White–Juday warp-field interferometer

The White–Juday warp-field interferometer is an experiment designed to detect a microscopic instance of a warping of spacetime. If such a warp is detected, it is hoped that more research into creating an Alcubierre warp bubble will be inspired. A research team led by Harold "Sonny" White in collaboration with Dr. Richard Juday at the NASA Johnson Space Center and Dakota State University are conducting experiments, but results so far have been inconclusive.

The NASA research team led by Harold White and their university partners currently aim to experimentally evaluate several concepts, especially a redesigned energy-density topology, as well as an implication of brane cosmology theory. If space actually were to be embedded in higher dimensions, the energy requirements could be decreased dramatically and a comparatively small energy density could already lead to a measurable (i.e. using an interferometer) curvature of spacetime. The theoretical framework for the experiment dates back to work by Harold White from 2003, as well as work by White and Eric W. Davis from 2006 that was published in the AIP, where they also consider how baryonic matter could, at least mathematically, adopt characteristics of dark energy (see section below). In the process, they described how a toroidal positive energy density may result in a spherical negative-pressure region, possibly eliminating the need for actual exotic matter.

The metric derived by Alcubierre was mathematically motivated by cosmological inflation.

The original device proposed by White after finding the energy-decreasing possibilities (see theoretical framework) is a modified Michelson interferometer that uses a λ = 633 nm beam from a helium–neon laser. The beam is split into two paths, with the space-warping device placed in or near one beam path. The space warp would induce a relative phase shift between the split beams that should be detectable, provided that the magnitude of the phase shift created by the change in apparent path length is sufficient. By using 2D analytic signal processing, the magnitude and phase of the field can be extracted for study and comparison to theoretical models. The researchers first tried to see whether the space warping by the electric-field energy of a high-voltage (up to 20 kV) ring (0.5 cm radius) of high-κ barium titanate ceramic capacitors could be detected. After the first tests the experiment was moved to a seismically isolated lab due to very high interference caused by people walking outside the room. The current goals are to increase sensitivity up to 1/100 of a wavelength and implement the oscillating field in order to get definite results.

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