Some questions about light.

I know that science says light is a constant speed in a vacuum or in space. But science has also admitted that gravity can alter the path of light. Has anyone ever figured out how strong gravity has to be to alter the path of light?

Being that light cannot escape from a black hole, also would mean that gravity can affect light speed. In this case, it was stopped. Which brings up another question. When light leaves the sun, does it have to escape a certain amount of gravity before it can reach it's final top speed?

In order for light path to be altered be gravity would mean that light would have to concede to it's pull. And being that light travels from the sun, would not gravity have a pulling motion that would try to pull it backwards, until light get far enough away from the sun, that the gravity no longer had a affect on it's speed?

To say that a black hole can hold light, then say gravity can bend light, but to say that light speed cannot be affected while leaving the sun, does not add up.

Studying about light got me to thinking about this.

Light cannot escape a black hole: http://www.sciam.com/askexpert_quest...B7809EC588F2D7

Indeed, light cannot escape a black hole. But what "gives" is not the speed of light, it is the passage of time itself. As one approaches the black hole, ones own time slows down relative to the rest of the universe. Light, measured by your rulers and your clocks, still travels at 186,000 miles per second. But if you do a low orbit of a black hole for a few days (measured by your clocks) many years will pass in the universe outside.

The same happens near the sun. The sun's gravitational field slows time locally (albeit very slightly), so the speed of light locally remains c.

Weird, innit?

That doesn't mean that it's all stored in some hyperbolical light resevoir.

I know that science says light is a constant speed in a vacuum or in space. But science has also admitted that gravity can alter the path of light. Has anyone ever figured out how strong gravity has to be to alter the path of light?

Being that light cannot escape from a black hole, also would mean that gravity can affect light speed. In this case, it was stopped. Which brings up another question. When light leaves the sun, does it have to escape a certain amount of gravity before it can reach it's final top speed?

In order for light path to be altered be gravity would mean that light would have to concede to it's pull. And being that light travels from the sun, would not gravity have a pulling motion that would try to pull it backwards, until light get far enough away from the sun, that the gravity no longer had a affect on it's speed?

To say that a black hole can hold light, then say gravity can bend light, but to say that light speed cannot be affected while leaving the sun, does not add up.

This would also mean that there would have to be some type of formula for each strength of gravity, and how long it would take for light to escape it's pull to reach it's top speed of travel. And no, I did not read this somewhere. Studying about light got me to thinking about this.

Has this been tested or observed? Or is this one of those science theories made to support something?

Light travels on geodesics in spacetime which in the presence of mass are not straight lines. Thus even though light still travels at the speed c, the path it is traveling is farther than you would think. Thus you can treat the problem as space near a mass having a refractive index. But unlike light traveling through glass the velocity has not changed - it's just what you thought was a straight line is not a straight line.

As stated above, it does not affect the speed. When light leaves the Sun it is slightly redshifted - the photons lose a little energy climbing out of the Sun's gravitational potential and hence are of a lower frequency (longer wavelength) i.e. redder.

I repeat the speed does not change!


Already answered above. Also gravity has an infinite range via the inverse square law.


Light is affected when leaving the Sun in the same way as trying to leave a blackhole. For the Sun it is ever so slightly redhshifted - for a black hole it is redhsifted out of existence to infinite wavelength i.e. zero energy - hence the light is trapped.


No you have got it wrong. Yes there is a formula for the strength of gravity - the typical g=GM/R^2 for Sun (or the Earth or whatever.)

But the light is not changing speed, hence the rest of your paragraph makes no sense.