I kept a notebook in 1971 where, besides writing short stories and calculating the strut size for odd geodesic domes (some based on ellipsoids and higher order volumes), I developed a theory of motion that was able to explain inertia as a gravitational effect of the expanding universe.
This theory was not just the Einsteinian space bending explanation, but one that summed gravitation forces of an expanding universe on a moving body and showed that it would keep it moving, with a very slight acceleration. The acceleration changed for the different models of the universe that I considered. I was able to build up a Hubble type expanding universe with a map to the acceleration which mathematically showed the motion effect on a body. Velocity became a condition of space … well enough of that stuff, because, although I can still intuit the results, I can’t reproduce the math.
Recently, I found the notebooks where I figured all of this out and I spent a few days trying to recover the math. I was a math major in 1971 with more calculus courses than anyone I’ve ever heard of under my belt. Since then, the real world has chewed me up and spit me out. I changed colleges a few times, got married, got fired from a bad job, went on food stamps, and made a living doing flea markets and reading tarot cards. By 1976 I was an accounting clerk trying to make a living and learn enough about computers to get a better job. I forgot all that math.
It is frustrating that there is now observable data that validates my work from 1971. Spacecraft are mysteriously speeding up. They are experiencing the violation of Newton’s first law that I predicted.