Lightning is electricity, of course. Storm clouds usually produce charges, with negative charges at the bottom and positive charges at the top. They also produce positive charges on the ground, which move around with the clouds. Positive and negative charges attract each other, but air is not a good conductor. Positive charges rush to tree tops, hills, tall buildings and even human bodies in an attempt to meet negatively charged clouds; The negatively charged dendritic antenna extends downward, and the farther it extends, the closer it is to the ground. Finally, the positive and negative charges finally overcome the air barrier and connect. A huge current rushed from the ground to the clouds along the conductive path, producing a bright flash. The length of lightning may be only a few hundred meters (the shortest is 100 meters), but the longest is also several kilometers. \ x0d \ x0d \ The temperature of lightning is between 17000℃ and 28000℃, which is 3~5 times of the surface temperature of the sun. The extreme heat of lightning caused the air along the way to expand violently. Air moves very fast, so waves are formed and sounds are made. When lightning approaches, you hear a sharp crack; If it's far away, you hear rumbling. You can start the stopwatch after you see the lightning, press the stopwatch to stop when you hear the thunder, and then divide the number of seconds by 3 to get a rough idea of how many kilometers the lightning is from you. \x0d\ Now we know that when the charge is neutralized, it will release a lot of light and heat, instantly heating the surrounding air to a high temperature of 30,000 degrees Celsius. When a powerful current passes through the air, the air along the way will suddenly expand, and at the same time, it will push the surrounding air and make the air vibrate violently. The sound produced at this time is [thunder]. Don't forget to tell the baby that lightning happens at the same time, because the speed of light is much faster than the speed of sound. Therefore, we always see lightning first and then hear thunder. ) \x0d\ If lightning falls nearby, we will hear deafening thunder. If lightning falls far away, we will hear an inaudible thunder. This is because sound waves are refracted by the atmosphere and reflected by ground objects.