News tagged with darkness

Universe older than it looks

When astronomers (Bond 2013) first dated the star HD 140283, which lies a mere 190 lightyears from Earth in the constellation of Libra, they were puzzled. This rare, star appeared to be rather ancient and ...

Oct 27, 2014
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The difficulties of cataloging dark nebulae

E. E. Barnard is an astronomer perhaps best known for measuring the proper motion of a faint red dwarf about six light years away, now known as Barnard's star. But Barnard was also a pioneer of astrophotography, ...

Oct 06, 2014
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How small can galaxies be?

Yesterday I talked about just how small a star can be, so today let's explore just how small a galaxy can be. Our Milky Way galaxy is about 100,000 light years across, and contains about 200 billion stars. Th ...

Sep 29, 2014
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What is the geometry of the universe?

One of the big questions in cosmology regards the shape of the universe. "Shape" in this case is not the distribution of galaxies, but rather the shape of space and time itself. In general relativity, space ...

Sep 24, 2014
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