If we’re looking at upper bounds, even the Stelliferous Era is highly conservative. The Black Hole era could last up to 10<sup>100</sup> years https://en.wikipedia.org/wiki/The_Five_Ages_of_the_Universe and it’s at least conceivable under known physics that we could farm their rotational energy or still more speculatively their Hawking radiation.
Usual Pascalian reasoning applies in that this would allow such a ridiculously large number of person-years that even with an implausibly low credence in its possibility the expectation dwarfs the whole stellar era.
The problem with this position is that the Black Hole Era—at least, the way the “Five Ages of the Universe” article you link to defines it—only starts after proton decay has run to (effective) completion,[1] which means that all matter will be in black holes, which means that conscious beings will not exist to farm black holes for their energy. (If do, however, agree that life is in theory not dependent on luminous stars, and so life could continue beyond the Stelliferous Era and into the Degenerate Era, which adds many years.)
Whether proton decay will actually happen is still a major open question in physics. See, for example, Hadhazy (2021) or Siegel (2020).
(Additionally, if proton decay does happen, there’s then the question of “could a technologically mature civilization stop proton decay?”. My money would be on “no”, but of course our current understanding of particle decay physics could be incorrect, or an advanced civilization might find an ingenious workaround.)
As you say, whether proton decay will happen seems to be an open question. If you’re feeling highly confident you could knock off another couple of zeroes to represent that credence and still end up with a number that eclipses everything else.
If we’re looking at upper bounds, even the Stelliferous Era is highly conservative. The Black Hole era could last up to 10<sup>100</sup> years https://en.wikipedia.org/wiki/The_Five_Ages_of_the_Universe and it’s at least conceivable under known physics that we could farm their rotational energy or still more speculatively their Hawking radiation.
Usual Pascalian reasoning applies in that this would allow such a ridiculously large number of person-years that even with an implausibly low credence in its possibility the expectation dwarfs the whole stellar era.
The problem with this position is that the Black Hole Era—at least, the way the “Five Ages of the Universe” article you link to defines it—only starts after proton decay has run to (effective) completion,[1] which means that all matter will be in black holes, which means that conscious beings will not exist to farm black holes for their energy. (If do, however, agree that life is in theory not dependent on luminous stars, and so life could continue beyond the Stelliferous Era and into the Degenerate Era, which adds many years.)
Whether proton decay will actually happen is still a major open question in physics. See, for example, Hadhazy (2021) or Siegel (2020).
(Additionally, if proton decay does happen, there’s then the question of “could a technologically mature civilization stop proton decay?”. My money would be on “no”, but of course our current understanding of particle decay physics could be incorrect, or an advanced civilization might find an ingenious workaround.)
As you say, whether proton decay will happen seems to be an open question. If you’re feeling highly confident you could knock off another couple of zeroes to represent that credence and still end up with a number that eclipses everything else.