Let there be light

Enormous leaps have been made in lighting technology in its surprisingly short history.

How did the use of electric light develop? From the first electrically lit world’s fair in 1878 to the Audi e-tron Sportback concept that uses lighting to communicate with its environment.

11 November, 2019

Light is a luxury. But we don’t think of it that way, because we just expect it to be there. We flick a switch on the wall or say to our digital assistant, ‘let there be light’ or words to that effect, and the light just turns on. But it’s only been about 140 years since the 1878 world's fair in Paris was lit for the first time with electric carbon arc lamps. 

It took another year before Thomas Alva Edison invented the light bulb, which was affordable enough for private households, and another 30 years after that before it made its way into the majority of homes. In the year 1910, just 10 percent of all households in Germany had electricity. 

And at that point, many people looked at this illuminating invention with skepticism. People suspected that electrical light might be harmful to their health because it was too glaringly bright in comparison to the cozy warm — and accustomed — candlelight.

These days, the number of different electric light sources are nearly innumerable. We know which light has which effect on our moods, and we can dim it, direct it, colour it, or make it blink and flash. 

There have always been people who have designed with light – from stage lighting technicians, architects, interior designers, photographers and videographers, not to mention neon sign manufacturers!

These days, the number of different electric light sources are nearly innumerable

..hundreds of thousands of tiny mirrors that are organised much like the individual eyes (ommatidia) in the compound eye of a dragonfly...

Advertisers were the first to recognise that light could be used for communication, heralding in the illuminated advertising sigh which remains in use today. But lighting was, and is, used for other forms of communication, warning signs and of course traffic signals, with the first electric traffic light in Germany installed in 1925.

Of course, cars already had lights at that point. In 1913, generator-powered Bosch lights replaced the gas-powered carbide lamps. They not only served to illuminate the road but also signalled to other drivers – and that hasn’t changed in the last 100 years. 

What has changed is the quality and flexibility of the light. Where the Bosch light from a hundred years ago could only illuminate a few metres of road, modern headlights can shine up to 600 metres with the help of matrix and laser technologies. And they are extremely targeted, with oncoming cars automatically recognised and the headlights dimmed accordingly. 

In the Laser Spots by Audi, this is made possible by hundreds of thousands of tiny mirrors that are organised much like the individual eyes (ommatidia) in the compound eye of a dragonfly. The difference to the dragonfly eye is that every one of these micro-mirrors can be individually controlled. When sensors recognise an oncoming car, lighting from the matrix laser literally shines around the vehicle. The driver isn’t blinded, yet the road is still ideally lit at all times. 

Audi has always placed tremendous importance on lighting and continues to lead the way in the field. In the Lighting Assistance Centre in Ingolstadt, lighting is seen, more than ever, as a medium for communication and information. There, vehicles that communicate with pedestrians are no longer a futuristic idea — they are reality. The high-resolution lights allow information to be projected onto the street like a video projector. So the car could, for example, make a polite and well-lit request for a pedestrian to cross the road.

It gets even crazier when you consider the possibilities offered by the new OLED coating. That is, to put it simply, an electric paint made of organic material. It is applied in a thin film and allows surfaces to be illuminated using electric voltage. 

In the future, the family car could have a different lighting design for each family member, highlighting individual personalities or low key for business applications. It will take some development time before we get to that point and, of course, lawmakers want to have their say before we all go rolling through the city in our driving balls of light.

But, by that point, maybe our cars will all be driving themselves, and we can just look out the window and enjoy the rolling street gallery of illuminated vehicles, while we are safely chauffeured to our next destination.

... an electric paint made of organic material, applied in a thin film and illuminated using electric voltage