Chris, I do not agree that the law of conservation of energy would be necessarily violated by gravity shield. I think energy will be conserved in the same manner as it remains conserved in a slingshot maneuver. The difference however would be - In case of sling shot, the distance changes and gravity is reduced/increased (shielded) with distance. I am not suggesting that a shielding sheet/object exists, actually, they do not. But I would not consider it impossible to have some mechanism that can shield gravity that would keep energy conserved. Actually, conservation law applies to a closed system. If we are shielding gravity, the setting may not be considered closed.
"conservation of energy" is not necessarily violated
Chris, I do not agree that the law of conservation of energy would be necessarily violated by gravity shield. I think energy will be conserved in the same manner as it remains conserved in a slingshot maneuver. The difference however would be - In case of sling shot, the distance changes and gravity is reduced/increased (shielded) with distance. I am not suggesting that a shielding sheet/object exists, actually, they do not. But I would not consider it impossible to have some mechanism that can shield gravity that would keep energy conserved. Actually, conservation law applies to a closed system. If we are shielding gravity, the setting may not be considered closed.