There are approximately 300 billion stars in our own galaxy. A handful of these might turn out to be within range of heroic future human efforts to reach them, via centuries-long one-way colony ship voyages. However, any ongoing process of leaping from star to star across our galaxy appears unlikely to ever be both worthwhile and feasible, unless the voyages are primarily undertaken by, and for, AI's. Furthermore, the same technologies that would be needed to make such voyages possible would also make arbitrarily large habitats within our own solar system possible too, at enormously less cost per person.
But let's say that contrary to all reasonable expectations, humanity manages to eventually explore and occupy a vast empire of a million star systems. That still leaves 299,999 million stars in our galaxy that will never be visited by humans and thus, as far as I and the rest of my species for the rest of time are concerned, are useless. That's a 99.7% uselessness rate, and as we look farther out, that figure only goes up from there.
The observable universe contains over 80 billion other galaxies. All of those are completely inaccessible -- as far as present day science can determine, permanently so. Forget generation ships, forget hibernation, even the AI's would evaporate in the time it would take to travel between galaxies by means of any known energy source. Even communication with another galaxy is impossible on any humanly comprehensible time scale. So, we can confidently characterize another 50 sextillion stars as so useless that they'd make tits on a bull seem like 29-accessory Swiss Army Knives by comparison.
According to the current prevailing inflationary cosmology mode, the entire universe may be 23 orders of magnitude larger still. That amounts to at least another 5 million billion billion sextillion stars that, being permanently outside our light cone, reach a degree of uselessness that is almost beyond conception.
And all those useless stars, orbited by countless useless planets, comets, and asteroids, occupy (to a trivially tiny extent barely deserving of the word) an immensely vast volume of even more useless empty space. Of course, not all empty space is useless. A minute fraction of it is good for some things like storing your Oort cloud in and keeping your planet far enough away from your star for comfort. But the total amounts of it in our universe are absurdly excessive. Which means that almost all of it -- the excepted fraction being almost too small to imagine -- is useless.
Thus we must conclude that pretty much the entire universe is profoundly useless. Indeed, there is probably no way for the human mind to truly grasp the extent of its uselessness. While cosmologists might someday be able calculate the uselessness of the universe (formally defined as the integral over all of space and time of the reciprocal of usefulness), the resulting figure will be so far outside our human experience of ordinary uselessness (which evolved to help us survive in a familiar world of ice sculptures, conspiracy theories, Chia Pets, Infomercials, Left Behind novels, and weekly staff meetings) as to be incomprehensible.
There are theories in cosmology and physics (and others in religion and philosophy) that attempt to explain various properties of the universe such as its size, its age, its curvature, and so forth. But is there any theory that can explain why it is so useless?
Respectfully,
Myriad
