Hi SDF

I think that you've really failed utterly with your "analysis" simply because interstellar travel hasn't been proven to be a futile business at all. Resources and energies needed to do it are large, but our collective energies seem to progress logarithmically and eventually we will have the spare energy to fly to the stars - and we won't miss it. The Sun puts out energy sufficient to launch a 4 million ton space-colony at 0.87c every second, assuming perfect efficiency. We could englobe the Sun in energy converters and leave a thin opening to illuminate all the planets.

Even more trenchantly you've sold David Brin short by thinking he ignores "Transcendence" - he discusses it albeit fictionally in his continuation novels of the "Uplift War" series. However he's cautiously vague about the details and rightly sees it as a potential dead-end.

Adam