How the World's Most Expensive Color is Made

This video definitely doesn't make me sad, though I would understand why you might end up a bit blue after learning about the manufacturing process of lapis lazuli-based paints.

The Cennini method described here is understandably expensive - because it's insanely labor-intensive.

Understandably, Mohammed has a less labor-intensive method that he developed, but he's not sharing that with us in the video.

From about 6:40 onward, the video shifts from following the production method to looking into the mining of lapis lazuli in Afghanistan, a more political discussion than the initial portion of the video. Then they come back to Mohammed as he explains why natural, lapis-based paints are 'better' than its synthetic replacements.

Units meme...

 Yeah, that's about right...I've said almost that exact phrase to my students probably a million times.

Why It Was Almost Impossible to Make the Blue LED

I was watching a YouTube video from a Scottish YouTuber recently and heard him refer to a light as being a LED bulb. He, however, pronounced LED as if it were the element lead. I, an American, pronounce those bulbs as their three separate letters El Ee Dee, like an acronym. 

Neither, of course, is correct, nor is it at all relevant to this video.

This video, just over half an hour long and produced by Dr Derek of Veritasium, goes through the quantum mechanic explanation of how semiconductors conduct at room temperature which also explains how LEDs produce light and - eventually in the video - how LEDs can be tuned to produce different colors.

This video is also a great exploration of how doped semiconductors conduct electricity. 

I'm really happy that I don't have to teach this concept in my chemistry - or material science - classes because this really pushes my understanding of quantum mechanics and electronics. I didn't thoroughly understand it when I first heard about it back in 1993 or 1994, and I don't entirely understand it now. I do, however, fully accept that there are people who do understand these concepts and that we owe those people a massive debt because the widespread use of LEDs has been a huge revolution in energy savings for our world.

Plus it lets people wrap their cars in Christmas lights.

Why Airport Security Suddenly Got Better

I'm far from a frequent flier, typically taking one or two round trips a year for our summer camps - and I'll admit to a fair skepticism of the security theater that we have at airport, but...

I find the science that we're using at airports kind of fascinating.

In the future, though, I'll be aiming for the dual-energy CT scanners that this video covers. 

The video - once the three-minute intro about travel wraps up - explains how X-rays are absorbed by various materials of various thicknesses. 

Oh, warning the Brian does say, "pain in the a**" at about 9:59.