0.69 x Boltzman's constant per binary bit in degrees C or K, it's a measure of entropy which equates to temperature, lab tested in 2010, can supply link if interested.
My own comment would be to say the assumption is to assume the universe is finite. Why would it not be infinite, why does there have to be a big bang at all, why do scientists need to believe it's finite, other than to try to validate the big bang theory?
To me it's the author starting out with the assumption that energy is finite, which is the real artificial limiter, and the tendency to want that, or need that, looks related to maybe our artificially limited economy on the planet, noting that money is energy, and nobody seems to get that we could supercharge the progression of humanity whilst eliminating the artificial limiter that appears to have been more or less imposed on ourselves, by believing everything had to be limited counted, commodified, known, determined, you know?
The desertification of the planet looks unnecessary and completely reversible, if we could somehow get rid of the tendency for humans to want artificial restriction.
Is that something genetically programed? How is it so prevalent, and apparently indusputable without actually any proof at all?