Testing Einstein’s E=mc2 in outer space. Is inertial and gravitational mass exactly the same? Reply

See on Scoop.itScience Communication from mdashf

University of Arizona physicist Andrei Lebed has stirred the physics community with an intriguing idea yet to be tested experimentally: The world’s most iconic equation, Albert Einstein’s E=mc2, may be correct or not depending on where you are in space.


This was first demonstrated by Albert Einstein’s Theory of Special Relativity and famously expressed in his iconic equation, E=mc2, where E stands for energy, m for mass and c for the speed of light (squared). Although physicists have since validated Einstein’s equation in countless experiments and calculations, and many technologies including mobile phones and GPS navigation depend on it, University of Arizona physics professor Andrei Lebed has stirred the physics community by suggesting that E=mc2 may not hold up in certain circumstances.


The equivalence principle between the inertial and gravitational masses, introduced in classical physics by Galileo Galilei and in modern physics by Albert Einstein, has been confirmed with a very high level of accuracy. “But my calculations show that beyond a certain probability, there is a very small but real chance the equation breaks down for a gravitational mass,” Lebed said.


If one measures the weight of quantum objects, such as a hydrogen atom, often enough, the result will be the same in the vast majority of cases, but a tiny portion of those measurements give a different reading, in apparent violation of E=mc2. This has physicists puzzled, but it could be explained if gravitational mass was not the same as inertial mass, which is a paradigm in physics.


“Most physicists disagree with this because they believe that gravitational mass exactly equals inertial mass,” Lebed said. “But my point is that gravitational mass may not be equal to inertial mass due to some quantum effects in General Relativity, which is Einstein’s theory of gravitation. To the best of my knowledge, nobody has ever proposed this before.”


According to Einstein, gravitation is a result of a curvature in space itself. Think of a mattress on which several objects have been laid out, say, a ping pong ball, a baseball and a bowling ball. The ping pong ball will make no visible dent, the baseball will make a very small one and the bowling ball will sink into the foam. Stars and planets do the same thing to space. The larger an object’s mass, the larger of a dent it will make into the fabric of space.

See on phys.org

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