TED-Ed: Can you solve the vampire hunter riddle? - Dan Finkel

The video tutorial presents a puzzle where sunlight must be directed into a vampire lair using mirrors. The challenge is to determine the correct corner to place a diffuser in a rectangular room. The solution involves understanding the path of light at a 45-degree angle and using coordinate grid logic to identify that the light will only pass through points with both even or both odd coordinates. This leads to the conclusion that the Southeast corner is the correct placement for the diffuser, successfully illuminating the lair and defeating the vampires.

Why will the light miss the top two corners of the room?

What happens to the vampires when the sunlight enters the chamber?