WAVELENGTHS

Wavelengths are the basis of how we perceive the world around us. We receive these wavelengths through two organs: we see light through our eyes and we capture sound with our ears.

From radio waves to gamma rays, wavelengths gradually constrict, causing their frequency to increase and making them consume more and more energy. Hence waves become gradually more penetrative and, therefore, more dangerous for the eyes.

Gamma rays are very dangerous and can permeate cement and even lead. They destroy cells in living organisms. X rays, on the other hand, can also go through our body's tissue but are halted by our bones – this is why radiography is possible. Ultraviolet rays, which come from the sun, are partially blocked by the ozone layer surrounding the Earth, and it is those that pass through that thrill tan-seekers – however, over-exposure to them can be very damaging. All hot bodies emit infrared waves. These rays are not visible but their heat can be detected. Radio waves are used to transmit sounds, images and digital data.

The human eye is not able to identify the various elements of a ray – it only sees the results, which are a function of the different wavelengths and their respective light intensity. The human eye can only see wavelengths that measure between 380 and 780 nanometres – this is known as the 'visible spectrum'.