Imagine a particle. What comes to mind? If you aren’t a theoretical particle physicist, chances are you picture a tiny ball, bobbing in space.
But that’s not quite correct. One way to prove it: Try to imagine that tiny ball as a particle with no mass.
Sometimes the word “mass” is used interchangeably with the word “weight.” That’s not entirely wrong. The mass of an object is measured by its resistance to a force. When you pick something up to test its weight, it is resisting the Earth’s gravity, so an everyday object’s weight on Earth is indeed one measurement of its mass.
But there’s more to mass than just a resistance to gravity, especially on the scale of the smallest pieces of matter. So physicists’ definition of mass gets a little more complicated.To read more, click here.