I recall speculating years ago that the universe might be starting a phase change from non-living to living matter. Life, left to its own devices, will eventual

I recall speculating years ago that the universe might be starting a phase change from non-living to living matter. Life, left to its own devices, will eventually (after billions and billions more years) transform all matter and energy in the universe into life, causing life to become the dominant physical process for a long epoch of time. The life we see (and are) now is the very beginning of that phase transition, the seed crystals if you will. It also leads to my personal speculation about the Fermi paradox: if the universe is relatively uniform and has cooled and evolved at a consistent rate, we might not see any star-faring aliens because there aren't very many of them around yet. All across the universe there could be a ton of worlds with life approximately as complex as is found on this one. I call this the "uniform cooling hypothesis." We don't see things like alien megastructures because that stuff hasn't happened yet. Of course for the uniform cooling hypothesis to fully explain the Fermi paradox the standard deviation for living complexity/diversity would have to be relatively small. The distribution would have to be tight enough that at least a non-trivial fraction of galaxies do not yet contain any significant number of star-faring aliens. We would therefore have a decent chance of being in one of those not-yet-colonized galaxies, explaining our "paradox." If the distribution is really tight we might go to the stars and run right into others who are on their first journeys, or get visited within a short time frame +/- our first interstellar trips. If some fraction of UFOs are aliens maybe we are seeing them because we are about to do the same thing. It's "steam engine time." Note also that intergalactic travel is many orders of magnitude harder than interstellar travel. It would require speeds close to 'c' and accompanying time dilation to even be imaginable, since over such long time scales complex materials actually start to fall apart at the atomic and molecular level. Sleeper ships could go to Centauri but they won't take you to Andromeda. The uniform cooling hypothesis would easily explain a lack of intergalactic colonists. They simply do not exist yet.