Digital Age
The Digital Revolution | Types of Light | Electromagnetic Spectrum in Stained Glass | Museum Road ShowThe Digital Revolution
Digital
technology has transformed how we explore the Universe. Telescopes, photography,
and spectroscopy remain our basic tools, but digital light detectors and processors
have enhanced their power. Observatories in space have broadened the range of
light we can gather. Our view of the Universe now extends from radio waves to
gamma rays. And new technologies are revolutionizing ground-based astronomy, enabling
us to create larger and more powerful telescopes than ever before.Types of Light
Our
eyes can see only a slice of the entire range of light, which is called the electromagnetic
spectrum. A continuous span of wavelengths ranging from very long to very short,
the electromagnetic spectrum consists of radio, infrared, visible, ultraviolet,
x-ray, and gamma ray light. But like different notes on a musical scale, all these
forms of light are variations of the same thing.
- Radio waves show regions of radiation caused by the motions of electrons in magnetic fields.
- Infrared light shows areas of interstellar dust warmed by nearby stars.
- Visible light shows the distribution of stars and gas in the galaxy's arms and nucleus.
- Ultraviolet light shows areas where hot young stars reside.
- X-rays show extremely hot regions-supernovae remnants (exploded stars), and areas where material is being drawn into black holes.
- Lastly, the most energetic events and processes produce gamma rays. Galaxies have not yet been imaged in this form of light.
Electromagnetic Spectrum in Stained Glass
The stained glass panel above depicts the range of light that shines onto the Earth from space, as well as how deeply different light rays penetrate the atmosphere. The light rays are arranged by wavelength (symbolized by the wavy white band) from long to short. Also shown are meteors and an aurora, which produce radio waves, and high-energy particles called cosmic rays. Colors depict these--Green: Radio waves, Yellow teardrops: Meteors, Orange teardrops: Aurora, Red: Infrared light, Rainbow colors: Visible light, Violet: Ultraviolet light, Dark violet triangles: X-rays, Light violet triangles: Gamma rays, Pink: Cosmic rays.
Museum Road Show
Join our resident experts as they explain--in the spirit of the PBS television program "Antiques Roadshow"--about various kinds of light detectors on display in "Explore the Universe."
Videos:
Intro
Dicke Radiometer
IRAS
CCDs
Copernicus
ROSAT
EGRET
WULF Electroscope
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