Objects without a rest mass, such as photons, also carry momentum.
It destroys the old idea that you cannot create more energy at a point than the rest mass of the matter residing there.
They're elementary particles, with no charge, and a tiny rest mass.
On the other hand, in his first paper on (1905) he treated m as what would now be called the rest mass.
That figure is almost twice the actual rest mass in the neighborhood.
Clearly it must have a rest mass of zero, like a neutrino.
All matter, such as any object, has some rest mass.
A body in space has a rest mass which determines its gravitational field.
In fact, since photons have zero rest mass, all their energy is kinetic.
Because the wave is always moving and never actually at rest, it does not have a rest mass.
It appears far more natural to consider every inertial mass as a store of energy.
Despite its low inertial mass, the big memoid clearly did not like this.
It may have taken a great deal of energy to get my inertial mass moving; once moving, I am very hard to stop.
It's the choppiness of that sea which creates inertial mass, not matter itself.
Our inertial mass has dropped to about half its normal value.
Our inertial mass is twenty-five per cent at the moment.
In a state-three field, however, all inertial mass drops to zero.
This is, in principle, how we would measure the inertial mass of an object.
In other words time and inertial mass are irrelevant.
No physical difference has been found between gravitational and inertial mass.