Modern Physics for Engineers Lecture slides 05a – The beginning of quantum mechanics

This lecture part starts by summarizing many of the puzzles in physics towards the end of the 19th century, including in particular the form in color or wavelength of the light from the sun, electric light bulbs, or more generally the light emission from a hot object if it is perfectly "black" or absorbing at all wavelengths. The resolution of this problem by Max Planck became the start of modern quantum mechanics.