My thoughts:
Time exists, just as gravity does, just our method of measuring it is man-made. Certainly you don't believe that there is no such thing as past, present, or future? If there was no time, we'd all be unable to move because we couldn't change from our current state. Without time, my typing this would have to occur simultaneously with every other occurrence in my life, which just isn't the case. For that matter, without time, none of us would exist. Things move forward, there is a possibility they can move backward, though we've yet to discover how. Just because we decided on an arbitrary way to measure time doesn't mean that time itself is a man-made concept. We can't see the future because it has not yet been determined. Every action we do affects the future, and we DO have a choice about what we do. This all reminds me of the last episode of Star Trek: TNG. An anti-time eruption grows backwards through time and almost destroys existence. Interesting, even if you don't like Star Trek. So, if the theories about anti-time are true, then time travel into the past would be possible by utilizing anti-time, but it would reset everything, including your memory and age, so you wouldn't know about the future anyway (which would make it pointless).
Comments?