Mirror reflection game
A physics game to understand the law of reflection hands-on: there is a laser, a sensor and some mirrors tilted at 45° that you turn with a tap. The goal is to get the beam to the sensor. Every time the beam bounces, the normal of the mirror is drawn, and when you solve it the two equal angles appear: the incoming one and the outgoing one.
Physics · Primary, Secondary, Sixth Form
The textbook sentence, "the angle of incidence equals the angle of reflection", is visible at every bounce: the dashed normal and the two equal arcs. On a 45° mirror, that means the beam turns 90°.
Turning mirrors at random works eventually, but it scores less: solving the board with the fewest taps earns a bonus. It pays to follow the beam with your eyes and decide which mirror is in the way before touching it.
Easy has two mirrors. Medium adds walls and spare mirrors. Hard reaches four or five bounces with more obstacles. Every board is generated on the spot and always has a solution.
"The laser fires to the right and the sensor is at the bottom right. The player sees the first mirror must send the beam down and turns it; the beam goes down, reaches a second mirror, and one more tap sends it right, into the sensor. It lights up green and the 45° angles appear at each bounce."
Prefer to learn without screens? Try this analogue version:
On squared paper, mark a laser on the edge and a sensor in another square.
Draw some mirrors as diagonal strokes inside the squares.
Follow the beam with your pencil: straight on until it meets a mirror, where it turns 90° depending on the tilt.
Change the tilt of one mirror and trace the beam again: does it reach the sensor now?
If you like Light Beam, these activities work similar skills:
After playing, review with the multiple-choice exam: waves, sound, light, reflection and refraction, with an explanation for every answer.
With a hand mirror and a torch in a dark room you can check the same thing: tilt the mirror and watch where the reflection lands on the wall.
Two mirrors at 45° inside a cardboard tube make a periscope: the same double bounce as in the game, to look over a fence.
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