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.

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There's a lot of discussion about if we are real or merely in someone's simulation or dream,

but what if we are real, we just died centuries ago and kept getting resurrected over and over again?

Some call it the simulation argument, some the simulation hypothesis, and it's a concept that in many

ways predates the computer age, but fundamentally comes down to asking if we are living in a dream

or computer program, or fundamentally, if we are real. Today we will be looking at the specific

case of ancestor simulations, and indeed this is the

actual case for computer simulation discussion, but that tends to get left out of most discussions.

And in my opinion, there's a lot of why the topic is both controversial and confusing to folks.

I want to start from the outset, since this topic tends to draw some reckless talk and clickbait,

that I'm not going to prove to you today that you are or are not in a simulation. It is not something

that you can easily prove either way. And it is a real possibility, but nothing approaching

a certainty or likelihood that we're in a simulation. We will want to explain why today and also how concepts

like ancestor simulations are distinct from classic notions of us living in a dream.

The basic notion is hard to credit anyone, and indeed the idea where in a dream probably

dates back to the dawn of humanity, or whenever the dreamer started dreaming. However, it was philosopher Nick Bostrom who developed the formal argument

a generation back, and it is very specific to the case of ancestor simulations.

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