The QI theory predicts that objects can be pushed by differences in the intensity of so-called Unruh radiation in space, similar to the way in which a ship can be pushed towards a dock because there are more waves hitting it from the seaward side.

The theory has already predicted galaxy rotation without dark matter, and the fact that if a system is accelerated enough – such as a spinning disc or light bouncing between mirrors – the Unruh waves it sees can be influenced by a shield. Therefore, if a damper is placed above the object, it should produce a new kind of upwards thrust.

Chemical rockets are very expensive because of the explosive propellant they need, so this new kind of thruster would be much cheaper and safer as it would only need a source of electrical power to accelerate the core of a thruster.

The research is being funded through DARPA's Nascent Light-Matter Interactions (NLM) programme, which aims to improve the fundamental understanding of how to control the interaction of light and engineered materials.