SAS Community Forum Update

Lance Osadchey's project to measure the absolute motion of the Earth is attracting discussion on the SAS Community Forum.

Among the more interesting comments is this by C. M. Edwards:

"I have much the same concerns regarding Lance Osadchey's experiment as George Habrovsky expressed in his letter (scroll down to responses) to The Citizen Scientist. The precision required to observe the effect without being swamped by experimental noise seems difficult to achieve using the apparatus shown in Lance's pictures. (The fact that Lance is apparently still pushing the shutter button with his finger is an obvious source for measurement error – and there are many others.) I have serious doubts about the long term accuracy of the sensor alignment Lance is using. (Generous use of duct tape is usually a design shortcoming, in my opinion.) The relaxation time of the CCD is probably irrelevant as long as there is no attempt to move the apparatus during measurements, but there's no information on the relaxation of the support beam after it's moved, either. I know from experience that battery operated laser beams vary in intensity with their remaining charge, which can affect the observed size of the image on the CCD chip. Despite Lance's claims of using no lenses, the filter he described can also be a source of error. And Lance's web site does not adequately address measurement error, lacking even a discussion of what error sources he expects, what sources he's seen, and how he compensates for them.

"So, when I reproduce this experiment, I'm going to try a few improvements."

To read about the ideas suggested by Mr. Edwards, check in at the SAS Community Forum.

While there be sure to consider commenting on other topics, including Shawn Carlson's big move to the Chicago area. If you have an interesting topic worthy of discussion, you can begin a new thread.

See you on the SAS Forum

Forrest M. Mims III