Markets have opinions. Experts have opinions. Headlines, trends and best practices are opinions. The conservation of energy is not an opinion. Neither is gravity, thermodynamics, or the fact that kinetic energy grows with the square of speed.
UsePhysics exists for one purpose: to help ordinary people and businesses make better decisions by computing them instead of guessing them. Not another educational website — an engine that takes the most reliable knowledge humanity has ever produced and points it at your electricity bill, your commute, your household, your company.
What that looks like in practice
A parent running a household is managing heat flows, levers and friction all day — and the family energy bill is a physics equation with a price tag. An operator running a business is managing flow through bottlenecks and friction in funnels. A country entering the AI age is managing the conversion of energy into intelligence — and thermodynamics, uniquely among constraints, cannot be engineered around.
Every tool on this site follows the same pattern: solve the equation, then show what it means in your life. The calculator gives you the number; the page tells you what the number is worth.
The rules we follow
First principles only. Every claim traces back to a law of nature, not a convention. Numbers over vibes. If it can be computed, we compute it. Honest limits. Our calculators state their assumptions (no air resistance, ideal conditions) because a number without its assumptions is an opinion in disguise.
Start anywhere: the calculators if you have a number to find, or the applied guides if you want to see how deep the physics of ordinary life goes.