Sam puts up a list of explanations about how he got from 2008 to 1973. Coma is at top of the list, ahead of time travel. The others - drugs, another planet, multidimensional travel (whatever that is) - I think we can safely rule out.
Why is coma at the top of the list? Because that's by far the most likely explanation. Time travel has going against it the fact that it's intriguingly, deliciously impossible.
But that's in our reality. So the question about Life on Mars can really be put as: is it a show about reality (as are most of the shows on television - cop shows, hospital shows, etc), or is it ... science fiction? Time travel, of course, is not only possible in science fiction, but is one of its staples.
On the actual evidence so far, coma looks the more likely explanation. Sam saw flashes in the first episodes - which could have been doctors shining light into his unconscious 2008 eyes. And last night he repeatedly saw a little futuristic gadget which didn't belong in 1973 - a Mars rover, which landed on the Red Planet in ... 1997. (The Soviets sent two rovers to Mars in 1971, but they didn't look like Sam's 1997 model.) Seeing things that don't belong in the past means that (a) you're dreaming from the future, not time traveling, or (b) objects in addition to what you may have carried with you are traveling to the past. (I'm doubting that somehow Sam is really on Mars...)
But come to think of it, even Sam's clothes were 1973 when he first arrived there. Another argument for coma.
But, I don't know, coma seems to easy and obvious an explanation.
At this point - and I haven't seen the BBC series, so this is truly just based on the first two American episodes - I'm thinking it's somehow coma as well as something else, maybe time travel... Hey, is that "multi-dimensional travel"?
See also Life on Mars Debuts in America ... Life on Mars Goes On in America: What Happens When a Time Traveler Runs Into His Earlier Self? ... Life on Mars #4: All in the Family ... Life on Mars #5 Meets the Wire ... Life on Mars #6 Meets Itself on Television ... Life on Mars #7: Is Annie Real, Or, Is Life on Mars a False Memory
The Plot to Save Socrates
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