On this day, in 1960, the first functioning laser was invented by Theodore Maiman. Often referred to as the father of the electro-optics industry, Maiman was then an employee of Hughes Aircraft Co. and later went on to receive many awards, including two nominations for Nobel Prizes.

Every now and then a scientific breakthrough happens that has a massive and continuous impact on not only scientific development, but on daily life. This is one of them. The invention of the laser (light amplification by stimulated emission of radiation) is one of the light-infused reasons we celebrate the International Day of Light on May 16.

But scientific innovations made possible because of light are not limited to lasers.

Albert Einstein’s theory of relativity — specifically, special relativity — is based on his recognition of the constant speed of light. Whether the light source is stationary or moving, the speed remains at 300,000 kilometers per second. This may seem a simple and unimpressive discovery, but it changed how the world understands time, space, energy and gravity.

For example, the speed at which something falls determines its mass. The faster it falls, the higher its mass.

Or every time you use your phone to check directions, track a delivery, or find someone’s location, you’re relying on Einstein’s theory of relativity to make sure it works correctly.

IMAGE: Shutterstock

This discovery also led to technologies used globally like the CERN particle accelerators doing revolutionary work in particle physics, contributing to our deeper understanding of matter.

Einstein’s theory also laid the foundation for high-speed electronics and materials science and contributes to numerous scientific fields like astrophysics and cosmology.

Light has enabled us to explore the universe, understand it and ultimately protect ourselves against its threats.

Today we enjoy therapies like laser eye surgery, life-saving imaging like X-rays, CT scans and PET scans that use light to see inside the human body. These technologies, plus fiber optic communication that uses light to contribute to telemedicine, make remote surgeries possible and save lives daily.

CAPTION: The logo of UNESCO on the main building in Paris, France. IMAGE: Shutterstock

A little closer to home, light also has enabled us to kill bacteria and viruses on surfaces and in water, and this makes hospitals, air filters and water purification systems available for use during times of global pandemics. It also enables traffic lights and emergency lighting that contribute to road safety and ensure quick emergency or crisis response.

And though light allows us to kill disease on surfaces and on the food we eat, it also allows us to grow it, maintain our circadian rhythms and build green technologies to save our planet.

From the ancient Greeks — the first to study the nature of light — to the most intricate mysteries of the universe, the impact light has had on science and technology throughout history is ample and endless. “Without light, our planet would be but a cold and barren place. Indeed, where there is light, there is often an abundance of life. Yet light represents even more for humanity. Light goes hand in hand with knowledge; it is a lens through which to see and understand the world,” says Audrey Azoulay, United Nations Educational, Scientific and Cultural Organization (UNESCO) director-general.

UNESCO leads the International Day of Light alongside a committee of representatives from global partners. It was created as an extension of the International Year of Light and was first celebrated in 2018. Celebratory events are listed on the UNESCO website.

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