A physicist, a mathematician and an astronomer stand in front of a flagpole

A physicist, a mathematician and an astronomer
stand in front of a flagpole and discuss how best to determine its height. The physicist is in favor of measuring gravity at both ends and drawing a conclusion from the measurement difference. The astronomer wants to determine the angle to Sirius and the Andromeda Nebula, this allows the most precise one in relation to the world axis, etc. - The mathematician rambles something about triangulation and angle functions...
An English professor comes along and says, why don't you just put the bar down and measure it?
As soon as he left, the physicist said to the other discussants, "you see it again, these laypeople have no idea, we are discussing height and he suggests a method for determining the length!"