This holiday season, 12 strangers, 12 tales.

Something was out there.

Whatever it is, it's ravenous.

Is that the last person to see you alive?

12 Ghosts, starring Malcolm McDowell.

Who are you?

I'm the in-keep.

Presented in immersive 3D audio, a co-production of I Heart Radio

and Grim and Mild from Erin Manky.

Listen to 12 Ghosts on the I Heart Radio app, Apple Podcasts,

or wherever you get your podcasts.

Welcome to Stuff to Blow Your Mind, a production of I Heart Radio.

Hi, my name is Robert Lamb and this is The Art Effect,

a short-form series from Stuff to Blow Your Mind focusing in on particular objects, ideas, and moments in time.

When we think about modern physical money, we're generally thinking about something that has very little material use in and of itself.

It's not that a common copper nickel-clad copper quarter is actually worth 25 cents, but rather it's accepted as a medium of exchange for that amount and issued by the governing authority.

The common US quarter was once made of silver, but the value of the metal now exceeds the value represented by the coin.

As pointed out by Brian Faken and Eleanor Robson in the 70 Great Inventions of the Ancient World,

the first coins emerged in the later part of the 7th century BCE in the Kingdom of Lydia, now located in Western Turkey.

These evolved from the use of silver ingots for trade throughout Mesopotamia and Egypt.

Certainly examples of the sort of money that humans used, at least as far back as the 3rd millennium BCE,

but the coins of Lydia differed in that they were marked with the emblem of the issuing body, ensuring consistent quality and weight.

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