Since these theories were not posted on the SDMB I thought a new thread was appropriate. When I was the Facility Manager of NASA’s Zero Gravity Research Facility in the 1990s I got a some odd mail because my office address was public. One guy mailed me two different theories hand written on many sheets of paper. I saved them but I guess I left them behind when I retired. I’ll describe them as best as I can.
Idea number 1: Although he recognized the facility’s ability to produce microgravity 5 seconds at a time, he had a better method. Picture a Ferris wheel type device 100 yards in diameter. This is mounted on a low friction track of some sort that was 100 yards long. On the Ferris wheel were research chambers where the microgravity was produced. I think each chamber slid on a track from the axle out to the rim. There was a vacuum in each chamber. As the wheel rotated it simultaneously slid along the track and the chambers slid along their tracks. About 2 pages of equations claimed this produced zero gravity in the chambers. The wheel may have been mounted on a vertical track that allowed 100 yards of motion also.
Idea number 2: He designed an airplane where some of the engines were thrusting forward instead of back. The exhaust from these engines was supposed to move the air out of the way and allow the aircraft to fly without much friction. He admitted this sounded counter-intuitive but he carefully calculated the thrust of the various engines so there was more forward thrust to overcome the reverse thrust of the backwards engines.