Errors in our Perception
We can’t trust things we think we see or perceive! There are just too many flaws in our perception.
Magicians: exploit the foibles of the brains sensory processing, they have developed over the centuries a practical knowledge of how to deceive us or do things right in front of our eyes without us seeing or perceiving these things.
Objects should have constancy (appear stable and accurate in accordance to reality). An Optical Illusion is an exception to constancy – when objects are not so stable or do not accord with reality. Here the brain is making assumptions: most of the time these assumptions are correct but when they are not correct then there is an optical illusion.
Great Example of a Size Illusion:
Moon Illusion: When the Moon is on the horizon it appears to be bigger then when it is high in the sky. Why is this?
When the moon is on the horizon it has objects in front of it that give it perspective, however when the moon is high in the sky there is nothing to give it perspective or compare its relativity to.