Why do we see stars at night ?

Back to basics :

If intelligent life in the universe overcomes practical issues, then some
species in the Galaxy would have evolved to a class III civilization on the
Kardashev scale. No theoretical limits prevent us from going there :
http://en.wikipedia.org/wiki/Kardashev_scale

If any civilization in the Galaxy evolved to a class III civilization, we
would not see any stars at night.
There would just be a glow of balmy infra-red across the sky.

This did not happen in any other Galaxy either, unless we overlooked
Galaxies which only radiate in infra-red.

The other alternative extreme : "we are alone in the Universe", is still
unacceptable, otherwise you should not be reading this news group.

But, there is a lot in the middle.
To go from where we are now (technological civilization which struggles to
survive on one planet) to a class III civilization (use all energy in the
entire Galaxy) is still a long way. We should not even dare to extrapolate
our current population growth or technology improvements (Moore's law) much
beyond what we have been doing in the past 50 years or so.

The basic question for SETI to answer is going to be :
"When do we go wrong" ?

Are we the only intelligent species in the universe ?
Are we not able to expand our population beyond a certain point ?
Are we not able to expand technology beyond a certain point ?
Are we not able to colonize other star systems ?
Are we not able to use all of our sun's energy for sustaining our increased
population ?
Are we not able to do all of the above ?

One of these questions must be answers with yes.
Otherwise, intelligent life would evolve into a level III civilization, and
you would not see stars at night.

The issue is now : How can we dis-prove some of these questions.

Maybe SETI is not about searching extraterrestrial life, but it is instead
searching for the absence of it. That might give us more answers to where we
are heading.

Rob