You say, anytime you have a vacuum state, you will discover that one wheel will not turn another one, if the only connection between them is whatever was there before the vacuum. That kind of thing.
例えば 向かい合う風車が 真空ポンプで吸い出すことのできる 何物かだけでしか繋がっていない場合 真空の状態にすると もう一方の風車を回すことはできなくなる