I've got some news for you here which is likely to ruin your day: Einstein blew it with relativity and it doesn't require much in the way of higher math to comprehend the problem. Nothing Einstein ever said about gravity would allow anybody to think that there might have ever been any sort of a major change in gravity on this planet, yet it is a very easy demonstration that such a change has in fact occurred. My own findings regarding gravity, dinosaurs, and weightlifting are one facet of the problem.
Moreover, The gravitational attenuation required for the super animals of past ages extended into the age of man:
The column stone the man is sitting on is about 100'x20'x20'.
Those column stones were not created by dinosaurs and the Army Corps of Engineers has flatly asserted that no modern technology, much less any ancient technology, could move them (in present gravity that is).
The idea of the theory of relativity being blown to hell by a simple finding from the realm of the weightlifting sports is comical in the extreme and kind of makes a joke out of Time Magazine's naming Albert Einstein as the man of the last century. It kind of says old Al should have spent less time doing "thought experiments" and more time in the gym. I mean, somebody should have figured that one out 90 years ago.
Einstein was trying to use relativistic time to account for the fact that light does not obey the ordinary additive laws for velocities. This was based on what he called "thought experiments", such as the mirror-clock experiment, rather than upon anything resembling real evidence or real experiments. Thought experiments, it turns out, are not a terribly good basis for physics. Moreover, the basic approach is unsound. Louis Carrol Epstein ("Relativity Envisioned"), uses the following analogy: a carpenter with a house in which everything worked flawlessly other than one door which bound, would usually plane the door until it worked. He COULD, however, purchase a couple of hundred jacks and jack the foundation of the house until the one door worked, and then try to somehow or other make every other door and window in the house work again... Light is the one door in the analogy; distance, time, mass etc., i.e. everything else in the house of physics are the other doors and windows. Epstein assumes that relativity is the one case you will ever find in which that sort of approach is the correct one, nonetheless, common sense tells us it isn't terribly likely.
It turns out there is another way in which one could account for light not obeying additive laws, and that this other way is the correct one. That is to assume that light simply does not have a velocity; that it is an instantaneous force between two points, and that the thing we call the "velocity of light" is the rate of accumulation of some secondary effect. The story on this one lives on Ralph Sansbury's www site
The basic Ralph Sansbury experiment amounts to a 1990s version of the Michelson/Moreley experiment using lasers and nanosecond gates, which Michelson and Moreley did not have. Wal Thornhill's description of the basic Sansbury experiment and my own totally simpleminded description of it reside on the Bearfabrique Catastrophism page
The idea of relativistic time, of course, is unnecessary within the context of Sansbury's theory. Sansbury describes gravity as a kind of an electrostatic dipole effect, and the "instantaneous" propagation rate of gravity as the computed necessary speed of a subelectron particle which would in fact get you to one of the near galaxies in a couple of seconds.