[1204.0492] Non-detection of the Tooth Fairy at Optical Wavelengths. They used a 1.3 m telescope aimed at a wisdom tooth under a pillow, but it disappeared during the night without any photometric evidence. "We report a non-detection, to a limiting magnitude of V = 18.4 (9), of the elusive entity commonly described as the Tooth Fairy." They discuss whether this could be because of a superluminal or very fast Tooth Fairy, or perhaps that she is transparent at optical wavelengths.
Personally I would not discount quantum tunnelling or wormholes, both which might explain the gift-giving abilities of Santa.
OK, it is a April fool's paper.Posted by Anders3 at April 23, 2012 03:53 PM