In case you have some spare time during Advent, here’s two things to keep you busy and (possibly) make you smarter. Both the ‘MATHEON calendar‘ (mathematics) and the ‘Physics in Advent‘ calendar are available in English this year. There’s also a juniors math version called ‘Mathe im Advent‘, though it’s in German only.
Feel free to share their Facebook (#PhysicsInAdvent) and Twitter (@PhysicsInAdvent) pages/posts/tweets and help spread the word!