On 16th May this year, people around the world celebrated the first ever International Day of Light!
Light is important to humans in many different ways that we use every day, many of which we take for granted or don’t even realise.
Plants use light to make food, through a process called photosynthesis. Animals eat the plants and humans eat both plants and animals, so without light we would have nothing to eat! Light bouncing off objects and into our eyes allows us to see.
The colour of the light in the sky can even wake you up in the morning and make you sleepy at night!
In film, art and photography, light is used to make us feel different emotions. Bright colours can make us feel happy, while darker colours can make us feel sad or scared. Next time you watch a television programme or a film, look out for how this is used.
Light is often used in science and technology in form of a laser.
Lasers were invented in the late 1950s and early 1960s; the first use of the laser was by Thomas Maiman on 16th May 1960 – the International Day of Light is on the anniversary of this date! Lasers have special properties, such as being very bright and have an exact colour.
They’re used in lots of different technology and can be found in factories, hospitals, printers, DVD players, and supermarket barcode scanners, to name a few! You have probably used a laser today without realising.
Photonics is the study of how we can use light and the technology that comes from this. This includes lasers, but many other things as well. Solar panels absorb light and convert its energy into electricity.
Light can be put into optical fibres to send information around the world or to make pressure sensors for bridges and borders.
Silicon chips can have microscopic channels made into them, to direct light for making computers faster or for detecting chemicals. Memory crystals that can last for billions of years without “forgetting” anything are written and read using light – these were recently launched into space on SpaceX’s Falcon Heavy rocket.
In the last one hundred years, the world was changed by electricity and electronics. Many people think the next one hundred years will have big changes as well, but this time by light and photonics.
Make sure you appreciate it and celebrate the International Day of Light!
Written by Callum Stirling, Postgraduate Researcher in the Optoelectronics Research Centre and Outreach Officer of the Optics and Photonics Society, both in the University of Southampton.Add a comment