history telescope
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Stripes (Extended Cut)
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DescriptionTen-hup! Hilarious military comedy stars Bill Murray and Harold Ramis (who also co-wrote) as a pair of losers who decide to enlist in the army where they, and the rest of their screwball platoon, make life miserable for tough-as-nails drill sergeant Warren Oates. It's a riot...that's the fact, Jack! With John Larroquette, P.J. Soles, Sean Young, and John Candy; look quickly for Bill Paxton. Includes the original theatrical version and the extended cut; 107 min./125 min. Widescreen (Enhanced); Soundtrack: English Dolby Digital 5.1; Subtitles: English, French; deleted scenes; "making of" documentary; interviews. Bill Murray was heading toward a career peak on the back of comedies such as this one from 1981, the second film in his ongoing collaboration with director Ivan Reitman (the two went on to make Ghostbusters). Murray plays a chronic loser who joins the army and fails to find a fan for his ironic sensibilities in his by-the-book sergeant (Warren Oates). When push comes to shove, however, the smirking hero takes charge of his ragtag unit and turns them into fighting machines, albeit to the rhythm of hit songs by Manfred Mann and Sly Stone. The film is occasionally funny, but it mostly plays like any one of a dozen underachieving comedies featuring players from Saturday Night Live and SCTV. --Tom Keogh Features
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The Exciting Possibilities Of A Liquid Mirror Telescope
A telescope is a viewing instrument that utilizes the refraction or reflecting of light rays and allows for images to be brought closer. This capturing of light is accomplished through a component that is called the objective. The objective is that part of the telescope which, through the captured light, provides an image of the object that is being viewed. Typically, the objective is either composed of a set of lenses or a concave mirror.
Now, think about the possibilities of utilizing liquid to mirror reflections back to our vision. The concept of a liquid mirror would be similar to the experience of looking at your image in a pool of water. However, a liquid mirror telescope would be used to peer into the depths of space. At first glance the concept of this telescope seems like something that is a far-fetched and very futuristic.
However, the future is now as astronomers realize the potential of employing this telescope to take the place of a concave mirror that is typically found in a reflecting telescope.
History Of A Liquid Mirror Telescope
Isaac Newton in the 17th century was the first individual to go on record about the possibilities of these telescopes. In his studies, he realized that when liquid is spun it forms a natural concave bowl-like shape. This spinning liquid would provide the same shape of the concave mirrors that are used in a reflective telescope.
Unfortunately, his idea was ahead of its time. The reason being is that the electric motor had not been invented. The electric motor would have been needed to provide the rotation required to give the liquid its concave form.
The first documented case of a this telescope being used was in 1909. However, it was not until 1982 that a physicist by the name of Ermanno Borra modified the design to improve the performance of these telescope. One such telescope is located in British Columbia, Canada.
Structure Of A Liquid Mirror Telescope
Fortunately, today, all of the needed technology is available and has, in fact, brought the practical use of a mirror telescope in to practice. Specifically, the liquid that is used is 30 liters of mercury. This mercury is poured into a concave dish that is built in segments. The dish itself is manufactured from a durable plastic coupled with polyester. The frame that holds the dish is a light metal.
The Process
In order to form the shape required to optimally provide the reflection needed, the dish begins to spin. The spinning speed is about 7 revolutions per minute. This speed is maintained so that the proper distribution of the mercury occurs.
Advantages And Disadvantages
The only disadvantage that has been demonstrated in the use of a mirror telescope is the need for the dish to remain parallel. This is obviously due to the fact that if tilted the liquid would flow gravitationally to the end that is tilted downwards.
The advantage is that the area of reflection is extremely large. This larger area provides a greater capacity to capture more light which adds to the visibility of the object being viewed. In turn, this larger area of reflection allows for greater distances in the galaxy to be observed.
About the Author
Rohit Chopra has written several useful articles on topics like
Telescopes,
Telescope Lens,
Meade Telescope,
Hubble Telescope, etc. Get more useful
information on Telescopes at
http://www.digitalphotographywiz.com
Where can i find Historical documents about Telescopes?
Okay so i'm doing a project for National History day at my school i picked "The Telescope" the theme this year is innovation in history....btw i'm in 8th grade. Anyway i need primary and secondary sources in the form of Documents.Journals,Letters etc Please try to avoid websites....P.S i really need primary sources
Since telescopes have been used for Astronomy for 400 years, all the primary sources like Galileo's Starry Messenger book are in museums and private collections. You will have to be content with secondary sources like library books, magazines about Astronomy, and newspaper articles.
You could interview an astronomer near you. You could go to an Astronomy club's meeting and this weekend's star party near you.
http://www.skyandtelescope.com has a search function for clubs by location.
A book that I have, "Astronomy, a history of man's investigation of the universe" by Fred Hoyle, covers telescope development thoroughly.
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