Todd Desiato (@WarpTech)'s Evanescent Wave Theory

Summary

Todd Desiato (@WarpTech on Nasaspaceflight forums) has put forth a theory that explains the EMDrive's thrust as a result of evanescent waves derived from the asymmetrical attenuation of the cavity. The evanescent waves interfere with the standing wave oscillations such that a pressure gradient is momentarily created inside the frustum that can cause impulses of thrust as the cavity charges and discharges its resonant stored energy. Evanescent waves are exponential functions, they are either increasing or decreasing in amplitude.

An Introduction to the Polarizable Vacuum Model of General Relativity

The idea that the vacuum of space-time could be modeled as a variable refractive index (K) was originally published by R. H. Dicke, in 1957 and was known as the "eps, mu formalism". [1] Before he had conceived of the General Relativity (GR) theory, Albert Einstein wrote a short paper about the work done by gravity on light propagating in a gravitational field and used a variable speed of light approach. [2] The Polarizable Vacuum (PV) Model was later developed by Harold Puthoff as an alternative approach to GR, merely a different interpretation of the data regarding gravity we have available to us today. It was shown that metric coefficients derived using Puthoff's Lagrangian density, which differed slightly from Dicke's, were a first order approximation of the Schwarzschild solution of GR and could account for the gravitational red-shift of light, gravitational time dilation and length contraction, the perihelion of the planet Mercury and of course, gravitational lensing. Puthoff also derived an alternative solution to the Reissner-Nordstrom solution of GR. [3] The PV Model however did not explain black holes. Todd Desiato wrote a paper explaining how the Event Horizon still existed in the PV Model for an inward falling particle that is emitting light. [4] Based on these works of Puthoff and Desiato, and also some online correspondence, Joe Depp wrote a pair of papers that simply changed the leading constant from c^4/K^2 to (c/K)^4, for consistency within the theory. This minor change corrected the Lagrangian density of Puthoff to yield the exact Schwarzschild and Reissner-Nordstrom solutions, identical to GR. Depp also showed the equations of motion of the refractive index provided the solution for an infinite massive wire, that matched the GR solution as well. [5, 6]

The PV Model is an Engineering tool. It facilitates an understanding of the vacuum medium in a way that is engineering friendly. It permits solutions in the context of a Lagrangian formalism, that can be applied to electromagnetic fields with the aid of QED and gauge potentials. In the model, a gravitational field is interpreted as a variable refractive index that alters space-time and determines the relative scale of rulers and clocks in the altered region, as measured by a distant observer in an unaltered region of space-time. One obvious advantage of working on warp drive and FTL travel from the perspective of a distant observer is that in Relativity, the speed of light remains constant in the local inertial reference frame. Observers in the local frame cannot measure anything moving FTL locally, with local rulers and clocks. Therefore, it is advantageous for engineers to understand what to expect, what to look for and why there is a need to make observations from the perspective of a distant observer in an unaltered reference frame, outside of the effects to be measured.

Application of Theory to the EmDrive

According to @WarpTech, the EMDrive function mimics this refraction, but only across the specific wavelengths that correspond to its internal geometry. As microwave energy builds within the frustum, the energy becomes concentrated at the larger end. Because the energy density is not evenly distributed, the refractive index has a gradient from the big end to the small end. This mimics gravity at the wavelength of microwaves. As the microwaves "fall" towards the small end, their wavelengths are attenuated and momentum is absorbed by the frustum as the group velocity goes to zero near the small end. The result is propultion in the direction of the small end of the frustum.

On 6/6/15 @WarpTech published the following papers to the NSF forum:

• File:Desiato-EM Drive Mechanism-v2.pdf which proposes an explanation of the underlying mechanism.
• File:Desiato-Energy Paradox Resolution.pdf which deals with the Energy Conservation objections.

Status

There is not yet enough experimental data to validate @WarpTech's theory. Additional data, particularly from superconducting EmDrive experiements, may result in data that is relevant to validating or disproving this theory.

Predictions and Evidence

Notably, it is solely the geometry of the frustum that is relevant to this effect under @WarpTech's theory. A higher power level or higher Q would not result in higher thrust. The Q factor is only relevant as a measure of the stored amount of energy. The frustum itself does not need to resonate, and to this end, @WarpTech has proposed decoupling the resonance chamber from the attenuation chamber. He suggests a design where resonance is induced in a long cylindrical waveguide, then energy is periodically dumped into a frustum to attenuate. So far this design has not been tested. See List of Suggested Experiments

Another interesting consequence of @WarpTech's theory is that the EmDrive must be considered a Warp Drive. However, because the warp effect is limited to a portion of the EM spectrum (with frequency corresponding to the size of the frustum), the effect would not be detectable via the laser warp interferometer employed by NASA EagleWorks, as the distortion would occur at microwave wavelengths. This prediction appears to be in conflict with the report of a positive distortion by the laser interferometer at EagleWorks. However, it remains to be seen if the interferometer test can be reproduced, especially in a vacuum. Also, it is unclear if according to @WarpTech's theory the EmDrive could theoretically be used for faster than light travel.