See subject. Videos and photos [In browser]. Only my observation, of course, but the jig and jag of a spine moved in 1 g seems to shake her breasts more, and (seriously)* I am trying to figure out where here and there I notice it and what is causing it. What’s the maximum force a human being can generate from body torsion alone–compared with, naturally, that expended on breast mass on a hop over 1/4 sec at 32 ft./sec*2 . (The movement of the breasts on a twist on Earth would differ less, I’m thinking, during the ballistic portion.)
The Strauss on the SI making-of clip merges grandeur of 2001 and cynicism of Clockwork Orange. Weird scene all around. I think Kubrick would be happy.
On earth, Upton does the Cat Daddy and the Dougie. [Youtubes]
*As serious as you can be in GQ on this perennial sophomore physics topic. And no, I don’t believe this is something mundane and pointless.
Model her jiggling breasts like a mass on a spring undergoing damped oscillation. Since on earth, movements against the direction of gravity will not go far unless the velocity is high, her breasts will only move upwards a small amount and then down again if they are oscillating in 1 G.
I’m assuming the material of her breasts, and the damping coefficients won’t change properties from 1G to zero. This is not true, but it simplifies the model.
In reality there’s a bunch of effects complicating this. For one thing, fluid is in her upper torso, which is why her breasts appear bigger.
The frequency of vibration is directly proportional to the size of the restoring force (the force that tends to bring things back to equilibrium). The restoring force in general has two components: the elastic response of her body and the force of gravity. Depending on the orientation of the motion relative to gravity, the force may vary significantly over the period of one oscillation, e.g. going up away from equilibrium gravity may add to the restoring force, while going down away from equilibrium it may reduce it.
Either way, in free fall gravity is subtracted from the restoring force, and you can therefore expect the frequency of oscillation, as well as the amplitude in both directions (up and down) to shift. I would expect longer oscillation periods, more equal excursions up and down, and somewhat shorter average amplitude.
The frequency of oscillation of a mass-spring system doesn’t actually change with or without gravity: Since the spring force is linear, all that changes is the position of the equilibrium point. So the primary effect is going to be just that her breasts are perkier.
Now, since breasts are not ideal springs, the elasticity is actually going to be different at this new equilibrium point, and so the frequency might change a bit. I would expect this to be a relatively small effect, though.
Does that really happen so quickly? I’ve heard that it happens on the space station, and that the astronauts have to deal with constant sinus congestion because of the same effect. But does it really happen in the 20-30 second intervals of free fall they were doing her modeling shots in?
It should also be mentioned, of course, that in any gravitational field, the jiggle is also going to be affected by the garments she’s wearing. Even in the brief freefall video, she wears several different garments, with different support properties.