Fear of fish footballer Paolo Di Canio describes finding that his then team-mate, Peter Grant suffered from ichthyophobia. During a practical joke, Di Canio describes Grant's fearful reaction after finding a salmon head in his bed. Grant told "The Independent" that item in his bed was in fact a "shark's head" and "to say I got a fright when I put my feet between the sheets is an understatement." The term "ichthyophobia" comes from the Greek ἰχθῦς - "ichthus", meaning "fish" and φόβος - "phobos", "fear". "Galeophobia" comes from the Greek γαλεός - "galeos", "small shark". Fear of fish Fear of fish or
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