When thunder strikes, why do you always see lightning before you hear it?

When people see lightning or hear thunder, they first have to look at the distance from the location where the lightning is generated to the location of the person's observation, so whether the lightning arrives first or the thunder comes first depends on the speed of the two propagation, lightning is propagating at the speed of light, the size is 300,000 kilometers per second, and the propagation speed of sound is 340 meters per second, so it is natural that the lightning travels faster, so we see the lightning first, and then hear the thunder.

Based on the time difference between seeing lightning and hearing thunder, the distance from the location where the lightning is generated to the observer's position can be calculated, and the equation can be as follows: (distance divided by the speed of sound) minus (distance divided by the speed of light) equals the time difference, and when estimated, the time obtained by dividing the distance by the speed of light is very short and negligible, so that the location of the lightning can be quickly calculated.

The same phenomenon occurs in various scenes in life, such as the starting pistol used in the sports meeting, when the starting gun sounds, there will be smoke floating out at the same time, so the athlete should see the smoke first or hear the gunshot, can see the smoke because there is light reaching the human eye, the speed of propagation is the speed of light, and the propagation of the gunfire is according to the speed of sound, so it is to see the smoke first and then hear the sound.

The speed of light propagation in a vacuum is the largest, and the speed of entering other media will be slower, and the speed of sound cannot travel in a vacuum, and the speed of entering other media from air will become larger.

Light is an electromagnetic wave, which is also a transverse wave, and when the distance is small, the propagation time is generally negligible due to the large speed of light; Sound is a mechanical wave, but also a longitudinal wave, and when the distance is smaller, the propagation time is also negligible. Of course, what kind of distance can ignore the propagation time, it is necessary to compare, for example, compare the propagation of light and sound at the same distance, then the propagation time of light is far less than the propagation time of sound, if you calculate the time taken by light to propagate from the sun to the earth, because the distance from the earth to the sun is very far, so the time of light propagation can not be ignored.

Because we know that light travels very fast, and sound travels with the help of some conditions, so we can see lightning before we hear sound.

It is because the speed of light travels faster than the speed of sound, so there is a scientific basis for seeing such a scene.

This is because light travels faster and faster than sound, so lightning is seen first.

Because light travels fast, lightning travels at the speed of light, and sound travels slowly in a vacuum.