Newton's rainbow. In the 1660s, Isaac Newton began a series of experiments with sunlight and prisms. He showed that clear white light was made up of seven visible colors. Newton's crucial experiment was to refract light onto a piece of wood, in which a small hole had been drilled. In this way, he was able to obtain a ray of pure color light. He was able to show that blue light, for example, when refracted through a second prism again casts only blue light. And white light when refracted through the prism produces the colors of the rainbow.
Herschel's Discoveries
Herschel made another discovery about colors in 1800. He wanted to know how much heat passed through the different colored filters that he used to observe sunlight. He observed that the different colored filters seemed to pass different amounts of heat. With this, he was able to create the table with the temperature of the colors. Furthermore, Herschel's experiment is important because it was the first time that it was shown that there are types of light that we cannot see with our eyes (infrared radiation). For more especific information, you can visit: Chapter 17: ANALYZING STARLIGHT where you can see information about each colours stars' temperature and more.
Ritter's Discovery
In 1801 Ritter made the discovery with the silver chloride, which decomposes in the presence of light, is more rapidly decomposed when exposed to the invisible, theretofore unknown radiation beyond the violet end of the spectrum. To discover the ultraviolet light, he split sunlight using a prism and then measured the relative darkening of the chemical as a function of wavelength.
Fraunhofer Lines
In 1814, he discovered and studied the dark absorption lines in the spectrum of the sun now known as Fraunhofer lines. Fraunhofer had invented the modern spectroscope. In the course of his experiments, he discovered a bright fixed line which appears in the orange color of the spectrum when it is produced by the light of fire. This line took him afterward to determine the absolute power of refraction in different substances. It led him to the discovery of 574 dark fixed lines in the solar spectrum. Today, millions of such fixed absorption lines are now known.
Continuing with the investigation, Fraunhofer detected dark lines also appearing in the spectra of several bright stars, but in slightly different arrangements. He concluded that the lines originate in the nature of the stars and sun and carry information about the source of light, doesn't matter how far it's. Concluding with the absorption and emission spectra.
The perfect body are the ones that have a continued spectrum.
