Residents and tourists alike have witnessed the jaw-dropping appearance of a “floating city” above the skies of China. Video shows what appears to be looming grey skyscrapers poking out of the clouds high above shocked onlookers.
The incredible sight has been spotted at least four times over the past two years. It’s led to all manner of conspiracy theories, from the emergence of a parallel universe to alien activity.
One theory suggested it was a hologram produced by the authorities carrying out a “Project Blue Beam test”. Project Blue Beam is a prolific conspiracy theory that believes NASA will one day simulate an alien invasion of Earth or the second coming of Christ through holograms.
But scientists have put the debate to rest, insisting the floating city is a bizarre optical illusion. Weather experts have explained the phenomenon as something called fata morgana.
Visible on land or sea, fata morgana involves the optical distortion and inversion of distant objects such as boats. These distortions can appear as skyscrapers because the images become stacked when rays of light bend as they pass through air of different temperatures such as in a heat haze.
Expert Suryanarayana Maddu explained to Quora: “Our brain assumes that light travels in a straight path, so when it bends, we think the object is where it would be if the light’s path runs straight.
“In this case, light reflected from the skyscrapers is bent downward as it passes through the colder, denser air.