Multi-Mirror

How do you look to other people? Take a look at yourself in the corner of the mirror.

Explanation

Your image appears reversed in the flat mirror. When you wave your right hand, your image waves its left hand.

The two mirrors at 90° combine to make your reflection appear as others see you. When you wave your right hand, your image also waves its right hand.

Interestingly, because your image’s right hand now appears on the left side of the mirror, you could say that only the multi-mirror truly flips your image around!

Extras for Experts

A mirror actually flips around your front-to-back axis, not your left-to-right axis. This sounds quite counter-intuitive, because when you wave your right hand at a mirror, your image seems to wave its left hand back.

However, this is because you have defined your image’s frame of reference as if the image is another person. What will help is to remove this frame of reference by pointing to something that is to your right. Your image will also point in that direction. This shows that your image is not reversed. If your image was truly reversed, your image would point in the opposite direction.

For another way to think of this, we don’t often say that mirrors reverse up and down. If you point at the ceiling, your image will also point at the ceiling. This is not a reversal—but it would be a reversal if your image pointed at the floor when you pointed at the ceiling.

In the same way, the corner point of the image actually reverses your image on the left-right axis, because if you point to the right hand side, your image will point to the left hand side. It does the opposite.

You can achieve the same effect on the up-down axis if you stand on top of a mirror (or look at your reflection in the surface of a still lake). Your image will have their head furthest from you and their feet closest to you—the opposite of you. By standing on top of the mirror, you have oriented yourself so that the front-to-back axis of the mirror is now along your height.

Things to Try

Test out your understanding of mirrors and their reflections by using rods to make cubes and double-pyramids in this multi-mirror.

Try an Activity

Salty prism
Grow crystals using ordinary salt! Can you make crystals that are shaped like cubes?

See more activities...

Explore More

Pendulum Snake
Start all the pendulums swinging and watch as they resolve from a random pattern of motion into a winding snake-like form. Then watch them randomise again, only to reform into the snake! It’s all done using common factors.

See more exhibits...