This is absolutely fascinating — a vision of a brief, primeval epoch when the universe might have been much friendlier to life than it is today. I can see a hundred big-think science-fiction writers sprinting to their keyboards….
Our universe is about 13 billion years old, and for roughly 3.5 billion of those years, life has been wriggling all over our planet. But what was going on in the universe before that time?
“But in the early universe, as Loeb speculates in a paper published in Astrobiology late last year, everything would have been a habitable zone. 10 to 20 million years after the Big Bang, the universe was still bathed in that warm gas we saw in the CMB, but it had cooled down to a temperature that would keep water liquid no matter where it was relative to its star. The ambient temperature of the universe would provide enough heat to turn an ice giant like Neptune into a water giant. That’s why Loeb has dubbed this era the “habitable epoch.””