Physicists often quote from T. H. White's epic novel The Once and Future King, where a society of ants declares, "Everything not forbidden is compulsory." In other words, if there isn't a basic principle of physics forbidding time travel, then time travel is necessarily a physical possibility. (The reason for this is the uncertainty principle. Unless something is forbidden, quantum effects and fluctuations will eventually make it possible if we wait long enough. Thus, unless there is a law forbidding it, it will eventually occur.)
Michio KakuScience is given almost no visibility in the media. If a Martian came down to Earth and watched television, he'd come to the conclusion that all the world's society is based on Britney Spears and Paris Hilton. He'd be amazed that our society hasn't collapsed.
Michio KakuThe best theory comes from string theory, which states that dark matter is nothing but a higher vibration of the string. We are, in some sense, the lowest octave of a vibrating string.
Michio Kaku