[论文解读] Reconstruction of vertical and L-shaped ancient Egyptian sundials and methods for measuring time

Larisa Vodolazhskaya|arXiv (Cornell University)|Aug 4, 2014

Historical and Architectural Studies参考文献 9被引用 3

一句话总结

本文利用天文方法重建了垂直式与L形古埃及日晷，提出一种带有倾斜表杆、按纬度校准并标记等时区间的模型。该研究提出了一种精确测量时间的方法，通过考虑12:00–12:30期间半小时的位移，解决了塞提一世墓中铭文的歧义，实现了对缺失垂直日晷刻度的准确解读。

ABSTRACT

The article presents the results of the study of design features of vertical and L-shaped ancient Egyptian sundials. With the help of astronomical methods were developed their models, based on which the reconstruction of a sundial was held. Also, the original scheme is a simple way to fairly precise of measurement of time with them has been developed. Large urgency of the task due to the lack of similar models and schemes to date. Model offered by us, which describes the vertical sundial, is a vertical sundial, with a sloping gnomon, which takes into account latitude of area. It is based on the assumption of the existence in ancient Egypt representations about an hour (and a half hour) of equal duration throughout the day, does not depend on the time of year. Offered by us model is characterized by marking hour lines from 6 to 12 hours after each hour. From 12 to 12.5 hours produced displacement in the markup of hour lines on half an hour, then the markup is repeated every hour. As a consequence, the reconstruction of the vertical sundials, we have developed and proposed a model that describes the design features and operation of the L-shaped sundials of two types. They had to work together with the inclined gnomon, like vertical sundials or directly with vertical sundials. In this case, L-shaped sundials can complement vertical sundials, providing an opportunity to read the caption to hour markers and interpret the indications of vertical sundials because vertical sundials inscription missing. The article also describes explanation of the inscriptions from the tomb of Seti I, long intriguing researchers. It is proved that the inscription contains the length of the intervals between adjacent markers L-shaped sundial of the second type, where the first interval corresponds to a half of hour. Keywords: sundial, model, astronomical methods, archaeoastronomy, ancient Egypt.

研究动机与目标

• 解决古埃及垂直式与L形日晷缺乏准确模型与测量方案的问题。
• 基于天文原理与已知考古遗存，重建功能性设计。
• 开发一种实用方法，利用此类日晷实现高精度时间测量。
• 解读塞提一世墓中铭文，特别是与L形日晷时间间隔相关的内容。
• 展示L形日晷如何通过提供缺失的小时标记参考，补充垂直日晷的功能。

提出的方法

• 应用天文方法，基于古埃及的纬度，模拟表杆的朝向与投影阴影。
• 设计一种带有倾斜表杆的垂直日晷模型，通过考虑观测者纬度，确保阴影准确对齐。
• 建立从6点至12点的小时线标记系统，其中12:00–12:30之间存在半小时位移，之后每小时重复一次。
• 提出一种双功能L形日晷模型，可独立使用，亦可与垂直日晷配合使用。
• 以塞提一世墓中的铭文为关键参考，验证第二种L形日晷上小时标记之间的间隔长度。
• 对模型进行校准，使第一个间隔对应半小时，从而实现在全天范围内的一致时间测量。

实验结果

研究问题

• RQ1 如何利用天文原理准确重建古埃及的垂直式与L形日晷？
• RQ2 哪些设计特征使古埃及人能够以相等的小时长度测量时间，而不受季节影响？
• RQ3 塞提一世墓中的铭文如何与L形日晷上的时间间隔相关联？
• RQ4 L形日晷在解读垂直日晷上缺失或模糊的刻度时，发挥何种作用？
• RQ5 第二种L形日晷的第一个间隔具有何种意义？它如何与计时系统保持一致？

主要发现

• 所提出的垂直日晷模型包含按纬度校准的倾斜表杆，可实现准确的阴影投射与时间测量。
• 小时线从6点标记至12点，12:00至12:30之间存在半小时位移，之后为规则的每小时标记。
• 第二种L形日晷模型的第一个间隔对应半小时，与塞提一世墓铭文数据一致。
• 重建结果表明，古埃及人很可能全年使用等长小时，不受季节性日照变化影响。
• L形日晷可作为参考工具，用于解码垂直日晷上缺失或不完整的刻度。
• 塞提一世墓中的铭文被证实代表L形日晷上的时间间隔，长期存在的解释歧义得以解决。