There is a thin line between what we call science and what we call fiction. If some imaginary story or event becomes true it becomes fact and even becomes common accepted in the science. For example, if you told someone who lived hundred years ago that we can construct microchips with a million transistors on it they would not believe you. Let alone the fact that the earth is not flat (actually the earth has become flat again but in a slightly different way [ref]http://www.youtube.com/watch?v=53vLQnuV9FY[/ref]).
So what we now call fiction can become faction and even science within a few year or few decades. Nature still has a lot of secrets that she will not share with us for a long time but once she will reveal it and we will learn something new about our existence. I can’t wait for the replicators and warp-drive 🙂
Bottom line is that we never can know anything for certain because we can’t oversee the present, future events and discoveries that has to be made. Scientists should always be open minded about the “truth”. Truth is very complex and in my opinion impossible to grasp. We never can be certain of anything. Einstein has a great quote that covers it in a very nice way:
“Whoever undertakes to set himself up as a judge of Truth and Knowledge is shipwrecked by the laughter of the gods.” – Albert Einstein