Thursday, July 21, 2011

NIST Posts Adjusted Values of the Physical Constants, Tweaking Gravity to Make Science More Precise | Popular Science

NIST Posts Adjusted Values of the Physical Constants, Tweaking Gravity to Make Science More Precise | Popular Science: The real news here isn’t really that we’ve discovered anything new but that science on the whole has reduced uncertainty, and that in turn impacts all physical science going forward. For instance, uncertainty in the constant alpha (that’s the fine-structure constant or the electromagnetic constant) has been reduced by 0.3 parts per billion, or cut in half based on the last evaluation of the constants in 2006.
Going forward, this adjustment to alpha will make a difference in (and--if the adjustment is correct--reduce the uncertainty of) all kinds of physics. The same is true for various other constants (there’s a nice overview of the heavy hitters here) like the radius of a proton or the Rydberg constant (relating to the atomic spectra in spectroscopy and thus far the most accurately measured fundamental constant--we think), whose values are still not completely “certain” but have been sharpened to introduce less and less uncertainty over the years.

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