gravity on oscillation. I started with light speed only because I was researching the oscillation thing, and stumbled on that. I figured I would get that out of the way first and maybe in the process some of my other questions would be answered.

    I am interested in what effects gravity and acceleration have on oscillators like atoms and light because it seems that we determine time by the cycles of things. Since all cycles are ultimately dependent on atoms and light, then it seems that which affects their oscillation also affects time. In other words, assuming time for our universe began with the big bang, and that time will end (also assuming proton decay) when all matter radiates away its energy and universal expansion forces EM to yield its energy, then oscillation would definitely be an indicator of how much “time” is left; that is, there are so many oscillations left before the end of time for any given bit of matter/light as well as the universe as a whole.

    After a discussion in a thread on relativity where the traveling twins paradox was being debated, I started wondering if the traveling twin’s rate of aging (compared to his previous rate at home on planet Earth), decreased because both the motion and acceleration of his spaceship had altered the oscillatory rates in his new frame of reference. Motion would elongate cycles, and so slow its oscillatory rate while acceleration (and here’s where I am seeking insight) I am thinking should energize and compact the ship’s atomic oscillators, which also will slow their rate of oscillation. I think this because of, say, what happens to a neutron star, whose gravity is so intense it stills the oscillatory relationship between electrons and protons. Now there is some matter which will take a long “time” to succumb to entropy.

    Returning to the twins, if the space twin does alter his atomic oscillatory rate (relative to Earth) as described then all atomic-dependent cycles will be affected too (which is just about everything), including clocks.
    Last edited: Jun 28, 2003

Have something to add?

Similar Discussions: Light Speed and Gravity
  1. Gravity and Speed (Replies: 2)