An LED is a p-n junction diode that emits light through the recombination of electrons and holes. The color depends on the band gap of the semiconductor material. Current must be controlled, not voltage, to avoid damage…

The Loudness War is the trend of compressing audio to make it sound louder, which began in the 1990s. It reduces dynamic range, compromising sound quality. Today, streaming platforms and vinyl are bringing renewed attention to dynamics. Software such as Audacity can measure crest factor, a useful metric for assessing compression in digital tracks.