Tofte Simulators
Science you can play with, in the browser. Every one runs on our own physics engine and shows its working.
GamesSand LabPour, burn, melt and mix metals, gases, acids and catalysts, wire up a battery, and set off real reactions.
GamesBoiler RoomRun a GregTech steam boiler by its own rules: feed the fire, keep the water up, and never water it once it has boiled dry.
GamesSurfCounter-Strike: Source surf on Source's own movement rules: strafe and turn together to gain speed on ramps too steep to stand on, on nineteen courses: zigzags, technical ones that switch faces and dive and climb, two tunnel courses with a tunnel over every ramp between the start and the last, long ones with the speed limit raised so you can go flat out, nine out in space, one spiralling down round a black hole, and Wormhole, with short technical ramps, tunnels you enter through swirling portals, two loops and burn rings that take the ghost past 10,000 units a second.
GamesWingsuitJump off a cliff in a wingsuit that glides 2.5 to 1, fly a valley through its rings and low over the trees, and open your canopy in time to land in the meadow. Five lines, among them one that falls away 1 in 2, a slot canyon about 110 m across, and a winding valley whose middle swings across 450 m as it bends one way and the other.
GamesFrisbee GolfNine holes on four real disc golf discs' own aerodynamics. Pick a disc, set the hyzer, and watch it turn and fade.
GamesLong RangeSteel plates out to 1,500 yards. Read the wind off the flags, dial the scope, and the bullet flies its real path.
GamesSiegeFive sieges with a trebuchet, an onager, a ballista and a bombard. The arm swings, the stone flies and the castle falls block by block, all solved, nothing scripted.
GamesLittle RocketBuild a rocket from a few parts, launch it off a made-up planet, and try to stay in orbit.
GamesOrbit GolfDrag back, let go, and every planet on the board pulls on the ball the whole way. Sixteen levels.
GamesPhysics PlaygroundTen toys, from a throw with and without air to a moon on three solvers, each with a meter that says whether to believe it.
GamesGame RopeA rope made of a handful of points and one rule. See how stiff the solver lets it be.
GamesFoucault's PendulumWatch the Earth turn under a pendulum, and the half millimetre that can fake it.
GamesArchimedes' PulleyCan any force move any weight? Stack up pulleys, add friction, and find out.
GamesPhysics ExperimentsRace beads down a straight line, an arc and a cycloid, or draw your own wire. Let beads go anywhere in a cycloid bowl and watch them arrive together. Let go of a hanging slinky and watch its bottom wait.
GamesPhysics in 3DSpin a top fast and it stands, slow and it falls. Roll a marble on a spinning record and it circles back to where it started. Watch a spring trade its bounce for a twist, and a T-handle flip itself over in space.
GamesPhysics TricksShake a pendulum fast enough and it balances upside down. Lift two balls of a Newton's cradle and two fly out. Throw a superball under a table and it comes back to your hand.
GamesDesk PhysicsStack sticky-note pads so the top one hangs wholly past the desk. Race a battery against a roll of tape. Pull paper from under a mug. Hear why a spinning coin whirrs faster as it settles. Every slider is something you can measure, so your phone's slow motion can check it.
CircuitsCircuit BenchBuild GregTech's first circuits part by part, on TerraFirmaGreg's own assembly lines.
CircuitsMachine HallRun the parts through the machines and watch each one work, from silicon to crystal chips.
CircuitsSand to SandboxClimb the circuit tiers one rung at a time, from sand to sandbox.
Space flightShip RaceEvery version of the fusion ship, and yours, drawn to its own size, launched and raced.
Space flightAir BrakePut a heat shield on the ship and let Mars's air do the braking.
Space flightThe Whole VoyageThe best version of the ship, drawn two ways: as the engine would build it, and as a film would.
Space flightSun DiveFall to 2.2 solar radii and burn at the bottom of the fall.
Space flightThe Sun as a TelescopeFly out to the line, 548 AU away, where the Sun's gravity focuses starlight.
Space flightThe Nearest StarFly the fusion ship to Proxima Centauri: five centuries to fly past, seven to stop.
Space flightThe ExplorerThe ship on the black hole drive, flown past everything as fast as it goes, and its door home.
Space flightWormhole StationsPut a station at every star within 12 light years and see whether you built a time machine.
Space flightClosest ApproachSample an asteroid's close pass, then refine it, and see why the closest sample is not the closest approach.
Space flightFusion NozzleDrag the one unmeasured number the nozzle's mass hangs on and watch it swallow the ship.
Black holesBlack Hole DrivePick how long it burns and how hot its shell may run, and see what the hole weighs and gives off.
Black holesA Black Hole From LightPick a mass and see the pulse of light it would take to make it.
Black holesA Black Hole From AnythingPick what the energy arrives as and how heavy the hole is, and see where the wall is.
Black holesThe Edges of the MapTake a black hole from the Planck mass to a trillion Suns, and from no spin to almost all it can have.
Black holesLight Between Two Black HolesAim a ray between two black holes and zoom in on the fractal where its fate changes.
Water, air and heatStrange WaterWaves that catch each other up into one rogue wave. A ship's wake that keeps the same angle at any speed, until the boat goes fast. Two waves that pass straight through each other. Water that jumps up and stands still.
Water, air and heatWhere the Water BoilsSpeed a shape up through water and find where the water starts to boil on it.
Water, air and heatHot Water, Cold WaterTwo cups in a freezer. Switch on the reasons the hot one might win.
Water, air and heatRain on a SlopeRain on a slope, and the point where the model stops answering.
Water, air and heatWhere the Water GoesShape some ground, rain on it, and watch where the water decides to be.
Water, air and heatSlippery ShapesA panel method and a boundary layer, solved live in your browser.
Water, air and heatSteer the FlowSix bodies and a flow you can steer, traced through the real velocity field.
Water, air and heatStretch a VortexStretch a vortex toward a blowup and see what the real fluid does first.
Shapes and chanceOrder and ChaosA waterwheel that reverses at random, forever. Five metronomes that fall into step by themselves. Fifteen pendulums that scatter and line up again every 60 seconds. A jar where the biggest ball rises to the top.
Shapes and chanceOptical IllusionsTwo squares that are the same grey. Level lines that slope. Two bars that take turns at one speed. A wheel that turns backwards, and a green disc that is never drawn.
Shapes and chanceLight and RainbowsSunlight on a drop of water, followed ray by ray, paints a bow 40.6 to 42.3 degrees from the shadow of your head. Flatten the drop, make it glass, or send white light through a prism.
Shapes and chanceKlein Bottle HeatThe same rectangle glued two ways, heating and cooling side by side.
Shapes and chanceWalk a CircleWalk the same distance in every direction and measure the loop you made.
Shapes and chanceFlood a LandscapeFlood a random landscape and find the moment the puddles join up.
QuantumQuantum and Your PasswordsPick two numbers and see what a quantum computer does to the things you use.