Eternity is not a long time. It is characterized by the absence of time.
It is unreasonable to try to describe eternity in concrete quantifications. It is even more than infinite, more than infinities and what mathematics and number theory can tell us about such.
Eternity is less comprehensible than the vastness of space. We cannot comprehend size. There is too much. We deceive ourselves into thinking we know something about it because it is easy for us to measure things from fractions of micrometers to thousands of kilometers. But the vastness is beyond that, beyond our ability to reason or analogize.
A rough approximation of the basics of small goes like this: If you place a sewing pin in the middle of the field of a domed football stadium, and then increase one of the iron atoms, proportionally, to where the nucleus was the size of the pinhead, then the rest of the atom would be close to the size of the domed stadium, and the electrons would still be too small to see even with a microscope. And that is only the beginning of small. Consider the Planck Length, at 1.6 x 10^-35 meters.
That brings us to a beginning of comprehending how utterly incomprehensible size and space really are. Think of all the empty space, the percentage of volume, within the atom, and remember that atoms cannot approach one another closely under the conditions in our living world. What we call solid matter isn’t solid in any quantitative mathematical sense.
Then we go the other way. There are many examples, and graphics, and short videos, and these help us realize that our whole planet is incomprehensibly tiny in light of the approximate 8.6 x 10^26 meters estimated for the observable universe. Then, how much bigger is what we can call space-time? Yeah, we don’t get it.
Eternity is even more. We don’t even have anything to compare it to.
We try to use time to comprehend eternity, especially since we do understand time, but we can’t.
We pretend we consider time. We always ask what time it is, but we don’t care. We know we have limited time, so we prioritize. Keeping time helps with that, but we don’t consider time, and we really don’t know, nor care, what time it is.
We all know we have very limited time, especially when we consider the span of history, and prehistory, and the time of the universe. We all die young. One hundred years is longer than most of us get, but even that is short. A single human life is a trivial amount of time in the scheme of history.
Yet, so many manage to do something of significance, by human reckoning. All of us do something significant for our loved ones. Sadly, that is sometimes a sad thing, but most of us have our moments where we positively affect others and improve our world. We don’t all get our 15 minutes of fame on the big stage, but we all do for a few.
Still, there are a few names that gained worldwide fame, and lost it. A few names have survived the millenia, but no name is known by every living soul on earth. Eventually, no name will be remembered among human descendants that we know today. If we continue for eons, it all obviously matters to us, but sooner or later, after some long time, all of humanity and our descendants will be gone, even erased. Even if we assume humanity spreads throughout the galaxy, even if we assume some means of spreading to many galaxies, eventually, it will all be gone. Millions of year? Billions of years? Even if we assume our descendents persist to the end of the universe, it will then all be gone.
See, we know where we sit there. We can comprehend the time. We know it all turns out insignificant in the end, but it is significant now, and some of us are better at using it well than others, but then again, “well” is subjective. Do we define doing well as becoming famous? By doing something important on the grand scale? Don’t we mostly define it as doing what we need to do, fulfilling our obligations, coming through when people are depending on us? Yeah. We advance mostly by people just doing what they need to do. We hold back the night by each of us keeping our candle and doing what good we can, and refusing to do something wrong, at least most of the time. Time. It will end.
All of space-time will end.
Will there be nothing then? Or will there be something still?
I am as confident of being there to see what it is, and I am as confident about it as I am of anything in the future.
Eternity. Don’t ask what will happen after some time. There is no time. We can’t think of before and after. That pertains to time, to space-time.
What will be after space-time is gone is simply unknowable.
In the meantime, don’t get hung up on how long things take. They really don’t take long.