# Spherical Geometry

After Simon read up on spherical geometry on Brlliant.org, he and Neva crafted some pretty colorful half-spheres. How’s that as an alternative to Easter eggs?

They also had fun looking for shortest routes across the Atlantic applying their knowledge of geodesics.

# Ancient Chinese Game Luk Tsut K’i Game in p5.js

Simon learned this game on Brilliant.org at https://brilliant.org/practice/winning-moves/?chapter=competitive-games (Warning: this link will only work if you have a Premium Subscription to Brilliant). Brilliant describes the game as follows: “Luk tsut K’i is a board game from China in the time of Confucius. In medieval Europe, it went by the title Three Men’s Morris. This game is very similar to tic-tac-toe; the objective is for one player to get their three pieces all on the same line. If this occurs, that player wins”.

# Fun crafty puzzles Simon did with Neva

Three boxes with fruit, all the three labels are misplaced. What is the minimum number of times one will have to sample a random piece of fruit from one of the boxes to know how to label all the three boxes correctly? From Mind Your Decisions.

Connect A and A’, B and B’, C and C’, D and D’ so that no lines intersect. (Neva added colors).

Dividing 11 coins among three people: “How many ways can you divide 11 coins to 3 people? How many ways are there if each person has to get at least 1 coin?” From Mind Your Decisions.

Solving a simple quadratic equation geometrically: the geometric interpretation of “completing the square”, a notion from deriving the quadratic formula. From Mind Your Decisions.

Which way do the arrows point? (Simon made this drawing in Microsoft Paint):

# Tic-Tac-Tic-Tac-Toe-Toe in p5.js

Simon has programmed this game of Tic-Tac-Tic-Tac-Toe-Toe Game in p5.js from scratch. He and his sister have had hours of fun playing it (and she turned out to be better at this strategic game):

Play Simon’s game online at: https://editor.p5js.org/simontiger/present/k9NfaDmpi

# Solving Logical Puzzles

The end of 2019 was packed with logic. Simon even started programming an AI that would solve logical puzzles, here is the beginning of this unfinished project (he switched to programming a chess AI instead). In the two vids below, he explains the puzzle he used as an example and outlines his plan to build the AI (the puzzles come from Brilliant.org):

And here are some impressions of Simon working on the puzzles and showing them to his sis:

# Discussing the news: dangers of shorting your mobile

Today we have heard about a new accident involving a teenager electrocuted by her mobile phone. Luckily, this time it was not a lethal case, but a quick search on the web has revealed that this is no joke: several teens have died in just a few years because they were either holding their phone with wet hands while the phone was being charged at the same time, or dropped their phone into the bath tub while the phone was plugged in, or because they were using wired headphones while charging their phone!

At first Simon and I didn’t believe this could be so dangerous, as he knew for sure that a mobile phone adaptor always has a voltage control built into it that reduces the voltage from 220V to something like 5 to 20V. But then we dove into it and found out that apparently, once a short circuit occurs, the adaptor’s voltage control unit also malfunctions and lets the 220V current through!