MerakSpielman said:
Let me get this straight... if you mixed a 50-50 specific gravity-ratio chunk of metal to make it weightless, it would weigh nothing but still have mass. So it would float on its own in midair, but you have to work against its mass in order to move it? If it's truly weightless, does that mean you can pick it up, toss it in the air, and it would float upwards forever? I'm trying to understand this...
Nit-pick: the "specific gravity" of an object has a meaning (density related I believe) in chemisty. Its confusing to me to see it used for "subjective gravity", which is really what we're talking about here.
The mixed subjective gravity alloy he's talking isn't really weightless. Remember, weight is really a function of mass in an acceleration field. I.e. weight is the Force part of good ol' F=M*A from high school physics. What he's done is ensure that he has two opposing accelerations operating on the same object. You can think of these accelerations as great big huge springs.
When the item is in the exact middle of the room, and the forces are balance (springs of equal length), the object will appear to have no weight along that axis (up/down). Moving it from side-to-side (left/right, forward/backward), it will still weigh the same, and still take as much work to move.
Now, the item will want to stay and return to its balanced state in the up/down direction. If you pull it down (or push it up), the object will start to oscillate around the balance point, becoming a pendulum. Over time, the object will move less and less distance with each oscillation, coming to rest in the middle.
Make the object a 4-gravity alloy, and it will travel a circular path (instead of a straight one). Make it a 6-gravity alloy, and it will orbit the balance point.
If you want real fun, mix the alloys in ratios other than 50/50.