Special to DVN by Ralf Klaedtke, former ZKW R&D Director
In a vacuum, light always travels at the same speed: exactly 299,792,458 m/s. For most space objects, we use light-years to describe their distance. A light-year is the distance light travels in one year, about 9 trillion km. Earth is about 8.3 light-minutes away from the sun.
About a year ago NASA scientists announced they had found the first Earth-sized, potentially habitable planet. That planet, currently known as TOI
700 d, is about 100 light-years away from Earth. It is orbiting a star that is about 40 percent of our sun’s mass and size.
Light emitted by the sun of TOI 700 d in Earth year 1921 is arriving on Earth now, in the year 2021. How has automotive lighting evolved since then?
When light started to travel back in 1921 from the sun of TOI 700 d, electric headlamps had become an industry standard among auto manufacturers. Headlamps were also now required to beam specific amounts of light, and only in specific directions. To better fulfill these requirements, engineers incorporated high and low beams into headlights.
369 trillion km further in our travel—back in 1962—European automakers unveiled the halogen car light. With its ability to produce a richer quality of light without using extra power, the halogen light became popular throughout Europe due to its brightness and durability.
630 trillion km further along, in 1991, the first Xenon headlights were introduced. Xenon lights were popular for their brightness, durability and energy efficiency. (though today’s LED lights last for periods that far exceed the life expectancy of halogen lights and emit strong levels of brightness with much lower energy consumption).
837 trillion km further, in 2014, laser headlights were introduced to challenge LEDs by offering a 600-metre range, about twice the distance of LED high beams.
In 2017, 864 trillion km along in, technologies for vehicle lighting are taking quantum leaps in capability. The new Digital Mirror Device chipset features over 1.3 megapixels in each headlamp enables seamless execution of ADB (adaptive driving beam) systems, which enhance safety for the driver and oncoming traffic by maximising the driver’s visibility while cutting glare to oncoming traffic.
After 900 trillion km, light from TOI 700 d arrives on Earth, where vehicle lighting is evolving at what seems like the speed of light to master an incredible variety of technologies like DLP, MicroLED, OLED, LCD, LCoS, and MLA…in combination with visual, infrared, and laser scanning sensors detecting and classifying objects like cars, bikers, trucks, and pedestrians. Vehicle lighting supports sensors and artificial intelligence to detect and classify objects in front of the car, and provides a significant contribution to safety. Ground projections allow dynamic, contextually relevant safety signs like an icy-road snowflake warning or width guidelines to help the driver through a tricky stretch of road narrowed by construction.
In addition to functionality and contribution to safety, vehicle lighting has become a key to the design of every carmaker. Light animations inside and outside of the car are a must, and not only for premium carmakers. Lighting design creates emotion and wow-effect for car enthusiasts.
As automotive lighting is evolving at the speed of light, lighting regulations around the globe seem to suffer from relativistic effects. If we drove a car with governmental regulations behind the steering wheel close to the speed of light relative to the ground, and turn on our headlights, light would leave our headlights at the same speed as always, the speed of light. However, for us being at rest on the ground, the governmental-regulations frame of reference moves close to the speed of light relative to our rest frame. Accordingly, governmental-regulations time slows down as observed by someone in the rest frame. This relativistic effect is known as time dilation. Our challenge is now to make sure that relativistic effects are avoided in governmental regulations, for the sake of safety of all participants to traffic and the future and speed of vehicle lighting evolution.