Astronomical Year in Westeros
In the world of Game of Thrones (popularly known as the 'World of Ice and Fire'), the measurement of time closely resembles Earth's. The night sky changes as Westeros orbits its sun, creating a predictable cycle that guides their understanding of time. Just like on Earth, the planet has an axial tilt believed to produce seasonal variations essential for an agrarian society.
Seasons and Agriculture
Throughout the series, we see that the people of Westeros rely heavily on agriculture, making the accurate estimation of seasons crucial. The Earth's axial tilt, which is tilted at approximately 23.5 degrees, ensures that different parts of the planet get more or less sunlight at different times, leading to the changing of seasons. Similarly, we can infer that Westeros has a similar axial tilt, ensuring that different parts of the continent experience varying levels of sunlight throughout the year.
Irregular Winters
The "Irregular Winters" with a capital 'W' present a different scenario. In the books, we witness winters of varying lengths, some lasting for several years. G.R.R.M. refers to this phenomenon as "magic," but it is worth considering other natural explanations. Volcanic eruptions that block sunlight can cause similar effects. For example, the "Year Without a Summer" and the "Little Ice Age" are historical phenomena where volcanic activity dramatically affected the climate.
The Long Summer
The decade-long summer observed after the Robert's Rebellion adds another layer of complexity to the climate in Westeros. During the summer in Westeros, the northern hemisphere experiences prolonged daylight, leading to a period of prosperity and growth. However, when the season ends, it plunges the continent into a harsh winter, driving the narrative tension and survival struggles that dominate the series.
Geographic and Magical Implications
For the people of Westeros, the irregular seasons mean that the length of a year is not strictly tied to a repetition of seasons but is rather determined by unpredictable celestial events. G.R.R.M. has hinted that the unusual climate is a result of magical influences, as revealed only at the end of the series. However, even without magical intervention, the climate could be influenced by astronomical factors such as the planet's orbit, axial tilt, and even periodic volcanic activity.
Theoretical Explanation
The most plausible explanation for the mysterious climate is that the world of Westeros revolves around a binary or tertiary star system. This solar arrangement would affect the planet's axis of rotation and introduce irregularities in the seasons. Additionally, the planet might have a wobbly or fluctuating axis of rotation. For instance, Earth's seasons are relatively consistent because its axis is relatively stable and slightly tilted at 23.5 degrees. If Westeros's axis wobbled or had significant tilt variations, it could result in prolonged winters and summers, as observed in the series.
It is important to note that the precise conditions of the world of Westeros exist solely to enhance the storytelling and do not adhere to literal astronomical rules. George R.R. Martin, in his creation, takes liberties with the physical laws to create a unique and engaging universe. Therefore, while the above explanation provides a theoretical framework, it is ultimately a creative element of the narrative rather than a scientifically accurate one.
In conclusion, the people of Westeros measure years based on a combination of observed celestial events, magical influences (as hinted by the author), and a complex interplay of atmospheric and astronomical factors. Despite the irregularities, their understanding of time and seasons is essential for their survival and the unfolding of their epic saga.