Paper on light quanta – In an earlier study [Einstein, 1904], Einstein applied statistical methods—normally used for gases—to the behavior of light and found a conflict between its wave description and his results. To resolve this, he built on Planck’s earlier work [Planck, 1901] and made the bold assertion that light consists of discrete energy packets, or “light quanta” [Einstein, 1905a], an idea that defied convention but became a cornerstone of quantum physics.

Doctoral thesis on atomic structure – According to Banesh Hoffmann [Hoffmann, p. 55], Einstein conceived his doctoral thesis [Einstein, 1905b] while watching lumps of sugar dissolve in tea. As noted in [Isaacson-1], when Professor Kleiner deemed the thesis too short, Einstein added a single sentence and it was accepted. Though the original manuscript was dedicated to “My Friend Marcel Grossmann,” that line was omitted when the work was published later in Annalen der Physik.

Paper on Brownian motion – The idea behind Einstein’s Brownian motion paper [Einstein, 1905c] may have been inspired while he was observing the swirling randomness of smoke clouds from his pipe [Hoffmann, p. 57]. His explanation of Brownian motion offered crucial evidence for the existence of atoms, which at the time was still not universally accepted.

Epiphany on relativity – The story that Einstein had a sudden revelation upon waking up one morning—where the key insight into special relativity fell into place effortlessly—is described by Banesh Hoffmann in [Hoffmann, p. 69]. After years of bafflement, the pieces of the puzzle reportedly came together as he sat up in bed. In the novel, this moment is dramatized with the addition of a fictional dream sequence leading into his awakening insight.

“Without even saying hello” – In a talk given many years later in Kyoto [Einstein, 1922], Einstein recalled how he blurted out to Michele Besso when meeting him one morning: “Thank you. I’ve completely solved the problem,” without even saying hello. He went on to say: “Time cannot be absolutely defined, and there is an inseparable relation between time and signal velocity.” This turning point, also referenced in [Fölsing, p. 177] and [Isaacson-1, p. 122], marked a key breakthrough on the path to special relativity.

“Moving train” thought experiment – One of Einstein’s favorite ways to explain the relativity of simultaneity involved imagining an observer on a moving train and another standing on the platform [Einstein-1]. In the novel, he shares a version of this thought experiment with Besso, although Besso, being well-versed in physics, may not have required such a simplified explanation as is presented here for the benefit of the lay reader.

Olympia Academy – During the Bern years, Einstein and two friends, Maurice Solovine and Conrad Habicht, formed an informal reading group they jokingly called the “Olympia Academy.” They gathered to discuss philosophy, science, and literature, with spirited debates that helped refine Einstein’s emerging theories. See [Clark], [Isaacson-1].

Letter to Habicht on first four Miracle Year papers – In a now-famous letter to his friend Habicht written between May and September 1905 [L-Einstein, 1905a], Einstein casually outlined the four revolutionary papers he was working on—light quanta, molecular dimensions, Brownian motion, and special relativity [Isaacson-1]. His tone was remarkably understated, given the groundbreaking nature of his work.

Paper on special relativity – Einstein’s landmark paper with the famous title “On the Electrodynamics of Moving Bodies” was published in Annalen der Physik in September 1905 [Einstein, 1905d]. It introduced the special theory of relativity, showing that the laws of physics are the same for all observers in uniform motion and that the speed of light is constant regardless of the motion of the source or observer—without requiring the concept of a “luminiferous ether.”