During the years following Hubble and COBE, the picture of the Big Bang gradually became clearer. But in 1996, observations of very distant supernovae required a dramatic change in the picture. It had always been assumed that the matter of the Universe would slow its rate of expansion. Mass creates gravity, gravity creates pull, the pulling must slow the expansion. But supernovae observations showed that the expansion of the Universe, rather than slowing, is accelerating. Something, not like matter and not like ordinary energy, is pushing the galaxies apart. This "stuff" has been dubbed dark energy , but to give it a name is not to understand it. Whether dark energy is a type of dynamical fluid, heretofore unknown to physics, or whether it is a property of the vacuum of empty space, or whether it is some modification to general relativity is not yet known.
Been a very long time since I’ve seen the show, but I think he simply wanted freedom for its own sake. He was imprisoned on the island by the will of others or the “will” of the mysterious island itself. He was rebelling. Lost was pretty much a mish-mash of a bunch of different religions or religious ideas thrown into a blender. One could see MIB as a fallen angel type figure rebelling against the rules of God, or rebelling against Nature itself. Or, very much like the Force from Star Wars, both good and evil, light and darkness, have their place. But there must be balance.