Giant Black Hole Looks Like 'Eye of Sauron,' Scientists Say - space.com, 11 March 2011
Observing the black hole that sits at the heart of a spiral galaxy called NGC 4151, which is 43 million light-years from Earth, scientists are trying to determine the cause of powerful X-ray emission which comes from that region. There're two possible scenarios. One possibility is that black hole was growing much more rapidly about 25,000 years ago and material was falling into the black hole which produced this powerful radiation. According to the second scenario, material spiraling into the black hole from an accretion disk spawned a vigorous outflow of gas from the surface of this disk, which then heated the gas in its path to X-ray-emitting temperatures.
Black hole research is one of the most challenging areas of astrophysics. No direct experiments are possible, and all results are based math used to build models to explain observation data, sometimes in more than one way. To me this always makes these explanations somewhat tentative, which is why i find methaphors like the one used in this article ("Eye of Sauron") very appropriate.
Showing posts with label books. Show all posts
Showing posts with label books. Show all posts
Friday, March 25, 2011
4. Bad Astronomy
Bad Astronomy: Misconceptions and Misuses Revealed, from Astrology to the Moon Landing "Hoax" - a book by Philip C. Plait.
This book by a science writer, who teaches in astronomy department at Sonoma State University, deals with common myths and misconceptions related to astronomy, like "The sky is blue because it reflects the blue color of the oceans", "The Hubble Space Telescope is bigger than all Earth-based telescopes." or "The Moon is bigger near the horizon than when it's overhead." One very interesting chapter deals with "conspiracy" theory, according to which American astronauts never landed on the moon, and the whole landing event was staged in one of the Hollywood studios.
I got this book in the local library and enjoyed it greatly. I've actually never heard about this "moon conspiracy theory", so it was very enlightening for me to learn truth about it so that if somebody mentiones this to me i'd be able to debunk this stupidity with the knowledge I learned from this book. I also found answers to the questions which seem to be simple on the surface, but the answers i though to be correct are actually wrong. For instance now i know that the seasons are caused by the Earth's tilt.
This book by a science writer, who teaches in astronomy department at Sonoma State University, deals with common myths and misconceptions related to astronomy, like "The sky is blue because it reflects the blue color of the oceans", "The Hubble Space Telescope is bigger than all Earth-based telescopes." or "The Moon is bigger near the horizon than when it's overhead." One very interesting chapter deals with "conspiracy" theory, according to which American astronauts never landed on the moon, and the whole landing event was staged in one of the Hollywood studios.
I got this book in the local library and enjoyed it greatly. I've actually never heard about this "moon conspiracy theory", so it was very enlightening for me to learn truth about it so that if somebody mentiones this to me i'd be able to debunk this stupidity with the knowledge I learned from this book. I also found answers to the questions which seem to be simple on the surface, but the answers i though to be correct are actually wrong. For instance now i know that the seasons are caused by the Earth's tilt.
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