Friday links

Today is Flag Day and the birthday of the U.S. Army.

Sunscreen Prevents Cancer, Right? Well, It’s Complicated.

When Foster Care Meant Farm Labor.

“Kids, you tried your best and you failed miserably. The lesson is, never try.” - A selection of parenting advice from Homer Simpson:  Related: one of my favorite Father's Day stories (NSFW- language).

Physics: on the physical (im)possibility of lightsabers". Direct link to the PDF.

The Literal Translation Of Every Country's Name, Mapped.

ICYMI, most recent links are here, and include urban and wilderness survival hacks, eating out in Victorian England, the photos on which classic pin-up girl paintings were based, and how Dr. Seuss changed education in America.