What does the horizon mean?

The horizon refers to the horizontal line, where the sky meets the ground.

From a scientific point of view, the horizon is actually a virtual circle, which is tangent to the ground and intersects with the zenith from the observer's point of view. This circle clearly separates the sky from the ground and delimits our field of vision. Above this limit, we can see the sun, moon, stars and other celestial bodies in the sky; And below the border, it is the ground where we live.

The horizon plays an important role in observing celestial bodies and calculating time. For example, when the sun is about to set, it will gradually disappear below the horizon, which marks the coming of night. At the same time, we can also calculate the height and orientation of celestial bodies by observing their positions on the horizon. This is of great practical value for astronomical observation and navigation.

The horizon can also help us understand the curvature of the earth. Because the earth is a sphere, the position of the horizon is not fixed and will change with our movement. For example, when we walk or drive forward, the horizon will go straight ahead. This phenomenon reflects the curvature of the earth and is an important manifestation of the shape of the earth.

Application of horizon:

1, navigation

On the vast sea, the horizon is the most reliable guide for navigators. By observing the position of the sun, stars or other celestial bodies on the horizon, navigators can determine the course and position of ships. Especially when modern science and technology are combined with traditional observation methods, such as observing the height of the sun on the horizon with sextant, navigators can judge their latitude and longitude more accurately and ensure navigation safety.

2. Astronomical observation

When astronomers study the height and orientation of celestial bodies, the horizon is an indispensable reference. By observing the time when celestial bodies rise or fall from the horizon with precision instruments, they can calculate the declination and hour angle of celestial bodies. This provides valuable data for studying the trajectory, distance and properties of celestial bodies.

3. The art of photography

In photography, the horizon is one of the key elements of composition. Photographers often skillfully use the horizon to create a deep, broad or dreamy picture atmosphere. For example, putting the horizon in one third of the picture can emphasize the details of the sky or the ground; The horizon photographed at sunrise or sunset can show the magnificence and mystery of nature. The use of the horizon makes every photo full of story and appeal.