# Theory

This page will outline some candidate theories of operation (or non-operation).

## Contents

## Proponent Theories

- Roger Shawyer's EMDrive basic theory
^{[1]} - Roger Shawyer's EMDrive full theory paper
^{[2]} - Prof. Juan Yang's theory
^{[3]} - Dr. Harold Sonny White's Quantum vacuum plasma thruster model (QVP thruster)
- Evanescent waves
^{[4]} - @notsosureofit Hypothesis
- Mike McCulloch's MiHsC Theory
- Todd Desiato (@WarpTech)'s Evanescent Wave Theory
- Curving Rf beams
^{[5]}- The magnitude of the bending needed, was not shown by the thermal camera images taken at Eagleworks. - Declan Traill's suggested Classical Physics explanation
^{[6]} - Michael Harney's explanation based on WSM
^{[7]} - Finnish researchers theory
^{[8]}

## Debunking Theories

*These theories should be explained, then debunked with the simplest explanation, with a link to a dedicated page to show the work or work in progress that backs up that explanation.*

### Energy and Momentum Conservation

If the EM Drive produces constant-acceleration it will violate Energy Conservation.

It may also violate Momentum Conservation.

### Exact Standing Wave Solution of Maxwell's Equations

On 8/5/14, Greg Egan posted an exact solution for the resonant modes (for modes having constant electromagnetic field variation in the azimuthal direction, such that m=0) of a cavity in the shape of a truncated cone with spherical ends. Egan also calculated the forces and showed a proof that the net force is zero and therefore that there is no thrust force in a resonant electromagnetic cavity of any arbitrary shape, for any arbitrary mode shape, when the cavity is analyzed according to the standing wave solution of Maxwell's equations (assuming no sources or sinks in the cavity).

### Experimental Artifacts

This assertion is that all positive experimental results are results of artifacts, such as:

- Measuring error
- Thermal effects
- Mechanical vibration
- Magnetic effects with environment

These are discussed in more detail at Possible Error Sources.

## References

- ↑ File:EmDrive Basic Theory.ppt
- ↑ Roger Shawyer EMDrive Theory
- ↑ Prof Juan Yang EMDrive Theory and Results
- ↑ 2/2/15 post by @aero modeled evanescent waves using MEEP. Conclusion was that, due to rapid dropoff at the frustum surface, these were of insufficient magnitude to explain the thrust.
- ↑ Post by @aero
- ↑ Classical Physics explanation
- ↑ Improvement In The Thrust of the Electromagnetic Warp Drive Using Stimulated Emission Similar to a MASER
- ↑ http://scitation.aip.org/content/aip/journal/adva/6/6/10.1063/1.4953807