> The challenge of understanding how quarks are bound inside exotic hadrons is the greatest outstanding question in hadron spectroscopy.
They must be more like knots: https://en.wikipedia.org/wiki/Knot_(mathematics)
Quarks are small masses, gluons are strings connecting them, and the whole thing is in a rapid periodic motion.
> Like Mendeleev and Gell-Mann, we are at the beginning of a new field, in the taxonomy stage, discovering, studying and classifying exotic hadrons.
The chemistry of matter that's smaller than protons and larger than electrons is indeed a missing piece. But the real breakthru will be discovering a membrane that's impenetrable to those multiquarks.