would be? Why on earth would they inevitably - every single one of them - develop such a civilization? We most certainly haven't; we'll set aside a few areas as parks, but even those are heavily contaminated by our civilization.
Why wouldn't they make Dyson spheres around all their stars - spheres which ought to have shown up on our infrared surveys - and use that energy? Think of all the computations and matter they'd be wasting by just letting the star blaze away. A few parks, sure, but an entire universe of them?
That point sounds like wishful thinking. 'They'll be, like, cosmic hippies man - they won't want to go around harshing Mother Nature's groove.'
> 3. In terms of the author's "Great Filter" idea, maybe some fraction of the supernovas observed by astronomers are really interstellar industrial accidents.
Then why aren't the astronomers & astrophysicists in a tizzy about how all these supernovas simply don't mesh with the well-thought-out models? Supernovas are the outcomes of processes which take millions upon millions (or billions) of years to finish. I doubt their models of include a random fudge factor to explain away alien Homers.
3. Don't get too attached to current favorite theories-Dark Matter-Dark Energy-etc(massive fudge factor) because they are always subject to reinterpretation when new data is uncovered. "Difficult to see, Always in motion the future is."
Which "we" are you referring to? Your idealized American conservationist, Canadians, Mexicans, Brazilians? Tibetans? Chinese? North Koreans? Australians? Indians? Nigerians?
There are many human cultures on our planet which haven't created bureaucracy preventing them from taking advantage of natural resources, and some of them are as technologically advanced as any other culture on our planet.
> 3. Don't get too attached to current favorite theories-Dark Matter-Dark Energy-etc(massive fudge factor) because they are always subject to reinterpretation when new data is uncovered.
And what does dark energy and other fudge factors relating to the overall structure of the universe have to do with narrow models of stellar evolution and the inevitable supernovae of any stars over the Chandrasekhar limit? Either admit it's baseless speculation (and not even bad humor), or provide an example of a star blowing when our equations say it shouldn't.
1. The current rate of technological advancement is so steep as to make even 100 years hence, a nanosecond in the grand scheme, absolutely unknowable.
2. Sufficiently advanced technologies would be indistinguishable, intentionally, a la Star Trek's noncontact per Federation agreement.
3. In terms of the author's "Great Filter" idea, maybe some fraction of the supernovas observed by astronomers are really interstellar industrial accidents.