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V · Physics & hardware limits

Speed of light

What it is

c ≈ 3 × 10⁸ m/s in vacuum, ~2 × 10⁸ m/s in fibre (refractive index ~1.5).

Where it lives

Cross-region replication latency, CDN edge placement, the floor under network round-trips.

The key insight

New York to London round-trip: ~56 ms minimum, just from light travel time. No protocol can beat this.

More in Physics & hardware limits

Memory hierarchy L1 ≈ 1 ns, L2 ≈ 4 ns, L3 ≈ 12 ns, RAM ≈ 100 ns, NVMe ≈ 100 µs, network… Landauer principle Erasing one bit of information dissipates at least kT·ln(2) joules of … Amdahl's law Speedup = 1 / (s + p/N), where s is the serial fraction. Maximum speed…

Across the foundations

VI One-way functions Cryptographic foundations VI Discrete log Cryptographic foundations VI Birthday attack Cryptographic foundations VI AEAD Cryptographic foundations VII P vs NP Computational complexity VII NP-completeness Computational complexity VII Approximation algorithms Computational complexity VII Reductions Computational complexity

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