Method for measuring duration of solar year

Abstract

The invention discloses a method for measuring the duration of a solar year. The shadow line difference of every 24 hours before and after the Autumnal Equinox is defined as X, the shadow line length of a certain day before or after the Autumnal Equinox is defined as Y, and the shadow line length of the same period in a next year is recorded at the same time, so that the duration of the solar year is 365+(Y-Z) / X. The time when the duration of the solar year is measured at winter solstice Festival is changed by measuring the shadow line of a building at sunrise or sunset before and after the Autumnal Equinox; the measuring principle is the same, and limitation on the geological position is eliminated; the shadow length of the same building is increased since the sun approaches the horizon line at sunrise and sunset; the angle of the sun varies greatly and stably every 24 hours before and after the Autumnal Equinox, so that the shadow change angle is enlarged, and an accurate and rapid measuring result is achieved; multiple measuring periods are available and vary according to the geological position at a track period when the earth runs around the sun with largest and most stable sun angle change before and after the Autumnal Equinox; and the duration of the solar year is measured in the morning and at night of the Autumnal Equinox, so that the method is suitable for any region in the world, and is a great progress in an astronomical surveying method.

Description

technical field [0001] The invention relates to a method for measuring the length of a solar year. Background technique [0002] The earth moves along the earth's revolution orbit, and the earth moves to the position of the revolution orbit, which is directly reflected in the shadow of the fixed building on the ground when the sun shines on it, and the shadow of the fixed building on the ground when the sun shines on it. Sooner or later, the sun is on the horizon, and the fixed building on the ground If the building is not tall, there will be a long shadow. The sun is at the mid-heaven at noon. The length of the shadow of a fixed building on the ground will change according to the latitude. The higher the latitude, the longer the shadow of the sun at noon, and the lower the latitude, the shorter the shadow of the sun at noon. There is not even the shadow of the sun at noon between the Tropic of Cancer and the astronomical phenomenon of "immediately disappearing". It is diffi...

AI Technical Summary

Problems solved by technology

The winter solstice point is on the line at 12 noon at local time, which happens every year, but the probability of being on the same line of the measurer is one in ten million, almost equal to zero, so astronomy uses the average of long-term measured values ​​to measure the sun The length of the year is also an approximation, not an exact number

Moreover, since the angle of the sun at noon before and after the winter solstice changes very little, the length of the shadow of the sun also changes very little. Astronomers need to measure the length of the shadow of the sun for a long time to calculate the length of the solar year. In low latitudes, the sun has a higher shadow length less variation, it is impossible to measure the length of the solar year

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