Let’s concentrate on how a two-dimensional being would perceive you, a three-dimensional being, if you were to enter their world. As an experiment, take a glass of water and consider the two-dimensional being’s world as the surface, and only the surface, of the water. Slowly stick your index finger into the water. How would a two-dimensional being on the surface of the water perceive the events that just took place? How would a two-dimensional being on the surface of the water view your index finger? Would their perception of your index finger be anything like what your finger really is? If you were able to communicate with these two-dimensional beings, that have only ever experienced forward, backward, left and right, how would you explain up and down? Go back to the glass of water. Place two fingers in the water. How would a two-dimensional being on the surface of the water view your fingers? How many two-dimensional beings would he or she perceive?

Spread your fingers apart and then move them together

• How would a two-dimensional being on the surface of the water perceive the events that just took place?
• Now move your hand further into the glass of water, up to your top knuckle.
• How would a two-dimensional being on the surface of the water perceive the events that just took place?
• Imagine that the being on the surface of the water is a circle with a diameter of 2inches.
• Could you stick your finger inside the being?
• How would a two-dimensional being on the surface of the water perceive the events that just took place?