Science Forums 2

[GOLDEN]

It seems like mass is possibly the most tricky subject for physics to describe in any realistic or accurate way. After 81 years of theoretical development and technological advances Einstein still provides the most accurate explanation of what mass is in general relativity. Mass and Gravity are inextricably linked and an explanation of gravity as a curved space-time clarifies the rules by which so called "massive objects" are constrained. Thus modern physics answers this question by posing it again as "what is mass if not a measure of its affect on the local universe?" It is for precisely this reason that gravity and the forces of the quantum field have not yet been neatly tied up under the umbrella of a single theory. Mass remains a mystery because science has not yet successfully detected the mechanism of gravity. Gravitons provide a theoretical grappling point but still only exist in theory as their direct observation has thus far eluded scientists. The best physics can do at present is measure and calculate the force of gravity for an object in a specific state and region. Even general relativity does not offer a complete explanation as to what specific property of an object is actually responsible for the measure of its mass (with the exception of answers like size, density or energy content). So to answer your question mass is the measure of inertia for small objects and the gravity of large ones beyond that is purely theoretical speculation.