Which brings up the interesting problem that, in theory, we can never be sure it is or is not a bubble unless we look at the behavior in the limit as t -> infin

Which brings up the interesting problem that, in theory, we can never be sure it is or is not a bubble unless we look at the behavior in the limit as t -> infinity. One problem with gauging things in the universe (or in the economic sense, the fundamentals in order to value something) is that we will likely never have the tools to do it in the "real" sense.