Originally posted by DeepThought
But you still have enough energy to keep you going past what otherwise would be the heat death of the universe - assuming moderate energy use and no really significant increase in population in the meantime. As long as our population doesn't increase by more than a factor of a million or so we can survive as a species for trillions of years on the cumul ...[text shortened]... a matter of feasibility. Once it's set up it's great, but setting it up is close to impossible.
I think it safe to rule out using entire galaxies as energy sources for sure. Besides, we are still in our infancy of physics, which has only been around for a couple thousand years at best, compare that to the age of Earth. The exponential growth in physics has only been around for about 100 to 200 years. a sniff in the time line of Earth, much less the universe.
The gist of that statement is this:
We have no idea where physics will be in another 100 years much less 1000 years or 1 million years assuming we as a civilization don't off ourselves in the meantime.
So given that we might be around after a thousand more years of growth in the sciences, we can't in all honesty say whether a Dyson sphere is even what would happen in an advanced civilization.
My guess is it would be a last resort effort.
My guess is that some other means of extreme energy will be found that obviates the need for a Dyson sphere in the first place, like my dream physics:
We find a simple almost energy free way to convert matter into anti-matter and then it is a simple matter to just combine the two to generate as much energy as anyone would ever want, a LOT more then would ever come out of a star, pound for pound.
Or something out of quantum physics tapping vacuum energy or some such.
I think it more likely that some kind of scientific development like that is much more likely to come about negating the need for any kind of large scale structure like a Dyson sphere.
With matter/antimatter generators, you only need micrograms of conversion for a person to have all the energy one would ever need for heating, cooling, cooking, transportation and industry, most industries anyway, for the heavy stuff you might even need a couple of MILLIgrams🙂
So my bet would be on the future advancement of physics we can barely imagine today.
Hyper super insulators, where one mm would equal 100 meters of blown glass insulation capable of holding off 100,000 degrees C on one side and absolute zero on the other side, hyper conductors where you get zero resistivity and full Meissner magnetic effects but working at 5000 degrees C and such for starters.
Supermagnetism like 1000 tesla magnets making tiny fusion reactors a reality.
Those are just the wish list of ordinary physics, not even going into exotic quantum effects like a real wormhole into other universes or a billion light years from home kind of thing.