Post #1779028

@Tho99 The speed of a molecule of a gas depends on temperature and its mass. James Clerk Maxwell worked this out when he developed his kinetic theory of gases (that, to be historically fair, was built on Bernoulli’s 18th century treatment/model). In the case of helium (and hydrogen too) the average speed at room temperature is so high that a) the speed of sound is very high (squeaky voice) b) it results in very high thermal energy transfer/conductivity and c) it can escape into space forever.