√2 FROM DYADIC REFINEMENT

METRIC COMPLETION • A_p = max{a : a² ≤ 2·2^(2p)} • DIAGONAL OF UNIT SQUARE

√2 AT PRECISION p = 16 BITS
1.41421356...
actual √2 = 1.41421356237309504880168872420969...
PRECISION p
VIEW
THE DEFINITION
√M := lim(p→∞) A_p / 2^p

where:
A_p = max{ a ∈ Z≥0 : a² ≤ M·2^(2p) }
= floor(√M · 2^p)

For √2: M = 2
CERTIFIED BOUNDS
--- √2 < ---
Bracket width: 2^(-p)
CURRENT COMPUTATION
A_p (INTEGER)
92681
A_p²
---
2·2^(2p)
---
GAP
---
CONVERGENCE (BIT-BY-BIT)
pA_p√2 ≈ A_p/2^p
GEOMETRIC MEANING
Metric Completion:
• Squared distance d² is always integer
• d² = Δx² + Δy² + Δz² + ...
• Length = √(d²) needs sqrt!

√2 specifically:
• Diagonal of unit square
• √2 = √(1² + 1²)
• Bridges discrete → continuous
NEWTON'S METHOD (INTEGER)
// All operations are integer!
X_{n+1} = (X_n + M·2^(2p)/X_n) >> 1

Converges in O(log p) iterations
Each iteration doubles correct bits