Ning Li is an American scientist best known for her controversial claims about anti-gravity devices.

There have been a number of attempts to build anti-gravity devices, and a small number of reports of anti-gravity-like effects in the scientific literature.

Various alleged anti-gravity devices may in reality work by electromagnetism.

One of the most common technologies of the setting are anti-gravity devices that allow vehicles and other machines to fly.

The novels feature entire cities that are able to fly through space using an anti-gravity device, the spindizzy.

Norby is equipped with a miniature anti-gravity device allowing him to float.

At first I thought you had some anti-gravity device - but even I know that's impossible.

And I knew my local friendly electric banker wouldn't be giving me a loan to work on a whacko idea like anti-gravity devices.

He began work on it in 1953, calling the dome at once a time machine, a rejuvenation machine and an anti-gravity device.

Imperial Guardsmen wear small anti-gravity devices permitting them to fly, designed by Shi'ar scientists and technicians.