Fear of fish Fear of fish Fear of fish or ichthyophobia ranges from cultural phenomena such as fear of eating fish, fear of touching raw fish, or fear of dead fish, up to irrational fear (specific phobia). Galeophobia is the fear specifically of sharks. Ichthyophobia is described in "Psychology: An International Perspective" as an "unusual" specific phobia. Both symptoms and remedies of ichthyophobia are common to most specific phobias. John B. Watson, a renowned name in behaviorism, describes an example, quoted in many books in psychology, of conditioned fear of a goldfish in an infant and a way of unconditioning of the fear
Quadratic irrational number be proved irrational. Theodorus of Cyrene proved the irrationality of the square roots of whole numbers up to 17 (except those few that are square numbers, such as 16), but stopped there, probably because the algebra he used could not be applied to the square root of numbers greater than 17. Euclid's Elements Book 10 is dedicated to classification of irrational magnitudes. The original proof of the irrationality of the non-square natural numbers depends on Euclid's lemma. Many proofs of the irrationality of the square roots of non-square natural numbers implicitly assume the fundamental theorem of arithmetic, which was first