raaaid,
The reason a swing works like it does is because from an external reference it does not contain any more "energy" then it did just hanging there. Because both high points counteract each other. Same thing happens with orbits. Physics is just another hobby for me, so please understand that I might have misused a word or two and always welcome correction.
And mentioning time travel is a good way to get banned on forums I would guess.
Hey, Pprune guys, when will your planes support 16x time compression like my flight sim planes do? Huh? I knew it. Too ashamed to admit it.