I do not want to drag in dirty laundry from other forums, but here is an interesting summary of Shanahan's views, from Forbes. I do not think he wants to participate here, so I'll copy this message, and my response.
In the following intro I am NOT denigrating Shanahan. It may sound like it, but I am not. This discussion illustrates a profound, fundamental difference between him and me. He believes in looking for errors by thinking or theorizing, whereas I believe in looking for them by hands-on tests. By calibrating, and comparing instrument readings. I distrust theory. Shanahan distrusts direct observations and hands-on techniques. He suspects that IR cameras do not function the way the manufacturers' claim. He wants to get back to first principles and prove to himself that the IR camera is or is not working, whereas once I see that it agrees with the thermocouple, I couldn't care less about the theory of operation. If the thing shows the right temperature it could be working by magic pixies for all I care. Both approaches have their strengths and weaknesses. This difference goes back centuries to the philosophies of France and England, specifically Descartes versus Francis Bacon, and later to the British empirical philosophies of Hume, Locke and Berkeley. Even today, you will see that French philosophy, engineering, social planning and so on tends toward idealism (in the technical sense) while British methods tend to empiricism and pragmatism. You can see expression of this in things like the design of the London Underground (subway) and the Paris subway. In the U.S. our subway systems resemble those of England because our intellectual traditions are British. - Jed - Kirk Shanahan <http://blogs.forbes.com/people/kirkshanahan/>4 hours ago For those who are following this debate, Jed, the King of Misdirection, is at it again. He says he wants to summarize my position, but actually summarizes his strawmen and mischaracterizations. What I have said, in summary is: - The temperature measurement device used is rarely used for absolute temperature determination such as is used in calorimetry (because…(see following)) - The likelihood that the Ecat is a perfect Planck radiator is small (we know this from the pictures) - The power computation used is based on Planck’s blackbody equation - Thus the power computation has some error implicit in it, which needs to be defined - You need the Ecat spectral radiance curve to do that - Because the Ecat is probably not a perfect Planck blackbody, the temperatures determined from the camera are probably not absolutely correct - Additionally, the geometry of the Ecat-camera setup does not fit a point-source radiator, which is what the Planck-derived power equation assumes, i.e. another implicit error - The paper reports some comparison to a thermocouple was done, but summarizes it down to a single number. This is not acceptable practice for a paper that supposedly will revolutionize physics as we know it Also - Levi used 723K in his power computation while reporting 709-711K depending on how he divvied up the viewed area, which produces a 100W error in radiated output power which needs to be explained - The convective power term depends on the temp too, so it will be wrong too if the T is off - Without having examined it in detail, I suspect the convective power calculation may have as many built in, unmet assumptions as the radiative computation Please look over what I said and compare to what Jed says I said, and then decide if you can trust Jed to give you the straight scoop… - [image: jedrothwell] <http://blogs.forbes.com/people/jedrothwell/> jedrothwell <http://blogs.forbes.com/people/jedrothwell/>1 hour ago Shanahan wrote: “- Thus the power computation has some error implicit in it, which needs to be defined.” No, the error needs to be measured. It was measured, by comparing the temperature detected with a thermocouple to the temperature detected with the IR camera. They were the same to within 2 deg C. They remained the same throughout the test. There is no chance that both instruments were wrong and yet they both showed the same temperature. Therefore all of this verbiage from Shanahan is nonsense. You do not compute errors. You do not wave your hand and theorize that there might be errors. You check for them. You calibrate your instruments. By the way, they also calibrated the thermocouple with ice slurry and boiling water, which is the standard technique. Despite what Shanahan believes, IR cameras in the hands of experts do work according to the manufacturers’ specifications. These seven experts followed instructions, measuring emissivity and comparing the output to another instrument. They did everything by the book. There are no better methods or methods of calibrating or cross-checking known only to Kirk Shanahan. Temperatures measured by IR cameras are used in industry, medicine, science and many other fields. If these cameras did not work as claimed, our industrial civilization would probably collapse. Millions of experts worldwide depend on these cameras. It is not possible that all of these people are wrong, and all of the manufacturers are wrong, and the cameras do not work as claimed, and the only person on planet Earth who realizes that is Kirk Shanahan.
