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Mass is the only one of the seven basic measurement standards that is still defined in terms of a physical artifact, a century-old platinum-iridium cylinder weighing one kilogram that is housed in a special vault in France. NIST's electronic kilogram project aims to stabilize mass-related measurements over the next several decades by defining mass through electrical and other electronic standards (such as lasers).

At the heart of the Electronic Kilogram project is a two story high apparatus that works on the same magnetic principles as electric motors and generators. It measures, with great precision, how much current passes through a wire coil in a strong magnetic field to balance the pull of gravity on a one-kilogram mass standard, and how much voltage is generated by moving the coil. Separate systems in the laboratory determine reference levels for voltage and gravity.

NIST physicist Dr. Richard Steiner is one of many individuals who have worked on the Electronic Kilogram project over the past several decades. The list includes recent Nobel prize winner Bill Phillips, and among the people presently working on it are: Drs. Ed Williams and Dave Newell, and Mr. Riumin Liu (from China.)

We asked Dr. Steiner where he expected the Electronic Kilogram to "go." He replied, "Consistent results from experiments like this could show that quantum and atomic theories are correct and consistent. Or not. Maybe there's something more to learn. It would be nice to see the experiment work as well as we want it to. It takes nearly the best measurements in existence, all combined, to get a result. As electronic measurement equipment gets better, we can apply it to the experiment to get better results, which may lead to even better equipment, which we can apply to the project, and so on..."

The late Dr. Dick Deslattes said something like, "If we ever have to communicate from afar with ET aliens, we could explain all our science standards in terms they would understand, but we'd have to throw them the mass standard to explain that."

Since there is so much in the way of classical mechanics and electromagnetic physics involved in this experiment, all related by measurements from quantum standards and tied up with information and signal analysis, it's sort of like getting rid of humanity's last stone tool.... Now imagine, 10,000 years from now, someone digs up our kilogram artifact and tries to understand why this metal cylinder was different from any other metal cylinder....

One last note: "I dream that it would be especially neat if the experiment didn't work as planned and we could prove that it was interference from an extraterrestial transmission of some sort.... Did I mention that I like science fiction?" More about Dr. Richard Steiner.

Go to responses: Electronic Kilogram Questioned