Visual explanations
The picture that makes it click.
Short, visual answers to the puzzles from our Reels: bet, move one thing, see why.
Geometry & puzzles
Visual explanations
Each one takes about 90 seconds. New ones arrive as the Reels do.
90-second ahaThe ant, the mug and the honeyAn ant at the bottom of a mug wants the honey on the rim, on the opposite side. The mug is 10 cm tall and 8 cm wide. Which crawl is shortest?→90-second ahaWhy Chicago to Delhi flies over the poleOn a flat map, Chicago to Delhi is a straight line across the Atlantic. Real flights head north, over Greenland. Why?→90-second ahaThe half-height cone glassA cocktail glass is a cone. The bartender fills it to exactly half its height. Is it half full?→Visual proofSee AM-GM Inside a SemicircleMove the split point in a semicircle and compare the geometric mean with the arithmetic mean. See why equality happens only at a=b.→PlayParadox LabMonty Hall, birthdays, checkout lines: bet first, then run 100,000 trials.→
For students
Visual Calculus track
15 interactive lessons on limits, derivatives and integrals. See the guided path →
- How to Read a Function Graph
- Approaching a Point vs Being at the Point
- A Limit Is Where Nearby Values Are Heading
- Slope Is a Number That Describes Direction
- Limit Definition of the Derivative: Secant to Tangent
- Accumulation Is a Running Total
- Removable Discontinuity: Definition, Graph Hole & Limit
- Horizontal Asymptote: Rules, Graphs & Limits at Infinity
- Small Angle Approximation: Why sin(x)/x Approaches 1
- Squeeze Theorem: Definition, Visual Example & How It Works
- Tangent Line at a Point: Derivative as Slope
- Chain Rule: Formula, Visual Meaning & Worked Examples
- Accumulation Function: Area That Becomes a Function
- Improper Integral: Infinite Interval, Finite Area
- Fundamental Theorem of Calculus: Part 1, Part 2 & Visual Meaning