Why Pianos Can't Be Perfectly Tuned

Technically speaking, pianos tuned to coventional 12-tone equal temperament aren’t actually in perfect tune. A new video from MinutePhysics explains the math behind this musical oddity, and why in the case of pianos, close enough is good enough.

To Scale: The Solar System

Alex Gorosh and Wylie Overstreet have created a model of our Solar System and they explain that using representations of the planets above a microscopic level requires your model to be rather huge. "To create a scale model with an Earth only as big as [a] marble you need seven miles [11 kilometers] of empty space," explains Overstreet in the video. So, to do just that, the team ventured out to Black Rock Desert in Nevada. They marked out the orbits of the eight major planets around the Sun, and then created a time-lapse by driving lights around the orbits.