"<a href=""https://www.youtube.com/watch?v=zJt8yzR2aoY&amp;t=3m06s"">3:06</a> what if putting a coil of wire around the falling magnet and generating electricity causes the object to slow down until it's just hovering", so it still obeys conservation of energy? why would a portal have gravity over it anyway? i feel like it would punch a hole in the gravity field.