Learn physics from first principles
In-depth articles written by working physicists. Every guide starts with the physical intuition โ the ‘why’ โ before the mathematics.
All Articles
Every article, organised by topic
Newton’s Laws of Motion โ The Complete Guide
Inertia, F = ma, and action-reaction pairs. The three laws that built all of classical mechanics, explained from first principles.
Conservation of Momentum โ Every Collision Explained
Why momentum is conserved, elastic vs inelastic collisions, centre of mass, and worked examples showing the principle in action.
Projectile Motion โ Range, Height, Time of Flight
All the equations with worked examples. Why 45ยฐ maximises range, and the most common exam mistakes corrected.
What Is Energy? Kinetic, Potential & Conservation
The most fundamental concept in all of physics. Why energy conservation is the deepest truth we know, explained clearly.
The First Law of Thermodynamics โ Energy, Heat & Work
How heat and work relate to internal energy. The mathematical statement and what it means physically โ with clear worked examples.
Kinetic Theory of Gases โ How Molecules Create Pressure
Why gases have pressure and temperature. The molecular model that connects microscopic motion to macroscopic properties.
Wave Speed, Frequency & Wavelength โ v = fฮป Explained
The universal wave equation from first principles. From sound waves to light โ worked examples and the Doppler effect.
Newton’s Law of Universal Gravitation Explained
Why every mass attracts every other mass, how the inverse-square law emerges, and what it means for orbits and tides.
Why Is Projectile Motion a Parabola?
The mathematical proof that any object thrown under gravity traces a perfect parabola โ and the physics behind why it must.