Did you know?

• Lighting reflects wealth. The average home in the UK now has more than 30 sources of light, but the richer you are the more lights you are likely to have. For example, people earning more than £50k have an average of more than 50 light sources in their homes.

 

• Sleep patterns are known to be effected by light. Recent research indicates that a bright light applied to the back of a person’s knee can change their circadian rhythms or daily sleep cycles. This suggests that the bloodstream, not just the neurons of the visual pathways, effects people’s biological clock.

 

• The first manmade source of light was fire and it is known that our early ancestors used fire to light caves, as well as to cook and keep warm, as long ago as 400,000 BC.

 

• Nothing travels faster than light – it travels at 299,792,458 metres per second. If we could travel at the speed of light we could go from Land’s End to John O’ Groats and back again more than a hundred times in a second!

 

• The Pharos of Alexandria was a lighthouse built in about 280BC. At more than 134m (440 ft) tall it was the same height as a forty-storey skyscraper and stood on an island at the entrance to the harbour at Alexandria, Egypt. An early form of reflector helped sailors see the fire that burned at the top of it from many miles away. It is believed to have collapsed after an earthquake in the 14th Century AD, when it was more than a thousand years old.

 

• In 1815 Sir Humphry Davy invented a safety lamp for use in gassy coal mines, allowing deep coal seams to be mined safely despite the presence of methane, but it seems that George Stephenson – the railway pioneer – may have just beaten him to it. Working in a colliery near Newcastle Stephenson claimed that he had already produced several safety lamps a month before Sir Humphry announced his breakthrough.

 

• Animals ranging from gnats to humans are naturally attracted by light but only a few luminous sea creatures use light to lure prey. Perhaps the most extraordinary example of bioluminescence is a siphonophore, a particular kind of jellyfish, which attracts its prey using a distinctive and eerie red light.

 

• Thomas Edison is usually credited with inventing the light bulb in 1879, but Joseph Swan began creating bulbs as early as 1850. Swan obtained a UK patent for a carbon filament incandescent lamp in 1860 and another one in 1878 for an improved incandescent lamb in a vacuum tube.

 

• Many people claim that full-spectrum lighting can help to relieve SAD (seasonal affective disorder), but there is actually very little scientific evidence to support their claims. There are other advantages to full-spectrum lighting though, for example, it allows you to see colours much more accurately.

 

• TNT Logistics delivers over four million light bulbs every week on behalf of just one company - GE Lighting.

 

• A chicken will lay bigger and stronger eggs if you change the lighting in such a way as to make them think a day is 28 hours long.

 

• Peak use of electricity usually occurs at around 1pm on most days.

 

• Reducing the voltage supplied to a light bulb reduces the filament temperature, which should result in a significant increase in the bulb’s life expectancy.

 

• Halogen bulbs are based on ordinary incandescent bulbs but are filled with a gas which includes traces of a halogen. In normal bulbs the tungsten slowly evaporates from the filament (eventually leading to it ‘blowing’), but in a halogen bulb the halogen gas reacts with the evaporated tungsten and helps to return it to the filament. This ‘halogen cycle’ extends the life of the filament and also helps to keep the inner surface of the bulb clean. Unlike most other bulbs, halogen bulbs can therefore stay close to full brightness as they age. The only potential problem is that the halogen cycle will only work if the bulb surface is very hot - generally over 250 degrees Celsius (482 degrees Fahrenheit).

 

• When in use, a tumble drier uses as much energy as 67 average light bulbs, a hair drier uses as much energy as 20 bulbs, an average fridge uses the equivalent energy of 17 bulbs and a computer with a monitor uses the same as 7 bulbs.