Substitution Cipher Puzzle

The phrase "the speed of light is constant in a vacuum" represents a foundational concept in modern physics, famously established by Albert Einstein. This principle, central to his theory of special relativity, asserts that light always travels at the same speed—approximately 299,792,458 meters per second—regardless of the motion of the observer or the light source. Einstein first postulated this revolutionary idea in 1905, fundamentally altering our understanding of space, time, and the cosmos.

Albert Einstein, a German-born theoretical physicist, developed many of his groundbreaking theories while working as a patent clerk. Beyond his scientific genius, Einstein was a passionate advocate for social justice, speaking out against racism and supporting humanitarian causes, having experienced life as a refugee himself. The puzzle you decrypted employed a substitution cipher, a fundamental method in cryptography where each letter in the original message is consistently replaced by a different letter or symbol.

This type of cipher has a long history, with early examples like the Caesar cipher, attributed to Julius Caesar around 50 B.C., used to secure military communications. While simple substitution ciphers served for centuries, a significant breakthrough in cryptanalysis occurred around 850 AD when Arab scholars developed frequency analysis, a technique that systematically breaks such codes by examining the commonality of letters.