Blue lasers

I spend too many hours a day watching YouTubes. Many of the channels I subscribe to produce content as good as or better than anything produced by PBS, cable TV, and your average documentary. For free. For a fantastic example of world class content on YouTube watch this Veritasium episode on Blue Lasers. Turns out blue lasers were “impossible” to create, but after decades of an insane amount of work by one crazy guy in Japan, they are now possible and all the cheap screens we have in our lives now are due to him. Veritasium tells this amazing human story, with heaps of illuminating technical detail on why blue lasers were nearly impossible and how they work, all in a brilliant 33 minutes. — KK