By Hamish Johnston

This week, people all over the world have been celebrating the 100th anniversary of Einstein’s general theory of relativity (GR). Einstein delivered his theory this week in November 1915. Not surprisingly, the Web has been buzzing with tributes to Einstein and explanations of his theory.

In the above video, the physicist Brian Greene and two young assistants demonstrate Einstein’s explanation of gravity using a huge piece of stretched Spandex. Why they have this Spandex ring in what appears to be their living room remains a mystery, but it and a large number of marbles do the trick when it comes to explaining GR.

Not wanting to be outdone, The Globe and Mail‘s science reporter Ivan Semeniuk seems to have commandeered an entire trampoline park to explain GR. Semeniuk dons a fetching pair of pink trampoline socks in his video “With just a ball and a trampoline, we explore Einstein’s general theory of relativity”. We don’t need gimmicky socks or Spandex here at Physics World to explain GR. Instead, we asked science philosopher Jürgen Renn to do the job in 100 sseconds and you can watch a video of his explanation “What is Einstein’s general theory of relativity?”.

GR was a triumph of theoretical physics, but what have theorists done recently? Over on the Backreaction blog a reader has asked if the discovery of asymptotic freedom in the theory of the strong interaction was the last big breakthrough?

Blogger and theoretical physicist Sabine Hossenfelder answers that question by listing some of the breakthroughs that have been made since the early 80s – and commenters have added even more. As someone who has been involved with physics since that time, I’m amazed at how many new ideas have popped up in my lifetime as a physicist! See Dear Dr B: Can you think of a single advancement in theoretical physics, other than speculation, since the early 1980’s?.