Why do you see lightning before you hear thunder when it rains?

This is because light travels much faster than sound. Light travels almost 300,000 kilometers per second in the air, and at such a speed, it can travel seven and a half times around the Earth's equator in one second. Sound travels about 340 meters per second in the air, almost 1/900,000th of the speed of light.

The time it takes for light to travel from the place where lightning occurs to the ground is generally only a few hundredths of a second, while it takes a long time for sound to travel the same distance.

Sometimes lightning is not thundering, because the discharge clouds are too far away from us, or because the sound is not loud enough. Because as the sound travels through the air, its energy becomes smaller and smaller, and in the end the sound is no longer audible.

Thunder and lightning in the air is a phenomenon in which electricity is discharged between clouds with a different charge, and the sound of the discharge (i.e., thunder) and light (i.e., lightning) are generated at the same timeIt's just that light travels much faster than soundSo, we see lightning first, and then we hear thunder.

Although lightning and thunder are produced at the same time, light travels much faster than sound, so when thunder strikes, lightning is seen first, and thunder is heard later. In summer, thunderstorms often occur, and when it rains, lightning and thunder are earth-shattering. We know that when the electric field between the positive and negative charge regions in a thundercloud is large enough to a certain extent, the two charges will be neutralized and a spark will occur, and a strong light will occur when the spark is discharged, which is lightning.

When a high temperature is generated in the path of light, the surrounding air suddenly expands due to intense heating, and the cloud droplets will also suddenly vaporize and expand due to the high heat, causing a loud noise, which is called thunder.

It's because the speed of light is faster than the speed of sound that lightning is seen first.

Because the human eye can see far away in a moment, and then the speed of transmission through the air is limited.

This is a natural phenomenon because lightning strikes at the touch of lightning.

Because the speed of light is faster than the speed of sound, seeing lightning proves that the speed of light travels faster.

Because light travels much faster than sound, this phenomenon occurs.

Because light travels much faster than sound.

The main thing is that their speed of light travels faster than the speed of sound, and there is a difference in medium.

Because sound travels slower than light, it reacts in this way.

This phenomenon is due to the fact that the speed of light is faster than the speed of sound.

Thunder and lightning is the discharge phenomenon of thunderstorm clouds, due to water vapor and violent air convective movement so that the clouds produce positive and negative charges, when the positively charged clouds and negatively charged clouds meet, the lightning phenomenon will occur, causing the air ** type vibration, this is thunder.

Therefore, thunder and lightning occur at the same time during a thunderstorm. But because light travels very fast. Light travels through the air, although more slowly than in a vacuum, but it is also close to 30 kilometers per second.

Sound travels much more slowly. The speed at which sound travels through the air is 340 meters per second. Therefore, even when thunder strikes far away, the light emitted by lightning travels into our eyes instantaneously, and we simply do not feel the time it takes to propagate.

Thunder, on the other hand, travels much slower, and it takes a long time to reach our ears from a distance.

Start the timer when you see lightning, measure the time until you hear thunder, and estimate the distance from the place where the lightning occurred according to the formula s v sound t. In the same way, after the artillery fires, the time from seeing the flash to hearing the ** sound when the shell is written down can estimate the distance from the place where the gun is fired to the place where the gun is fired. But this method doesn't work in space, you may have seen the sci-fi film of the Earth Guardian fighting with alien invaders in space, when the spaceship is hit, it is also the first to see the flash and then hear the sound, it is pure fantasy.

Because light propagation does not need a medium, and sound propagation requires a medium, and a vacuum cannot transmit sound, so, it really happens in space, and you can only see flashes, but you can't hear the sound. As you know, astronauts who land on the moon also need to speak face-to-face through a walkie-talkie, because there is no air on the moon, and the sound of human speech cannot be transmitted.

We can tell by the time difference between lightning and thunder how far away the thunder is from where we are. Assuming that we hear a rumbling thunder 5 seconds after seeing the lightning, the lightning is happening 1,700 meters away.

In particular, it is important to note that the phenomenon of atmospheric discharge during thunderstorming, lightning is very dangerous. Try not to stay outside during thunderstorms in summer, and do not take shelter under large trees to avoid lightning strikes.

There must have been lightning before you arrived, so you can see the lightning first, and slowly you can hear some sounds, and that's it.

Actually, they happen at the same time, but lightning travels faster than sound, and lightning does not need to travel physically, so people will see lightning first and then hear thunder.

Because the speed of light travels much faster than the speed of sound, lightning is seen first and then thunder is heard.

The main reason is that the speed of light is faster than the speed of sound, so you can see lightning first and then hear thunder.

Because light travels faster than sound, it is only when lightning is seen and then sound is heard on rainy days.

According to physics, the speed of light in the air is greater than the speed of sound, so when it rains, lightning is seen first, and then thunder is heard.

In detail, in fact, in the distance, thunder and lightning appear at the same time, (thunder and lightning are the process of self-motion of clouds, which produces electric charges, and electric sparks are generated when discharged, both light and sound), and light travels 3,000,000 kilometers per second, while sound can only travel kilometers in the air in one second, and the speed of sound is only one-ninety thousandth of the speed of light. Therefore, the light travels very quickly, and the sound is relatively slow, which also produces the phenomenon we see in our lives, "when it rains, there is often thunder, but we see lightning first, and then we hear thunder."

Extended Knowledge:1The air temperature affects the density of the air, the air temperature is high, the density of the air is small, and the resistance received by the sound wave in the propagation process is small, so the sound velocity is larger, so the sound does not necessarily propagate in a straight line after the sound source is emitted.

2.Speed of light: The speed at which electromagnetic waves travel in a vacuum. The speed of light is the maximum speed at which an object can move in nature.

3.Lightyear: A unit of length that measures the distance between celestial bodies.

4.The appearance of lightning:

The spark occurs due to the separation of positive and negative charges between this cloud and that cloud and between the cloud and the ground in a cumulonimbus cloud.

Raindrops, hail, and snowflakes will separate the charges as they fall, like rubbing a balloon on a cardigan. The movement in the clouds leads to precipitation, which also causes some of the clouds to be dominated by negative charges and others to be dominated by positive charges.

When the difference between positive and negative charges is too large for the air to be isolated, a discharge phenomenon occurs, and a spark appears, that is, lightning. When lightning occurs, the temperature of the air in the lightning zone can reach as high as 27,760°C, which is times the temperature of the sun's surface. The hot gas expands rapidly into the air outside the lightning zone, resulting in a huge sound wave at the edge of the lightning, that is, lightning travels at the speed of light, reaching 299338 kilometers per second; Thunder travels at a very fast speed, only 317 meters per second, so we will see lightning first.

In a rainstorm, if you want to know how far away from lightning is, start counting from the moment it arrives until you hear thunder. Note that the pattern of 1-1000, 2-1000, and 3-1000 is used to count, and each count indicates that the lightning is outside. In other words, if you count to 3-1000 whole days, then the distance of lightning is 3 times that of a kilometer, that is, about 1 kilometer away.

If there is almost no gap between the lightning and the thunder, then the lightning is very close, and you may be in trouble.

Because the speed of light and sound is different, the speed of light is relatively fast, so lightning will be seen first.

Because light travels faster than sound, we generally see lightning before we hear thunder.

Not every rainy day will have lightning and thunder, lightning and thunder generally occurWhen it rains in spring and summerOn some winter snowy days, lightning and thunder can also occur.

In warm and humid times,The air is heated and rises and condensesCloud, clouds accumulate more and more and eventually form rain. In the process of moving clouds in the atmosphereAll kinds of particles collide and rub against each other, will cause the amount of positive and negative charges to continue to accumulate, and add toThe voltage of the air medium also increases, in a certain wayThe charge will be released under these conditionsThis act of discharging produces strong lightning, some of which are lightningCurrentVery large and achievableTens of thousands of amps.

When lightning passes through the air, it willThe air heats up sharply, so thatThe air expands rapidly, creating thundersound；From a practical point of view,Lightning and thunder occur almost simultaneously.

The reason why people willLightning is seen first and thunder is heardAnd that's becauseLightning is the speed at which light travels, whileThunder is the speed at which sound travelsLightIt will propagate very quickly in the natural environment, and the propagation speed in the earth's atmospheric environment is approximately300,000 kilometers per second, whileThe speed at which sound travels through the atmosphere is about 332 meters per secondThe speed of propagation between the two is very different, and people can feel it even at very close distancesThere is a time lag between these two phenomena.

Strong lightning can cause harm to people, and we need to be inOn rainy days, try to avoid thunderstorm areas as much as possible。In everyday life, we can come by observingEstimate the distance of the thunderstorm zone from yourself, generally only see lightning, but do not hear thunder, that means that the thunderstorm area is far away from you; If lightning and thunder arrive at about the same time, you may be in or near a thunderstorm and need to find a safe place to take shelter.

There is an easy way to estimate distance, and that isDivide the speed of seconds between lightning and thunder by 3, you can roughly get the distance between yourself and the thunderstorm area, if you are inThunder is heard 6 seconds after the lightning, and the center of the thunderstorm is 2 kilometers away from youIt's basically safe here.

Because light travels very fast, we can see lightning first and then hear sounds, and light is everywhere.

This is because light travels faster than sound.

Because the speed of light is faster than the speed of sound, we will see lightning and then hear thunder.

The third reason is that lightning is actually below the horizon, because most of the light is propagating the earth's gravitational pull in a straight line, and there is no way to make them turn. So most of them have escaped from our business, and the sound has reached our ears through different media.

Obscured by the clouds. When the clouds are very thick, they can block the light of lightning, and sometimes you can't see lightning, only thunder can be heard.

If it's during the daytime, there will be lightning before the rain, but it can't be seen during the day, most of the lightning will be before the rain, and there are very few times when there is no lightning.

Because lightning only forms and disappears in an instant. I didn't see the lightning, probably because I missed it. But as long as there are no anomalies, the sound is audible.

That means that the thunder is far away from us, and that place can be seen, or the clouds are too thick for us to see the thunder, but the sound can be heard.

When it rains, you see lightning and then hear thunder.

The speed of sound propagation in the air is 340m s, the speed of light in the air is 300000000m s, lightning and thunder occur at the same time, the distance to the observer is equal, and the propagation time is determined by t=s v Light arrives first, sound arrives later.

So. When it rains, you see lightning and then hear thunder.

Actually, lightning and thunder occur at the same time, except that lightning is light and runs very fast, while thunder is sound and runs much slower. Because the speed of light is 300,000 kilometers per second, it can circle the earth seven and a half times in one minute; And the speed of sound in the air is about kilometers per second.

Thunder and lightning are generated at the same time, according to physics, thunder is the speed of sound propagation 340 meters per second, but lightning is the propagation of light elements, propagating to the 8th power per second, therefore, the lightning is seen first, and then the thunder is heard.

The speed of light is much greater than the speed of sound in the air.

Speed of light: 3 10 8m s

The speed of sound in air: 340m s

Because the speed of light is faster than the speed of sound, light reaches your eyes first, and sound reaches your ears.

If you're asking about brain teasers, the answer is eyes in front and ears in the back, haha.

Thunder is a version of sound waves due to lightning, that is, when the air near it is rapidly heated and expanded, even if lightning strikes.

It occurs at the same time as thunder and travels from the same place at the same time, but the light produced by lightning reaches our eyes at a speed of 3 million kilometers per second, while the sound comes at a speed of only 360 meters per second, and the speed of light is faster than the speed of sound, so the lightning is seen first and then the thunder is heard.