sidereal noon

简明释义

恒午(恒星时零点

英英释义

例句

1.The astronomer noted that the stars were at their highest point in the sky during sidereal noon.

天文学家注意到星星在天空中的最高点出现在恒星正午。

2.To accurately track celestial events, we must account for sidereal noon in our calculations.

为了准确跟踪天文事件，我们必须在计算中考虑恒星正午。

3.At sidereal noon, the position of the sun is not relevant to the stars' positions.

在恒星正午时，太阳的位置与星星的位置无关。

4.The telescope was calibrated to align with the sky at sidereal noon.

望远镜经过校准，以便在恒星正午时与天空对齐。

5.During sidereal noon, the Earth rotates enough to bring a different set of stars into view.

在恒星正午时，地球旋转足够使另一组星星进入视野。

作文

The concept of sidereal noon is fascinating and often overlooked in our daily lives. To understand this term, we first need to define what 'sidereal' means. In astronomy, 'sidereal' refers to the stars. Thus, sidereal noon is the time when the Sun is at its highest point in the sky, relative to the distant stars, rather than to the Earth. This moment occurs when the Sun crosses the local meridian, which is an imaginary line that runs from the North to South Pole through a given location on the Earth's surface. For most people, noon is simply the time when the Sun is at its zenith, which is commonly referred to as solar noon. However, due to the elliptical shape of the Earth's orbit and its axial tilt, solar noon does not occur at the same time every day. This discrepancy leads to the existence of sidereal noon. The difference between solar time and sidereal time can be attributed to the fact that the Earth not only revolves around the Sun but also rotates on its axis. To illustrate this further, let’s consider a practical example. Imagine standing outside at noon on a clear day, watching the Sun reach its highest point in the sky. This moment, known as solar noon, can vary significantly depending on the specific date and your geographical location. However, if you were to measure the position of the stars at that same moment, you would find that they do not align with the Sun's position. Instead, sidereal noon would occur approximately every 23 hours, 56 minutes, and 4 seconds, which is the time it takes for the Earth to complete one full rotation relative to the stars. Understanding sidereal noon is crucial for astronomers and navigators who rely on precise measurements of celestial bodies. For instance, when astronomers observe the night sky, they must account for the difference between solar time and sidereal time. Knowing when sidereal noon occurs allows them to accurately track the movement of stars and other celestial objects. Additionally, sidereal noon has practical applications in fields such as satellite communication and GPS technology. These systems require synchronization with the stars to ensure accurate positioning and timing. By understanding the concept of sidereal noon, engineers and scientists can improve the accuracy of these technologies, ultimately benefiting society as a whole. In conclusion, while sidereal noon may seem like a niche topic, its implications extend far beyond the realm of astronomy. It serves as a reminder of the intricate relationship between the Earth and the cosmos. By grasping the significance of sidereal noon, we can appreciate the complexity of timekeeping and navigation in our universe. As we continue to explore the stars and our place within them, concepts like sidereal noon will remain essential for unlocking the mysteries of the cosmos.

“恒星正午”的概念令人着迷，常常在我们的日常生活中被忽视。要理解这个术语，我们首先需要定义“恒星”是什么意思。在天文学中，“恒星”指的是星星。因此，恒星正午是指太阳相对于遥远的星星在天空中的最高点，而不是相对于地球。这一时刻发生在太阳穿过当地子午线的时候，子午线是从北极到南极穿过地球表面某个特定位置的想象线。对于大多数人来说，正午仅仅是指太阳在其顶点的时刻，通常被称为太阳正午。然而，由于地球轨道的椭圆形状和其轴倾斜，太阳正午并不是每天都在同一时间发生。这种差异导致了恒星正午的存在。太阳时间和恒星时间之间的差异可以归因于地球不仅围绕太阳旋转，还围绕其轴自转。为了进一步说明这一点，让我们考虑一个实际的例子。想象一下，在一个晴朗的日子里站在户外，观察太阳达到它在天空中的最高点。这个时刻，被称为太阳正午，可能会根据具体日期和你的地理位置而有显著变化。然而，如果你在同一时刻测量星星的位置，你会发现它们与太阳的位置并不对齐。相反，恒星正午大约每23小时56分钟和4秒发生一次，这就是地球相对于星星完成一次完整自转所需的时间。理解恒星正午对于依赖精确天体测量的天文学家和导航员至关重要。例如，当天文学家观察夜空时，他们必须考虑太阳时间和恒星时间之间的差异。知道何时发生恒星正午使他们能够准确追踪星星和其他天体的运动。此外，恒星正午在卫星通信和GPS技术等领域也具有实际应用。这些系统需要与星星同步以确保准确定位和计时。通过理解恒星正午的概念，工程师和科学家可以提高这些技术的准确性，最终使整个社会受益。总之，虽然恒星正午看似一个小众话题，但其影响远远超出了天文学的范围。它提醒我们地球与宇宙之间复杂的关系。通过掌握恒星正午的重要性，我们可以欣赏到时间计算和导航在我们宇宙中的复杂性。随着我们继续探索星星及其在我们宇宙中的位置，像恒星正午这样的概念将始终是解开宇宙奥秘的关键。