The proton, the positively charged particle at the center of every atom, is an incredibly complex object that scientists are still trying to fully understand. It is not simply a featureless ball with three quarks, as high school physics teachers may describe it. Recent research has revealed that the proton can take on different forms depending on how it is probed. In fact, it sometimes includes particles called charm quarks, which are larger than the proton itself. Scientists are using advanced techniques, such as machine learning, to unravel the mysteries of the proton and delve deeper into its composition.
https://www.quantamagazine.org/inside-the-proton-the-most-complicated-thing-imaginable-20221019/