The discussion centers on the historical assumptions in physics regarding the nature of fundamental particles, space, and molecular structure. Scientists initially considered fundamental particles as point-like due to the mathematical simplicity and the success of this model in explaining various phenomena. The notion of flat space and two-dimensional molecules arose from similar simplifications. However, modern string theory, which posits that particles are one-dimensional strings or branes without thickness, aims to address the limitations of solid particle models. Attempts to create theories with particles modeled as small spheres faced significant challenges, leading to their abandonment. These challenges often stemmed from issues such as the inability to reconcile the behavior of solid particles with quantum mechanics, which string theory successfully navigates by treating particles as extended objects, thus avoiding the complications associated with solid structures.
