Why Some Ancient Maps Seem to Show Things Their Makers Shouldn't Have Known

The Piri Reis map has everything an ancient-mystery story could want.

It is old.

Only part survives.

Its creator was an Ottoman admiral.

It depicts coastlines from an age when European knowledge of the Atlantic had changed dramatically within a generation.

And, according to one enduring claim, it shows Antarctica centuries before its recognised discovery.

The surviving map dates to 1513.

UNESCO describes it as a portolan-style world map and an important early cartographic record of the newly explored Atlantic world, including information connected with the voyages of Columbus. It was rediscovered in Istanbul's Topkapı Palace in 1929.

Piri Reis did not claim to have personally surveyed the entire world.

He compiled information.

That matters.

Mapmakers copied older charts, sailors brought new geographic reports home, coastlines were combined from sources of varying quality and projection methods distorted shapes.

A map can therefore preserve knowledge older than the physical document containing it without requiring a vanished technological civilisation.

Then there is Antarctica.

The southern land on the Piri Reis map has been interpreted by some writers as an impossibly early depiction of the Antarctic coastline, sometimes even supposedly without ice.

Mainstream cartographic interpretation does not require that conclusion.

Early modern maps frequently included conjectural southern lands, while distorted coastlines could be bent, compressed or extended by copying and projection.

UNESCO itself identifies the map among early representations of Terra Australis, the hypothetical southern land that appeared on maps long before Antarctica was properly charted.

This is arguably more interesting than the paranormal version.

Piri Reis lived during a moment when the known geography of the world was being violently rewritten.

Old knowledge, rumours, ancient geographical ideas and brand-new voyages were colliding on the same pieces of parchment.

The map does show things its maker had probably never seen.

That was the point.

It was a network of information drawn before anybody invented the network.