HARAKU vs Wave Simulator Lab by CS

HARAKU is an interactive educational app that visualizes the physics of waves in real time. Designed for students, teachers and anyone curious about science, it lets you control how waves behave just by moving sliders, so you can intuitively connect the equations with what you see. Developer: Fuji Bit Inc. HARAKU is the waves edition of the "-raku" physics simulation series. It helps you understand the wave concepts taught in middle school, high school and university physics as moving pictures, not just formulas. 12 simulations in 3 categories: - Wave basics - Superposition: Combine two sine waves and watch them reinforce or cancel. Change the amplitude, frequency and phase of each wave independently to see the principle of superposition. - Reflection: See the moment a traveling wave reflects at a boundary. Switch between a fixed end (phase inverts) and a free end (phase is kept), with the incident, reflected and total waves shown in three layers. - Standing waves: Watch standing waves on a string fixed at both ends while changing the harmonic. Check the positions of nodes and antinodes and the effect of tension and damping. - Fourier synthesis: See how square, triangle and sawtooth waves are made of sine waves (harmonics). The more terms you add, the closer the sum gets to the target waveform. - Sound waves - Beats: Overlap two waves with slightly different frequencies and feel the beats. The envelope clearly shows how the amplitude changes. - Doppler effect: Drag the source and see the wavefronts bunch up in front and spread out behind. Go past Mach 1 to create a shock wave. - Air column resonance (new): Switch between closed and open pipes and change the length, air temperature and resonance number to see the resonant frequency and wavelength. The motion of air particles (a longitudinal wave) is shown next to a graph that draws the displacement as a transverse wave, so you can find the nodes and antinodes. - Waves in a plane & light - 2D ripples: Tap the screen to place sources; a numerical solution of the wave equation draws the interference pattern in real time. - Interference: See the lines of reinforcement and cancellation made by two point sources. The fringe spacing changes with the source separation, frequency and speed. - Diffraction: See waves spread through a slit according to Huygens' principle. The ratio of slit width to wavelength changes how strongly they diffract. - Refraction: Visualize Snell's law, including how waves bend at a boundary and total internal reflection at large angles. - Thin-film interference (new): See why soap films and oil slicks shine in color by changing the film thickness, refractive index, angle and what lies below (air or glass). The phase shift on reflection, the color seen under white light, a color-vs-thickness strip and a reflectance-vs-wavelength graph are shown together. Features: - Clean, easy-to-read design (dark and light themes) - Home screen organized by category - Intuitive parameter sliders: touch, try and understand - An explanation sheet with formulas for every simulation - On iPad in landscape, the canvas and control panel are shown side by side - 16 languages (Japanese, English, Chinese Simplified/Traditional, Korean, Spanish, Portuguese (Brazil), German, French, Hindi, Indonesian, Russian, Italian, Turkish, Thai, Vietnamese), following your device language - No sign-in: start exploring right away Price: - Free - In-app purchases: none - Subscriptions: none - Ads: a banner ad by Pangle at the bottom of the screen

Wave Simulator Lab is a beautifully designed, hands-on physics simulator for students, teachers, and curious learners. Slide the controls and instantly see how frequency, amplitude, and wavelength shape a wave — no math headaches, no equipment, just pure visual understanding. From a single sine wave to interference patterns, standing waves, damped oscillations, and real audible tones — every feature is paired with clear explanations, interactive controls, and ready-to-share visuals. Built for classrooms, study sessions, and after-school curiosity. WHY LEARNERS LOVE IT • See physics, don't just read it — every parameter updates the wave instantly • Friendly UI built for touch, with smooth animations at 60 fps • Clear, jargon-free explanations next to every concept • Quiz pack with answers explained, so mistakes turn into lessons • Designed for iPhone and iPad, light & dark mode supported FREE FEATURES • Real-time animated sine wave • Frequency, amplitude, and wavelength sliders • Automatic wave speed and period calculation • Play / pause / reset controls • Grid and axis toggles • Light, dark, and themed appearances • Basic learning library • Quiz pack with explanations UNLOCK ALL FEATURES (one-time purchase) • Remove all ads forever • All wave types — cosine, square, triangle, sawtooth, pulse, standing, damped • Compare two waves on one graph • Interference & superposition mode • Standing wave & damped wave modes • Sound wave tone generator (hear what you see) • Advanced measurement tools (ω, k, T, v) • Export wave images to share with classmates or teachers • Save unlimited custom presets • Full learn library + full quiz library • Extra themes (Space Wave, Graph Paper, and more) GREAT FOR • High school & university physics students • STEM teachers preparing live classroom demos • Homeschool families exploring science visually • Sound engineers and curious tinkerers • Anyone who wants to finally "get" waves NO SUBSCRIPTIONS. Pay once, keep forever. All your presets and preferences live safely on your device. Made with love for science classrooms and self-learners everywhere.