The equivalence principle is one of the more fascinating ideas in modern science. It asserts that gravitational mass and inertial mass are identical. Einstein put it like this: the gravitational force ...

The equation F = ma is one of the most important in physics. Yet we have so far not explained how to get a quantitative operational definition of either mass or force. Somehow, from this one ...

Mass is mass is mass. Physicists have three different definitions of mass, all thought to be equivalent. Measurements of the distance between Earth and the moon confirm that two of those masses are ...

Physicists report that electrons in semiconductor crystals have a negative inertial mass when strongly accelerated in an electric field. Physicists of the Max Born Institute in Berlin report in the ...

Antimatter is anti- a lot of things, but it’s not supposed to be antigravity. An antimatter particle does have the opposite electric charge of its ordinary matter counterpart. But the mass of both ...

I've been trying to explain quantum physics, forces, relativity, and space-time to my kid and we had a question that I'm finding difficult to find a solid answer to. Background you can skip if you ...

What is this thing called mass? Pondering this apparently simple question, two scientists have come up with a radical theory that could explain the nature of inertia, abolish gravity and, just ...

Salvatore Cezar Pais is a US Navy researcher. Salvatore has three amazing patents that would be incredible breakthroughs in physics if they are true. The least extreme is a patent for Piezoelectricity ...