The inconstant constant - speed of light
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The inconstant constant - speed of light
http://www.economist.com/science/displaySt...tory_id=1066862
[QUOTE]At the heart of the controversy is the number known as alpha, a quantity that can be calculated by combining several fundamental physical constants. To get alpha, square the charge of the electron and divide it by the speed of light times Planck's constant, a key value used in quantum theory. Then multiply the result by two times pi, the ratio of a circle's circumference to its diameter. When the right units of measurement are chosen for each component, they cancel out. All that remains is alpha, a pure number.
Scientists who nursed Platonic ideas about physics once suspected that alpha's value was an exact fraction, one over 137. Today, physicists reckon the denominator of this fraction is actually closer to 137.036. Yet the mystery persists: why is this seemingly arbitrary figure stitched into the fabric of reality? The work performed by John Webb, Victor Flambaum and Mr Murphy at the University of New South Wales, and their colleagues elsewhere, has only fuelled this enigma. If they are correct, it is pointless to ascribe significance to the measured value of alpha, because it has grown with time: by 0.0006% over the past 9 billion years.
[QUOTE]At the heart of the controversy is the number known as alpha, a quantity that can be calculated by combining several fundamental physical constants. To get alpha, square the charge of the electron and divide it by the speed of light times Planck's constant, a key value used in quantum theory. Then multiply the result by two times pi, the ratio of a circle's circumference to its diameter. When the right units of measurement are chosen for each component, they cancel out. All that remains is alpha, a pure number.
Scientists who nursed Platonic ideas about physics once suspected that alpha's value was an exact fraction, one over 137. Today, physicists reckon the denominator of this fraction is actually closer to 137.036. Yet the mystery persists: why is this seemingly arbitrary figure stitched into the fabric of reality? The work performed by John Webb, Victor Flambaum and Mr Murphy at the University of New South Wales, and their colleagues elsewhere, has only fuelled this enigma. If they are correct, it is pointless to ascribe significance to the measured value of alpha, because it has grown with time: by 0.0006% over the past 9 billion years.
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