Astronomy Concept: Electromagnetic Spectrum

Also known as the EM-band, the electromagnetic spectrum made many stops on the road to scientific discovery before astronomers recognized the gamma rays and radio waves that it contained. In this article, you will learn of the contributions made by such scientific greats, including Sir Isaac Newton and Sir William Herschel.

The first person recorded to set off the chain reaction of discovering the electromagnetic spectrum is the infamous Sir Isaac Newton, who used a prism to split sunlight into its elemental colors of the rainbow. However, it was Sir William Herschel that accidentally discovered the infrared portion of the spectrum when he positioned thermometers above the red portion of a projected spectrum.

The German chemist and physicist, Johann Ritter took a look at the spectrum and believed that an ‘invisible’ light was located on the opposite (blue) end of the spectrum. He went about proving it by using paper drenched in silver chloride. Beside discovering the ultraviolet component of the electromagnetic spectrum, Ritter also delivered the dry pile electric battery to the world.

The English scientist Thomas Young examined the diffraction patterns through slits of the electromagnetic spectrum and confirmed the wavelike nature of light, which travels much like the waves of an ocean. Young also contributed to the study of energy, solid mechanics, physiology, and vision. He also earned acclaim for deciphering Egyptian hieroglyphs before his nearest opponent.

The theories surrounding electromagnetic nature of light, which changes the electric current in the wave that affects a magnetic field came from the combined effort of English chemist and physicist Michael Faraday and James Maxwell , a Scottish theoretical physicist and mathematician.

After experimenting with ‘Maxwellian Waves,’ German physicist Heinrich Hertz brought to light the presence of radio waves. The discovery of X-rays was credited to the German physicist Wilhelm Rontgen, who would later earn the first Nobel Prize in Physics in 1901. Rontgen was playing around with cardboard tubes that had exposed film and an electric current. When the current made contact with the tubes located at the other end of the room, he was able to see the bones in his hand.

Further understanding of the electromagnetic spectrum concept became heightened when Albert Einstein won the Nobel Prize for discovering the photoelectric effect, which shed light on the wave-particle duality of electromagnetic waves.

Over time, the electromagnetic spectrum was developed within the form of a tool. To truly understand the spectrum, you should know that visible light only covers a small part (between 400 nanometers -blue and 700 nanometers – red). When taking a look at an image of the full electro-magnetic spectrum, note that a minute portion of the spectrum (found in the middle) is comprised of visible light.