Hi AJ
Thanks for sharing your essay.
You state that a mass of one object blocks off the repulsive force of gravity of another object in a straight line which you state is a gravitational shadow.
Doesn't that mean as a planetary object becomes smaller, but more dense, that its shadow would also get smaller and thus block less repulsion? If using straight lines, doesn't that also require one to take into consideration physical size as well as the mass? What are the differences between your concept and LeSage's, not counting particle collisions?
There are also other ways to make repulsive gravity, have a look at a sketch I recently added.
Btw, if you read enough essays in the contest, you will notice that quite a few of them are written too vague to get a concrete grasp of how it relates to real physical assumptions. I thank you for your boldness.
Thanks
Jeff