Key Facts at a Glance
- Anniversary: UV radiation was discovered in Jena 225 years ago (1801).
- Discoverer: The physicist Johann Wilhelm Ritter (1776–1810).
- Significance: Foundation for numerous modern technologies such as the chip industry, medicine, and analytics.
- Location: Jena has since been considered the historical cradle of photonics and light research.
Jena. It is an anniversary that could easily be lost in the hustle and bustle of everyday life, but for the city of science, Jena, it marks one of the most significant milestones in its history. Exactly 225 years ago, in February 1801, the physicist Johann Wilhelm Ritter succeeded in Jena in proving the existence of a previously unknown force: ultraviolet radiation. What began then as a pure experiment in a Thuringian study has evolved over two centuries into a key technology without which our modern life would be hard to imagine.
The Historical Experiment: Light Beyond the Visible
The time around 1800 was an era of intellectual awakening in Jena. While Goethe and Schiller were revolutionizing literature, natural scientists were researching the foundations of our physical world. Johann Wilhelm Ritter, a brilliant, though often unrecognized, mind of the Romantic era, dealt intensively with galvanic processes and the effects of light.
Inspired by the discovery of infrared radiation by Wilhelm Herschel the previous year, Ritter suspected that there must also be “something” at the other end of the color spectrum – beyond violet. Using silver chloride paper, which blackens when exposed to light, he conducted his experiments. He found that the paper darkened even faster beyond the visible violet light than in the visible range. Ritter had found the “invisible chemical rays” that we know today as ultraviolet light (UV).
From the Laboratory Bench to Key Technology
A scientific sensation at the time, UV radiation is now indispensable in our daily lives and industry. Mitteldeutscher Rundfunk (MDR) honored this anniversary on Saturday with a report in the Thüringen Journal, highlighting the bridge between history and modernity.
The areas of application are diverse and often surprising:
- Medicine and Hygiene: UV light is used worldwide for the sterilization of water, air, and surfaces – a property that can be life-saving, especially in hospitals.
- Semiconductor Industry: Without UV radiation, there would be no modern computer chips. Extremely short-wave lithography, as advanced by Jena-based optics companies, uses UV light to burn microscopic structures onto silicon wafers.
- Art and Culture: In museums, UV light helps restorers identify overpainting on historical paintings or verify the authenticity of documents.
Jena’s Legacy as the “Lichtstadt”
Ritter’s discovery is more than just an anecdote in history books; it is a foundation for Jena’s self-image as the “Lichtstadt” (City of Light). The tradition that began with Ritter was later industrialized and continued by Ernst Abbe, Carl Zeiss, and Otto Schott. The fact that institutes and companies in Jena today work at the limits of what is physically possible in the field of optics and photonics is also a late confirmation of Ritter’s pioneering spirit.
While Johann Wilhelm Ritter often struggled with financial difficulties during his lifetime and only received full recognition for his achievements posthumously, today’s anniversary serves as a reminder of how basic research can change the world over centuries. Anyone walking through Jena today is following in the footsteps of a discovery that made the invisible visible and thus paved the way for technological modernity.
Source:
225 Years of UV Discovery: From the Jena Experiment to Key Technology | MDR.DE
Transparency Note: This article was created automatically, editorially reviewed, and expanded with AI support.