The Arcade

Interactive toys for the greatest unsolved problems, curious sequences, and beautiful structures in mathematics. Pick one. Play.

New · research.rondanini.com

Research Solver — Multi-Agent Frontier Problems

From playful undecidables to working AI: a multi-agent system attacking frontier research problems.

Open Research Solver →
🌀

Collatz Conjecture

Enter any number. Halve if even, triple-plus-one if odd. It always reaches 1 — but nobody can prove it.

Unsolved
🔗

Goldbach's Conjecture

Every even number > 2 is the sum of two primes. See the prime pairs arc across a number line.

Unsolved
🌀

Ulam Spiral

Plot integers on a spiral, highlight the primes. Mysterious diagonal lines appear from nowhere.

Prime Mystery
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Mandelbrot Set

The most famous fractal. Click to zoom infinitely deep. Endless complexity from z² + c.

Fractal
🎵

Recamán's Sequence

Jump forward or back — whichever hasn't been visited. The arcs paint themselves into art.

Curious
🐜

Langton's Ant

Two rules, one ant. 10,000 steps of chaos — then a highway emerges. Emergent order from nothing.

Automaton
👫

Twin Primes

Primes differing by 2 — (11,13), (41,43). Are there infinitely many? Watch them thin out.

Unsolved
🎲

Riemann & Primes

How many primes below x? Plot π(x) against its approximations. The $1M question lives here.

Millennium Prize
🔺

Pascal mod N

Color Pascal's triangle by remainder. Mod 2 = Sierpinski. Mod 3, 5, 7 = other fractals.

Fractal
🌊

Lorenz Attractor

The butterfly that started chaos theory. Two nearly identical points → wildly different futures.

Chaos
🧮

Busy Beaver

The hardest function in math. Watch Turing machine champions write as many 1s as possible before halting.

Uncomputable
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Rondanini Problem

Collatz meets the Halting Problem. A rigorous, original formulation that is provably undecidable.

Undecidable
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Rondanini Diophantine

One explicit polynomial in 16 variables. Pure integers, no machines. A named instance of Hilbert's 10th — provably undecidable.

Hilbert's 10th

Mirrane Geometry

Can one collection of polygons be cut and reassembled into another? Scissors, glue — and undecidability.

Geometry
⚛️

Mirrane Quantum

Predict a quantum measurement outcome above a threshold. Nature itself performs uncomputable processes.

Quantum
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Mirrane Chaos

Does this deterministic system enter a chaotic attractor? Even fully predictable equations can hide the uncomputable.

Dynamical Systems
🧭

Mirrane Topology

Is this triangulated space a sphere? In high dimensions, no algorithm can always tell you.

Topology
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Mirrane Alignment

Will this AI ever violate a safety rule? Rice's theorem says: no universal checker exists.

AI Safety
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Gallery of Impossible Questions

The complete Rondanini–Mirrane collection. Seven problems across six domains. All provably unsolvable.

The Collection
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The Human Wing

Nine paradoxes of being. Identity, meaning, regret, empathy, love — questions that live inside consciousness.

Human
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The Civilizational Wing

Six paradoxes of societies. Progress, values, collective will, culture — questions that emerge from coordination.

Civilization
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The Perception Wing

Six paradoxes of seeing. Representation, reality, illusion, silence — the space between seeing and knowing.

Perception

The Time Wing

Six paradoxes of temporality. The present, the arrow, impermanence, continuity — questions from inside the flow.

Time
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The Music Wing

Nine paradoxes of sound. Tuning, silence, resolution, authorship — the bridging exhibit that touches every wing.

Music