Hello, SFIA audio listeners.

In this month's Nebula exclusive, big alien theory,

we're asking the reason alien civilizations might be rare is because most aliens are huge.

To hear it and every episode early and ad-free, plus hours of bonus content,

check out go.nebola.tv slash Isaac Arthur and use my code, Isaac Arthur.

Time is vast, and yet in our brief candle flicker of existence, we forge civilizations

a seat to outlast the stars themselves, and map the ages to come.

We live in a moment, a flash of thought and breath, amid a universe whose lifetime defies comprehension.

The cosmos did not begin with stars or galaxies, with a blinding surge of energy and symmetry,

broken in an instant, setting to motion a chain of epochs that span for the tiniest fraction of a second

to ages far longer than the current age of the universe itself. Some of these epochs are so

brief they slip through our fingers like grains of sand. Others stretch into eons that could swallow

the entirety of recorded history a billion times over and still be young. The stars, so

eternal to us, are but a chapter, perhaps not even that, in the larger chronicle of time.

And through it all, the great question lingers. Can civilizations endure through these epochs?

Will we simply fade like starlight or find new ways to

shine long after the stars are gone? Can life, thought, and purpose outlast the death of stars

and the dissolution of matter? Could it even have existed before they did? Today, we will begin a journey not just across

space, but through the very eras of time itself, mapping out the cosmic calendar, from

the first quantum flickers of existence to the last twilight of the universe, perhaps even beyond,

and asking what kind of civilizations might rise and fall across this timeline.

Of course, before we begin counting down the birth and death of everything, now is a good time

...