On Aug 4, 2014, at 3:24 PM, Ian Whitchurch <ian.whitchurch@gmail.com> wrote:

> Im just going to leave this here
>
> http://journals.jps.jp/doi/pdf/10.7566/JPSCP.1.015059

This is an ion drive, not the allegedly ‘massless' EM drive under discussion. There is a reaction mass here, it’s the plasma created by the cathode arc.

This is why more efficient ion drives use really heavy ions. Ion drives are a well tested technology and have been utilized on a ‘production’ space probe:

<http://nmp.nasa.gov/ds1/tech/ionpropfaq.html>

--
Bruce Johnson
University of Arizona
College of Pharmacy
Information Technology Group

Institutions do not have opinions, merely customs