Olympics prompted. Gymnastics on the Moon would be awesome, and all sorts of new maneuvers, eg “the 1/2 Bloom,” which is too difficult too describe here. But to begin, my original thought/query. There are any number of maneuvers–I don’t know the real word–often named after their creator, which are analyzed as, eg [“two flips with planked body”] followed by [“two spins around body axis”], etc. I’m using brackets because the technical description is very precise and I don’t know the words anyway.
Basic physics question: can you extrapolate using elementary dynamics how a maneuver on Earth would play out in a different gravity, all other things being equal?
I.e., would a “triple Bloom” on earth be a “36-Bloom” on the moon?
ETA: Mods, if you can, leave this in this GQ forum. It should be the physics and physiology of a hypothetical, not a Fantasy Sport.
If you apply the same upward force when you jump as you would on Earth, you will still need to apply the same amount of force to stop your body when you land. You’ll just jump higher.
But impact may be spread over more time. Your muscles have more time to absorb the equivalent change in force. Er… actually I think the *work *is equal, so you need to apply less force over more time. If I remember my physics correctly.
No, if you take off with the same amount of force, then you leave the ground at the same speed, regardless of gravity. It’s just a function of force and mass. Gravity only affects how quickly you decelerate after leaving the ground, which affects how high you get, and how soon you come back down. When you do come down, you hit the ground at the same speed.
Well, if you jump like a figure skater with your arms and legs held far out and then pull your limbs in quickly to convert angular momentum to rotational, I guess the extra “hang time” might allow for a septuple+ axel.
Probably the bigger problem is how to maintain athletic conditioning in a low-gee environment. Even if you start out as an Olympian, the longer you stay on the moon, the “softer” you’ll get. Would it be possible to stay in Olympic shape even with extended hours of daily resistance training? The cooler impossible-on-Earth gymnastic moves might only be doable for a few months.
Well, there’s the minor wrinkle of terminal velocity. As pointed out in this long-ago thread, the moon doesn’t have terminal velocity as such since it has no atmosphere, but if we’re staging a Moonlympics in a stadium-sized dome with Earth-level air pressure so the athletes won’t have to wear bulky spacesuits…
Well, probably there’s no appreciable effect anyway. I just picture a pole-vaulter able to land without a mat by flapping his arms after he clears the bar.
If you jump up from the floor with the same amount of effort, then you come back down just as fast on the Moon as on the Earth. So the stress on your legs from landing should be the same.
Or to put it another way - on the Moon, you can jump 6 times higher, so you’re falling from a height 6 times higher.
Ok, but you don’t have to jump as high to start with on the moon. On earth it’s hard to stick a landing for the minimal moves. On the moon you can do much more without coming down so hard. So yeah, if you take advantage of maximum height for the most complex moves then I guess you’ll hit just as hard.
If you play it conservatively like that, you may stick more landings, but you’ll lose out overall in points to my YUGE aerial stunts.
Well maybe not; there may be a point where the landings become impossible to stick (due to bounce) and where landing failures lose more points than extra turns gain.
One problem I can foresee with the Moon Olympics (inside a pressurised arena, of course) is that for the same effort you jump higher and longer, but still land with the same force. During this long ballistic curve you will have plenty of time to do somersaults, tumble, and do impressive manoeuvres of that kind; in fact they would be unavoidable. Mis-time your tumble and you could land on your head, or your neck.
Long jump and high jump would share many characteristics with competitive gymnastics, and you’d get extra points for landing gracefully without breaking your ankle or neck. Remember that your inertia remains the same on the moon, despite weighing much less.
It’s true that inertia is the same and you’d land with the same force, if anything perhaps slightly slower as there’d be more distance for air friction to slow you down. Presumably the dangers of a botched landing would be roughly equivalent to the Earthly dangers, though again if anything it’d be slightly safer as you’d have more time to react during flight time to minimize those risks that might arise from a botched start.
So, if anything the odds of breaking your head or neck would be somewhat less than when doing the equivalent sport on Earth… and here such things are quite rare in sport.
It’s not on the moon, but in this video Apollo astronaut Alan Bean does gymnastics in zero-g on Skylab. From about 1:05 to 1:13 he is twisting pretty fast. He was a gymnast in college:
This cannot be done on the International Space Station since it doesn't have a large unobstructed habitable volume. The total habitable volume on Skylab was 12,500 cubic feet, whereas ISS is 13,696 cubic feet (both excluding spacecraft), but ISS is divided into many small compartments.
The above video is probably the only low-g or zero-g gymnastics anyone will see until a large habitat is built in space or on the moon.