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.

A civilization may last a million years, but if it forgets its past, it therefore truly endure.

Perhaps a civilization isn't measured by how long it exists, but by how long it is remembered.

When I was younger, time capsules were all the rage.

It wasn't uncommon for a school to have students put some items and notes in a capsule and

bury it for later recovery, and had grown quite popular in the 1970s and 80s, probably at least

in part from the Cold War. Those were not the first time capsules.

We have many examples back to at least the 1700s.

Indeed, one was rather famously placed by Paul Revere and Samuel Adams shortly after the

American Revolution.

Now today we're defining a time capsule as an item built with an intent of keeping historical

information or goods

to be passed on to a distant generation, and will be one of the major concepts under discussion

today, as you consider how to preserve yesterday for distant tomorrows. We'll also be examining

how you can preserve information, or objects, or people, against both natural events and time and intentional

destruction, those aimed at civilization in its entirety, or even aimed attacks on archives.

We'll be discussing how you can do this without some time freezing stasis device, and

also what the impact of such time freezing stasis faults would be on a civilization if you did have them.

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