To be transient is to not last. It is the opposite of permanent. But permanent, like infinity, is a useful concept that does not present itself in reality. Nothing in our lives can be permanent because we are not. Life is transient. When we feel this transience there is often a pull to connect to those things that seem to us rooted in eternity. The mountains or the desert or the sea. But mountains rise and crumble, the deserts grow and shrink, and though the sea has been here longer than any desert or mountain it has been very different in different times and even it will not last forever. Eventually the engine that powers the tides will weaken and fail as the moon drifts ever farther from the Earth, its gravity pulling upon our sea and air less and less.
If we cannot turn to things then perhaps we can turn to processes. The mountains may die but life will go on. The great, unbroken chain of life in which we are one small link. It may even be possible for it to outlive the transience of this world, migrating across the stars long before the tides die and sun grows red with senescence. It is a comforting thought. That we might spread across a thousand worlds and go on until the ends of the universe. But there is an end. The universe itself is not free from transience. There will eventually come the day, unimaginably far from now, when each atom is too far to ever again interact. When all that is left is black holes slowly evaporating into endless night. Unless some fringe theories are true and those singularities are secret seeds. Each, or perhaps just those massive enough, will someday gave birth to their own big bang. The ultimate graveyards of our universe, the monsters that devour even the light that crosses their path, will be the mothers to new ones. And perhaps the black holes created in our universe have inside them the laws of physics that birthed them stored away like the genes lying in the heart of a seed. The code may be altered, mutated slightly, by the furious energy that is the birth cry of a new universe, but it will be largely the same. In this way the universes themselves may be evolving. Changing with each iteration, and the direction they would take by rules of natural selection is that those with more black holes would outproduce those that produce life. Thus the universal generations would tend toward more and more star creation which means more complexity. More life. A great chain of life and complexity in which the entire history of our world is but one link. One tiny, infinitesimal link. But a link nonetheless. A part in something permanent.