Light is all around us in many forms, but have you ever taken a moment to consider just how incredible it really is? It’s one of nature’s offerings we cannot live without and for centuries scientists have been researching its powers and trying to understand its uses better. And whilst we’ll never know everything there is to know about the stuff, here are a few fascinating facts that us humans have discovered so far.
It’s a High-speed Affair
Light travels through empty matter at an incredible speed of 186,000 miles per second, which is one million times quicker than sound and 6,000 times faster than your car at top (legal) speed! This means that if the sun suddenly was to suddenly give up the ghost, we wouldn’t notice for over eight minutes here on earth.
Light Makes Us Sneeze
Whilst up to 10% of us are allergic to cats and between 10-30% of us suffer from hay fever, amazingly, a quarter of us will respond to bright lights by having a good old sneeze. Caused by confusion between nerve signals, the messages become scrambled on their journey as the brain thinks the stimulus is nasal rather than visual.
It Can’t Light Up Everywhere
Natural sunlight can reach depths of around 80 metres beneath the ocean, but around half of it is absorbed within three feet of the surface. And by the time we’re down to depths of 100 metres, just 0.3% of light is visible. There is an area known as the aphotic zone, 1000 metres beneath the surface, where there is not light at all. But this doesn’t mean the zone is lifeless, as around 80% of deep sea creatures are bioluminescent.
Light is Beautiful
These beautiful, swirling, dancing and enigmatic waves of light in the sky are no freak event – they are the aurora borealis and are the result of solar flares reacting with particles of oxygen atoms. Although typically green in colour, hues of blue, pink, yellow and purple are just some of stunning shades to be emitted, lighting up the sky in the northern hemisphere and drawing in people from all over the world.
You Can Thank Light for Rainbows
Rainbows are made when light enters a water droplet in the air which is then refracted and reflected inside, before being refracted once more upon exit. In a double rainbow, light is reflected two times within each droplet of water and the colours on the outer arc therefore appear in reverse order.
LED is becoming the lighting of choice as unlike incandescent bulbs, LEDs only emit visible light that the human eye can see as part of the electromagnetic spectrum. Even more amazingly, the future of LED design is being guided by the likes of fireflies, whose bodies emit cold light through a chemical reaction with near-100% efficiency – something scientists are now trying to mimic.
Fireflies Image source: Flickr
There Are Health Benefits
Whilst as humans we have had great success in replicating various materials, ranging from quorn for non-meat eaters to luscious locks for sufferers of hair loss, who’d have thought we’d be able to replicate the almighty power that is natural light? In fact, lighting specialists have developed artificial lighting techniques that can help sufferers of medical conditions such seasonal affective disorder to improve their condition.