By: James Felton/IFLScience  A flat-Earth conspiracy theorist has been mocked online after leaving a bizarre sign at a beach.

Stephen Voss was walking St Kilda beach in Dunedin, New Zealand, when he came across a sign. Rather than giving a usual warning, such as “mind your step” or “look out! Sharks!”, it appeared to be telling beach-goers that the Earth is flat.

People who go to the beach at St Kilda for a paddle are now met with the sign, challenging their beliefs that the world is round. It’s extremely convincing stuff.

Stephen Voss posted an image of the sign to Facebook with the mocking caption “funny how they equate doing research with watching YouTube videos!” The sign shows a picture of a boat with the caption “it’s sea level, not sea curve”.

Ironically, whoever placed the sign there put it in one of the easiest places to prove that the world is in fact round. Just by looking out to sea and finding a boat. You can see, if it’s distant enough, that it appears to start below the horizon.

This wouldn’t happen if the world was flat – you would never see boats dipping below the skyline in this way. Unless you caught the boat or building during the precise moment it fell off the edge of the Earth, of course, which nobody in the history of our species ever has.

The video recommended in the sign, 200 Proofs Earth is Not a Spinning Ball, is a 2-hour-long YouTube video by flat Earth conspiracy theorist Eric Dubay. Watch it here.

Eric’s video has racked up an alarming 1,790,500 views on YouTube, though probably not due to the sign alone.

Mr. Dubay also has his own flat-Earth society on Facebook, with 8,000 members from all around the globe. It’s unclear whether the sign was placed by Mr. Dubay himself, or one of his fans. Either way, people online have been poking fun at Eric and the signmaker’s beliefs, which were disproved centuries ago.

If you’d like to see the sign for yourself, all it requires is a quick trip around the world to the southern hemisphere of our planet.

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