This article originally appeared in The Skeptic, Volume 4, Issue 3, from 1990.
A Matter of Gravity – Hits and Misses (Steve Donnelly)
If you are an inventor of an antigravity machine based on spinning discs or rings (aren’t they all?) then a paper published in the highly respected physics journal, Physical Review Letters (PRL) on 18 December 1989 will provide scientific support for your claims. The paper, entitled ‘Anomalous Weight Reduction on a Gyroscope’s Right Rotations around the Vertical Axis on the Earth’ by Japanese scientists Hideo Hayasaka and Sakae Tacheuchi reported that measurements on a spinning gyroscope revealed that it became lighter when spinning in a clockwise sense (viewed from above) than when static or spinning in an anticlockwise sense.
Although the weight reduction, measured on three different gyroscopes, was only a few milligrams (corresponding to about one ten thousandth of the total weight) it is a much greater change than any current physical theory predicts. The experiments consisted of simply weighing the gyroscopes using an ordinary chemical balance whilst they were spinning at different rates and in different senses. To avoid any aerodynamic effects, the gyroscopes rotated inside a small vessel from which the air had been evacuated. The original manuscript had been received by PRL in March 1988 indicating that the journal, which prides itself on its prompt publication, did not take the decision to publish the paper lightly. Unlike the Benveniste homeopathy publication in Nature, however, the gyroscope paper was published without any comment from the editors of the journal.
The authors obviously anticipated a critical response from fellow scientists as they devoted almost a page of their short article to listing and dismissing possible sources of error which could have given the same result. They concluded that ‘the experimental result is independent of the Earth’s spinning’ and that ‘the weight reduction cannot be explained by the usual theories’. If these results can be replicated by other laboratories and no mundane explanation of them can be found, then their effects on research into gravitation will be as profound as the effects of a successful demonstration of cold fusion would have been on energy research programmes.
New Scientist on 17 February, however, reported that other researchers feel that electromagnetic interactions between different components of the experiment or the effects of the transfer of angular momentum to the balance could explain the results. They report also that American researchers at a major U.S. government laboratory have repeated the experiments and failed to detect the effect.
Perhaps it only works in Japan and presumably also Melbourne, Australia where Sandy Kidd, the Scots inventor whose anti gravity machine based on gyroscopes was widely reported in the tabloids last year, is now living and developing his technology. A belated prediction for 1990 is that as a result of the Japanese research, Mr Kidd will rise again in the British media (if not in the air atop a spinning gyroscope).
Hits and Misses in the last issue carried an item on the rather unbelievable report from Hayasaka and Takeuchi [1] of a reduction in weight of gyroscopes dependent on their direction of rotation relative to that of the earth. There have been some recent (and probably final) developments in this episode of fringe science which are the subject of this article. Although there are some odd aspects to the first report, this affair does not seem to merit the label of pathological or pseudoscience as I and others have recently had recourse to describing ‘cold fusion’, for example: it was published in the appropriate place after prolonged peer review and presents an apparently clear-cut result from a fairly easily repeatable experiment which is not at the limit of sensitivity of the apparatus. It seems to have come to an unusually swift conclusion after a good deal of commotion involving crank inventors and UFO enthusiasts.
Gyroscopes simply consist of some sort of spinning wheel mounted in a framework which can move freely. They behave rather counter-intuitively, tending to move at right angles to the direction in which you push them. You may be familiar with the behaviour of toy gyros, like the one I had as a child and recently rediscovered, or with the classic ‘ top’ . For instance, if after spinning up the rotor with a drawstring you let one end pivot in a hollow and it leans over under the influence of gravity it merely rotates (‘precesses’) about the pivot as long as it keeps spinning fast enough. If you put it in a box and move it around it reacts back on your hand in a surprising way.
Even if you’ve never played with one of these interesting toys, you may have had the help of the gyroscopic effect of the wheels of a bicycle to keep you upright – ever wondered why you fall over when the wheels stop going round? This behaviour, although surprising, is perfectly well understood in standard mechanics [2], although only with the aid of some non-trivial maths. It is so well understood that gyroscopes form the basis of highly accurate navigation (‘inertial guidance’) systems which rely in various different ways on the gyro’s tendency to react against attempts to push it at right angles to the direction it spins.
Better people than amateur ‘inventors’ like Sandy Kidd have concluded that gyros don’t obey the usual laws of mechanics and could be used as anti-gravity or free-space propulsion devices. Eric Laithwaite, Professor of Electrical Engineering at Imperial College, was once given an unfortunate opportunity to expound such views in an otherwise good series of the annual televised Royal Institution Christmas lectures for children. I don’t know whether he still holds such opinions, but they are odd coming from him since his electrical machines have some rather similar features. Apparently Hayasaka and Takeuchi have a history of similar opinions. There seems to have been no other motivation for their experiment
So, what did they claim, exactly, and why wasn’t it credible? They spun up gyroscopes to high speeds (over 10,000 rpm) and then weighed them on an ordinary chemical balance (familiar from school chemistry or physics classes) as they slowed down. The gyros were spun about a vertical axis both clockwise and anticlockwise. Apparently the weight increased as they slowed, but only for clockwise rotation. An anticlockwise-spinning gyro showed no change in weight. They ascribed this to some sort of interaction of the gyro’s spin with that of the earth about its axis, but did not present evidence to confirm this by repeating the measurement at different latitudes.
If they were correct, the size of the effect should depend on latitude, disappearing at the equator and switching direction in the southern hemisphere. If they really believed in the effect it seems surprising that they didn’t dispel more doubt by arranging a trip to a lab at a different latitude. The size of the effect, incidentally, is quite small – the gyroscopes weighed a bit under half a pound and the claimed change in weight was up to about 10 mg, which is roughly the weight of a stamp.
It is interesting to consider whether there is evidence from other sources for or against such an effect, ie whether like many paranormal claims, it flies in the face of evidence to the contrary. It seems that there isn’t much, but maybe you can think of some. One place where it might show up is in the motion of the planets in the solar system, which is well understood in terms of standard gravitational theory.
A spin-dependent contribution to the weight should lead to inconsistencies in the description of the motion of the planets and moons, which all influence each other to some extent. Note, for instance, Venus spins in the opposite direction to the rest of the planets. However, the rotational speeds involved (once per day in the case of the earth) are so much smaller than than those used by H&T that such an effect would probably not have been observed. Whether there is good evidence against it from other sources like navigational gyros, I don’t know, but it does seem plausible that any such effect could have escaped detection previously.
So why should there be such a problem accepting the result? Unlike Benveniste ‘s water with memory or Fleischmann and Pons’ cold fusion, it is not so much because it flies in the face of established physical theories and measurements, but rather because of deep ideas about the form such theories should take (and always do). The angular momentum of a gyroscope, which is proportional to its mass and speed of rotation, is a ‘vector’ quantity as obviously is the corresponding quantity for the spinning earth. Vector quantities have both a size and a direction, in this case the speed of rotation and the direction in which the axis about which the rotation occurs points.
When you write down a mathematical equation which describes an effect due to the interaction of two vector quantities it can be such that the effect either is the same or reversed when you reverse the direction of one of the vectors. H&T’s supposed new physical phenomenon does not work like this; the effect which is apparently seen for the vectors with one orientation just disappears when one is reversed, contrary to the the general principle.
Well, this result became widely known. It was immediately obvious to some that the effect was responsible for powering UFOs, despite its reported very small size. Many claimed to have thought of it first, although they didn’t publish it like H&T for some reason – they can’t say that the establishment rejects such things out of hand. There were even stories of patents having been granted previously on the basis of such an effect, although I am surprised that they would be granted any more than for perpetual motion machines. Physics departments in the US, at least, got a lot of callers, although I haven’t heard of too many in the UK.
It didn’t cause a stir to the extent that cold fusion did, but rather more than another recent slightly fringe suggestion of a flaw in gravitational theory, the ‘fifth force’. I’m not sure why, especially as the fifth force could be interpreted as ‘antigravity’ and presumably could also power UFOs; and crackpots are always gunning for Einstein. For some reason, his theory of gravitation (general relativity) which both the filth force and H&T’s result disagree with, doesn’t seem to attract the same amount of knockers as his theory of special relativity, which describes motion at very high speeds.
Well, the fifth force now seems to be ruled out after a year or two of investigation. Rather faster, I’m sorry to have to tell any experts in UFO propulsion, H&T’s result has also been squashed, as widely expected by physicists. Two groups, experts in the weights and measures game, have repeated the experiment with improved apparatus and published null results [3 ,4] . The American group [3] found no effect with an improved gyro design. They did not suggest what error there was in H&T’s result although they did point out that vibrations had a big effect on the balance readings. Vibrations had been blamed for the effect previously [5]. The French group used a different, more sensitive balance and did observe the effect However, they could account for it in terms of temperature variations and the subtle effect of the twist applied to the balance pan as the gyro rotor slowed down. The effect of vibrations was also evident in their work.
The lesson, as in the case of cold fusion, is that you have to be careful of anomalous results like this obtained by non-specialists (H&T don’t seem to have a metrological pedigree.) Unfortunately the careful, reliable results from the experts only come along rather later after unnecessary fuss from UFO buffs and aggrieved ‘inventors’ in this case. Fortunately this period has been unusually short this time, and there has been no sign of the reprehensible behaviour on the part of the originators of the claim as there was with cold fusion. This appeared to be a clear-cut result from a simple measurement in physics, but turned out to have serious problems not appreciated by the experimenters. One is tempted to extrapolate the lesson to (para)psychology experiments with all their additional complications to trap the unwary compared with the behaviour of a simple chemical balance.
References
- H. Hayasaka and S. Takeuchi, Phys. Rev. Lett. 63 (1989).
- See, for instance, The Feynman Lectures, volume I, or many mechanics or general physics books.
- J.E. Fuller et al, Phys. Rev. Lett. 64 (1990) 825.
- TJ. Quinn and A. Picard, Nature 343 (1990) 732.
- S.H. Salter, Nature 343 ( 1 990) 509 and R. Baker, ibid p.518.
