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 expressed as for integers ; with , and non-zero, and with square-free. When is positive, we get real quadratic irrational numbers, while a negative gives complex quadratic irrational numbers which are not real numbers. This implies that the quadratic irrationals have the same cardinality as ordered quadruples of integers, and are therefore countable. Quadratic irrationals are used in field theory to construct field extensions of the rational field . Given the square-free integer , the augmentation of by quadratic irrationals using produces a quadratic field ). For example, the inverses of elements of ) are of the same form as