翻译：光速的测定 光速的测定在光学的开展史上具有非常特殊而重要的意义。它不仅推动了光学实验的反站也打破了光速无限的传统观念；在物理学理论研究的开展里程中它不仅为粒子说和波动说的争论提供了判定的依据而且最终推动了爱因斯坦相对论理论的开展。 在光速的问题上物理学界曾经产生过争执开普勒和笛卡尔都认为光的传播不需要时间是在瞬时进行的。但伽利略认为光速虽然传播得很快但却是可以测定的。1607年伽利略进行了

The measurement of the speed of light has a very special and important significance in the history of optics. It not only propelled the development of optical experiments, but also broke the traditional concept of infinite light speed. In the development of theoretical physics, it not only provided a basis for the debate between particle theory and wave theory, but also ultimately promoted the development of Einstein's theory of relativity. In the past, there was controversy in the physics community regarding the speed of light. Kepler and Descartes believed that the propagation of light did not require time and was instantaneous. However, Galileo believed that although light propagated very quickly, its speed could be measured. In 1607, Galileo conducted the earliest experiment to measure the speed of light. His method was to have two people stand on two mountains one mile apart, each holding a lamp. The first person would lift their lamp, and when the second person saw it, they would immediately lift their own lamp. The time interval from when the first person lifted their lamp to when they saw the second person's lamp was the time it took for light to travel two miles. However, because the speed of light is too fast, this method was not feasible. But Galileo's experiment opened the door to the study of the speed of light in human history. In 1676, Danish astronomer Roemer proposed an effective method for measuring the speed of light. He observed the eclipses of Jupiter's satellites and found that their periods varied at different times of the year. The period when the Earth was between the Sun and Jupiter was 14-15 days different from the period when the Sun was between the Earth and Jupiter. He believed that this phenomenon was caused by the speed of light, and he also deduced that it took 22 minutes for light to cross the Earth's orbit. In September 1676, Roemer predicted that the eclipse of Jupiter's moon, which was expected to occur at 5:25:45 am on November 9, would be delayed by 10 minutes. Scientists at the Paris Observatory observed and ultimately confirmed Roemer's prediction with skepticism. Roemer's theory was not immediately accepted by the French Academy of Sciences, but it was endorsed by the famous scientist Huygens. Based on the data he proposed and the radius of the Earth, Huygens calculated the speed of light for the first time: 214,000 km/s. Although this value differs greatly from the most accurate data currently measured, it inspired Huygens' research on wave theory. More importantly, the error in this result was not due to a methodological error, but rather to Roemer's erroneous speculation about the time it took for light to cross the Earth. The result obtained by modern laboratories using Roemer's method after various corrections is 298,000 km/s, which is close to the precise value currently measured. In 1725, British astronomer Bradley discovered the phenomenon of "stellar aberration" and accidentally confirmed Roemer's theory. At first, he could not explain this phenomenon until 1728, when he was inspired by the relative relationship between the wind direction and the ship's heading when he was on a boat, and realized that the speed of light and the Earth's revolution together caused the phenomenon of "stellar aberration". He estimated that it took 8 minutes and 13 seconds for sunlight to reach the Earth using the ratio of the Earth's revolution speed to the speed of light. This value is more accurate than Roemer's measurement. Bradley's measurement value proved Roemer's assertion that the speed of light is finite. The measurement of the speed of light became an important basis for the debate on the nature of light that had been unfolding since the seventeenth century. However, due to the limitations of the experimental environment at the time, scientists could only measure the speed of light in a vacuum using astronomical methods, and could not solve the problem of the influence of the propagation medium on light. Therefore, the debate on this issue remained unresolved. In the eighteenth century, the scientific community was dull, and the development of optics was almost stagnant. After Bradley, it took more than a century of brewing for new scientists and new methods to emerge to measure the speed of light. In 1849, Frenchman Fizeau designed an experimental device on the ground to measure the speed of light for the first time. His method was similar to Galileo's. He placed a point light source at the focus of a lens and placed a gear between the lens and the light source. At a distant point on the other side of the lens, he placed another lens and a flat mirror, with the flat mirror at the focus of the second lens. The light emitted by the point light source became parallel light after passing through the gear and lens, and converged on a point on the flat mirror after passing through the second lens. After reflecting on the flat mirror, it returned along the original path. Because the gear had gaps and teeth, when the light passed through the gap, the observer could see the returning light, and when the light encountered a tooth, it would be blocked. The time from the beginning to the first disappearance of the returning light was the time it took for the light to travel back and forth once. In 1983, the International Bureau of Weights and Measures redefined the unit of light speed, taking 299,792.458 km/s as the exact value of the speed of light. Modern scientific and technological advancements can accurately measure the value of the speed of light, which has further advanced the development of optical theory and applications. The measurement of the speed of light played an important role in promoting the development of physics and optics, and provided profound insights into the nature of light for humanity