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05 September 2003
E-Bulletin Backscatter
The Ethics of Collecting
Dear Susan Campbell,
Thank you for your very interesting article on the widespread criminal activity, commerce in artifacts, which promotes destruction of prehistoric monuments. The problem of preserving the scarce evidence of our prehistoric past is formidable considering the widespread approval and acceptance of that commerce.
I would like to hear about proposed remedies for this modern vandalism. There are laws in many countries prohibiting export or transport of their own national treasures; which may drive up the prices and profits; while increasing the impoverishment of knowledge.
At the very least, I would contribute cash for rewards to the "finders" of artifacts for photos of the items in situ before removal for "safe keeping" or for sale.
Glen Hemerick
Magnetic Effect of Moving Charged Bodies: a Proposed Experiment
Sheldon:
I would like to propose redoing an experiment performed in 1878 that was fundamental in choosing Maxwell's equations.
The experiment was by Henry Rowland and it involved spinning a disk with a gold surface. The surface had been charged with an electrostatic source and presumably the spinning disk lead to a magnetic field. The problem was that the experiment was very difficult given the equipment of those times and the results were rather slight. Rather than measure the a magnetic field the best Rowland could do was to show a magnetic polarity reversal when the electrostatic charge was reversed.
The experiment was repeated in an attempt to verify it and these efforts were generally successful but two experimenters were not able to verify the results and one flatly stated that he did not believe the experiment worked.
J. J. Thompson commented that what Rowland measured was 10% of the expected value.
This was an important experiment and lead to the choosing of Maxwell's electrodynamics over that of others. For an experiment of this importance, the effects should be revisited. With the vastly improved equipment available today it could be done easily.
The Shuttle Columbia Report
Every day, deaths are caused because of decisions made by government officials. Decisions about war, foreign policy, foreign aid, drug patents, pollution, nutrition, health care, medical insurance, tobacco regulation, tobacco promotion, highway safety, railroad safety, airline safety, food safety, drug safety, workplace safety. Every day.
How many of these everyday deaths are of volunteers?
When will these other decisions enjoy the scrutiny that NASA is getting?
Doug Strain
Doctored Blackout Photo
Sheldon,
Readers may wish to look at www.snopes.com/photos/blackout.asp which includes actual photographs of the event to highlight how the "unusual" picture was doctored.
Paul Curtin
Forum on Wind Power?
Sheldon,
Forrest Mims interesting article "POWER FROM THE WIND" generated so many questions that I began searching the internet for answers. Questions such as, "What is the weight of the propeller?" "What material is used to manufacture it?" "Could it possibly be hollow?" My search in turn generated still more questions. Questions such as. "Which is the most economical method to produce power using a reasonably clean source?" As the night wore on and I became tired, I started to ponder about a good retort to the question "If the wind generators in Texas are so huge, how much bigger must they be in Alaska?"
Next morning it occurred to me that there must be members with varying degrees of knowledge and/or opinions on the subject that a discussion on "wind power versus solar power" in the forum, could prove to be very informative and interesting. I believe solar wind power, solar power using photo cells and solar power using heat obtained from sunlight should be included. However in an effort to prevent comparing apples with oranges, power should be defined as that amount of electrical energy deliverable in a usable format (phase and voltage) to a local power vender.
Jim Simmonds
