Lost Season 5 premiered this week, and I was so happy that it did.  I’ve been in Lost withdrawal for the last 8 months.  It (along with Battlestar Galactica) is the best show on television right now.

The premiere episode gave us our first real confirmation that time travel will be a major theme in this series.  There were previous allusions to it, along with the various “time anomalies”, but this episode showed us the first real cases of time travel.

Lost’s time travel theories match mine to some degree.  Daniel Faraday says that the past cannot be changed:  that time is a string which you can travel forward and backward on, but cannot create new strings.  There’s the “kill your own grandfather” paradox which this can nicely avoid.

On the other hand, Back to the Future uses the multiverse theory:  if you go back in time and change history, you are changing an alternate realities history.  That’s exactly what Doc Brown describes in Back to the Future 2.

I, on the other hand, believe (in as much as I believe in time travel) that what has happened, happened, and it cannot be changed.

If today is Monday and tomorrow (Tuesday) you were to go back in time to yesterday (Sunday) and talk to yourself, then today (Monday) you would remember talking to yourself yesterday (Sunday).  You wouldn’t not know about it today (Monday).  If you don’t remember talking to yourself yesterday, then you didn’t, and won’t, and there’s no way you can go back to that day to talk to yourself on that day.

What has happened, already happened, and will continue to have happened.