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A Far Galaxy and the Speed of Light

11 Feb 2014, 15:22 UTC
A Far Galaxy and the Speed of Light
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The Spitzer and Hubble Space Telescopes have together found one of the most distant galaxies ever sighted. Abell2744 Y1 was formed about 650 million years after the Big Bang. Astronomers have now found many such galaxies from the universe's early years. Every galaxy ever found contains at its centre an enormous Black Hole, with millions of times the mass of our Sun. Science is baffled as to how galaxies and supermassive Black Holes could have formed so early. Many theorists believe that the Big Bang created billions of primordial Black Holes. They would have formed from quantum density fluctuations grown large by expansion of the universe. Everything within reach of the fluctuation would collapse into a Black Hole. Size of a primordial Black Hole would be limited by a "horizon distance" related to the speed of light. If the speed of light were always the same value as today, primordial Black Holes would be tiny. The enormous Black Hole at the centre of Abell2744 Y1 may be primordial, formed shortly after the Big Bang. This distant galaxy is one more sign that the speed of light was once much greater. Many discoveries of galaxies formed early after the Big Bang ...

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