Many people, who vaguely remember their school physics classes, would have some trouble differentiating between “mass” and “matter”.   Modern physics, however, is beginning to show that these two words really refer to two different physical manifestations.  All matter that we can perceive on earth, and all the billions of stars and galaxies that we can [...]

We are all pretty sure we know what force is.  Gravity, for instance, is a force and gravity needs no further explanation.   Newton was the first scientist to state the law of gravity in mathematical terms and for many years we thought that this was the final answer to what the force of gravity really [...]