A brain teaser is a short, playful puzzle designed to make your mind stretch and smile. It could be a riddle, a tricky question, a visual illusion, or a logic twist that nudges you to think beyond the ...

A brain teaser is a short, playful puzzle designed to make your mind stretch and smile. It could be a riddle, a tricky question, a visual illusion, or a logic twist that nudges you to think beyond the ...

Remember the graph paper you used at school, the kind that’s covered with tiny squares? It’s the perfect illustration of what mathematicians call a “periodic tiling of space”, with shapes covering an ...