Today I Learned: August 16, 2019
The bluest blue. The shortest paper. The most sales.
1) The bluest blue (on a plant)
This is the berry of the plant Pollia condensata, also known as the marble berry:
The berries’ intense blue doesn’t come from a pigment. It creates color the same way as butterfly wings and peacock feathers — very fine, uncolored microstructures that refract light in a way that only lets certain colors back out. It’s not dissimilar from the effect caused by thin layers of oil on top of water.
More information here:
2) The shortest paper (title)
Here’s the scientific paper with the shortest name: P’
tldr; it’s a seminal geology paper about how seismic waves refract and bend when they hit different layers of the Earth’s core.
3) The most sales (of any company online, in the US)
Amazon is absolutely, ridiculously enormous. I knew that already, abstractly. But today I learned that Amazon accounts for 49% of online sales in the US, as of 2018. I thought it would be more like 20%.