The world of light and energy in which we live today

The world we take for granted today is a world of light and energy. Picture, for example, the night side of the earth as seen from space. Today’s amazing hi-resolution images taken from above the earth’s atmosphere, reveal a magnificent vista. They show a spectacular mosaic and tapestry of luminescence down below.

Amazingly, there are few regions anywhere across the globe, without sparkling points of light illuminating the darkness of the earth’s surface. But imagine how different the night scene would have looked only 200 years ago!

Our ancestors of only several generations back, lived in a world, where sunset was a time to wind down and prepare for sleep. Without the artificial lighting that has since become the norm, little productive could be done. Soon after the sun disappeared below the horizon, absolute darkness would settle over the earth. Except for the moon and the starry heavens above, there was no ambient light, and little could be seen. A thick darkness blanketed the earth and only the animals of the night moved in the darkness.

People slept undisturbed until the cock crowed announcing the advent of dawn. For modern city dwellers, this is something quite remote. Anyone, though, who has been on the African veldt at night, knows what night was like for the ancients. With only the Milky Way shimmering above, and the eerie sounds of animals in the night, one stays indoors!

When did all this change?

Amazingly this situation pertained until relatively recently. Only with Thomas Edison’s invention of the incandescent light bulb in 1879, did it all change. The darkness of thousands of years now made way for easily available artificial light, and the world changed forever.

Edison’s first incandescent light bulb

Edison had always been an inventor, applying for his first patent in 1868, when he was only 21 years old. This was the start of a prolific career in which he would obtain 1,093 successful U.S. patents!

Then, in January 1879, at his Menlo Park laboratory, Edison, and his team, developed a rudimentary incandescent light bulb. The current he passed through a fine platinum filament within a glass vacuum tube, caused it to glow brightly. However, after emitting light for only a few hours the filament melted, and bulb no longer worked. There was much more work still to be done.

Experimenting with thousands of alternative materials, he eventually hit on using a carbonized cotton thread. And this filament worked well! On January 27, 1880, Edison received his historic patent for his light bulb. As a result, the way was open for the universal domestic use of electric light.

Who really invented the light bulb

While Edison is popularly credited as being the inventor of the incandescent light bulb, this is not altogether accurate. Many others before him, some as early as 1835, had shown that artificial lighting was possible. But mass production of these early attempts was not economically viable. Coupled with an extremely short life span, they used much too much power and were expensive to produce.

Edison’s real genius was in inventing a bulb that lasted long enough to make it a viable option for general use. Carbonized bamboo filaments and a more efficient vacuum pump enabled him to manufacture a really efficient product. The result was a bulb that would continue burning for around 1,200 hours. Eventually Edison’s company merged with other manufacturers to form the giant General Electric company.

The evolution of lighting over the ages.

While we are accustomed to well-lit homes and cities today, it is interesting to look back at how this developed.

Without a source of energy, there can be no light. The ultimate source of energy with which we are familiar is of course our sun. But until the advent of solar panels this was not a source that could be harnessed to our wider needs.  So, in tracing the progress of lighting, the first place to look is the alternative sources people utilized. The earliest of these was fire.

Lighting a fire with no available flame

Imagine a world where one had to first kindle fire in order to boil water or cook food. It was no quick or easy task. Involving time, effort, and expertise. How much the invention of the simple match changed all that!

So how did one create fire without a match? The two basic techniques were through friction or sparks. Of these, the second method was by far the most efficient, and user friendly. While it requires a certain amount of dexterity, striking suitable rocks against each other will generate sparks. Fortunately, the ideal materials required to do this are quartz and flint, both of which are found everywhere. One grasps a piece of quartz with a sharp edge, that fits comfortably into the palm. This is then struck down at an angle against a second piece. Directing the sparks that result onto some dry tinder, will hopefully ignite it, producing a usable flame.

Once a flame is kindled it is placed in the stove, and can produce glowing coals from wood that is added. As long as one keeps feeds the stove with more fuel, the fire will continue burning.

The discovery that changed the world

The invention of the friction match literally changed society. It enabled anyone to light fires quickly, essentially revolutionizing daily living. John Walker, a pharmacist living in England, apparently discovered the technique accidentally in 1827 while working in his laboratory. When mixing some chemicals, he scraped the wooden stirring instrument, and it burst into flame. Walker subsequently started coating sticks with this flammable chemical mix and began selling them.

The sale of these “friction sticks” was an immediate success, but he never patented them. It seems that because of the danger inherent in using these primitive matches, he was reluctant to do so. However, many others immediately copied his technique, and the match became a household commodity. Production was fraught with danger for the factory workers, as the white phosphorous originally used was terribly toxic. Ultimately, its use was outlawed, and safer compounds were employed.

How artificial illumination developed over the ages

The dark and dank corridors of ancient castles are usually shown with flaming torches mounted along the walls. Suitable resinous wood wrapped with combustible substances could conceivably burn for a few hours. However, this was both a primitive and inconvenient way of lighting for individual homes. A much more suitable method was using wax candles and oil fueled lamps.

Early lamps were usually only earthenware bowls with suitable wicks. The one end of the bowl had a narrowed end along which the wick would securely lie. Olive oil was wonderfully good producing a clear strong flame and was the fuel of choice.

Candles, using a central wick, and made from beeswax or tallow, soon became the light of choice. Once placed in a secure candlestick, it to be positioned where required and easily carried around the home.

Candelabrums holding as many candles as required, could illuminate even large rooms and became extremely popular.

The development of practical outdoor lighting

The next major advancements in lighting was the introduction of gas lamps heralding the Gas Light era.

Once again, it was in England that they were first produced in the 1790s. William Murdoch, experimenting with gas produced by coal distillation, succeeded in illuminating his home. Within a few years he had developed a system of supplying gas through pipes to light up his place of work, and then the outside of the building.

In 1807 Pall Mall, the famous London thoroughfare became the first street lit with gas lamps. Special poles held the lamps at regular intervals. But these had to be manually lit each evening and put out the next morning. A new class of lamp lighters subsequently arose, whose job it was to see to the lamps and ensure that they were burning safely. Gas streetlights became the standard in many cities, enabling social activity to continue during the night hours.

In the United States, Baltimore and Philadelphia were soon using gas streetlamps, and other countries quickly followed. The big gas producing companies entered the world scene utilizing a variety of different types of gas. As a result, gas lighting became the global default method for lighting cities until the early 20^th century. Subsequently, the development of electric lighting took over and the Gas Light era came to an end.

The modern era of electric lighting

The evolution of lighting from candle, to incandescent, to halogen, to CFL, to the LED

The Carbon Arc lamp

The first practical electric light, invented by an Englishman, Humphry Davy around 1805, was the carbon arc. Using a bank of batteries, he passed a current between two charcoal rods. The arc light was in use commercially until the early 20^th century, until incandescent bulbs became the standard. However, it continued in use in searchlights and movie projectors until after World War II.

The Incandescent bulb

After Edison developed a long-lasting electric light bulb, electricity began to replace gas lighting for most practical uses. Incandescent bulbs would go on to dominate the world of lighting until quite recently. Finally, Congress halted their manufacture in 2014, as they didn’t meet federal energy-efficiency standards.

Fluorescent lights

In 1895, Daniel McFarlan Moore one of Edison’s former employees developed what was to become the well-known fluorescent tube. Although it was more complicated to operate, it was significantly more efficient than the incandescent globe. As a result, General Electric improved their incandescent technology. They achieved this largely by manufacturing a bulb using a tungsten filament.

In 1901, the inventor Peter Cooper Hewitt produced and patented a mercury-vapor light. His invention was compatible with normal electrical standards and energy-efficient to run. Because the color of the light was a blue hue, though, it was not practical for most applications.

The next step was the introduction of tubes filled with Neon gas which extended the range of colors available. A commercially practical fluorescent lamp finally appeared in the 1920s in France. This lamp, due to its internal coating, generated light of a more appealing hue.

Finally, in 1934, a group of scientists at the British GE company, developed what became the fluorescent tube that we are familiar with today.

The CFL compact fluorescent light bulb

Next came the ubiquitous Energy Saving Spiral CFL Light Bulbs, replacing incandescent bulbs in our home light fittings. Offering up to a 10-year life and 10,000 hours they were the bulb of choice for many years.

Halogen bulbs

Halogen bulbs worked in a similar way to old incandescent light bulbs, using a filament enclosed in halogen gas. With instant warm, bright light and good color rendering, they used much less current, and became very popular.

The Global Move to  LED Lighting

With the global search for more efficient and energy saving lighting, traditional bulbs are phasing out. A number of countries have already banned or limited the manufacture and sale of these light bulbs. The world is now rapidly moving to a new LED standard.

The Light Emitting Diode bulb

The old incandescent light bulb produces light by passing electricity through a filament. Because of the electrical resistance of the filament to the current, it heats up to a point where it glows.

In contrast to this, an LED bulb produces light by passing the electric current through a semiconducting diode. This creates light through a process known as electroluminescence. The LED, therefore, does not utilize heat to generate light. As a result, it runs cooler, and is much more energy-efficient than an incandescent light bulb.

The advantages of LED bulbs

Highly energy-efficient: using much less energy than incandescent bulbs, giving the same light with less wattage.

Safer: LEDs don’t contain poisonous mercury, unlike CFLs and fluorescent bulbs.

Long-lasting: Lasting up to 50,000 hours with incandescent bulbs burning out after 1,000 – 2,000 hours and CFLs after around 10,000.

Dimmable: Dim them to suit required lighting levels.

Variable color temperatures: Able to choose color temperatures from cool white to warm yellow light.

Slow fade out: When reaching the end of their useful life, they fade slowly. One can thus switch them before burnout.

Suitable for old fittings: they match all existing light fittings that previously holding older types of bulbs.

Suitable for motor vehicles: most newer cars come with bright, energy-efficient LED headlamps.

These bulbs provide much more light output than older lamps, for the same wattage. Consequently, a 10-watt LED bulb will produce the same light output as a 60-watt incandescent bulb.

The future of LED lighting

From a market of $2 billion in 2014, the LED lighting market grew to $75 billion in 2020, and may reach $160 billion by 2026. Delivering energy-efficient lighting to a world intent on reducing global power demand, the future for LED lighting indeed looks bright.