Scale: 10^-16 meters = 100 am = 100 attometers

Inside a Proton

This image is a conceptual representation of the interactions of the three quarks that make up a proton -- two Up quarks and one Down quark. Evidence so far indicates that quarks are permanently bound within the particles they compose. Indeed, the energy required to separate quarks within a proton or neutron is enough to create other quarks and antiquarks -- all bound tightly within a slew of other particles created in high-energy collisions.