In fact, lightning is a huge electric spark. This is obvious when lightning rushes from the ground to the clouds or from the clouds to the ground, although it can also spread in or between clouds. The airflow that makes up a storm cloud can separate powerful electric energy from the cloud.

Positive current is concentrated in the lower part of the cloud, and negative current is concentrated in the upper part of the cloud or on the ground. Just like electromagnetism, positive and negative electricity attract each other. After continuous transmission, positive and negative currents collide, forming a huge electric spark, thus forming lightning.

Because the speed of light is about 6.5438+0 million times that of sound, there will be a certain time difference between lightning and accompanying thunder. The distance between you and the storm can be calculated by counting the seconds of the time difference between lightning and thunder, and then dividing by 5 meters. The number is the number of miles you are away from the storm, that is, your distance from the storm (miles) = the time difference between lightning and thunder (seconds) /5 (meters).

Lightning strikes millions of volts, causing air to expand and explode, thus forming lightning. Thunder itself is harmless. The possibility of being struck by lightning in thunderstorm weather is very small, but the lightning phenomenon cannot be predicted completely and accurately, so be careful to prevent and reduce the danger.

Lightning always twists and turns along the path of least resistance. Its path in the air depends entirely on the electric field and charge distribution in the air, and it is usually only affected by the ground conditions when it is more than ten meters away from the ground to 100 meters. Generally speaking, the ground has good conductivity and there are prominent tall objects. , vulnerable to lightning. For example, the geological conditions of metal minerals with good conductivity are more vulnerable to lightning strikes than general geological conditions, and the chances of being struck by lightning in wet soil are more than in dry soil, sandy land and rocky land. The water surface is more vulnerable to lightning strikes than in dry land, and prominent buildings such as tall buildings and chimneys are more vulnerable to lightning strikes than in flat land, and mountainous areas are more vulnerable to lightning strikes than in valleys.

There is no doubt that it hurts to be directly hit by lightning, but sometimes, even if it is not directly hit by lightning, it will cause accidents because it is very close to the lightning strike point. This is because when the lightning current leaks into the ground, the voltage near the lightning strike point is much greater than the voltage far away from the lightning strike point because of the existence of grounding resistance. Therefore, if people stand with their feet apart, one foot is close to the lightning strike point and the other foot is far away from the lightning strike point, a certain potential difference will occur, which is often called "step voltage". Part of lightning current will also cause harm because of "step voltage" flowing through human body. The worse the surface conductivity, the greater the "step voltage".

The period from vernal equinox to autumnal equinox is the period of lightning activity. After the autumnal equinox, the weather is getting colder, and there is generally no more lightning. At this time, everything is gradually turning yellow and declining.