Evolution of the Lightbulb
The lightbulb, which we now look upon in our brightly lit, energy guzzling homes as the simplest of all technologies, embarked upon a journey of many light-years to get where it is today. Ever since the dawn of time, man has instinctively urged to illuminate the world around him. “Why?” you may ask, well thousands of years on, the lightbulb has completely transformed the way we humans live. Among other things it allows us to navigate and travel safely in the dark and has increased the length of the average workday almost trifold. DARN YOU LIGHTBULB!
In the beginning
Artificial light began with the creation of fire in the Stone Age, formed by rubbing stones or wood together to create an ember from friction. The next advancement in lighting came from the Romans in around 500 BC when they created the first wicked candle by repeatedly dipping papyrus in beeswax.
The Arc Lamp
In the first decade of the 1800’s, Humphrey Davy invented Britain’s first electric arc lamp. This invention created light via an electrical spark generated between two rods made of charcoal. Although this was a major innovation, it was not practical for most people to use. It was too bright to be used in everyday life and It consumed huge amounts of power which drained batteries rapidly. With the invention of the electric generator, which greatly reduced the consumption of power, people used arc lights for searchlights.
Over the next 40 years or so scientists around the world worked on the incandescent lamp, tinkering with the filament (the part of the bulb that produces light when heated by an electrical current) and the bulb’s atmosphere (whether air is vacuumed out of the bulb or it is filled with an inert gas to prevent the filament from oxidizing and burning out).
Among these scientists, Joseph Wilson Swan, Henry Woodward and Mathew Evans made notable contributions. Swan created a long lasting bulb using a treated cotton thread, while Woodward and Evans patented a design which saw carbon rods held between electrodes in glass cylinders filled with nitrogen. Woodward and Evans attempted to commercialize their lamp, but were unsuccessful. They eventually sold their patent to Edison in 1879.
Taking the credit
Thomas Edison, often dubbed ‘the creator of the lightbulb’, came onto the scene in the 1870’s. Although often granted the privileged reputation of lightbulb fore founder, Edison in fact worked upon pre-existing designs in order to create Britain’s first long-lasting, commercially practical incandescent light bulb. He began making bulbs with filaments of uncoated cotton thread which lasted for around 14.5 hours, until settling on a filament made from bamboo that gave his bulbs a whopping 1,200-hour lifespan.
Scientists continued to make improvements over the next 40 years that reduced the cost and increased the efficiency of the incandescent bulb. For example, using tungsten filaments for a brighter light and inert gasses to increase efficiency. However, by the 1950’s researchers had still only figured out how to convert about 10% of the energy the incandescent bulb used into light and began to focus their energy on other lighting solutions…
The standard fluorescent lamp was developed for commercial use during the 1930’s. The idea of the fluorescent lamp had been around since the 1880’s however it took steady work over the decades to finally create a working commercially viable model. As with the incandescent light bulb, this work was done by many, not one single inventor.
Fluorescent lamps work by ionizing mercury vapor in a glass tube. This causes electrons in the gas to emit photons at UV frequencies. The UV light is converted into standard visible light using a phosphor coating on the inside of the tube.
Compact fluorescent light bulbs offer a considerable increase in luminous efficacy compared with incandescent and halogen alternatives. On average, a compact fluorescent light bulb can replace an incandescent lamp of equivalent lumen output for 25% of the energy consumption. Furthermore, the useful life of CFL lamps is considerably longer.
One of the fastest developing lighting technologies today is the light-emitting diode (or LED). A type of solid-state lighting, LEDs use a semiconductor to convert electricity into light, are often small in area (less than 1 square millimeter) and emit light in a specific direction, reducing the need for reflectors and diffusers that can trap light.
LED lamps offer the highest luminous efficacy and lifespan of all commercial light bulb options. They tend to have the highest price, but can save above 80% of the energy compared with incandescent alternatives, and about 40% of the energy compared to fluorescent options. An additional advantage of LED lamps is that their heat footprint is extremely small, providing indirect energy savings by reducing air conditioning loads.
Luminous efficacy: 12 – 22 lumens / watt
Average lifespan: 1000 hours
Luminous efficacy: 40 – 70 lumens / watt
Average lifespan: 6,000 – 15,000 hours
Luminous efficacy: 70 – 100 lumens / watt
Average lifespan: 50,000 hours or more
Talking walking thinking drinking robot bulbs
Fast-forward to the 21st century and lightbulbs now have minds of their own, or so it seems.
In line with the rise of the smart-home, a number of bulbs are now on offer that do extraordinary things.
BeON bulbs can learn your habits and replicate them if you go on holiday. So if anyone knocks at the door then all lights in house turn on in a sequence. Click here to read more.
Sengled offer bulbs such as the Pulse which can play audio via Bluetooth from any compatible device and the Boost which can increase the range of your Wi-Fi bulb by bulb. Not only this, but the bulbs can link up to a free app on your phone so that they can be turned on or off anywhere and at any time.