Meade Rb-60 / 70055Lf 60Mm A-Series Altazimuth Refractor Telescope Amazon Price: Customer Review: The telescope has been everything that I expected of it. The only thing it lacks is a barlow lens. The 2 included eyepieces work well, and viewing is easily tracked via the red-...
MEADE 20218 NG-70SM 70MM Altazimuth Refractor Telescope Amazon Price: $72.84
Customer Review: We purchased this telescope to give to our grandsons who live outside the country. On delivery to them we discovered that the switch on the red dot viewfinder was broken. On cont...
Sky & Telescope's Pocket Sky Atlas by Roger W. Sinnott Amazon Price: $13.57
Customer Review: A great sky atlas, perfectly detailed and colorful. I often use it rather that the large format atlas I also have.
Star Gazing by Linda Gillard Amazon Price: $11.01
Customer Review: Star Gazing is one of those books that keeps you up til 4am with its twists and turns, engrossing story and totally yummy hero. I've lent it to many friends since I read it and we'...
Refracting Telescopes
As glassmaking became more refined and lenses were made of greater
quality, someone wondered what would happen if you placed two lenses in a row. The result of the experiment
eventually became the
refracting telescope...
The exact date of the building of the first refractor telescope is not known, but there is strong
documentary evidence for the presence of refracting
telescopes in England as early as the Sixteenth Century, though they did not
become widespread in Europe until the Seventeenth in the Netherlands. Hans Lipperhey (whose patent was rejected as being too easy to copy) and Zacharias
Janssen of the Netherlands, both claim the invention of the revolutionary device
that caused a whole new world view and spread all over Europe.
Whoever the inventor, the original telescope consisted of both a convex and
concave lens so the image could be viewed the right way up. In 1909, Galileo
refined the design by putting distance between the two lenses, refining the image
and reducing the rainbow effect of refracting light that had previously
surrounded distant objects. Galileo continued to refine the telescope improving
the magnification from a power of three to a power of thirty-three. In 1910 he
used the telescope to discover the moons of Jupiter, sunspots and the craters,
hills and valleys of the moon. His observations helped to challenge the view
that the Earth is the center of the universe.
Today telescopes that can match and improve on the observations of Galileo are
widely available. Created of a long tube of wood or metal with a lens at both
ends and an eyepiece, the tube keeps the lenses free from dust, debris and water.
The two lenses work in the same way as the original, focusing and refracting the
light that is then magnified by the eyepiece producing a clear image.
Modern telescopes are expensive and have a high resolution.They are able to see
in great detail binary stars and planets as well as a large number of other
objects, though they are less useful for looking at very large distant objects
such as nebulae and galaxies.
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It's Not Just The Astronauts That Are Getting Older Universe Today ... not return a reliable signal if it is in sunlight, probably because heating affects the reflectors' refractive index and distorts the return signal. ...
(#pharyngula on irc.synirc.net) ScienceBlogs (blog) Its coats and humours, constructed, as the lenses of a telescope are constructed, for the refraction of rays of light to a point, which forms the proper ...