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Top Document: [sci.astro] General (Astronomy Frequently Asked Questions) (2/9) Previous Document: B.02 What are the largest telescopes? Next Document: B.04 What is the resolution of a telescope? See reader questions & answers on this topic! - Help others by sharing your knowledge William Keel <keel@bildad.astr.ua.edu>, Steve Willner <swillner@cfa.harvard.edu>, Joseph Lazio <jlazio@patriot.net>, Jennifer Imamura with corrections and additions by many others (These lists are undoubtedly incomplete. Additions and corrections welcome!) A list of astronomical instruments is also at <URL:http://www.futureframe.de/astro/instr/index.html>. Optical/Infrared Telescopes (nighttime): Now actually under construction: 16.4 Very Large Telescope Cerro Paranal, Chile (quartet of 8.2-m telescopes) <URL:http://www.hq.eso.org/projects/vlt/> 11.0 Hobby-Eberly Telescope, Mt. Fowlkes, Texas (spectroscopy only) <URL:http://www.as.utexas.edu/mcdonald/het/het.html> <URL:http://www.astro.psu.edu/het/> 8.0 Gemini North Mauna Kea, Hawaii 8.0 Gemini South Cerro Pachon, Chile <URL:http://www.gemini.edu/> 8.2 Subaru (JNLT) Mauna Kea, Hawaii <URL:http://www.naoj.org/> 6.5 MMT Mt. Hopkins, Arizona (replace current six mirrors with single one; see B.01) <URL:http://sculptor.as.arizona.edu/foltz/www/mmt.html> 2.2 SOFIA NASA (included because it will be an airborne observatory) <URL:http://sofia.arc.nasa.gov/> Others likely to start soon: Large Binocular Telescope, (Italy; U. Arizona), pair of 8-m telescopes, Mt. Graham, Arizona <URL:http://lbtwww.arcetri.astro.it/> Canary Islands Large Telescope Canary Islands, Spain, 10 m segmented mirror <URL:http//www.iac.es/10m/uk10m.html> Magellan (Carnegie Institution Observatories), 6.5 m, Las Campanas <URL:http//medusa.as.arizona.edu/mlab/mag.html> Radio telescopes under construction in design stages: Submillimeter Array, (Smithsonian Astrophysical Observatory), six 8-m dishes at Mauna Kea <URL:http//sma2.harvard.edu/index.html> Millimeter Array (MMA) (NRAO) <URL:http//www.mma.nrao.edu/ Green Bank Telescope (NRAO) <URL:http//www.gb.nrao.edu/GBT/GBT.html> X-ray: Astro-E (ISAS) <URL:http//www.astro.isas.ac.jp/xray/mission/astroe/> High-Throughput X-Ray Spectroscopy Mission (ESA) <URL:http//astro.estec.esa.nl/XMM/xmm.html> Gamma-ray: INTEGRAL (ESA) <URL: http://astro.estec.esa.nl/SA-general/Projects/Integral/integral.html > Neutrino: Antarctic Muon and Neutrino Detector Array (AMANDA) <URL:http//amanda.berkeley.edu/> Deep Undersea Muon and Neutrino Detection (DUMAND) <URL:http//www.phys.washington.edu/~dumand/> Gravitational Waves: LIGO, (US), 4 km path <URL:http//www.ligo.caltech.edu/> Virgo, (Italy), 3 km path <URL:http//www.pi.infn.it/virgo/> User Contributions:Comment about this article, ask questions, or add new information about this topic:Top Document: [sci.astro] General (Astronomy Frequently Asked Questions) (2/9) Previous Document: B.02 What are the largest telescopes? Next Document: B.04 What is the resolution of a telescope? Part0 - Part1 - Part2 - Part3 - Part4 - Part5 - Part6 - Part7 - Part8 - Single Page [ Usenet FAQs | Web FAQs | Documents | RFC Index ] Send corrections/additions to the FAQ Maintainer: jlazio@patriot.net
Last Update March 27 2014 @ 02:11 PM
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with stars, then every direction you looked would eventually end on
the surface of a star, and the whole sky would be as bright as the
surface of the Sun.
Why would anyone assume this? Certainly, we have directions where we look that are dark because something that does not emit light (is not a star) is between us and the light. A close example is in our own solar system. When we look at the Sun (a star) during a solar eclipse the Moon blocks the light. When we look at the inner planets of our solar system (Mercury and Venus) as they pass between us and the Sun, do we not get the same effect, i.e. in the direction of the planet we see no light from the Sun? Those planets simply look like dark spots on the Sun.
Olbers' paradox seems to assume that only stars exist in the universe, but what about the planets? Aren't there more planets than stars, thus more obstructions to light than sources of light?
What may be more interesting is why can we see certain stars seemingly continuously. Are there no planets or other obstructions between them and us? Or is the twinkle in stars just caused by the movement of obstructions across the path of light between the stars and us? I was always told the twinkle defines a star while the steady light reflected by our planets defines a planet. Is that because the planets of our solar system don't have the obstructions between Earth and them to cause a twinkle effect?
9-14-2024 KP