I read an article by Michio Kaku about how a highly advanced civilization might be able to escape the impending heat death of the universe by going to another one. I have a few questions. 1) He says that a wormhole to a parallel universe would have to be held open with negative energy. But according to Thomas Roman, Larry Ford, etc, quantum inequalities place restrictions on how much negative energy can be amassed, thus making the construction of traversable wormholes highly unlikely. So are quantum inequalities fundamental constraints like the speed of light, or are they merely engineering challenges that can be overcome by a highly advanced civilization? 2) Kaku also mentions the possibility of creating a baby universe in a lab, perhaps by particle collisions. However, from what I've read about inflationary cosmology, these universes pinch off very quickly and expand in their own space-times, forever separated from ours. Exactly how quickly do they pinch off? Could anything pass into them from this universe? Could negative energy hold the portals to these baby universes open, or would quantum inequalities render that impossible? Thanks.