- Incredible Moiré Patterns! (youtube.com)
Sir Roger Penrose demonstrates the extraordinary moiré patterns produced by overlaying and rotating two identical, repeating patterns. As the two patterns overlapped and rotated they interfere with each other to produce tertiary patterns.
- Denmark (Wikipedia)
Denmark (Danish: Danmark, pronounced [ˈtænmɑk]) is a Nordic country in Northern Europe. It is the metropolitan part of and the most populous constituent of the Kingdom of Denmark, a constitutionally unitary state that includes the autonomous territories of the Faroe Islands and Greenland in the North Atlantic Ocean. Metropolitan Denmark is the southernmost of the Scandinavian countries, lying south-west and south (Bornholm and Ertholmene) of Sweden, south of Norway, and north of Germany, with which it shares a short border, Denmark’s only land border.