What is Mass and Where Does it Come From?
It seems so simple. Our world is made up of all kinds of stuff. We call it matter, and it possesses something we call mass. But what is mass? Dip into Isaac Newton’s Principia and you’ll soon discover that we’ve never really got to grips with it. And, of course, Albert Einstein subsequently informed us that mass is, in fact, energy: E = mc2.
The discovery of the Higgs boson tells us that the universe contains an invisible energy field, called the Higgs field. About a trillionth of a second after the big bang, interactions with this field resisted the acceleration of the some of the particles that prevailed, and slowed them down. We call such resistance inertia, a property of objects with mass. In other words, these particles ‘gained mass’.
About 100 seconds later, quarks combined to produce protons and neutrons, and today we trace the mass of a substance to the protons and neutrons in its atomic nuclei. But consider this. The masses of the quarks, gained by interactions with the Higgs field, account for only 1% of the masses of protons and neutrons. The other 99% comes from the energy of the force particles (called gluons) that bind the quarks together.
Not so simple, then.