Historical research guide · 0685 · 2005
Gravitational Wave Propulsion
Giorgio Fontana
In one minute
Giorgio Fontana’s argument is that gravitational waves are not only something to detect — they are something to fly on. Writing for the 2005 STAIF meeting, he reviews and compares the routes that have been proposed for turning gravitational radiation into thrust. A craft can radiate gravitational waves and recoil, exactly as a rocket recoils from its exhaust, but with radiation instead of propellant. And because Einstein’s equations are non-linear, gravitational waves can be converted into a static gravitational field, which opens a second route Fontana calls artificial gravity assist: make your own gravity well and fall through it, rather than waiting to pass a planet. Compared with rocketry, he argues, the advantage in efficiency and performance is undeniable. What the idea needs is hardware — generators powerful enough and at wavelengths short enough to reach high energy density, and detectors designed for this specific job. Fontana puts that within reach of a large national or worldwide programme.
Connection
Chapter four is about moving by changing the metric rather than by throwing mass backwards, and this is the paper that lays the propulsion options out side by side and asks which one an engineering programme should pick. Chapter ten supplies the missing half — the laboratory generator, the device that turns electromagnetic power into gravitational radiation — which is exactly the piece Fontana names as the thing to build next.
From the source
The emission of gravitational waves from astrophysical sources has been confirmed by observation, so the preliminary discovery a propulsion programme depends on has already been made; it is no longer reasonable to wait for additional confirmation before starting to build generators and testing their application to space travel.Abstract, sentences 2 to 6
A vast literature shows that gravitational waves can be employed for space propulsion, and gravitational wave rockets have been proposed.Abstract, sentences 7 and 8, first clause
The non-linearity of the Einstein equations allows the conversion of gravitational waves into a static gravitational field, so that artificial gravity assist may become a new way of travelling in space-time.Abstract, sentence 8, second clause
Different approaches to gravitational wave propulsion are reviewed and compared, and against traditional rocket propulsion an undeniable advantage can be demonstrated in terms of efficiency and performance.Abstract, sentences 9 and 10
Testing the predictions will require gravitational wave generators with high power and a wavelength short enough to produce high energy densities.Abstract, sentence 11
Detectors designed for this specific application must be developed, taking into account that non-linearity effects are expected; the study and development of gravitational wave propulsion appears to be within the reach of a large national or a worldwide research programme.Abstract, sentence 12 and closing sentence
The way in
https://doi.org/10.1063/1.1867262How to cite it
Giorgio Fontana (2005) Gravitational Wave Propulsion doi:10.1063/1.1867262