Hello, SFIA audio listeners. In this month's Nebula exclusive, big alien theory,

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

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

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

Soon humanity may reach out to the galaxy and spread ourselves to every world in it, but in the

billions and billions of years to come, on those billions and billions of worlds,

humanity shall surely diverge down many roads and post-human pathways.

Records of the entity known as the Spirit of the Air are sparse, and best known from the

account known as the House of Sons, given by Persoling Gentian of the

House of Flowers, recorded 6 million years from when humanity first left Earth.

But accounts agree it had once been a human and born in humanity's original solar system

sometime in the third or fourth millennia.

Those were early days when the first interstellar ships

were heading out, and many pursued various post-human pathways and life extension through

relativity or cloning, often shattering their consciousness into many bodies at once,

to explore the galaxy and ensure no cataclysm could get every copy. His name had been Abraham Valmic,

or something similar, a man of immeasurable wealth and considerable longevity, who nonetheless

wanted more out of the universe than it had so far given him. For Valmic, neither

shattering, time dilation, nor biological transformation offered sufficient

guarantees, he wished instead to make himself into a machine, so that his consciousness

might be embodied in something as close to indestructible as physics allowed.

Neuron by neuron, he allowed his brain to be supplanted by mechanical parts.

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