Nuclear physics exhibits many characteristics associated with emergent phenomena. These include a hierarchy of scales, effective interactions and theories, and universality.
The table below summarises how nuclear physics is concerned with phenomena that occur at a range of length and number scales. At each level of the hierarchy, there are effective interactions that are described by effective theories. Some of the biggest questions in the field concern how the effective theories that operate at each level are related to the levels above and below.
Moving from the bottom level to the second top level, relevant length scales increase from less than a femtometre to several femtometres.
The challenge in the 1950s was to reconcile the liquid drop model and the nuclear shell model. This led to the discovery of collective rotations and shape deformations. The observed small moments of inertia were explained by BCS theory. Integration of the liquid drop and shell models led to the award of the1975 Nobel Prize in Physics to Aage Bohr, Ben Mottelson, and Rainwater.
Since the 1980s a major challenge is to show how the strong nuclear force between two nucleons can be derived from Quantum Chromodynamics (QCD). The figure below illustrates how the attractive interaction between a neutron and a proton can be understood in terms of the creation and destruction of a down quark-antiquark pair. The figure is taken from here.
I found your exploration of emergence in nuclear physics fascinating. The way you break down complex concepts into understandable analogies makes the topic accessible. I think If you want to pursue higher education in the fields of Science, Engineering, Information Technology, etc. then you'll need to have a strong knowledge of physics. Physics is the one subject that connects many other subjects in one way or another. Self-study is not enough, you'll need the help of a physics tutor to understand the difficult concepts of physics.
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