A refracting or refractor telescope is a type of optical telescope that uses a lens as its objective to form an image (also referred to a dioptric telescope).
Optical telescopes may be divided into two general categories: (1)
Celestron Powerseeker 50 AZ Telescope. Item # CE-21039 ... Celestron Travel
Scope 50 Portable Telescope ... Vixen Nature Eye 50mm
How Refraction WorksLight travels through a vacuum at its maximum speed of about 3.0 × 108 m/s, and in a straight path. Light travels at slower speeds through ...
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Galileo wasn't the first to build the device that would become known as the
Jan 7, 2011