The thermal images will form an important test because a large number of mundane propulsion mechanisms can be tested for by showing where the cavity is and is not heating. Hot jets perhaps? Weird buoyancy effect from hot air? Twisting action of a hot cable? The thermal images will also be useful during testing to see if the cavity is in the right mode (hopefully by the pattern of hot spots) and to find early warning signs of problems.
An Extech I5 Thermal Imaging Camera, shown right, was purchased off eBay for $1700 (including shipping and taxes).
It was then unleashed around the house to see what could be learned and one of the first things was that the temperature difference between a CFL and regular light bulb is considerable:
Inside a computer at idle, note the graphics card on the bottom left, how hot is that?
The first two images show what the inside of a computer looks like and a potential hot spot along the lower left hand side. A closer inspection shows the graphics card is rather warm.
The images above show how the process of finding hot spots has changed from a hunt and peck with a Extech thermometer to an instantaneous “oh, how hot is that bright spot?” With a digital readout on the thermometer, it is really easy to miss what exactly is causing the smoke, but with the camera, it is possible to watch the entire apparatus through 6400 pixels (80×80 resolution). The price difference is $70 versus $1700 though!