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Energy that travels through space at the speed of light. The total range of electromagnetic wavelengths and frequencies is called the electromagnetic spectrum. Our eyes are sensitive to a sliver of the electromagnetic spectrum we call visible light, from red to blue. Beyond the blue end, as wavelength decreases and frequency increases, lie ultraviolet light, X-rays, and gamma-rays. In the other direction past red, as wavelength increases and frequency decreases, lies infrared, microwave, and radio regions of the electromagnetic spectrum. Radio waves are the longest, extending on the order of meters, while X-rays and gamma-rays are the shortest, on the order of atomic size. Light wavelengths are measured in microns, millionths of meters. For all forms of electromagnetic radiation, the speed of light must remain constant, regardless of wavelength or frequency.

Radio Programs

Wilhelm Roentgen Looking “deep” into the universe March 27, 2020

Staying Safe Staying safe on a trip to the Moon July 18, 2019

South Atlantic Anomaly Zapped over the South Atlantic April 4, 2019

Moon and Mars Getting zapped on the way to Mars December 14, 2018

Moon and Jupiter Protection against a “dead zone” May 7, 2017

More Reionization An early light in the young universe November 4, 2016

Reionization Giving the universe a charge November 3, 2016

Moon and Jupiter Danger from giant volcanoes June 11, 2016

Van Allen Belts Earth’s dynamic radiation belts May 4, 2016

Featured Images

Possible Mars habitat

Staying Safe December 14, 2018