Colm Fitzpatrick
There’s are old phrase that goes, ‘What you see is what you get’ – and while this might be true sometimes, it’s not always the case. Often, we can be deceived by what see, and our brains might not be able to fully process what’s right in front of us.
One way to demonstrate this phenomenon is by looking at optical illusions. Simply put, optical illusions are visual puzzles that appear to defy reality and make us question what we’re observing. They’re really fun to look at, and can be a source of confusion of amazement.
In fact, it has been suggested that prehistoric artists were the first to create optical illusions given that several caves in France show engravings of woolly mammoths and bison which share certain lines and features. The overlapping imaging means that they’re both distinctive but you can look at them simultaneously.
Illusions like this are very simple, but artists throughout history have created some very complex pieces that still continue to boggle the mind. It may seem like creating optical illusions is a craft only geniuses can accomplish but you can actually find and make some in the comfort of your own home – all that’s needed is a glass of water!
For the first illusion take a piece of paper and with a marker draw a big arrow that’s pointing to the left.
Direction
When you place the paper behind the glass of water and slowly move it horizontally, the direction of the arrow will change, so that it will be pointing to the right.
This may seem like a magic trick but really, you’ve just demonstrated a physics concept called refraction, which means the bending of light. When the arrow is moved to a particular distance behind the glass, it looks like it reversed itself. When light passes from one material to another, it can bend or refract. In the experiment that you just completed, light travelled from the air, through the glass, through the water, through the back of the glass, and then back through the air, before hitting the arrow.
Anytime that light passes from one medium, or material, into another, it refracts.
An even easier way to see refraction happening is by placing a straw in a glass vertically and watch it from the side. If you slowly tilt the straw, it appears to be broken at the surface of the water. For onlookers, it will look like you’re able to drink from a straw that’s disconnected. These illusions go to show that the world we live in is not always what it seems, so it’s important to explore and learn whenever we can.