Quarks and Gluons — Odd Building Blocks

Quarks stick together and won't come apart. When pried even one proton's width apart — an extremely minuscule distance — quarks experience ten tons of force pulling them together. Quarks are not dimensional objects, such as billiard balls. In fact, quarks are so small that we have not been able to measure their size; they take up less than one billionth of the space inside the proton, and make up only a few percent of its mass.

So, what takes up the rest of the space and gives protons the rest of their mass? The strong force itself, via carrier particles called gluons. Surrounding and connecting the quarks, this binding glue generates 98% of the universe's visible mass. Scientists have discovered that nature builds particles in hundreds of ways from these point-like quarks and forceful gluons.

It's not just the matter that matters. Nature's real building block is the dynamic, mysterious strong force.