Physics Inconsistency

You're right that photons have mass 0

Mass warps space-time, (which is  why gravity and acceleration are indistinguishable), pulling space-time towards it.
Light will follow the geodesic (a straight line, or shortest distance between two points, in non-euclidean geometries) that it is currently on. This will appear as light bending around large masses.

Quote from: momentia on September 13, 2011, 03:21:24 PM

Mass warps space-time, (which is  why gravity and acceleration are indistinguishable), pulling space-time towards it.
Light will follow the geodesic (a straight line, or shortest distance between two points, in non-euclidean geometries) that it is currently on. This will appear as light bending around large masses.

I feel like your entire purpose was to post the comment 

Mass warps space-time, ...

Photons have no rest mass. But they have energy, and energy and mass are interchangeable.

Quote from: momentia on September 13, 2011, 03:21:24 PM

Mass warps space-time, ...

What about objects with no mass?

If GR is true, then photons would have to exhibit gravitation because they contribute to the stress-energy tensor. Yet noone seems to have any clue how or why this would happen, only that it must.

Why?

Because the photons contribute to the SEM tensor. According to GR they must exhibit gravitation because of this. This is precisely why Wheeler alludes to the possibility of geons. It is possible (probable) that GR is wrong, but if GR is true, then a photon will exhibit gravitation.

Because the photons contribute to the SEM tensor. According to GR they must exhibit gravitation because of this. This is precisely why Wheeler alludes to the possibility of geons. It is possible (probable) that GR is wrong, but if GR is true, then a photon will exhibit gravitation.

Quote from: Ski on September 15, 2011, 08:05:53 PM

Because the photons contribute to the SEM tensor. According to GR they must exhibit gravitation because of this. This is precisely why Wheeler alludes to the possibility of geons. It is possible (probable) that GR is wrong, but if GR is true, then a photon will exhibit gravitation.

We've observed the gravitational effect light in many different ways. Gravitational lensing as mentioned in the OP is just one example. Another result is that there needs to be a very tiny redshifting of light when it comes from a gravity well out of the well, and this has been successfully tested.

Note that even if one had a purely Newtonian universe one would still expect gravity to effect light, but photons would then have non-zero mass. The key differences are the amount of effect not whether or not there is an effect.

Under Newtons theory light should not interact with gravity (and I have refuted Newtons theory earlier).

Are you arguing just to argue? If a photon were to contribute to the SEM tensor, of course it is affected by it, and yes, if they do exhibit gravitation it must needs be quite small.

neither of the phenomena you mention imply that light itself emits gravitational waves, simply that it is subject to them.

Under Newtons theory light should not interact with gravity (and I have refuted Newtons theory earlier).

Quote from: three-dimensional-world on September 16, 2011, 01:31:20 PM

neither of the phenomena you mention imply that light itself emits gravitational waves, simply that it is subject to them.

Conservation of momentum is pretty well-established.

Quote

Under Newtons theory light should not interact with gravity (and I have refuted Newtons theory earlier).

This is wrong. Cavendish and von Soldner both predicted around 1800 that sufficiently massive objects would bend light based on essentially Newtonian considerations.

This argument is funny, half the people in the thread understand what they're talking about, the other half are using vague definitions they learned on the history/science channel to try to sound like they are adding to the argument.

(here's a hint, when everyone else is talking about something causing gravity and you talk about how gravity affects it, you aren't on subject)

Quote from: Raist on September 22, 2011, 10:11:40 AM

This argument is funny, half the people in the thread understand what they're talking about, the other half are using vague definitions they learned on the history/science channel to try to sound like they are adding to the argument.

(here's a hint, when everyone else is talking about something causing gravity and you talk about how gravity affects it, you aren't on subject)

^^^ This

Newton's equations describe how gravity affects objects, and it mostly works, thought not completely. It lays down the fundamentals of gravitational force decreasing exponentially with distance and directly with mass. It's an equation for an effect.

Einstein's General Relativity attempts to explain how gravity works, and it turns out Newton was not completely correct. For one, yes, photons are affected by gravity. According to Einstein, things with mass curve space time, and objects follow these curves. Even if one of the objects is massless, it will still be affected by the gravitational force of the other.

So basically, these two men explained two different things. Newton found an equation that worked to explain the effects of gravity. Einstein attempted to find out how gravity works. There is no inconsistency.

Quote from: Raist on September 22, 2011, 10:11:40 AM

This argument is funny, half the people in the thread understand what they're talking about, the other half are using vague definitions they learned on the history/science channel to try to sound like they are adding to the argument.

(here's a hint, when everyone else is talking about something causing gravity and you talk about how gravity affects it, you aren't on subject)

^^^ This

Newton's equations describe how gravity affects objects, and it mostly works, thought not completely. It lays down the fundamentals of gravitational force decreasing exponentially with distance and directly with mass. It's an equation for an effect.

Einstein's General Relativity attempts to explain how gravity works, and it turns out Newton was not completely correct. For one, yes, photons are affected by gravity. According to Einstein, things with mass curve space time, and objects follow these curves. Even if one of the objects is massless, it will still be affected by the gravitational force of the other.

So basically, these two men explained two different things. Newton found an equation that worked to explain the effects of gravity. Einstein attempted to find out how gravity works. There is no inconsistency.