Activity 3: Science and Art of Illusions

There are many aspects that are used to create illusions. In addition, these aspects have been applied to scientific research and artistic exploration.

Activities and videos that introduce the applications of illusions in scientific research and art.

Activity 1.1 Pinocchio Illusion

Do you want to feel like Pinocchio?

Supplies: Two people to help you and a blindfold (optional)

Instructions: Stand or sit in like the illustration below.

Have the person standing to your side, start tapping your nose at a consistent rate. While you tap the nose of the person in front at the same rate at the same time. Keeping your eyes closed.

You should start to feel the illusion of taping your very long nose.

Activity 1.2 Modified Thermal Grill Illusion

Supplies: You will need two glasses and three butter knives (NOT SHARP KNIVES) that have metal handles and someone to help you.

Experiment 1Instructions:

  1. Fill one glass with cold water and ice cubes, and place one of the knives handle first into the water.
  2. Fill the second glass with warm tap water, not too hot, it should not be painful, just warm. Place the handles of the remaining two butter knives into the warm water.
  3. Keep the knives in the water for two minutes.
  4. Have the person helping you place the knives on the table, without touching the handles, so that the handle on the knife in the ice water sits snug between the two that were in the warm water, but NOT touching. Quickly lay the underside of your wrist on top of the knife handles. If you act quickly you should feel a burning sensation on your wrist.

You should feel a HOT sensation much warmer than the hot water actually was.

Experiment 2 Instructions:

  1. Place the cold knife back into the ice water and the two warm knives back into the hot water.
  2. Wait for two minutes.
  3. Have the person help you pick up the knives and hold them so that they are not touching but close together in the order warm, cold, warm, and then quickly place them on your lips.

This time you should not feel the illusion of the knives being hot, instead, you should be able to identify warm, cool, and warm for each knife.

Extension: There are several different types of sensory receptors found in the skin. There are ones that sense the stretching of the skin, hot, cold, texture, vibrations, and pain. The number of each type of receptor and how close they are to each other varies with different parts of your body. This experiment tested thermoreceptors on the underside of your wrist and on your lips. Your lips have more thermoreceptors most of the rest of your body that is why you were not tricked by this illusion when the knives were placed on your lips. See if other parts of your body can be tricked. Do you think your feed has more or fewer thermoreceptors? If they feel the burning sensation, they have less.

Cheshire Cat

Troxler Fading

Focus on the + in the center

Activity 2.1: Strange Face in the Mirror.

Supplies: You will need a mirror that you can see your entire face in and a comfortable place to sit in a dimly lit room. You need just enough light that you can somewhat make out your face in the mirror. The light source needs to be behind your head and not in front of you. We recommend using a 25W incandescent light or a night light.


  1. Perfect the lighting so that you can just barely make out your face in the mirror
  2. Set a timer for ten minutes and look directly into the mirror. Within two minutes your face should start to morph into something different. You might see a different person, animal, or the size of your eyes, nose, and/or mouth might change. Try to keep track in your head of what you see.
  3. Click here to record what you saw in the mirror.

Extension: Conduct this experiment on some of the people you live with. You can record what they are seeing while they are doing the experiment and add it to our class data.

Activity 2.2 Ambiguous Illusions

There are a lot of ambiguous illusions and drawing them can be fun. Come up with your own ambiguous illusion! If you’d like us to add your illusion to our hall of fame, email a picture to and we will try to add it for you. If you want some credit, add your name and the name of the school you attend. Remember we cannot post pictures of our students so only send a picture of your work.

Activity 3.1 Sidewalk Chalk Illusions

If you’d like us to add your sidewalk chalk illusion to our hall of fame, email a picture to we will try to add it for you. If you want some credit, add your name and the name of the school you attend. Remember we cannot post pictures of our students so only send a picture of your work.

Activity 3.2 Dining Illusions

There are a lot of ways to manipulate how someone perceives what they are eating. Design and conduct an experiment on your family. You can serve the same food twice in two different ways or serve it to different people in different ways. You can change the color of the plate, the style of the plate, what the plate is made out of. You can manipulate the silverware you serve with your food. You can serve it, plan or add some drizzle and sprinkles.

Have fun with this one. We would love to hear about what you tried and if it had any effect on the perception of taste, feel free to send us an email to and tell us about your experiment.


This module has multiple activities. Needed material and alternatives are listed within each activity. 0
Build date: 2020-07-13 16:03:10.93051784 +0000 UTC m=+0.093993645