Historical research guide · 1036 · 1998
Interstellar travel by means of Wormhole Induction Propulsion (WHIP)
Eric W. Davis
In one minute
Eric Davis proposes abandoning the rocket entirely and moving a spacecraft by reshaping the spacetime around it. His starting point is Claudio Maccone’s claim that a strong, cylindrically symmetric magnetic field bends space into a traversable wormhole. Davis checks the mathematics and corrects it: the field does bend space, but into a hypercylinder with a position-dependent gravitational potential, not a wormhole with a throat. What survives the correction is the useful part. Light genuinely slows inside that curved region, and how much it slows is calculable from the field strength alone — which turns a piece of exotic propulsion theory into a bench experiment. Davis argues that flux-compression magnets already reach fields rising at about a billion tesla per second, and that this rate of rise, rather than any achievable static field, is the near-term way to make and measure real curvature in a laboratory. He then sketches WHIP, a two-mode craft that would raise the curvature envelope, pinch a throat into it, and coast through.
Connection
Chapter 4 is the site’s account of metric engineering, and this is one of the few papers in that literature that ends with an experiment a laboratory could actually attempt: apply a very strong field to a vacuum, send a light beam through it, and measure whether the beam slowed. Chapter 8 gets the architecture — a craft that carries no reaction mass for the journey itself, because the journey is done by the geometry and not by the engine.
From the source
Levi-Civita’s 1917 solution for a static uniform magnetic field does create spacetime curvature, but changing to cylindrical coordinates and then to a radial angle variable shows the spatial part to be the three-metric of a hypercylinder with a position-dependent gravitational potential: no asymptotically flat region, no flared-out mouth, no throat. Maccone’s identification of it as a traversable wormhole, and his radial pressure, stress and energy-density equations for that configuration, are therefore not correct.Theoretical Brief, Equations 6 and 7
The radius of spacetime curvature induced by a homogeneous, cylindrically symmetric magnetic field is a constant of about 3.4840 times ten to the eighteenth in tesla-metres divided by the field strength, and the paper tabulates the resulting ladder: about 3.484 tesla gives a curvature radius of some 105.7 light-years, a thousand tesla gives 0.368 light-years, and each further factor of ten in field takes a factor of ten off the radius, down through solar radii and Earth radii.Theoretical Brief, Equation 2; Experimental Approach, Table I
Maccone’s speed-of-light function, derived from the metric coefficient, gives the gravitationally induced variation of light speed inside the field region and can be inverted to give the field strength required for a chosen slowing — so applying a powerful static homogeneous magnetic field in a vacuum and measuring the speed of a light beam through it is a direct laboratory test for induced curvature.Theoretical Brief, Equations 3 to 5; Experimental Approach, opening paragraph
Static fields of roughly ten to the ninth or ten to the tenth tesla would be needed before the slowing of light became measurable, and chemical implosive or explosive flux compression tops out near several thousand tesla. Davis’s proposal is to exploit the peak rate of rise instead — about ten to the ninth tesla per second at the Russian MC-1 generator, Los Alamos ATLAS, the National High Magnetic Field Laboratory and Sandia’s SATURN, whose roughly ten-centimetre solenoids hold a thousand tesla for a few nanoseconds, which he argues is long enough for a good measurement of the speed of light.Abstract; Experimental Approach, Table II and following paragraphs
Static radial electric or magnetic fields are borderline exotic for threading a wormhole — they would qualify if their tension were infinitesimally larger for a given energy density — and the other known energy-condition-violating fields are squeezed states of the electromagnetic field and Casimir zero-point energy. Davis argues that the alarm around this is unfounded, because every energy-condition hypothesis had already been tested in the laboratory and found not to hold in general.Technical Issues, closing paragraph
The proposed craft, Wormhole Induction Propulsion Integrated Technology, runs in two modes: an advanced conventional system for moving through the throat and for orbital manoeuvring, constrained to regenerate or gather its own fuel; and a stardrive mode that raises a static cylindrically symmetric ultrahigh field to pre-stress space into a hypercylinder envelope no smaller than the craft’s largest dimension, then turns that field radial with a tension greater than its energy density so a throat is induced and patched to the envelope.WHIP Spacecraft Concept, both modes; Conclusions
The way in
https://doi.org/10.1063/1.54779How to cite it
Eric W. Davis (1998) Interstellar travel by means of Wormhole Induction Propulsion (WHIP) doi:10.1063/1.54779