International Day of Light

This year, we also celebrate the 61th anniversary of the first operating laser on the International Day of Light.
International Day of Light






Humans have had a special relationship to light since prehistoric times. Presumably, this is not only because to this day darkness suggests a certain danger, but also because 90% of the information our brain processes is visual. Although light itself does not provide us with nutrients – the opposite is claimed only by a few, but related experimentations have never ended well – without light we would have nothing to eat. Light has intrigued everyday people and scientists alike. The outstanding Arabic scientist, Alhazen, who is considered by many as the founder of exact scientific methodology, had his most important achievements in optics. Newton was probably most proud of his experiment in which he divided white light into colours. (It’s no accident that he called it “experimentum crucis”, i.e. “crucial experiment”.)


Although science had revealed many facts about light in the 1,000 years since Alhazen’s time, scientists were unable to produce a light source the light of which would significantly differ from natural light. This, in part explains that the years leading up to 1959-60 saw the tightest race in the history of science for the development of the laser. The race was won by Theodore Maiman “in a photo finish”. On 16 May 1960, he recorded the first measurement data that proved that his laser was operational. The intensity of the competition for the development of lasers is probably best illustrated by the fact that in the same year four other teams could demonstrate laser operation: Arthur Schawlow and Irwin Wieder in ruby crystals (independently from each other, and of course, from Maiman), Peter Sorokin in a uranium-doped CaF crystal, and Ali Javan in a mixture of He-Ne.


The pioneers of laser science were aware of the fact that the laser would outperform any other previously known light sources. However, they could not have known that they started a revolution in science and technology. By today, lasers have appeared in almost all fields of life from barcode scanners to operating theatres to the detection of gravitational waves. They support applications (e.g. high-speed optical data transmission) without which our everyday life would be unimaginable.


Despite the breath-taking achievements of the laser revolution, we are far from the end of the road. This was the starting point for Europe’s leading scientists, including Nobel Prize laureate Gérard Mourou, when they compiled their 2005 study that laid the scientific foundation for the Extreme Light Infrastructure (ELI). One of the declared goals of the proposal was the construction of a large research infrastructure facility which would set the direction for the development of laser science for decades to come. In the meantime, the scientists’ dream has come true: ELI has been established, and the impressive building of ELI-ALPS, one of its pillars, has been constructed in Szeged.


If anyone, we at ELI-ALPS have all the reason to celebrate the 60th anniversary of the laser. Opening the Scientific Outreach Centre on 16 May 2020 would have provided a fitting framework for this. Unfortunately, the circumstances have prevented us from celebrating with our guests, so instead of holding an opening ceremony, in the spirit of lockdown we have produced a short film in which young people walk around the premises in lieu of real visitors. 


Naturally, the real event cannot be totally cancelled. Hopefully, we will soon be able to hold a proper opening ceremony, and as soon as life gets back to normal we look forward to receiving large numbers of visitors eager to gain an insight into the backstage aspects of research, or to train themselves to become (light) harpists or (light) chess masters.


Prof. Gábor Szabó, 16 May 2020