Max Planck's theory that black bodies emitted radiation only in discrete energy units proportional to their frequency avoided the so-called UV Catastrophe of classical physics that incorrectly predicted that black bodies would

UV Catastrophe of classical physics that incorrectly predicted that black bodies would emit all frequencies.

Explanation:

The UV (ultraviolet) catastrophe of classical physics states that an ideal black body will absorb and emits all frequencies, this is also known as the Rayleigh-Jeans catastrophe However Max planck's theory states that a black body completely absorbs all radiant energy falling upon it, reaches some equilibrium temperature, and then reemits that energy as quickly as it absorbs it, in discrete energy units proportional to their frequency.

E1 - E2 = hν, where h = planck's constant