One of my favourite stories of 2015 was the report from two Chinese cities of a mirage, a mysterious ‘city in the sky’ that appeared out of nowhere.
Residents of Foshan, near Hong Kong, and Jiangxi – 500 miles to the north – spoke of a surreal sky city that suddenly appeared above the clouds. The incident was reported across the world and pictures showed a blocky futuristic skyline floating in the air.
So how did this happen? There were some creative explanations. The Telegraph newspaper said conspiracy theorists were pointing the finger at NASA’s secret ‘Project Blue Beam’. Blue Beam fans have NASA as an organisation that is trying to create a technological second coming, with the antichrist at the head of a new world order.
But when the mushrooms wore off, the most likely explanation for the apparent mirage was a Fata Morgana. Yes, I had to look it up as well. Wikipedia, fount of all knowledge, says a Fata Morgana is a ‘superior mirage’ caused by layers of cold and warm air that produce a distorted image of a faraway object in the sky.
“In calm weather, a layer of significantly warmer air can rest over colder dense air, forming an atmospheric duct which acts like a refracting lens, producing a series of both inverted and erect images.”
Fata Morgana mirages significantly distort the object or objects on which they are based, often such that the object is completely unrecognizable. A Fata Morgana can be seen on land or at sea, in polar regions or in deserts. This kind of mirage can involve almost any kind of distant object, including boats, islands and the coastline.
Fata Morgana is the Italian name for the Arthurian sorceress Morgana Le Fey and the effect is so-called because the appearance of ‘fairy castles’ was explained by her witchcraft, there to lure sailors to their deaths.
Another explanation thrown out for the sky city was the incursion of a parallel universe into our own. This was a favourite of a friend of mine, Paulo, who thought it may be a temporary puncturing of the membrane between our universe and another, allowing us to see an alien city. Just a theory.
Mere days before the sky city appeared scientists were talking about an unusual light signal from the star KIC 8462852 as a possible alien megastructure. Paulo said the sky city could also be a freak, or possibly purposeful, projection of said alien megastructure, some form of first contact between an alien race and our own. Creative minds are at work here.
What came out of this admittedly short burst of text activity between pals was some learning on my part. First of all, the idea of a Dyson Sphere/Swarm came to light, plus the concept of the Kardashev Scale.
When a civilisation develops it needs more and more energy to meet the demands of its technologies. Dyson Spheres or Shells are hypothetical megastructures, constructed shells that surround a star to harvest solar energy. One variant is a Dyson Swarm – a dense web of solar satellites – that could be put in place bit by bit.
If an alien race were so advanced that it could construct a solar harvesting megastructure, it would, theoretically, likely be able to cause a projection of its city in our atmosphere. The spheres get their name from physicist and astronomer Freeman Dyson who first explored the idea in a 1960 paper called Search for Artificial Stellar Sources of Infrared Radiation. He thought the search for such technologies around stars would reveal advanced civilisations within the Milky Way.
Which handily leads on to the Kardashev Scale. Our civilisation is a ‘Type 0’ on Kardashev’s Scale of energy technology, whereas a Type 1 would be capable of harnessing all the energy from a neighbouring star and all of the Earth’s energy sources (controlling weather, volcanoes or earthquakes). By implication this means advanced space travel, energy gathering, control and storage technologies. Dyson Spheres are attainable by Type II civilisations.
Check out the Kardashev Scale (astrophysicist Nikolai Kardashev, 1964) on the infographic below. He did not believe a civilisation could advance beyond Type III, with knowledge of all available energy. Type IV and V are approaching god-like status. Others, such as theoretical physicist Michio Kaku, have expanded on the theory.
In conclusion, thanks Paulo for the heads up on Dyson and Kardashev. Since the sky city faded from view scientists have concluded that it is probably not a megastructure around KIC 8462852. Not that the two were related. That was just a conversation between friends.