How's your experiment doing, Al?
The first four weeks of running, sensitive to about 10 parts-per-trillion difference/average, summed to null output. We haven't violated any existing observations in physics or chemistry. The Eotvos rotor is presumably properly balanced for mass and momenta, there are no magnetic impurities coupling to external field, and there is no coincident periodic noise input.
In a couple of weeks we will be overall sensitive to 1 ppt. That is where it gets interesting - small enough to happen, large enough to believe. I'll send an e-mail to China for an update. In mid-September we hit 0.1 ppt and that is our noise limit.
Quartz, SiO_2, is an extreme favorable example of all variables we can imagine, analytic and aesthetic, except for average nuclear charge. Weak Interaction neutral current exchange and relativistic electron behavior both scale as Z^4, Z being atomic number. If we get a clean null at the end, there are three choices,
1) Quit.
2) Mount the cylindrical test masses on their sides 45 degrees rotated off vertical and do it again. Does orientation make a difference? They are now mounted on their flat bottoms with coincident cartesian z-, crystallographic c-, and optical-axes radial to the suspension filament and tangent to the Earth's surface. It's cheap to do and a very weak experiment in terms of expectation.
3) Repeat the parity Eotvos expriment with tellurium. Average quartz Z=(14+8+8)/3=10
(52/10)^4 = 731
That would be serious additional monies spent to custom grow and fabricate new test masses.
We'll see.
