INTRODUCTION Invention of the telescope in 1608 Telescope: an
object that makes distant objects appear to be closer Since then,
we have built bigger and more powerful telescopes
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ELECTROMAGNETIC RADIATION Electromagnetic radiation: energy
that can travel through space in the form of waves Forms of
Radiation - Visible light: all the colors that you can see, one
type of radiation - Radio waves - Microwaves - Ultraviolet
Radiation
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ELECTROMAGNETIC RADIATION The Electromagnetic Spectrum -
wavelength: the distance between the crest of one wave and the
crest of the next wave - spectrum: range of different colors, with
different wavelengths - The electromagnetic spectrum includes the
entire range of radio waves, infrared radiation, visible light,
ultraviolet radiation, X-rays, and gamma rays.
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ELECTROMAGNETIC SPECTRUM
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TYPES OF TELESCOPES Telescopes are instruments that collect and
focus light and other forms of electromagnetic radiation. Optical
Telescope: Telescope that uses lenses or mirror to collect and
focus visible light. Two types: refracting telescope and reflecting
telescope
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TYPES OF TELESCOPES Refracting Telescopes - uses a convex lens
to gather and focus light. - convex lens: a piece of transparent
glass, curved so that the middle is thicker than the edges.
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TYPES OF TELESCOPES Reflecting Telescope - uses a curved mirror
to collect and focus light - the largest telescopes today are
reflecting Radio Telescope - devices used to detect radio waves
from objects in space
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OBSERVATORIES Observatory: a building that contains one or more
telescopes - Many large observatories are located on mountaintops
in space. - The sky on mountaintops is clearer and not brightened
much by city lights Advanced Telescopes - new telescopes now have
computer systems that correct images - technology that can
automatically adjust parts of the telescope
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OBSERVATORIES Telescopes in Space The atmosphere blocks out a
lot of radiation EX: The Hubble Space Telescope - because it orbits
Earth above the atmosphere, it can produced very detailed
images
