21 Jun '10 06:30

This came up in the thread on consciousness and quantum mechanics, but it deserves its own thread.

I know that light is 'bent' by gravity, so it is affected by gravity. Einstein explains this by saying that spacetime is curved and the light is in fact moving in a straight line.

In the famous two split experiment the observer (a subject of discussion in the other thread) has no way of knowing which slit a photon has gone through. If this is the case, can we correctly conclude that the photon does not exert any gravitational pull on the universe, as, if it did, its path would be detectable by that means?

I know that light is 'bent' by gravity, so it is affected by gravity. Einstein explains this by saying that spacetime is curved and the light is in fact moving in a straight line.

In the famous two split experiment the observer (a subject of discussion in the other thread) has no way of knowing which slit a photon has gone through. If this is the case, can we correctly conclude that the photon does not exert any gravitational pull on the universe, as, if it did, its path would be detectable by that means?