An abbreviation for Bohr Sommerfeld (quantization), which states that for a bound quantum state, the action of its classical equivalent is quantized. An improved version of this method is known as
EBK quantization, which includes the phase
jump corrections at the classical turning points (the simplest correction is the
1D case, where a factor of 1/2 appears as a result of applying continuity and differentiability near classical turning points).
Person A: I can't believe it,
everything that comes out of
that guy's mouth is BS.
Person B: Yeah, he's really finding it
hard to accept the new quantum theory.