03 MAR 2014 by ideonexus
The Silence of the Universe is Significant
Geoff Marcy, the University of California at Berkeley astronomer who has found scores of exoplanets, and who has diligently searched for signs of anything artificial in the data, says the silence is significant: “If our Milky Way Galaxy were teeming with thousands of advanced civilizations, as depicted in science-fiction books and movies, we would already know about them. They would be sending probes to thousands of nearby stars. They would have a galactic Internet composed of laser beams a...Folksonomies: extraterrestrial life
Folksonomies: extraterrestrial life
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notes
notesThe fact that we can't detect anything out there means there may be nothing to detect.
15 MAR 2013 by ideonexus
Einstein's "Biggest Blunder"
For much of the modern era, scientists followed Nicolaus Copernicus, Galileo Galilei, and Isaac Newton in believing the cosmos to be eternal and unchanging. But in 1917, when Albert Einstein applied his theory of relativity to space-time as a whole, his equations implied that the universe could not be static; it must be either expanding or contracting. This struck Einstein as grotesque, so he added to his theory a fiddle factor called the "cosmological constant" that eliminated the implicatio...
1 The story of how Einstein's belief in a static Universe prompted him to introduce a fudge-factor in his Theory of Relativity, the Cosmological Constant.
18 JAN 2013 by ideonexus
Einstein's Cosmological Constant
Georges Lemaitre was a pudgy, pinkish Belgian Jesuit abbe—a Catholic priest—who also happened to be a skilled astronomer. Lemaitre had noticed that Einstein's general theory of relativity would have implied that the universe was expanding but for a troublesome little mathematical term called the cosmological constant that Einstein had inserted into his equations. Lemaitre saw no convincing reason why the cosmological constant should be there. In fact, Einstein himself had originally calc...He put the constant into his theory to keep the Universe static, but observations demonstrated it was expanding, so he changed his theory to match the evidence.
06 JUL 2012 by ideonexus
The Bootes Void
In the course of a redshift survey of galaxies brighter than R approximately equal to 16.3, 133 redshifts were measured in three fields, each separated by roughly 35 deg from the other two. If the galaxies in these fields were distributed uniformly, the combination of a galaxian luminosity function and the magnitude limits predicts that the distribution of redshifts should peak near 15,000 km/s. In fact, only one galaxy of the 133 was observed with a redshift in the 6000 km/s interval centere... 1 notes
notesAn inconceivably massive region of space extremely sparsely populated with galaxies, strangely spherical in shape.
04 JUN 2012 by ideonexus
Big Bang Does Not Preclude a Creator
Hubble's observations suggested that there was a time, called the big bang, when the universe was infinitesimally small and infinitely dense. Under such conditions all the laws of science, and therefore all ability to predict the future, would break down. If there were events earlier than this time, then they could not affect what happens at the present time. Their existence can be ignored because it would have no observational consequences. One may say that time had a beginning at the big ba... 1 notes
notesBut sets limits on when it did the creating.
