This is a classic. REBUTTAL 7 Physics refutes this. From "New Scientist" December 1989: In Search of Schrodinger's Reindeer. With the festive season upon us, many scientific minds will yet again be attempting to solve that perennial chestnut, the Travelling Santa Problem (or TSP). This problem was first brought to our attention by the child prodigy, Vernon P. Templeman, in his seminal paper "Please may I have a bike for Christmas, Daddy" (J. Appl. Window Shopping, December 1988, vol 7, p 1-122). In simple terms, the problem boils down to one of speed. How can Father Christmas visit the homes of all the children in the world in a single night, albeit 24 hours long? Templeman demonstrated that the classical (sequential) explanation forces us to invoke faster-than-light travel, which is somewhat at odds with current thinking. Thus, he argued, we should infer that the Father Christmas effect does not really exist. This contentious hypothesis was the subject of much debate at a recent symposium held at the Santa Fe Institute for Present Research. Our initial thoughts were that Templeman had over-estimated the size of the problem, forgetting that Santa only visits good children. This would reduce the number of visits by a factor of order 10^9. However, a simple back-of-the-lab-coat calculation shows that this renders the problem no more tractable. This threw suspicion on the use of classical physics. At this stage, the teachings of our old mentor, Erwin Schroedinger, came back to us ("Famous people that we claim to have known, honest", by Matthew Davies and Martin Slaughter, Annals of Physics, 1983, vol 12, pp 379-381). From a detailed study of reported phenomena, it became apparent that Santa shared many of the characteristics of elementary particles, suggesting a quantum mechanical interpretation of his behaviour. We have since developed this theory, and are confident that a quantum mechanical model of Santa Claus allows many of his observed properties to be explained, and several interesting predictions to be made. Clearly, viewing Santa as a waveform removes the apparent paradox of his "presence" being measured in several locations within a short interval of time. As the waveform collapses down in a specific location (attracted, we suggest, by the Goodness Quantum number of the recumbent child) it becomes perfectly valid to state that a "visitation" has occurred. However, our calculations suggest that the process of measurement (for example, turning on the bedroom light) will almost certainly lead to a localised, space-time instability which, in turn, will cause the waveform to relax and render detection almost impossible. Once again, this ties in with the experimental evidence that Father Christmas is rarely caught delivering. Indeed, on those few occasions when a sighting has been claimed in the literature ("Mummy, mummy, there's a strange man in my bedroom" by S. T. U. Peedo, Journal of Sleepless Nights, 1979, vol 5, p 35), closer scrutiny has often revealed it to be an imposter wearing a red cloak and beard. Moreover, the quantum mechanical model predicts that energies involved in a waveform collapse will result in the emission of a jet of sub-atomic particles. Studies of bedroom carpets in the vicinity of alleged sightings, using an X-mass spectrometer, have often revealed evidence of mince pion activity; though these have usually been Hoovered up. One of the most appealing aspects of our theory is the manner in which it allows the most likely sites for visitation to be estimated. These may be identified from the first derivative of the expectation value as: d (Spot) | -----------------| d (Fireplace) | night It turns out that the distribution of household chimneys is exactly that required to act as a diffraction grating for objects of Santa's predicted wavelengths, focusing the zeroth order onto the bedroom floor below ("Chimchimmeny, chimchinny, chimchin cheroo", by Bert, Mar. Popp. 1969). Yet another predication which agrees with commonly reported observations concerns the Christmas Stocking effect. Within the general theory, the stocking would be expected to act as an infinite potential well, momentarily capturing the Santa waveform. The resonance within the stocking is predicted to transfer energy from any batteries within the well (causing them to run out by Boxing Day) before collapsing back down to a new ground state characterised by a tangerine in the toe. Apart from the successes reported above, the theory makes a number of predictions about rather low probability events; that is, events expected to occur in fewer than one hundred homes in the world each year (for example, a full night's sleep for parents of under-8s; no clothes given as presents; fairy lights still working from last year). In order to collect the huge volume of data needed to assess these rare events, we have decided to appeal to the scientific community for help. Well as the few observations available fit the theory, a detailed experiment to provide quantltatlve.support is now necessary. This will require a vast amount of data to be collected with observations from as many global locations as possible. New Scientist's readers are, therefore, asked to maintain a Yule log of the events in their domestic laboratories and to send their results to the authors via the magazine. Participants are requested to make a note of thefollowing: (1) Their children's Goodness Quantum number; (2) The approximate dimensions of their bedroom; (3) Whether Santa visits and, if so, at what time; (4) Their address and galactic bspace coordinates (or postcode); (5) Any evidence of Charm or Strangeness; (6) Whether Santa is seen to be spinning (needed to check the "No L" theory) (7) The number of presents left; (8) The colour of his reindeer's nose (often quoted as red when seen moving away at speed, but unknown in its rest frame). On a note of caution, participants are urged not to try to localise Santa as the delta p. delta x equals or is greater than h relationship suggests that the energies involved could demolish a timber frame building. At a time when Europe is leading the world in fundamental physics research we hope that this knotty problem can be resolved with this experiment. The Americans are not far behind, with Senate approval for the $12 trillion Turkey/ Anti-Turkey Synchronous Santatron. Let us make sure we cook their goose before they foil our efforts. -------- Matthew Davies and Martin Slaughter are physicists working in the computer industry.