Physical Science
Physical science is the systematic study of non-living matter and energy—examining how things move, interact, and transform in the natural world. It encompasses physics, chemistry, astronomy, and earth sciences, unified by the goal of understanding the fundamental rules governing our universe.
Building from First Principles
What exists? At the most basic level, we observe that things exist in space and time. We can measure quantities—how much, how far, how fast, how hot. This leads us to the concept that reality consists of matter (stuff that has mass and takes up space) and energy (the capacity to cause change or do work).
How do we know what we know? Physical science rests on empiricism—knowledge comes from observation and measurement. We assume the universe operates according to consistent, discoverable patterns. When we drop objects, they fall. When we heat water, it boils. These regularities suggest underlying laws.
What are the fundamental interactions? Everything we observe emerges from four basic forces: gravity (pulls masses together), electromagnetism (governs charged particles and light), and two nuclear forces (hold atoms together). These forces explain why planets orbit, why materials have different properties, and why stars shine.
How does complexity emerge? Simple rules operating at small scales create the rich complexity we see. Atoms bond according to electromagnetic principles to form molecules. Molecules interact to create materials with emergent properties—wetness, hardness, conductivity. Gravity organizes matter into planets and galaxies.
Conservation principles guide everything. Energy cannot be created or destroyed, only transformed. Mass-energy, momentum, and electric charge are conserved in all interactions. These constraints limit what’s possible and help us predict outcomes.
Quantification enables prediction. Physical science translates observations into mathematics. When we can measure and calculate, we can predict future states and test our understanding. The ability to make accurate predictions distinguishes scientific knowledge from mere speculation.
This first-principles approach reveals physical science as humanity’s systematic effort to understand the fundamental architecture of reality through observation, measurement, and logical reasoning.