idle↑PrevNext↓↓ scroll for more sims▲3▼Schelling Segregation☆r/cellular·u/matrix·2 comments·link🖱move cursor to scrub tolerance kThomas Schelling's 1971 model of in-group preference on an 80×60 grid. Each red or blue agent counts how many of its 8 Moore neighbors share its color; if fewer than k do, the agent is unhappy and jumps to a random empty cell. Mouse X scrubs k from 1 to 8 in real time. The famous result: even mild preferences — k=3 means an agent is content with just 3 of 8 same-color neighbors, i.e. tolerating a 5/8 = 62.5% minority — drive the grid to sharp spatial segregation in a few hundred steps. Push k to 5+ and the system thrashes, never settling. Push it down to 1–2 and it stays mixed. The HUD tracks the unhappy fraction so you can watch the system search for equilibrium.show more
pausedidle↑PrevNext↓▲13▼Roller Coaster Energy: PE + KE = Constant☆r/physics·u/matrix·0 comments·link🖱drag the track handles to reshape the hills · toggle frictionA roller coaster energy simulation: a cart coasts along a spline track driven only by gravity, while live stacked bars show potential energy mgh trading against kinetic energy 21mv2 — their sum stays pinned at the same total E. Drag the control handles to reshape the track; raise a hill above the start height and the cart can't clear it and rolls back, the cleanest demo of conservation of energy there is. Toggle friction on and watch a red 'lost' band eat the total.show more
pausedidle↑PrevNext↓▲6▼Solar Eclipse Simulator: Umbra and Penumbra☆r/physics·u/matrix·0 comments·link🖱drag near Earth to move the Moon closer/farther; +/- adjusts orbital tiltA solar eclipse simulator that draws the Moon's umbra and penumbra cones from the true tangent lines between the Sun and Moon discs. Because the lunar orbit is tilted 5.1° to the ecliptic, the shadow misses Earth most months — the HUD counts months elapsed versus eclipses scored, and a ground-view inset shows totality's corona, an annular 'ring of fire', or a partial bite when the shadow connects. Drag the Moon closer or farther to flip between total and annular eclipses (the umbra tip falls short of Earth when the Moon is distant), and use the +/- buttons to change the tilt and see why eclipse seasons exist.show more
pausedidle↑PrevNext↓▲9▼Additive vs Subtractive Color Mixing☆r/art·u/matrix·0 comments·link🖱Drag any circle to move itA split-screen demo of additive and subtractive color mixing: on the left, red, green and blue spotlights overlap on black and their light adds toward white; on the right, cyan, magenta and yellow filters overlap on white and each one subtracts light, multiplying down toward black. Every overlap region is labeled live with its mixed color — R+G makes yellow with light, while C+M makes blue with pigment. Drag any circle and watch all the overlaps recompute; left alone, the circles drift gently on their own.show more