From astrophysics prof Geraint Lewis at New Scientist:
What if aliens are out there after all, only they are sleeping, awaiting a glorious future when the universe is cooler, providing the right conditions for them to fulfil their ultimate ambitions?
According to this new idea, alien civilisations emerged and flourished in the early universe, growing in size and developing technology to harness the energy from stars and galaxies. Eventually, after material expansion, these aliens would turn to more philosophical musings, pondering the big questions of the cosmos.
Lewis spots flaws in the hypothesis and suggests,
It is little more than guesswork and speculation. There is nothing wrong with a bit of speculation, it can inspire new thinking and new solutions, but it should be taken with an appropriately sized pinch of salt. More.
Indeed. Isn’t the current absolute dearth of aliens also consistent with the simpler idea that there are no aliens? (Occam’s razor)
Okay, maybe there are aliens, who knows? But is there a point beyond which the question ceases to be a science subject?
See also: “Weird” radio signal has conventional, non-ET explanation
Authors of SETI paper defend selves against charges of support for ID
But surely we can’t conjure an entire advanced civilization?
and
How do we grapple with the idea that ET might not be out there?