apparent diameter

简明释义

视直径;

英英释义

例句

1.The telescope allows us to measure the apparent diameter of celestial objects, which is their size as seen from Earth.

这台望远镜使我们能够测量天体的视直径，即从地球上看到的大小。

2.Astronomers often compare the apparent diameter of planets to better understand their sizes and distances.

天文学家常常比较行星的视直径以更好地理解它们的大小和距离。

3.The apparent diameter of a star can change based on its brightness and distance from Earth.

一颗恒星的视直径可能会根据其亮度和与地球的距离而变化。

4.In photography, the apparent diameter of the lens affects the depth of field in an image.

在摄影中，镜头的视直径会影响图像的景深。

5.The apparent diameter of the moon appears larger when it is near the horizon due to atmospheric effects.

当月亮靠近地平线时，由于大气效应，其视直径看起来更大。

作文

In the realm of astronomy, understanding various concepts is essential for grasping the complexities of the universe. One such concept is the apparent diameter, which plays a significant role in how we perceive celestial bodies from Earth. The apparent diameter refers to the size an object appears to have from a specific viewpoint, particularly in relation to its actual size and distance from the observer. This measurement can be crucial when studying planets, stars, and other astronomical phenomena.To illustrate this concept, let’s consider the Moon. The Moon has a physical diameter of about 3,474 kilometers. However, its apparent diameter varies depending on its distance from Earth. When the Moon is at its closest approach, known as perigee, it appears larger in the sky than when it is at apogee, the farthest point in its orbit. This variation in apparent diameter can lead to fascinating visual effects, such as the so-called "supermoon," where the Moon appears significantly larger and brighter than usual.The importance of apparent diameter extends beyond just visual perception; it also affects scientific measurements. Astronomers use this concept to calculate distances to celestial objects. By measuring the apparent diameter of a star or planet and knowing its actual size, scientists can apply trigonometric methods to ascertain how far away these objects are. This information is vital for constructing models of our solar system and beyond.Moreover, the apparent diameter can influence our understanding of light and visibility. For instance, a star that is much larger than our Sun may have a smaller apparent diameter if it is located at a great distance. This phenomenon can lead to misconceptions about the relative sizes of stars and their brightness. In fact, some stars that appear dimmer and smaller may actually be much larger than those that shine brightly in the night sky.In addition to astronomy, the concept of apparent diameter can be applied in various fields such as optics and photography. In optics, the apparent diameter of lenses can determine how much light they can gather, affecting the clarity and brightness of images. Photographers often consider the apparent diameter of the aperture when adjusting settings to achieve the desired exposure and depth of field in their images.In conclusion, the apparent diameter is a multifaceted concept that holds significance in both scientific and practical applications. From understanding the sizes of celestial bodies to influencing the art of photography, it is a term that encapsulates our perception of size and distance. As we continue to explore the universe and enhance our technological capabilities, the study of apparent diameter will remain a fundamental aspect of our quest for knowledge. Recognizing its implications not only enriches our understanding of the cosmos but also enhances our appreciation of the intricate details that govern our observations of the world around us.

在天文学领域，理解各种概念对于掌握宇宙的复杂性至关重要。其中一个概念是表观直径，它在我们如何从地球上感知天体方面发挥着重要作用。表观直径是指物体从特定视角看起来的大小，特别是相对于其实际大小和与观察者的距离。这一测量在研究行星、恒星和其他天文现象时至关重要。为了说明这个概念，让我们考虑月球。月球的实际直径约为3474公里。然而，其表观直径根据与地球的距离而变化。当月球处于最近点，即近地点时，它在天空中看起来比处于远地点（即轨道的最远点）时要大。这种表观直径的变化可能导致迷人的视觉效果，例如所谓的“超级月亮”，在这种情况下，月球看起来明显比平时更大、更亮。表观直径的重要性不仅限于视觉感知；它还影响科学测量。天文学家利用这一概念来计算天体的距离。通过测量恒星或行星的表观直径并知道其实际大小，科学家可以应用三角测量的方法来确定这些物体的距离。这些信息对于构建我们的太阳系及其以外的模型至关重要。此外，表观直径还会影响我们对光和可见性的理解。例如，一个比我们的太阳大得多的恒星，如果位于非常远的地方，可能会有一个较小的表观直径。这种现象可能导致人们对恒星的相对大小和亮度产生误解。实际上，一些看起来更暗、更小的恒星可能比那些在夜空中闪耀的恒星大得多。除了天文学之外，表观直径的概念还可以应用于光学和摄影等各个领域。在光学中，镜头的表观直径可以决定它们能够收集多少光，从而影响图像的清晰度和亮度。摄影师在调整设置以实现所需的曝光和景深时，通常会考虑光圈的表观直径。总之，表观直径是一个多方面的概念，在科学和实际应用中都具有重要意义。从理解天体的大小到影响摄影艺术，这个术语涵盖了我们对大小和距离的感知。随着我们继续探索宇宙并增强技术能力，对表观直径的研究将始终是我们追求知识的基本方面。认识到其影响不仅丰富了我们对宇宙的理解，也增强了我们对支配我们周围世界观察的微妙细节的欣赏。