Why electromagnetic spectrum

Ultraviolet Waves. Earth's Radiation Budget. Diagram of the Electromagnetic Spectrum. Recommended Articles. September 24, Solar Eclipse - June 10, June 09, Aurora-Chasing Citizen Scientists Help November 13, Electromagnetic radiation can be expressed in terms of energy, wavelength, or frequency. Frequency is measured in cycles per second, or Hertz. Wavelength is measured in meters. Energy is measured in electron volts. Each of these three quantities for describing EM radiation are related to each other in a precise mathematical way.

But why have three ways of describing things, each with a different set of physical units? Comparison of wavelength, frequency and energy for the electromagnetic spectrum. The short answer is that scientists don't like to use numbers any bigger or smaller than they have to. It is much easier to say or write "two kilometers" than "two thousand meters.

Astronomers who study radio waves tend to use wavelengths or frequencies. Most of the radio part of the EM spectrum falls in the range from about 1 cm to 1 km, which is 30 gigahertz GHz to kilohertz kHz in frequencies. The radio is a very broad part of the EM spectrum. Infrared and optical astronomers generally use wavelength. Infrared astronomers use microns millionths of a meter for wavelengths, so their part of the EM spectrum falls in the range of 1 to microns.

Optical astronomers use both angstroms 0. One is frequency, which counts the number of waves that pass by a given point in one second. Another is wavelength, the distance from the peak of one wave to the peak of the next. These properties are closely and inversely related: The larger the frequency, the smaller the wavelength — and vice versa.

A third is energy, which is similar to frequency in that the higher the frequency of the light wave, the more energy it carries. Your eyes detect electromagnetic waves that are roughly the size of a virus. Your brain interprets the various energies of visible light as different colors, ranging from red to violet. Red has the lowest energy and violet the highest. On one end of the electromagnetic spectrum are radio waves, which have wavelengths billions of times longer than those of visible light.

On the other end of the spectrum are gamma rays, with wavelengths billions of times smaller than those of visible light. Scientists use different techniques with telescopes to isolate different types of light.

To study the universe, astronomers employ the entire electromagnetic spectrum. Different types of light tell us different things. See interactive examples. ESA's Integral spacecraft, launched in , takes this work forward, studying the phenomenon known as 'gamma-ray bursts'. You have already liked this page, you can only like it once! Radio wavelengths greater than 0.

Microwaves wavelengths between 1 millimetre and 0. Infrared wavelengths between nanometres — 1 millimetre The primary source of infrared radiation is heat. Visible wavelengths between — nanometres Until , most astronomy was optical.

Ultraviolet wavelengths between 10 — nanometres As soon as observations from above the atmosphere became possible, the classical techniques of optical astronomy were extended into the ultraviolet.

X-rays wavelengths between 0. Gamma rays wavelengths less than 0. Like Thank you for liking You have already liked this page, you can only like it once!