Ransacking of Einstein’s cottage – After Einstein left Germany in 1933, Nazi agents raided and ransacked his cherished cottage in Caputh. They confiscated his sailboat and left the home in ruins—a symbolic act of hatred against everything Einstein represented. News of the attack made it clear to Einstein that there was no future for him in Germany [Isaacson-1].

Einstein’s quote engraved at Princeton – Upon joining the newly formed Institute for Advanced Study (IAS) in Princeton, Einstein’s famous saying “Subtle is the Lord, but malicious He is not” was later engraved into the marble above the fireplace in the IAS common room. The phrase, reflecting Einstein’s belief in an underlying order in the universe, had first been uttered by him during his 1921 visit to Princeton and became iconic [Isaacson-1]. (See also Chapter 12 notes on Princeton.)

Einstein’s first day at Princeton – Einstein’s arrival at Princeton in October 1933 was met with quiet excitement—and unavoidable publicity. Although he tried to keep a low profile, he could not escape the spotlight. Among his first acts was to buy a newspaper, only to find headlines speculating about his own whereabouts. Seeking some normalcy, he wandered into a local ice cream parlor and bought a cone, but even this simple outing caused a stir; he was simply too famous to remain unnoticed [Isaacson-1].

Einstein’s letter to FDR – Alarmed by the possibility that Nazi Germany might develop an atomic bomb, Einstein signed a letter drafted by physicist Leo Szilard and sent it to President Franklin D. Roosevelt on August 2, 1939 [L-Einstein, 1939]. The letter urged urgent U.S. action to investigate nuclear chain reactions and ultimately led to the establishment of the Manhattan Project. FDR acknowledged the letter and thanked Einstein [L-FDR, 1939]. It was one of the few times Einstein directly intervened in world affairs—an action he later deeply regretted.

The EPR paper – In 1935, Einstein, together with Boris Podolsky and Nathan Rosen, published a landmark paper [Einstein, 1935], often called the “EPR paper,” challenging the completeness of quantum mechanics. They introduced the concept of “spooky action at a distance” to highlight what they saw as troubling paradoxes in quantum entanglement—a phenomenon that Einstein never fully accepted, but which became foundational for modern quantum theory. Bohr’s famous rebuttal to the EPR paper based on the principle of ‘complementarity’ was published later that same year [Bohr, 1935].

Schrödinger’s Cat – Later that same year, Erwin Schrödinger published a thought experiment [Schrödinger, 1935] now famously known as “Schrödinger’s Cat.” Designed to illustrate the absurdity of applying quantum superposition to everyday objects, the cat paradox complemented Einstein’s critiques of quantum mechanics. Both men, though from different angles, highlighted the philosophical tensions at the heart of the emerging quantum worldview.

Paper on stimulated emission (early laser concept) – In 1917, Einstein published a paper titled The Quantum Theory of Radiation [Einstein, 1917], where he introduced the concept of stimulated emission—the idea that an incoming photon could trigger an excited atom to release another photon of identical energy and direction. This theoretical insight, though largely overlooked at the time, would decades later become the foundation for the invention of the laser nearly forty years later [Isaacson-1].

Collaboration with Satyendra Nath Bose – In 1924, Indian physicist Satyendra Nath Bose sent Einstein a groundbreaking paper on the statistical behavior of particles after it had been rejected by leading journals. Recognizing its originality, Einstein immediately responded [L-Einstein, 1924c], helped get it published [Bose, 1924], and expanded the work into what became known as Bose–Einstein statistics [Hoffmann], [Crease, 2024]. This collaboration laid the foundation for the later discovery of the Bose–Einstein condensate, for which the 2001 Nobel Prize in Physics was awarded [W-Nobel-Physics-2001].

Feynman on quantum mechanics – The celebrated Caltech physicist Richard Feynman famously quipped, “If you think you understand quantum mechanics, you don’t understand quantum mechanics” [W-Feynman-Q]. A paraphrased version of the quote appears in the novel.