from the summon-bruce-willis dept.
An anonymous reader writes "Comets could be the most significant impact hazard to Earth, with sky surveys underestimating the number that are potentially devastating by a factor of between 10 and 100, UK astrophysicists say."
We warn the reader in advance that the proof presented here depends on a
clever but highly unmotivated trick.
-- Howard Anton, "Elementary Linear Algebra"