School Launch · See it move
Interactives
Thirty-six things to turn, slice, build and play with. Each one was made for a particular lesson, and each stands on its own: open it, drag the slider, and watch the idea work. Free, with nothing to install and no sign-in.
Take-apart machines
Seven 3D machines to turn, take apart and put back together. Tap or hover over any part for its name. From the Engineering courses.
Machine 1Pendulum Clock
A weight-driven clock, step by step: escapement, gear train and the swing that keeps time.
Take it apart →
Machine 2Mechanical Wristwatch
A spring-driven watch, step by step: mainspring, balance wheel and the hands.
Take it apart →
Machine 3Four-Stroke Engine
Intake, compression, power, exhaust: turn the crank and watch the piston and valves.
Take it apart →
Machine 4Bicycle Drivetrain
Pedals, chain and gears, and why a small cog at the back makes the hill easier.
Take it apart →
Machine 5Pin Tumbler Lock
Plug, pins and key: see what lines up when the right key goes in.
Take it apart →
Machine 6Gutenberg Printing Press
Screw, type and ink: the press that put a Bible in ordinary hands.
Take it apart →
Machine 7Steam Engine
Steam, beam and flywheel: how heat became motion and started the industrial age.
Take it apart →
Great structures
Seven famous structures to build up from the ground: how they stand, what they are made of and who built them.
Structure 1Pyramids of Giza
Build it up, stone by stone.
Build it up →
Structure 2Great Wall
Build it up, ridge by ridge.
Build it up →
Structure 3Eiffel Tower
Build it up, rivet by rivet.
Build it up →
Structure 4Tallest Skyscrapers
Build it up, floor by floor.
Build it up →
Structure 5Big Bridges
Build it up, cable by cable.
Build it up →
Structure 6Windmills
Build it up, brick by brick and sail by sail.
Build it up →
Structure 7Hydroelectric Dams
Build it up, column by column, then follow the water through the turbines.
Build it up →
Math & physics, step by step
Seventeen ideas that are hard to believe until you see them move. Each one is drawn honestly from the real equations, with sliders to pull and a numbered path through the idea.
Algebra IGrow the Spiral
Add the last two numbers, watch the Fibonacci squares and the spiral grow, and see the ratio close in on the golden number and the sunflower's seeds.
Open →
Algebra II · Pre-CalculusEvery Conic Is a Slice of One Cone
Cut a double cone with a flat plane and tilt it: circle, ellipse, parabola and hyperbola are all the same cut at different angles.
Open →
Pre-Algebra · GeometryTwo Honest Proofs of the Pythagorean Theorem
Slide four copies of one right triangle around a square and watch c² appear where a² and b² were, then a second proof to be sure.
Open →
GeometrySlice the Sphere
Where the 4/3 in a sphere's volume comes from, one slice at a time and with no calculus: Cavalieri's principle in 3D.
Open →
GeometryFlower Geometry
Design a flower with any number of petals, see the polygon and symmetry hiding in it, build the classic rosette with a compass, and count the petals on real flowers.
Open →
GeometryTwelve Pentagons
Spin balls made of pentagons and hexagons and see why every one has exactly 12 pentagons, from soccer balls and geodesic domes to the C₆₀ molecule.
Open →
Trigonometry · PhysicsCircles That Draw
Circles riding on circles, each turning at its own steady speed, and a pen at the end that traces almost any shape you like.
Open →
Trigonometry · Grades 10–12The Parallelogram Law
Bend a parallelogram and watch its two diagonals change, measured honestly with the distance formula, until the law shows itself in the table.
Open →
Physics · CalculusThe Fastest Way Down
Three beads race down a straight track, a circle and a cycloid. The shortest path is not the quickest, and the page shows why.
Open →
PhysicsQuantum Wave Packet
A free particle as a wave that spins, travels and spreads, drawn in 3D with its probability curve underneath.
Open →
Physics · ChemistryQuantum Explorer
Hydrogen orbitals, an electron tunneling through a barrier, the light an atom gives off and the true size of the atom, all computed from Schrödinger's equation.
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PhysicsSound and Waves Explorer
Sand that settles on the still lines of a ringing plate, and sound waves that pile up into a sonic boom at Mach 1, both computed from the physics.
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Physics · Earth ScienceHow Fast Are We Moving?
Find your speed on the spinning Earth, race it against Earth’s trip around the Sun, and see why rockets launch east to borrow the spin.
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Physics · Grades 5–12Newton’s Mountain
Fire a shot from a high mountain until it falls around the Earth, or leaves. Then see why a two-stage rocket gains more speed than one stage with the same tanks.
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Physics · Grades 8–12Energy Lab
Send a skater down a rough ramp, launch a ball with a spring, and compare two lifts. The bars show kinetic energy, height, spring energy, and heat.
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Earth Science · K–8Sun, Moon and Seasons
Tip the Earth and walk through a year, move the Moon to name its phase, and watch a stick’s shadow shrink at noon.
Open →
Boats · Chemistry · PhysicsArchimedes’ Tank
Test King Hiero’s crown, load a foil boat to the point it sinks, and paint a Plimsoll line on a ship.
Open →
Labs, tools & games
Things to build, practice and figure with. Each one belongs to a course but works on its own.
ElectronicsBreadboard Lab
Build six circuits one part at a time on a simulated breadboard and Uno-style board, from lighting an LED to a traffic light. Nothing here can break.
Open the lab →
HistoryLayered History Timeline
500 B.C. to A.D. 1800 on one zoomable page: empires, documents, events and people side by side, so you can see what overlapped.
Open the timeline →
MathGraphing Calculator
Type an equation in x, drag sliders for a, b and c, then zoom, pan and trace the curve. Built for the math courses.
Open the calculator →
Pre-AlgebraMochi Paws Sushi
A gentle cat sushi-shop game for fractions, decimals, integers, ratios, percents and equations. No timers, no lives, no sign-in.
Play →
Math · Grades 1–4Number Grid Tic-Tac-Toe
A hundreds chart with almost every number missing. Take turns writing the number that belongs and get four in a row, pass-and-play for two or three, with printable boards.
Play →
Real Estate InvestingDeal Analyzer
Four worksheets for judging a property the way careful small investors do: rental, house hack, BRRRR and fix-and-flip, with every result updating as you type.
Open the analyzer →
Recommended PhET sims
These open in a new tab. They are made by PhET Interactive Simulations, University of Colorado Boulder, and are free for a school to use under CC BY-NC 4.0. School Launch does not embed them. Each link below was checked as an HTML5 sim.
- Chemistry · Physics
Build an Atom
Protons, neutrons and electrons, and the charge and mass that follow.
Open at PhET → - Physics · Electronics
Circuit Construction Kit: DC
Wire series and parallel circuits and read the meters.
Open at PhET → - Physics
Energy Skate Park
A skater on a track: kinetic energy, potential energy and heat.
Open at PhET → - Physics · Earth Science
Gravity and Orbits
Sun, Earth and Moon, and what happens when you change a mass or a speed.
Open at PhET → - Chemistry · Physics
Density
Mass, volume and density, and which blocks float.
Open at PhET → - Physics
Buoyancy
What a submerged block pushes aside, and the force that lifts it.
Open at PhET → - Physics
Projectile Motion
Angle, speed and air resistance, and where the shot lands.
Open at PhET → - Physics
Pendulum Lab
Length, mass and gravity, and what actually changes the period.
Open at PhET → - Chemistry · Earth Science
States of Matter
Particles in a solid, a liquid and a gas as you heat or cool them.
Open at PhET → - Physics · Grades K–8
Forces and Motion: Basics
Pushes, friction and a tug of war, with the net force shown.
Open at PhET → - Physics
Collision Lab
One-dimensional and two-dimensional collisions, elastic or not.
Open at PhET →
Looking for the courses these come from? Every piece here is linked from the lesson that uses it. See all courses, or the machines and structures on their own page.