Astraphobia immediately identified as a phobia because children naturally go through many fears as they mature. Their fear of thunder and lightning cannot be considered a fully developed phobia unless it persists for more than six months. In this case, the child's phobia should be addressed, for it may become a serious problem in adulthood. To lessen a child's fear during thunderstorms, the child can be distracted by games and activities. A bolder approach is to treat the storm as an entertainment; a fearless adult is an excellent role model for children. The most widely used and possibly the most effective
Irrational number if complex number exponentiation is used). An example that provides a simple constructive proof is The base of the left side is irrational and the right side is rational, so one must prove that the exponent on the left side, formula_17, is irrational. This is so because, by the formula relating logarithms with different bases, which we can assume, for the sake of establishing a contradiction, equals a ratio "m/n" of positive integers. Then formula_19 hence formula_20 hence formula_21 hence formula_22, which is a contradictory pair of prime factorizations and hence violates the fundamental theorem of arithmetic (unique prime factorization).