The phrase "thermal equilibrium" hints at the fact that when two things are at the same temperature then the rate of heat transfer is the same in both directions, not that there is no heat … (View Post)

One parsec is the distance at which a star will have a parallax angle (over six months) of one arcsecond. Think of it as a right angled triangle where the angle is 1", the opposite side is one A… (View Post)

Also, to paraphrase Portia, there are a lot of people who say they want justice but might be very disappointed if they actually got it. (View Post)

Only for those who don't realise that the second in "parallax second" is an angle rather than a duration. (View Post)

The earliest reference to "normalcy" seems to be in the mid 19th centaury, used in mathematics to mean being normal (i.e. at righ-angles) to something: a synonym might be orthogonal. So not… (View Post)