Experiments to try at home

We hope you enjoyed trying out the experiments after attending the Institute for Quantum Computing Open House!

We will have some more experiments coming for you soon.

Did you think about the questions after each experiment? We have some information to help you through those...

Experiment 1: Can you explain why waves would create the interference pattern you just saw?

This is actually very similar to a droplet of water hitting a puddle's surface and you watch as droplet spreads. The crest of the wave arrives at the slots at the same time. That nature, the wave, makes the light waves passing through the two slits to interfere - crossing over each other. This produces the bright and dark areas on the paper in the experiment you did.

Yet the light on the piece of paper, just like in the double-slit experiment, gets absorbed at discrete points - as individual particles. That pattern, caused by the interference appeared on the paper with different densities of the particles as they hit the paper. This demonstrates the principle of wave-particle duality.

Experiment 2: Why did we need to add the milk to see the laser in the liquid?

Without the milk, light travels straight through the water - there's nothing to interrupt it so the light goes in every direction and you can't see the laser through the water. The milk causes some of the light to scatter, but some light gets bounced off and that you can see.

Experiment 3: Can you explain how you can use polarization to create 3-dimensional effects?

Because your eyes are separated, you don't see the image. Don't believe us? Hold up your finger and look at it with only one eye. Now without moving your finger, look with the other eye. It looks like your finger moved.

With a 3-dimensional (3D) movie, it's like two images are slightly shifted. It's projected using different projectors. One has a certain polarization - say horizontal, and one has the opposite polarization - say vertical. The Glasses are polarizers. One lens of the glasses sees one of the images from one projector while the other lens sees the images from the other project. This gives you the illusion of 3D.