Who is John Wilhelm Ritter?
Who is John Wilhelm Ritter?
Johann Wilhelm Ritter, (born December 16, 1776, Samitz bei Haynau, Silesia [now Zamienice, Poland]—died January 23, 1810, Munich), German physicist who discovered the ultraviolet region of the spectrum and thus helped broaden humanity’s view beyond the narrow region of visible light to encompass the entire …
How are ultraviolet waves created?
Ultraviolet radiation is produced by high-temperature surfaces, such as the Sun, in a continuous spectrum and by atomic excitation in a gaseous discharge tube as a discrete spectrum of wavelengths. Of the ultraviolet that does reach Earth’s surface, almost 99 percent is UVA radiation.
When was UV light first used?
UV lamps first became commercially available in 1930 and following the end of the Second World War in 1945, germicidal UV lamps became more and more commonly used to disinfect air.
How did Johann Wilhelm Ritter discover Ultraviolet?
Ultraviolet light was discovered by Johann Wilhelm Ritter in 1801 when he noticed that invisible light beyond the optical region of the electromagnetic spectrum darkened silver chloride. He split sunlight using a prism and then measured the relative darkening of the chemical as a function of wavelength.
Can humans see ultraviolet?
The human retina is sensitive to the ultraviolet (UV) spectrum down to about 300 nanometres, but the lens of the eye filters it out. Artificial lenses are designed to block UV. But people born without a lens, or who have a lens removed and not replaced, sometimes report seeing ultraviolet as a whitish-violet light.
Where did the name Ultraviolet come from?
“Ultraviolet” means “beyond violet” (from Latin ultra, “beyond”), violet being the color of the highest frequencies of visible light. Ultraviolet has a higher frequency (thus a shorter wavelength) than violet light.
How was blacklight discovered?
Byler is credited with inventing the black light in 1935, and according to the University of Central Missouri, Byler graduated there in 1927 with a major in chemistry and physics. The black glass in a black light blocks normal visible light so the only light hitting the phosphor coating is in the ultraviolet spectrum.
What is the color of UV light?
Q: What is the UV Index (UVI)?
Category | UVI Range | Color |
---|---|---|
Low | 0 – 2 | Green |
Moderate | 3 – 5 | Yellow |
High | 6 – 7 | Orange |
Very High | 8 – 10 | Red |