This is a podcast from BBC Studios.

BBC Studios.

A commercial subsidiary of the BBC.

Welcome to the BBC Earth podcast, the podcast that'll be here until the end of time.

I'm Emily Knight.

In this episode, we're asking, does anything really last forever?

And our journey starts on a quiet sandy beach 100 million years into the future strolling along this

beach is well let's just say it's someone maybe it's a human although what

humans will look like in 100 million years

is anyone's guess. Perhaps this is an alien doing the walking, or perhaps an earth species

evolved out of all recognition. But don't mind that for a second. This person, this entity of the

distant future saunters along, squinting down at the pebbles under her feet.

She's looking for something.

She kneels, let's just assume she has knees, and picks up a smooth, round object.

A hard black stone, rippled with a curious and quite beautiful texture.

It's a fossil. A relic from the past, from the beginning of the 21st century.

Perhaps it was something you dropped, a hundred million years ago.

One can certainly imagine far future geologists or paleontologists or archaeologists, is scratching the heads over the

kind of things that we will have left fossilised, which will last for perhaps even billions of years

into the future. But what is it? What kind of traces will our civilization leave behind?

It is a big question and it's one that we're studying right now.

We know that even delicate, fragile things from the past, leaves, twigs, bones, even feathers,

...