Maybe we've reached it. Maybe all the easy stuff has been discovered, from now on we may have to pay a big price for every new breakthrough. The idea that science, and therefore technology, would continue to expand exponentially may be a thing of the past.

Statements like that are usually shot down with that old story about the head of the 19th century patent office suggesting it be shut down because everything of value had already been discovered. But maybe it's not a question of the end of discovery, but the end of easy, cheap discovery. Also, another factor in research and discovery, market incentive and return on investment, may dry up as markets saturate and economic growth stagnates.

As technology groupies, we've always assumed the exponential technological growth since, say, 1800, has always been a given, but maybe it was an aberration. We won't be the first civilization that has rapidly progressed and then stagnated.

For what its worth, I think this may be the best reason for continued investment in space. I suspect that big breakthrough we may need to keep things rolling is more likely to come "out there" than "down here".

Just a thought.