possible, even if all the variables were known to more precision. In this case, observation trumps theory . Not surprisingly, Algol has appeared in many science fiction books and films. References: L. Jetsu, S. Porceddu, J. Lyytinen, P. Kajatkari, J. Lehtinen, T. Markkanen and J. Toivari-Viitala, "Did the ancient Egyptians record the