But I was wondering out loud about simple technologies that are different than the one's we've mastered. Is it possible for an advanced technology to be based on sciences we don't know, or have just barely investigated? In other words, is there anything we missed? Its hard to believe another advanced civilization would have gotten to the exact place we have, and taken the exact same path. For example, the Romans and the Chinese were of comparable technological and social development, but they each developed technologies and sciences the other did not have.

It's hard to speculate about what never happened, or the unknown, but we have to imagine that if ETI had never seen the stars due to meteorological or astronomical obstacles, would they have developed Newton's Laws? If there was no SiO2 (glass) on their planet, would they have had telescopes and microscopes? And if not, what would they have replaced them with? Would a species living underwater ever develop fire or electricity?

If it is unrealistic to expect they had the exact same technologies we did, then is it not unreasonable to expect they may have stumbled onto stuff lying right in front of us that we missed. I can't give you better examples because I can't go there, but I find it hard to accept that ETI followed the same scientific development we did. There must be other paths, paths we can't even imagine.

A very poor example: Western Man developed relatively few unarmed martial arts; just a few variations of boxing and wrestling, and they go back to Graeco-Roman times. But they are truly crude in comparison to what the Asians developed.