longitude by lunar distances

简明释义

月角距求经度

英英释义

例句

1.In the 18th century, the British government offered a reward for anyone who could accurately calculate longitude by lunar distances at sea.

在18世纪，英国政府为任何能够准确计算海上月距经度的人提供奖励。

2.Navigators used to determine their position by calculating longitude by lunar distances, which is a method of finding out how far east or west they are from a reference point.

导航员曾通过计算月距经度来确定他们的位置，这是一种找出他们距离参考点有多远的东西或西方的方法。

3.The ancient mariners relied on longitude by lunar distances to avoid getting lost at sea during long voyages.

古代水手依靠月距经度在长途航行中避免迷失在海洋中。

4.With the invention of more accurate clocks, sailors could measure longitude by lunar distances more effectively.

随着更精确时钟的发明，水手们可以更有效地测量月距经度。

5.The method of calculating longitude by lunar distances was crucial for navigation before the advent of GPS technology.

在GPS技术出现之前，计算月距经度的方法对导航至关重要。

作文

The quest for accurate navigation has been a significant part of human history, particularly during the Age of Exploration. One of the most critical challenges faced by sailors was determining their position at sea, especially their longitude. Before the invention of precise timekeeping devices, mariners relied on various methods to calculate their location. Among these methods was the technique known as longitude by lunar distances, which played a crucial role in maritime navigation. This method involved measuring the angle between the moon and a specific star to determine the observer's longitude. To understand how longitude by lunar distances works, one must first grasp the concept of celestial navigation. Celestial navigation uses the positions of celestial bodies, such as the sun, moon, planets, and stars, to find one's location on Earth. The Earth is divided into degrees of latitude and longitude, with lines running horizontally (latitude) and vertically (longitude). While latitude can be determined relatively easily by observing the sun's position, calculating longitude has historically posed a greater challenge.The longitude by lunar distances method emerged in the 18th century and was based on the predictable movements of the moon. Sailors would use an instrument called a sextant to measure the angle between the moon and a fixed star at a specific time. By consulting tables that provided the moon's position at that time, navigators could calculate their longitude. This technique was particularly useful because the moon moves quickly across the sky, allowing for frequent measurements.Despite its effectiveness, longitude by lunar distances had its limitations. The method required precise timing and calculations, as well as a good understanding of astronomy. Additionally, the accuracy of the measurements could be affected by atmospheric conditions, such as clouds or fog, which could obscure the view of the moon or stars. As a result, many sailors found this method challenging to master.The introduction of marine chronometers in the 18th century revolutionized navigation by providing a reliable means of keeping time at sea. With a chronometer, sailors could compare the local time, determined by the sun's position, with the time of a reference point (usually Greenwich Mean Time). This advancement made it much easier to calculate longitude without relying solely on lunar distances. However, the longitude by lunar distances method remained an important tool for navigators, especially in situations where chronometers were unavailable or unreliable.In conclusion, the method of longitude by lunar distances represents a fascinating chapter in the history of navigation. It highlights the ingenuity of early navigators who sought to overcome the challenges of determining their position at sea. While modern technology has largely replaced this method, understanding its principles helps us appreciate the complexities of navigation and the advancements that have shaped our ability to explore the world. As we continue to navigate the oceans and skies, the legacy of techniques like longitude by lunar distances reminds us of the enduring human spirit of exploration and discovery.

准确导航的追求是人类历史上一个重要的部分，尤其是在探索时代。水手面临的一个关键挑战是确定他们在海上的位置，尤其是他们的经度。在精确计时设备发明之前，航海者依赖各种方法来计算他们的位置。其中一种方法就是被称为通过月球距离测定经度的技术，它在海洋导航中发挥了至关重要的作用。这种方法涉及测量月亮与特定星星之间的角度，以确定观察者的经度。要理解通过月球距离测定经度的工作原理，首先必须掌握天文导航的概念。天文导航利用天体（如太阳、月亮、行星和恒星）的位置信息来找到地球上的位置。地球被划分为纬度和经度的度数，水平线（纬度）和垂直线（经度）交错。虽然纬度可以通过观察太阳的位置相对容易地确定，但计算经度历来是一个更大的挑战。通过月球距离测定经度的方法出现在18世纪，并基于月亮的可预测运动。水手会使用一种叫做六分仪的仪器来测量月亮与固定星星之间的角度，时间要准确。通过查阅提供该时刻月亮位置的表格，导航员可以计算出他们的经度。这种技术特别有用，因为月亮在天空中快速移动，允许频繁的测量。尽管有效，通过月球距离测定经度也有其局限性。这种方法需要精确的计时和计算，以及对天文学的良好理解。此外，测量的准确性可能会受到气象条件的影响，例如云或雾，这可能会遮挡月亮或星星的视线。因此，许多水手发现这种方法难以掌握。18世纪海洋计时器的引入彻底改变了航海，通过提供可靠的海上计时手段，使得航海更为简便。借助计时器，水手可以将当地时间（由太阳的位置决定）与参考点的时间（通常是格林威治标准时间）进行比较。这一进步使得计算经度变得更加容易，而不再单纯依赖于月球距离。然而，通过月球距离测定经度的方法仍然是导航员的重要工具，尤其是在计时器不可用或不可靠的情况下。总之，通过月球距离测定经度的方法代表了导航史上的一个迷人篇章。它突显了早期航海者的智慧，他们努力克服在海上确定自己位置的挑战。虽然现代技术在很大程度上取代了这种方法，但理解其原理帮助我们欣赏导航的复杂性以及塑造我们探索世界能力的进步。在我们继续在海洋和天空中航行之际，像通过月球距离测定经度这样的技术的遗产提醒我们探索和发现的持久人类精神。