A picture of a ship 'floating in the sky' is sending netizens into a tizzy. An entire cruise liner appears to defy gravity to float in the air above the surface of the sea in this photo snapped off the coast of Cornwall.
But the vessel was of course in the water - appearing to be floating due to a phenomenon known as a 'superior mirage' and is an example of the perfect optical illusion.
Dave Medlock spotted the bizarre apparition as he was out walking his dog. Medlock said: "I took the picture on Sunday, March 7, when I was walking my dog along the seafront. It looks like something from Back to the Future, but I know it's a special type of mirage," as quoted by Mirror.uk.
The effect is caused by light rays bending to displace an image and make it appear above where it really is. A superior mirage describes a spectacle in which the displaced image appears to be located above the real object. It occurs when the air below the line of sight is colder than the air above it.
