The kilogram finally has a precise meaning despite defying a rigorous definition for over a century. Delegates of the General Conference on Weights and Measures unanimously voted Nov. 16 in favor of a ...

It's a constant on SciNoFi that we do one post per episode of a given show. But as we all now know from watching the unexpectedly epic season finale of Fringe last week, constants can change, ...

In physics, there are a host of standard constants: the speed of light, the charge-to-mass ratio of the proton, and Planck's constant, to name just a few. Repeated measurements going back a few ...

For years, astronomers and physicists have calculated the age of our universe by measuring the time elapsed since the Big Bang and by studying the oldest stars based on the redshift of light coming ...

The kilogram — anywhere in the world, for any purpose — is based on the exact weight of a golf-ball-sized chunk of platinum and iridium stored under three glass bell jars in a vault in an ornate ...

It seems that nothing stays the same: not even the 'constants' of physics. An experiment suggests that the mass ratio of two fundamental subatomic particles has decreased over the past 12 billion ...

The strength of the electromagnetic interaction, one of physics’s most fundamental constants, is actually very slowly changing, and has different values in different parts of the universe. This ...

YET another fundamental constant of nature may have changed over the last 12 billion years. If confirmed, the result could force physicists to radically rethink their theories and provide support for ...

Through extremely high precision measurements of a pulsar orbiting a white dwarf star, astronomers have found that the gravitational constant, which dictates the force of gravity, is "reassuringly ...