This introduction covers Why a Straw Looks Bent in Water within Reflection & Refraction for GCSE Physics. Revise Reflection & Refraction in Waves for GCSE Physics with 15 exam-style questions and 15 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 1 of 13 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 1 of 13
Practice
15 questions
Recall
15 flashcards
📖 Why a Straw Looks Bent in Water
Drop a straw into a glass of water and it appears to bend at the surface. Nothing has physically bent — what changed is the speed of light. Light travels more slowly in water than in air, so when it crosses the boundary at an angle, it changes direction. This is refraction, and it explains rainbows, lenses, fibre-optic internet cables, and why swimming pools look shallower than they are. Understanding how waves change direction at boundaries is fundamental to almost all optical technology!