In 2011 it was reported that the average Briton is captured on CCTV 70 times a day. Living in an age where we use CCTV monitors to safeguard our society, we have come to rely more heavily on vision to provide security.

But our eyes have played tricks on us for centuries, and as technology increases, this leads to more illusions being invented.

Sometimes even the camera lies! 

Image by John McKee

1) Will – o’ –the –wisp

One spirit that has entered legend all over the world is the ‘will-o’-the-wisp’ or ‘jack-o-lantern’. A malevolent and mischievous spirit that appears as a ghostly light to travellers lost on marshlands.

The legend goes that a weary traveller follows the light, hoping to find safety, and instead finds themselves in further danger. The light then disappears!

But science has an explanation for this occurrence and it’s not to do with evil spirits. In fact, a clue can be found in its Latin name ‘Ignis fatuus’ – meaning ‘foolish fire’.

Marsh gas is a combination of methane, phosphine, diphosphane. A dangerous mixture that can spontaneously burst into flames when it comes into contact with the air!

So by following the light, a traveller is likely to walk further into the marsh and meet an unfortunate end.

The moral of the tale?

Don’t go for midnight ramblings on a marsh!

2) Pareidolia

Have you ever spotted Jesus on a burnt piece of toast, found Bob Marley on a creased shirt or seen Madonna on a dirty sock?

Objects that appear to resemble faces are frequently found and often profitable; in 2004 a grilled sandwich resembling the Virgin Mary sold for $28,000!

But this determination to spot meaning in randomness is called Pareidolia and is instinctive. Carl Sagan hypothesised that identifying faces from basic details gives humans an evolutionary advantage.

It explains how we spot shapes in clouds, and how ghostly faces can appear in pictures which were never seen at the time! 

Image by Tup Wanders

3) Pepper’s Ghost

Tupac’s recent return from the grave to perform on stage at the Coachella music festival left many people amazed and unable to believe their eyes.

But while a lot of effort went in behind the scenes to make the figure appear convincing, the actual projection is quite simple!

The trick was invented in the 16th century and instead of using complex technology and holograms, it relies on reflections to depict a figure in a hidden room.

Pepper’s Ghost features in the James Bond film ‘Diamonds are Forever’ during the girl to gorilla scene, and is often used in haunted houses! 

Image by Evsmitty

4)  Light Painting

Light painting is an extension of you effect you get when you quickly spell your name with a sparkler. With our eyes we can read the word for a split second, but by adjusting the shutter speed on a camera, you can make complete words and images appear.

You can build an entire cityscape out of light!

There are even apps that let you create 3D words with this effect on your iPad or iPhone!

This video shows some of the amazing effects that can be created! 

Image by VFS Digital Design

 

5)  3-D Imaging

When you’re sat in a dimly lit cinema with an angry shark swimming towards your face, it can be hard to convince your racing heart that 3-D images aren’t real!

But while the use of 3-D in TV and films has surged to popularity in recent years, the concept behind it was discovered by Charles Wheatstone in 1838.

3-D works by creating an illusion of depth; your brain overlaps two pictures (one viewed by each eye) to create a third dimension.

It’s an illusion, but an enjoyable one, and it certainly makes for a more intense cinematic experience.

Image by Matt Neale

Optical Illusions in Medicine

Despite the trickery involved, optical illusions can often do good things!

In December the BBC reported that scientists have developed an optical illusion to help sufferers of phantom limb syndrome; sufferers often develop an itch in their missing limb that they cannot scratch. By using mirrors to reflect an image of their working limb, they can scratch the mirrored limb and alleviate the problem!

Optical illusions have also been shown to help with arthritic pain!

So as long as you avoid mysterious lights the next time you get lost on a marsh, tricks of the light are unlikely to cause you any harm. They may even help you!

Have you ever seen something you couldn’t explain?

Image credit newopticalillusions.blogspot.com


Author: Estelle Page.