Liquid-mirror telescope
A rotating liquid mirror forms a parabolic reflector for low-cost telescopes.
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A liquid-mirror telescope uses a rotating liquid surface as its primary mirror, typically mercury, to form a parabolic shape that focuses light.[1] The mirror can only point straight up, so objects cannot be physically tracked as the Earth rotates.[2][3]
Quick Facts
- Common liquid
- mercury
- Other liquids
- low-melting point alloys of gallium
- Largest ever built
- 6 metres (20 ft) diameter (Large Zenith Telescope, Canada)
- Rotation rate of largest
- about 8.5 revolutions per minute
- Cost of largest
- $1 million
- Decommissioned
- 2016
- Planned larger project
- 8-metre (26 ft) ALPACA; LAMA with 66 individual 6.15-metre (20.2 ft) telescopes
Facts from the source article.
Key facts and history
Ernesto Capocci of the Naples Observatory further developed the concept in 1850.[4] Henry Skey of Dunedin, New Zealand, constructed the first working laboratory liquid-mirror telescope in 1872.[4] The greatest advantage of a liquid mirror is its small cost, about 1% of a conventional telescope mirror, cutting the entire telescope cost at least 95%.[2] As of 2006, plans were being made to build a larger 8 m liquid-mirror telescope called ALPACA and a project called LAMA with 66 individual 6.15 m telescopes.[5]
A rotating liquid's free surface takes the shape of a circular paraboloid, a fact Isaac Newton observed and recognized could serve as a telescope mirror, but he lacked the technology to control rotation speed and so never constructed one.[4][1] The 6-meter Large Zenith Telescope at the University of British Columbia was built for roughly one-fiftieth the price of a standard glass-mirror telescope.[2]
What the cited sources add
The American Chemical Society reported in 2008 that researchers had developed a new deformable liquid mirror composed of magnetic iron particles, ethylene glycol, and a coating of silver nanoparticles.[6] In lab studies, this new material showed better reflectivity and stability than current liquid-mirror materials, according to the scientists.[6] The advance could lead to improved instruments for diagnosing eye disease and more powerful telescopes, the researchers say.[6]
References
- Weishaupt, "What Is a Liquid-Mirror Telescope? The Interesting Answer!", Optics Mag, 2022-12-19. facts only, no text reused. opticsmag.com
- Wikipedia, "Liquid-mirror telescope" (CC BY-SA 4.0), which cites: "Liquid-mirror telescope set to give stargazing a new spin", Govert Schilling, 2003-03-14 (original not read by us) en.wikipedia.org
- Wikipedia, "Liquid-mirror telescope" (CC BY-SA 4.0), which cites: Rabinowitz, "Drift Scanning (Time-Delay Integration", Yale University Center for Astronomy and Astrophysics (original not read by us) en.wikipedia.org
- Wikipedia, "Liquid-mirror telescope" (CC BY-SA 4.0), which cites: "What is an LMT?"; Weishaupt, "What Is a Liquid-Mirror Telescope? The Interesting Answer!", Optics Mag, 2022-12-19; Capocci, "M. Quetelet lit extraits suivants d'une lettre de M. Capocci, astronome à Naples", Bulletins de l'Académie Royale des Sciences, des Lettres et des Beaux-arts de Belgique, 1850, p. 299–302; Krecke, "M. Quetelet fait part d'une lettre qu'il a reçu de M. Krecke, …", Bulletins de l'Académie Royale des Sciences, des Lettres et des Beaux-arts de Belgique, 1851, p. 363–365 (we also read that source) en.wikipedia.org
- Wikipedia, "Liquid-mirror telescope" (CC BY-SA 4.0), which cites: Crotts, "ALPACA: An Inexpensive but Uniquely Powerful Imaging Survey Telescope", American Astronomical Society Meeting Abstracts, 2006-12-01, p. 99.05; ALPACA overview.; Hickson, "Second Backaskog Workshop on Extremely Large Telescopes", 2004, p. 115–126; The University of British-Columbia Liquid-Mirror Observatory - Perfecting the next generation of super telescopes. (original not read by us) en.wikipedia.org
- American Chemical Society (2008, November 12), "'Liquid Mirror' Advance May Lead To Better Eye Exams, Improved Telescopes", Science News, November 12, 2008. facts only, no text reused. sciencedaily.com
Each numbered sentence above was checked against the source it cites before publication. Sentences citing Wikipedia adapt text from the English Wikipedia article Liquid-mirror telescope (contributors), used under CC BY-SA 4.0; this entry is available under the same licence. Other sources were used for facts only; no text or images are copied from them.
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Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Liquid-mirror telescope (CC BY-SA 4.0).
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