Mercury-based technology

A number of speculative or rumoured technologies involve mercury, besides mainstream ones.

Red mercury

Probably a scam.

Mercury vortex engine

A device that can supposedly generate anti-gravity using rotating mercury.

Samarangana Sutradhara

The idea may come from Samarangana Sutradhara, an 11th-century Indian treatise on architecture. Chapter 31 of the book discusses machinery and automata, discussing their operation in terms of the four elements and aether, but suggesting that mercury may be an element in its own right. The author says he has personally seen most of the devices he describes in use, but does not specify which ones. The list includes two wooden aircraft, referred to as "vimanas": a "light" one shaped like a huge bird and a "heavy" one shaped like a temple. Both types contain a fire chamber which heats a container of mercury, somehow causing the aircraft to rise from the ground.

   “Strong and durable must the body of the Vimana be made, like a great flying bird of light material. Inside one must put the mercury engine with its iron heating apparatus underneath. By means of the power latent in the mercury which sets the driving whirlwind in motion, a man sitting inside may travel a great distance in the sky.”
   “Similarly by using the prescribed processes one can build a vimana as large as the temple of the God-in-motion. Four strong mercury containers must be built into the interior structure. When these have been heated by controlled fire from iron containers, the vimana develops thunder-power through the mercury. And at once it becomes like a pearl in the sky.”

However, the description is purposely left incomplete for ethical reasons:

   The construction of the machines has not been explained
   For the sake of secrecy, and not due to lack of knowledge.
   In that respect, that should be known as the reason—
   They are not fruitful when disclosed

This was discussed in George Adamski and Desmond Leslie's 1953 book Flying Saucers Have Landed. They suggested that this might be the means of propulsion of UFOs.

The term 'mercury vortex engine' may first have been used by Professor Dileep Kumar Kanjilal in a book called Vimāna in Ancient India (1985), a study of references to flying machines in ancient Hindu literature and legends.

Leslie and Adamski's idea was taken up by Bill Clendenon. After extensive research he believed that he had discovered how the mercury vortex engine worked, and in Mercury: UFO Messenger of the Gods (1991) he discussed his design, his numerous sightings of UFOs, and the strange interactions he had had (after revealing his theory) with Adamski, other UFO researchers, and Men In Black who he believed to have been aliens.

David Hatcher Childress discusses the mercury vortex engine in, for instance, Technology of the Gods (2000) and Atlantis and the Power System of the Gods (2002).

Die Glocke

Descriptions of the alleged Nazi superweapon Die Glocke are similar to the description of a mercury vortex engine in that they involve rotating a metallic liquid, although the liquid was supposedly not mercury but 'a purplish, liquid metallic-looking substance that was supposed to be highly radioactive, code-named Xerum 525'.

Mercury ion engine

The 'mercury ion engine' developed by NASA is sometimes cited as proof that the mercury vortex engine works, but it is rather different. The mercury ion engine used electricity to ionise mercury vapour and accelerate it out of the rear of the vehicle, propelling it in the same way that a rocket is propelled. A vehicle that left a trail of mercury vapour as it flew would obviously have drawbacks for use on Earth, suggesting that if the mercury vortex engine existed this was not it. The use of mercury turned out to have another drawback - the mercury vapour tended to condense and build up on the outside of the spacecraft. NASA switched to other substances such as xenon for later ion engines.

Energy generator

Vague claims circulate that it is possible to use mercury to generate electricity, sometimes involving putting a mercury-filled sphere on a high tower to extract electricity from the atmosphere.