The Electromagnetic Spectrum http://amazing-space.stsci.edu/resources/explorations/groundup/lesson/basics/index.php?return=true

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The Electromagnetic Spectrumhttp//amazing-space.
stsci.edu/resources/explorations/groundup/lesson/b
asics/index.php?returntrue
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Electromagnetic Waves

• 1. Stars send energy called electromagnetic waves
  into space.
• a. Unlike other types of waves, electromagnetic
  waves travel through empty space.
• b. The kind of energy that electromagnetic waves
  carry is called radiant energy.
• 2. The electromagnetic spectrum is the entire
  range of energy carried by electromagnetic waves.
• a. The shortest electromagnetic waves are called
  gamma rays.
• b. The longest electromagnetic waves are called
  radio waves.
• c. Humans can directly observe a small part of
  the electromagnetic spectrum, which is called
  visible light.

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• 3. The amounts of different types of radiant
  energy stars emit vary from star to star,
  depending on the temperature of the star.
• a. Hot stars emit most of their radiant energy as
  short electromagnetic waves, such as gamma rays
  and X-rays. These waves have higher energy.
• b. Cool stars emit most of their radiant energy
  as long electromagnetic waves with low energy,
  such as radio waves and infrared waves.

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• 4. Planets and moons do not emit their own light.
  Instead, they reflect light from the Sun. That is
  the reason we can see these objects in the sky.
• 5. All light waves travel at 300,000 km/s, which
  is called the speed of light.

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What is the electromagnetic spectrum?

• The electromagnetic spectrum consists of all the
  different wavelengths of light (also known as
  electromagnetic radiation), including visible
  light, radio waves, and X-rays.
• Light is a continuum of wavelengths. We name
  regions of the spectrum a bit arbitrarily, but
  the names give us a general sense of the energy
  for example, infrared light has shorter
  wavelengths than radio light. The only region in
  the entire electromagnetic spectrum that our eyes
  are sensitive to is the visible region.
• http//www.youtube.com/watch?vlwfJPc-rSXwlistPL
  09E558656CA5DF76index1

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Wavelength and frequency

• Light is measured by its wavelength (in
  nanometers) or frequency (in Hertz).
• One wavelength equals the distance between two
  successive wave crests or troughs.
• Nanometer - A very small fraction of a meter.
  There are a billion (1,000,000,000) nanometers
  (nm) in one meter
• Frequency (Hertz) equals the number of waves that
  passes a given point per second.

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Wavelength, Frequency and Energy

• Short wavelength high frequency high energy
• Long wave length low frequency low energy

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Gamma rays

• Gamma rays have the shortest wavelengths, lt 0.001
  nanometers (about the size of an atomic nucleus).
  
• This is the most energetic region of the
  electromagnetic spectrum.
• Gamma rays can result from high-energy reactions
  taking place in objects such as pulsars, quasars,
  and black holes.
• http//www.youtube.com/watch?vTA5SLDiIUWslistPL
  09E558656CA5DF76

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X-rays

• X-rays range in wavelength from 0.00110
  nanometers (about the size of an atom).
• They are generated, by superheated gas from
  exploding stars and quasars, where temperatures
  can reach more than 10 million degrees Celsius.
• http//www.youtube.com/watch?vCCAYcuCWOnMlistPL
  09E558656CA5DF76

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Ultraviolet Radiation

• Ultraviolet radiation has wavelengths of 10400
  nanometers (about the size of a virus).
• Young, hot stars produce a lot of ultraviolet
  light that bathes interstellar space with this
  energy and causes nearby gas to glow as nebulae.
• http//www.youtube.com/watch?vQW5zeVy8aE0listPL
  09E558656CA5DF76

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Visible light

• Visible light covers the range of wavelengths
  from 400700 nanometers (from the size of a
  molecule to a protozoan).
• Our Sun emits most of its radiation in the
  visible range, which our eyes perceive as the
  colors of a rainbow. Our eyes are sensitive only
  to this small portion of the electromagnetic
  spectrum.
• ROY G BIV

Red Orange Yellow Green Blue Indigo Violet
http//www.youtube.com/watch?vPMtC34pzKGclistPL
09E558656CA5DF76
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Infrared wavelengths

• Infrared wavelengths span from 700 nanometers 1
  millimeter (from the width of a pinpoint to the
  size of small plant seeds).
• Infrared radiation is associated with heat. At a
  temperature of 98.6 degrees Fahrenheit (37
  degrees Celsius) , our bodies radiate with a peak
  intensity near 900 nanometers.
• http//www.youtube.com/watch?vi8caGm9Fmh0listPL
  09E558656CA5DF76

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Microwaves

• Microwaves have wavelengths between 1 millimeter
  and 1 meter.
• The radiation resulting from the "big bang" is
  detected in the microwave region and is often
  referred to as the microwave background
  radiation.
• Microwave ovens use a specific microwave
  frequency to cause water molecules to absorb the
  energy and thus heat food.
• http//www.youtube.com/watch?vUZeBzTI5OmklistPL
  09E558656CA5DF76

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Radio Waves

• Radio waves are longer than 1 meter. Because
  these are the longest waves, they have the lowest
  energy and are associated with the lowest
  temperatures.
• Radio wavelengths are found many places in a
  variety of stars (especially binary, X-ray, and
  other active stars), in interstellar clouds, in
  pulsars, and in the cool remnants of supernova
  explosions.
• Radio stations use radio wavelengths to send
  signals that our radios then translate into
  sound.
• http//www.youtube.com/watch?vOzDmEA8x0nQlistPL
  09E558656CA5DF76

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EMS SONG

• www.youtube.com/watch?v5UK5_P2bW9g
• Whole EMS video
• http//www.youtube.com/watch?vpYE8UHcL_gU