I am impressed with the six quantised inertia experiments that are going on around the world. The spirit of science and curiosity is being brilliantly represented by the people who agreed to be part of my DARPA project, and by some of those I met at conferences or on twitter. It is exciting to see the number of experiments growing every month. To recap, all you need to do is to get light to accelerate enough (bounce around, circulate) inside an asymmetric metallic setup.
However, there is a learning process due to my lack of experience in experimental design .. and telling people what to do! The aim is to prove or disprove quantised inertia in a lab test. To do that, we have to be able to make a specific enough prediction that the lab tests can detect or rule it out. With QI this is uniquely possible since, in its simplest form, the expected thrust is F=PQ/c. The power of the light used (P) is known, so is the speed of light c. What is difficult to know is the Q factor, which is crudely the number of times the light bounces around / circulates in the cavity before dissipating as heat. What thrusts the cavity in QI is not the force from the photons (F=P/c) but the metal cavity making a gradient in the Unruh radiation pushing on the cavity (F=PQ/c).
So far, in all the tests done by, for example, the lab in Dresden, we have not known the Q factor of the cavity. In Dresden this is because Tajmar could only determine that Q was "greater than 19" and also because, as a quick and dirty approach, he used a system (an open cavity) that our cavity model could not cope with. What has proved to be a better experiment is the fibre-optic loop being tested in Madrid. The great advantage of this setup is that the Q is simply the number of times the light goes around the loop - a sort of electromagnetic version of a Formula One race. Orderly & quantifiable!
From now one we need to make sure that in all experiments both Power P and Q are known. I should have listened to my mother who always used to tell me to "mind my Ps and Qs".