Father Physics

On Uncertain Principles, Chad Orzel counts down to—what else?—Isaac Newton’s birthday. Opening a link on this advent calendar yields not a chocolate, but an equation and an important piece of the physics puzzle. For December 19th, we come to “one of the most revolutionary moment in the history of physics,” Max Planck’s “formula for the spectrum of the ‘black-body’ radiation emitted by a hot object at temperature T.” Chad writes that Planck’s initial mathematical trick became “the opening shot of the quantum mechanical revolution that completely changed physics.” For the 18th, Chad delves into statistical mechanics and entropy, writing “The key realization that makes it possible to extract predictions without needing to know the state of all 1027 atoms making up some object is that such huge systems can be described statistically.” But we’re working backwards; if you want the whole story, start on December 1st with “the absolute cornerstone of what’s now known as classical mechanics,” Newton’s second law of motion. The most recent items are below, and don’t hesitate to get excited as the 25th draws near.