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.

In the grandeur of the universe, the tapestry of

life may be woven from stranger threads than we ever dared to dream, and spun from

materials far different to our own. As we've studied the immensity of the cosmos, we've spent decades searching for life as

we know it, clinging to the belief that the universe must be teeming with carbon-based organisms

like ourselves.

But what if life's building blocks are not limited to the familiar carbon atoms that

compose our DNA and proteins?

What if, out there are among the stars, there exist beings, unlike

anything we've ever imagined, life forms fashioned from the silicon of alien worlds.

Today, we'll embark on a journey of imagination and scientific exploration to ponder

the possibilities of silicon-based life forms, creatures that could thrive in environments

hostile to all kind, and challenge our very understanding of life itself.

I am your host, Isaac Arthur, and I hope you'll join me today as we delve into the realms

of silicon-based biology, where the chemistry of the cosmos takes on new and exotic forms. This is not our first look

in alternative chemistries for life, and when we explored ammonia-based life forms earlier this year,

there were many requests that we should look at other chemistries, silicon-based life forms

being foremost amongst them. We may cover those others down the road, but Silicon turns out to be a big enough topic

on its own, so grab a drink and a snack, and relax, we'll be here for a bit, and make sure

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