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For over two thousand years, the greatest minds in physics believed matter was made of tiny, indivisible balls. Today, we know an atom is mostly empty space governed by probability clouds of quantum wavefunctions.
Scientific theories are never absolute truth; they are working models that survive only until an experiment proves them wrong.
How did a series of unexpected experimental anomalies force scientists to continuously discard and rebuild our picture of reality?

The Epistemological Hierarchy in Science

Scientific knowledge is organized within an epistemological hierarchy that distinguishes observations from explanations.
A hypothesis is a tentative proposal, whereas a scientific law mathematically describes observed regularitiesβ€”such as the Law of Conservation of Mass or Coulomb's Law (Fe=ke∣q1q2∣r2F_e = k_e \frac{|q_1 q_2|}{r^2})β€”without explaining why they occur.
In contrast, a scientific theory, such as Atomic Theory, is an overarching, evidence-based framework that explains how and why nature behaves as it does. Theories never 'graduate' into laws.

The Epistemological Hierarchy

To understand how science progresses, we must distinguish between the levels of the epistemological hierarchy: hypotheses, laws, and theories.
A hypothesis is a tentative, testable proposal, while a scientific law mathematically describes an observed regularityβ€”such as the Law of Conservation of Mass or Coulomb's Law (Fe=ke∣q1q2∣r2F_e = k_e \frac{|q_1 q_2|}{r^2})β€”without explaining why it occurs.
A scientific theory, such as Atomic Theory, is an overarching, evidence-based explanatory framework that explains why and how phenomena occur. Theories explain laws and never 'graduate' into them.

Dalton and the Indivisible Sphere

In 1803, John Dalton synthesized empirical chemical lawsβ€”specifically the Law of Definite Proportions and the Law of Multiple Proportionsβ€”into a unified model of matter.