*Read the full article for free* in Classical and Quantum Gravity:
On the Bartnik mass of apparent horizons
Christos Mantoulidis and Richard Schoen 2015 Class.* 1,025 more words

## Tags » Geometry

#### The curvature on a black hole boundary

#### Tuesday, October 6th

We spent a second day working on proofs in Lesson 9. If you missed any part of Lesson 9, you should get the notes from your partner in class. 40 more words

#### Making Math Stations Easy By Using Folders!

In Geometry, we have been working on even/odd proofs. Some students were picking it up extremely quickly, but others were struggling (mostly over thinking everything)! 561 more words

#### A quick review of Laser Khet 2.0

Was in Cambridge today and saw a neat-looking game at the MIT bookstore – Laser Khet 2.0

It looked like a fun game all by itself, but also a great game for kids to learn a little bit about geometry. 185 more words

#### October, 5th

Hope you had a nice start of the week. My Monday was a little bit lazy, but I know my recovery from weekend starts on Tuesday (when I will be already be thinking of next weekend). 60 more words

#### Why do soccer balls have the shape they have? Platonic solids | Science4All 8

Episode 8 here is quite a detour on the way to general relativity. It’s about a very cool piece of geometry that’s embedded in the well-known shapes of soccer balls. 15 more words