Energy cannot be created or destroyed, only transformed. This fundamental law underlies every decision, every system, and every action. When energy is utilized, some becomes useful work while some dissipates as unusable heat—creating entropy and disorder. Understanding energy flows and constraints is understanding reality's operating system.

Information is measured by the number of alternatives it eliminates. It's the fundamental currency connecting energy, matter, and consciousness. The physical world isn't just colliding atoms—it's a network of correlations and information exchanges between systems. Information is finite, observer-dependent, and inseparable from physical reality.

Quantum systems don't have definite properties until measured. The act of observation collapses possibilities into actualities. This isn't philosophy—it's the foundation of physical reality at small scales. Understanding quantum mechanics means accepting that consciousness and measurement play roles in determining what exists.

Space and time are unified into spacetime, and there's no absolute reference frame. Each observer has their own personal measure of time depending on location and velocity. What you experience as "now" isn't universal—simultaneity is relative. Understanding relativity means accepting that the universe doesn't have a privileged perspective.

Small changes in initial conditions create vastly different outcomes in complex systems. This sensitive dependence—the butterfly effect—means long-term prediction is impossible even when rules are deterministic. The world is fundamentally non-linear, yet we study linear systems because they're mathematically tractable. This gap between our tools and reality has consequences.