[Junior]

Then that means that there is no "Big Bang Theory" since it cannot be falsified - which means it is not a theory in the scientific sense.

Beep. Circle takes the square. There are all sorts of ways the Big Bang theory could be falsified -- if for instance it was shown that space really wasn't expanding. There is a line of research going on this right now -- based on an alternate theory of what the red shift of astronomical objects really means -- unfortunately, it doesn't take into account the background radiation that the Big Bang theory accounts for nicely (and predicted years before it was discovered).

[Frumious Bandersnatch]

Ah, but the point is that it hasn't as of yet been shown to be falsifiable.  Therefore, according to your definition of science (though not according to the classic definition of science), the Big Bang Theory is not a theory.