Subject 27 · Galilean & Special Relativity
Chapter 27
Galilean & Special Relativity
Start with Galilean frames and velocity addition, then follow Einstein's postulates into simultaneity, time dilation, Lorentz transformations, spacetime, and relativistic energy.
Build galilean & special relativity one idea at a time.
Start with the foundations, then explore advanced ideas and calculus at the depth your course needs.
6 of 6 lessons
Frames & Galilean Relativity
Use inertial frames and see why Maxwell's light broke classical addition.
The Postulates of Special Relativity
Understand the Michelson–Morley result and Einstein's two postulates.
Time Dilation & Length Contraction
Use proper time, proper length, gamma, and muon evidence.
Lorentz Transformations & Velocity Addition
Keep c invariant and combine high speeds correctly.
Spacetime Diagrams & the Twin Paradox
Read worldlines, light cones, invariant intervals, and changing frames.
Relativity Calculus
Differentiate for momentum and energy and integrate proper time.
Change one variable. Watch the physics respond.
Explore Δt = γΔτ, then take the idea into the full lessons.
Compare two clocks
Earth-frame elapsed time is γ times the traveller's proper time.
Everything around the chapter, in one place.
Keep building with practice, classroom presentations, formulae, and a game that puts these ideas to work.
Exam practice
Questions, guided reasoning, and exam-style problem solving.
Browse exam questions →Formula toolkit
Keep the key relationships and their units close to hand.
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View files →Gamma Run
γ = 1/√(1−v²/c²). Choose a relativistic speed that satisfies both Earth time and ship ageing limits.
Play the free chapter game →See it. Read it. Work it.
Connect diagrams to physical relationships and exam reasoning.
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Ask for a hint, check your reasoning, or explore a similar problem.
Ask GioAI →Key ideas to remember
Move without losing your place.
Extra challenging questions
Take the ideas further with course-specific extension questions, supplied-data graphs and worked solutions.