Greenwich hour angle mean sun

简明释义

格林尼治平太阳时角

英英释义

例句

1.To determine local solar time, one must adjust for the Greenwich hour angle mean sun.

为了确定地方太阳时间，必须调整格林威治时间角均值太阳。

2.The calculation of the position of celestial bodies often involves the Greenwich hour angle mean sun, which is crucial for navigation.

天体位置的计算通常涉及格林威治时间角均值太阳，这对于导航至关重要。

3.The Greenwich hour angle mean sun is essential for understanding solar eclipses and their timings.

理解日食及其时间的关键在于格林威治时间角均值太阳。

4.Sailors use the Greenwich hour angle mean sun to calculate their longitude while at sea.

水手们使用格林威治时间角均值太阳来计算他们在海上的经度。

5.In astronomy, the Greenwich hour angle mean sun helps astronomers track the movement of the sun across the sky.

在天文学中，格林威治时间角均值太阳帮助天文学家跟踪太阳在天空中的运动。

作文

The concept of the Greenwich hour angle mean sun is an essential aspect of celestial navigation and timekeeping. It refers to the angular measurement of the position of the mean sun relative to the Greenwich meridian, which is located at zero degrees longitude. Understanding this concept is crucial for astronomers, navigators, and anyone interested in the precise measurement of time based on the position of celestial bodies.The Greenwich hour angle mean sun is defined as the angle that measures the time difference between the mean sun and the observer's local meridian. This angle is expressed in degrees, where 360 degrees represents a full rotation of the Earth. As the Earth rotates, the position of the mean sun changes, and this change can be quantified using the Greenwich hour angle.To comprehend the significance of the Greenwich hour angle mean sun, one must first understand the concept of the mean sun itself. The mean sun is a theoretical construct that represents the average position of the sun over the course of a year. Unlike the actual sun, which moves irregularly due to the elliptical shape of the Earth's orbit, the mean sun provides a consistent reference point for timekeeping. This consistency is vital for navigation and for maintaining accurate time across different regions.In practical terms, the Greenwich hour angle mean sun allows navigators to determine their longitude by comparing the time of solar noon at their location with the time at the Greenwich meridian. By knowing the hour angle, navigators can calculate how far east or west they are from Greenwich. This calculation is fundamental for maritime navigation, especially before the advent of modern technology.Moreover, the Greenwich hour angle mean sun plays a crucial role in the development of time zones. The world is divided into 24 time zones, each corresponding to 15 degrees of longitude. This division is based on the Earth's rotation and the position of the mean sun. Therefore, understanding the hour angle helps in establishing local times in relation to Greenwich Mean Time (GMT), which is derived from the position of the mean sun at the Greenwich meridian.In addition to its practical applications, the Greenwich hour angle mean sun also has theoretical implications in the field of astronomy. It helps astronomers calculate the positions of stars and planets in the sky. By knowing the hour angle of celestial objects, astronomers can predict when these objects will be visible from a specific location on Earth. This predictive capability enhances our understanding of celestial mechanics and the movements of planetary bodies.In conclusion, the Greenwich hour angle mean sun is a fundamental concept that bridges the gap between timekeeping, navigation, and astronomy. Its significance extends beyond mere calculations; it is a critical tool that has shaped our understanding of time and space. As we continue to explore the universe, the principles behind the Greenwich hour angle mean sun will remain relevant, guiding us in our quest for knowledge about the cosmos and our place within it.

“格林威治时角平均太阳”是天文导航和计时的一个重要概念。它指的是相对于位于零度经线的格林威治子午线，平均太阳位置的角度测量。理解这一概念对天文学家、导航员以及任何对基于天体位置的时间精确测量感兴趣的人来说都是至关重要的。“格林威治时角平均太阳”被定义为测量平均太阳与观察者本地子午线之间的时间差的角度。这个角度以度数表示，其中360度代表地球的完整旋转。随着地球的自转，平均太阳的位置发生变化，这一变化可以通过格林威治时角进行量化。要理解“格林威治时角平均太阳”的重要性，首先必须了解平均太阳的概念。平均太阳是一个理论构造，代表了太阳在一年中的平均位置。与由于地球轨道的椭圆形状而不规则移动的实际太阳不同，平均太阳提供了一个一致的时间参考点。这种一致性对导航和在不同地区保持准确时间至关重要。在实际应用中，“格林威治时角平均太阳”使导航员能够通过比较他们所在位置的太阳正午时间与格林威治子午线的时间来确定他们的经度。通过知道时角，导航员可以计算出他们距离格林威治的东西方位置。这一计算对于海上导航至关重要，尤其是在现代技术出现之前。此外，“格林威治时角平均太阳”在时区的发展中也起着关键作用。世界被划分为24个时区，每个时区对应15度经度。这种划分是基于地球自转和平均太阳的位置。因此，理解时角有助于建立与格林威治标准时间（GMT）相关的当地时间，后者是根据平均太阳在格林威治子午线的位置得出的。除了其实际应用外，“格林威治时角平均太阳”在天文学领域也具有理论意义。它帮助天文学家计算天空中恒星和行星的位置。通过知道天体的时角，天文学家可以预测这些天体何时会在地球特定位置可见。这种预测能力增强了我们对天体力学和行星运动的理解。总之，“格林威治时角平均太阳”是一个基本概念，连接了计时、导航和天文学。它的重要性超越了简单的计算；它是一个关键工具，塑造了我们对时间和空间的理解。随着我们继续探索宇宙，围绕“格林威治时角平均太阳”的原则将保持相关，引导我们在追求关于宇宙及我们在其中位置的知识的过程中。