An unambiguous spin test.

MiHsC (quantised inertia) gives an explanation for the galaxy rotation problem and cosmic acceleration, but other proposals like dark matter are flexible enough that they can also explain these observations. What is needed is a controlled laboratory experiment that can test MiHsC with no ambiguity.

The consequence of MiHsC is that if any object accelerates, then the inertial mass of all nearby objects increases slightly. One experiment that involved a huge change in acceleration was that of Podkletnov et al. (1992). They cooled a super-conducting disc (so there was little thermal acceleration) and then suddenly rotated and vibrated it (high acceleration). Sure enough, nearby objects appeared to lose weight, just as if they had gained a bit of inertia and were less sensitive to gravity (specifically objects above the disc). In some ways this is a good test of MiHsC since the change in acceleration is so large that the MiHsC effect is more easily detectable. The disadvantage is that this experiment is hard to reproduce since the half-superconducting disc is difficult to make.

Another experiment was done by Tajmar et al. (2009) who noted nearby horizontal (not vertical) acceleration anomalies in laser gyroscopes close to a spinning supercooled Teflon ring. This anomaly is exactly predicted by MiHsC, but the disadvantage of this experiment is that the disc accelerations are small so the effects are difficult to detect and reproduce, and the accelerometers (laser gyroscopes) needed are more complex than simply measuring weight.

A better experiment would include a bit of both and would go as follows: 1) cool a Teflon disc down to 5K in a cryostat (Teflon survives low temperatures), 2) suspend a test mass (say 30g) over the disc's edge (to get maximum mutual acceleration) from a pivoted cross bar, and suspend another mass from the other end onto a precision balance (with milligram sensitivity), 3) spin the disc as fast as possible and monitor the weight of the test mass. MiHsC predicts that for a disc with a radius of 5 cm and spun at, for example, 10,000 rpm and 30,000 rpm, the test mass will gain inertial mass and appear to lose 0.017% (5.1 mg) and 0.16% (48 mg) of its weight respectively (see eq. 11 of McCulloch, 2011). Maybe in 2014 a test can be done.. Happy New Year!

McCulloch, M.E., 2011. The Tajmar effect from quantised inertia. EPL, 95, 39002. Preprint

Jumping flash drives?

I'm always looking for simpler experiments to test MiHsC. It seems every few months I find a simpler one, so maybe I should just wait till I find one simple enough to do with Lego :) Anyway, one I have recently noticed was by Kish (2007). He took flash drives, weighed them to milligram accuracy and noticed that whenever they were written to, or erased, they lost a bit of weight (about 0.001%) for a short time.

First the caution: what could be happening is that the flash drive is getting hot and moving the air nearby by convection, or water is evaporating from it. Kish (2007) thought not, because the effect did not depend on humidity, or decay with time in the right way. A better experiment would use a vacuum to eliminate these possibilities.

Second the wonder: this could be due to MiHsC. Whenever flash drives are used, the electrons in them are hugely accelerated (flash drives write to memory in one go rather than bit by bit) and you may remember that in MiHsC, whenever there is an acceleration, the inertial mass of everything close by increases slightly. This means that the flash drives, when used, should gain inertial mass by MiHsC and become slightly less sensitive to gravity, ie: they will appear to lose weight, as observed.

This is a simple experiment to do, requiring only flash drives and precision balances, and ideally a vacuum. Without the vacuum it could be done at home. Also unlike the superconductor experiments I've been discussing, the motion of electrons in flash drives should be calculable, and so it should be possible to make a prediction of the weight loss with MiHsC (see McCulloch, 2011) and then test it.

I intend to try this experiment at home (vacuumless) during 2014, but I thought I would mention it here so if anyone out there has the equipment, skill and enthusiasm, you could try it too (the more the merrier). I'd love to see your results: especially estimates of the electron acceleration and a measurement of the drive's weight loss, if any.

References

Kish, L.B., 2007. Gravitational mass of information. Fluct. Noise Letters, Vol. 7, No. 4, C51-C68 (see section 3, experiments). Preprint

McCulloch, M.E., 2011. Physics Procedia, Vol. 20, 134-139. Preprint , Paper