Astraphobia Astraphobia Astraphobia, also known as astrapophobia, brontophobia, keraunophobia, or tonitrophobia is an abnormal fear of thunder and lightning, a type of specific phobia. It is a treatable phobia that both humans and animals can develop. The term astraphobia is composed of the words ἀστραπή (astrape; lightning) and φόβος (phobos; fear). A person with astraphobia will often feel anxious during a thunderstorm even when they understand that the threat to them is minimal. Some symptoms are those accompanied with many phobias, such as trembling, crying, sweating, panicked reactions, the sudden feeling of using the bathroom, nausea, the feeling of dread, insertion
Proof that e is irrational Proof that e is irrational The number "e" was introduced by Jacob Bernoulli in 1683. More than half a century later, Euler, who had been a student of Jacob's younger brother Johann, proved that "e" is irrational; that is, that it cannot be expressed as the quotient of two integers. Euler wrote the first proof of the fact that "e" is irrational in 1737 (but the text was only published seven years later). He computed the representation of "e" as a simple continued fraction, which is Since this continued fraction is infinite and every rational number has a terminating continued