And who shall separate the dust
Which later we shall be?
Whose keen discerning eye will scan
And solve the mystery?
The high, the low, the rich, the poor,
The black, the white, the red,
And all the chromatic in between,
Of whom shall it be said:
Here lies the dust of Africa,
Here are the sons of Rome,
Here lies the one unlabeled,
The world at large his home.
When one can one then separate the dust,
Will mankind lie apart.
When life has settled down again
The same as from the start.
Georgia Douglas Johnson (1880-1966)
There is an old Latin proverb "Est deus in nobis." Literally, "A god is in us" but a better translation is that there is something god-like about humankind that seems to separate us from the rest of creation. For example, so far as we can tell we are the only animals on Earth who sense we absolutely must die. Some animals may have some vague knowledge and fear of death, but we alone feel it is inevitable.
Before we look closer at where we are going, let's take a peek at where we came from. Lately you have probably been hearing frequently that we are made of stardust. That's not a new idea but it seems to be catching on with social media memes and geeky witticisms that fit nicely on a t-shirt. It certainly has a romantic ring to it. But why do astronomers say it? How do they know it? What is the real nature of stardust and how could it come to be us? The story of life and death is the story of dust.
Dust appears to be a relative newcomer to the Universe. Mostly it joined the gases only after the very first stars had matured and their more over-bloated members exploded. It was these “supernovae” that seeded the interstellar medium with heavier elements of which dust, by definition, is composed. Along with the introduction of dust came larger assemblies of dust, which are the asteroids, moons, and rocky earth-like planets. But a lot of the dust still swirls and eddies along with gases in great big clouds called nebulae. Large collections of these nebulae orbit along with associated stars around common central points. These collectives are of course, the galaxies.
The oldest stars still living in our galaxy contain much less of the heavy elements than our Sun. That's because these original beacons of the Big Bang were born before heavy stuff was invented. Over the eons since the beginning, moderately sized stars have manufactured the medium sized atoms, like carbon, nitrogen, and oxygen. These are great for forming organic molecules. But we also need metals and other elements in our bodies to survive, and to make a big rocky planet on which to live. It was only after some of the most massive stars exploded that the heavy atoms such as iron and nickel and gold were introduced into the space between the stars.
So the death of one star and the birth of another brings the "story of us" more or less up to date. Meanwhile we seem like so much more than just highly organized and conditioned aggregates of matter. And perhaps we are. We come from dust and to dust we return but it's the returning part we fret about.
Here is the hypothetical scenario. About five billion years ago, a massive star near the end of its life crushed its core under its own weight. Under that irresistible pressure the core suddenly converted its contents into heavy elements, while releasing enough energy to blow the star apart (a supernova) thus sending much of its material into the surrounding space. The shock wave caused a nearby cloud to collapse into a cluster of stars. Meanwhile gravity collected some of the heavier elements into rocky planets and moons etc. One of those stars was our Sun, and one of the planets was Earth. Our planet eventually went on to give rise to life, which is composed in large part of the tiny particles that were forged in that ancient explosion. We are the dusty remnant of stellar evolution.
And yet death is not entirely a bad thing. Death is why we are not all just microorganisms, or worse. Without death there is no reason for a species to adapt, no 'survival of the fittest' and no mechanism for advancement of the gene pool. In fact without death the opposite would be true, disadvantaged mutants would thrive until life was nothing but deviant strains of sub-cellular strands of protein. Death is the most brilliant part of life, the pressure that makes evolution work. It is the very reason "Est deus in nobis."
As for life and its repeated, temporary, localized reversals of entropy, it is the how the Universe is able to appreciate itself. Allowing that we are not truly separate from the Universe but part and parcel of it, then life is a strange loop, where the Universe gains self awareness. When you look through a telescope the Universe is saying "Whoa, hey, check me out." On the other hand if compelled to compartmentalize individual life forms into genus and species, then different forms of life have differing levels of appreciation. My dog would howl at the moon, but humans went there and brought back rocks and said, "Holy crap, rocks from the goddamn moon!"
Personally I have little doubt there are life forms out there with an even higher level of awareness of nature than we, all thanks to evolution, which in turn is thanks to death. But in my humble opinion, life and death are not about me and some personal relationship I might have with eternity. It's not even about survival of our species. It's about the overall progress of large groups of species working together over the eons.
Humans can simply not exist without billions of other organisms, tiny ones and larger ones, within us and around us. And although we each contribute some detail to a story, the bigger story is about the Earth and quite possibly other planets full of life that formed from the same original pile of particles as we did. Together all the life in the cosmos provides an increasing level of self awareness and appreciation for the universe itself to engage in as a whole.
Someday it will be the Sun's turn to supply raw material for the forging of the next generation of stars and planets. As the Sun's outer layers peel off into the void, they will pass over the Earth, disintegrating and removing our atmosphere, oceans, trees, cities, and everything we have built on the surface. Every single artifact of humanity that we haven't already purposely sent escaping into the cosmos will be delivered back to the cosmos anyway as a cloud… of dust.