Spacetime Intervals: Not EVERYTHING is Relative | Special Relativity Ch. 7

Go to http://brilliant.org/MinutePhysics for 20% off a premium subscription to Brilliant! Mark Rober's youtube channel: https://www.youtube.com/markrober This video is chapter 7 in my series on special relativity, and it covers the idea that some things AREN'T relative: there IS a sense of absolute length and absolute time, which can be agreed upon from all moving perspectives (as long as they're inertial reference frames). In particular, proper length and proper time, aka the spacetime interval. Essentially, this is the spacetime version of the pythagorean theorem, and we'll explore it using the Lorentz transformations of lengths and time intervals, enacted with a mechanical minkowski diagram, aka mechanical Lorentz transformation, aka spacetime globe. Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters/ MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics And Google+ (does anyone use this any more?) - http://bit.ly/qzEwc6 Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich