Alpha is often used in physics and chemistry as a symbol or in the names of things, for example alpha particles (which are two protons and two neutrons bound together into a particle the same as a helium nucleus). The symbol is also used a lot in mathematics in algebra, for example naming angles.
Recurve bow. A recurve bow is a bow with limbs that curve away from the archer when unstrung. A recurve bow stores more energy and delivers energy more efficiently than the equivalent straight-limbed bow, giving a greater amount of energy and speed to the arrow.
One method is to use a draw length tool which is a recurve bow with a permanently attached measurement arrow. The archer draws back the arrow while someone checks to see what the measurement is at the front of the arrow rest/riser. This is a decent method if the archers form is perfect. We prefer the wingspan method.