As our technology has progressed we have become much more inward looking..by that I mean that there is cable moreso than broadcast...what broadcast there is is short range, (cell phones)...the long range stuff is fiber optic.
It might make it harder for someone a zillion lightyears away to detect...and vice versa if that happens to be the natural upgrade path of technology.
For another thing...virtual reality.
Why look OUT when we can look IN...There is absolutely NO LIMIT to what can be done in VR...
If THIS is the upgrade path of advancing technology...maybe they are out there all right..but they have no plans to go anywhere, and are undetectable at a distance.
The issue is that even if a civilization goes almost fully into a virtual world, it is likely it will still be growing and thus needing more and more resources over time, thus expanding further.
why do you say that?
we are currently making less resources go much further than ever before.
technology keeps doing more with less.
the only thing we consistently need more of is energy.
A dyson sphere would provide a BUNCH of energy..
...and mask the emissions of those who live in it.
Ever wonder about all of those brown dwarves?
Brown dwarves are the most common star there is...
A dyson sphere would still be most likely detectable. Maybe not with our current technology, but with future technology for sure.
what about brown dwarves?
since we don't have very much observational information about them, I do not really have an educated opinion of them.