Johann Wilhelm Ritter

Johann Wilhelm Ritter (1776–1810) was a German physicist and chemist whose 1801 experiments revealed invisible radiation beyond violet light, later called ultraviolet radiation.

Connect

Ultraviolet: Ultraviolet is electromagnetic radiation with wavelengths shorter than visible violet light and longer than X-rays. Ritter’s experiment revealed this invisible region of the spectrum.
Prism: A prism is an optical element that refracts light and separates it into its component wavelengths. Ritter used a prism to position colors and test regions beyond violet.
Alexander von Humboldt: Alexander von Humboldt was a Prussian naturalist and explorer who studied the interconnected physical processes of nature. Humboldt and Ritter shared interests in galvanism and the unity of natural forces.
Infrared: Infrared is electromagnetic radiation with wavelengths longer than visible red light and shorter than microwaves. Infrared is the opposite invisible extension of visible light, discovered just before ultraviolet.
Silver chloride: Silver chloride is a light-sensitive chemical compound that darkens when exposed to light. Its darkening made the chemical action beyond violet detectable.
Fraunhofer lines: Fraunhofer lines are dark absorption features in the solar spectrum first systematically mapped by Joseph von Fraunhofer. Precise study of the spectrum formed the wider experimental setting for Ritter’s work.
Johann Christian Reil: Johann Christian Reil was a German physician and anatomist who helped establish psychiatry as a medical discipline. Reil was among the medical and scientific contemporaries in Ritter’s intellectual networks.
Spectroscopy: Spectroscopy studies how matter interacts with electromagnetic radiation across different wavelengths. Ritter’s discovery broadened the spectral region available for investigation.
Electromagnetic spectrum: The electromagnetic spectrum is the full range of electromagnetic radiation, arranged by frequency or wavelength. Ultraviolet placed Ritter’s discovery within a broader, ordered range of radiation.
Isaac Newton: Isaac Newton was an English physicist and mathematician whose prism experiments established that white light contains different colors. Newton’s account of prismatic color supplied the framework Ritter extended beyond visible light.