Difference between revisions of "Evanescent waves"
From EM Drive
(Updated to reflect Rodal's latest on this theory. Need to add more details & reconcile with Aero's theory.) |
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| − | As proposed by Aero on the NSF forums, the | + | As first proposed by Aero and later refined by Rodal on the NSF forums, this theory proposes the EmDrive's tapered conical design causes a gradient in the electric field generated by the Rf source. As the EM waves inside the fustrum travel toward the small end, they are attenuated by the constricting geometry, producing evanescent waves that carry momentum. The device must then move to preserve conservation of momentum.<ref>[http://forum.nasaspaceflight.com/index.php?topic=37642.msg1382031#msg1382031 Forum post by Rodal]</ref> |
== Status == | == Status == | ||
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== Evidence == | == Evidence == | ||
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* "Electromagnetic fields and transmission properties in tapered hollow metallic waveguides" by Xiahui Zeng and Dianyuan Fan. Optics Express Vol. 17, Issue 1, pp. 34-45 (2009) •doi: 10.1364/OE.17.0 | * "Electromagnetic fields and transmission properties in tapered hollow metallic waveguides" by Xiahui Zeng and Dianyuan Fan. Optics Express Vol. 17, Issue 1, pp. 34-45 (2009) •doi: 10.1364/OE.17.0 | ||
* [http://arxiv.org/pdf/1308.0547.pdf "Extraordinary momentum and spin in evanescent waves"] by Konstantin Y. Bliokh, Aleksandr Y. Bekshaev, and Franco Nori - See Supplementary Table 1. | * [http://arxiv.org/pdf/1308.0547.pdf "Extraordinary momentum and spin in evanescent waves"] by Konstantin Y. Bliokh, Aleksandr Y. Bekshaev, and Franco Nori - See Supplementary Table 1. | ||
| + | * https://en.wikipedia.org/wiki/Mie_scattering | ||
| + | * http://thermopedia.com/content/137/ | ||
| + | * http://www.orc.soton.ac.uk/publications/theses/1460T_lnn/1460T_lnn_03.pdf | ||
* [http://arxiv.org/pdf/0712.0347.pdf "Superluminal propagation of evanescent modes as a quantum effect"] by Zhi-Yong Wang, Cai-Dong Xiong, Bing He. | * [http://arxiv.org/pdf/0712.0347.pdf "Superluminal propagation of evanescent modes as a quantum effect"] by Zhi-Yong Wang, Cai-Dong Xiong, Bing He. | ||
* http://wwwsis.lnf.infn.it/pub/INFN-FM-00-04.pdf - I like Appendix B | * http://wwwsis.lnf.infn.it/pub/INFN-FM-00-04.pdf - I like Appendix B | ||
Revision as of 13:19, 1 June 2015
As first proposed by Aero and later refined by Rodal on the NSF forums, this theory proposes the EmDrive's tapered conical design causes a gradient in the electric field generated by the Rf source. As the EM waves inside the fustrum travel toward the small end, they are attenuated by the constricting geometry, producing evanescent waves that carry momentum. The device must then move to preserve conservation of momentum.[1]
Contents
Status
Evidence
Initial calculations by Aero were showing an efficiency rating 2-3 times that of a perfect photon drive, which is beneath the observed ratings of Q-thruster test articles.[2]
Utilizing MEEP, the conclusion was that due to rapid dropoff at the frustum surface, evanescent waves were of insufficient magnitude to explain the observed thrust.[3]. See details about @aero's MEEP control file.
Relevant Papers
- "Electromagnetic fields and transmission properties in tapered hollow metallic waveguides" by Xiahui Zeng and Dianyuan Fan. Optics Express Vol. 17, Issue 1, pp. 34-45 (2009) •doi: 10.1364/OE.17.0
- "Extraordinary momentum and spin in evanescent waves" by Konstantin Y. Bliokh, Aleksandr Y. Bekshaev, and Franco Nori - See Supplementary Table 1.
- https://en.wikipedia.org/wiki/Mie_scattering
- http://thermopedia.com/content/137/
- http://www.orc.soton.ac.uk/publications/theses/1460T_lnn/1460T_lnn_03.pdf
- "Superluminal propagation of evanescent modes as a quantum effect" by Zhi-Yong Wang, Cai-Dong Xiong, Bing He.
- http://wwwsis.lnf.infn.it/pub/INFN-FM-00-04.pdf - I like Appendix B
- http://arxiv.org/pdf/1211.0530v2.pdf - This one just hints at our situation.
- http://bit.ly/1Ja6QLV - Again, hints
- http://tuttle.merc.iastate.edu/ee439/topics/tunneling.pdf - Tunneling and evanescent wave math are very similar.
- http://en.wikipedia.org/wiki/Maxwell_stress_tensor - Not quite sure why this is here, maybe the stress-energy tensor derivation?
