Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: thetexan on 24/12/2010 17:25:55

Title: Original 'proof' of general relativity
Post by: thetexan on 24/12/2010 17:25:55
I just watched a show on Einstein concerning this theory of general relativity.  Around 1922 photographs of stars from an eclipse were used to measure the bending of light from those stars around the gravitational field of the sun.  Those measurements were used to confirm Einstein's theory.  All through the program it was stated that the predicted observed amount of bending proved his theory of space/time and the warping of space in the presense of a mass.

How so?

It seems that, at most, this proves that gravity has a predictable and measurable effect on light just like it has on an apple dropping from a tree.  But how does this prove that the cause of the effect is a warping of space/time rather than the more classically accepted attracting force of Newtonian physics.

If the argument is that since photons have no mass they cannot be effected by an attracting force, therefore, the bending must be caused by something else....the bending of space/time, shouldnt it be pointed out that it has not been proven, at least to my knowledge, that photons indeed do not have mass.  And, certainly, in 1922 it was not known whether photons had mass.

If photons are massless and are simply a unit of energy it should be remembered that fields of energy can be effected by other similar fields.  For example, put two magnets, each with their own magnetic field, in close proximity to each other and the resulting field will be a warped, merged, combination of the two fields.  Each field has some effect on the other.

If that is true, and photons are simply a small unit of an electromagnetic field, and that field can be influenced by another field, then isnt there at least one other possible explanation of the bending of starlight?

tex
Title: Original 'proof' of general relativity
Post by: Pikaia on 24/12/2010 20:21:55
Einstein predicted that starlight would be deflected by a specific amount, an amount which is different from Newtonian physics, and which is not predicted by any other theory. His prediction proved to be very accurate. Doesn't the fact indicate that his reasoning was correct?
Title: Original 'proof' of general relativity
Post by: yor_on on 27/12/2010 02:46:39
Tex, read this one Bending the light fantastic. (http://www.mathpages.com/rr/s6-03/6-03.htm) Don't get stuck, it's possible to get the idea even if not having all that math.

" Einstein became very exasperated over the repeated failures of the experimentalists to gather any useful data, because he was eager to see his prediction corroborated, which he was certain it would be. Ironically, if any of those early experimental efforts had succeeded in collecting useful data, they would have proven Einstein wrong! It wasn't until late in 1915, as he completed the general theory, that Einstein realized his earlier prediction was incorrect, and the angular deflection should actually be twice  the size he predicted in 1911. Had the World War not intervened, it's likely that Einstein would never have been able to claim the bending of light (at twice the Newtonian value) as a prediction of general relativity."