First, this all came after the latest MythBuster's episode where they tried to have a surf board fly off a crashing car and into another car. I don't have the exact quote, so I am just going to make ...

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 ...

We're only going to deal with one dimension here so we'll neglect the vector nature of the force. Let's consider a force, $F$, which increases linearly with ...

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 ...

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 ...