Basically all races use a starting gun. When the starting gun sounds, the athletes start running and the timekeeper starts timing. The athletes and timekeepers rely on the sound and light of the starting gun to react.
However, it should be noted that athletes start based on sound, because the distance between the athletes and the starting gun is short, so the propagation speed of sound has little effect. But the timekeeper cannot use sound to time the time. Some people think that smoke is used as the standard. In fact, this is also wrong. Pay attention! Timekeepers are not judged by the smoke of the starting gun, but by the light.
I mentioned before that relying on the sound and light of the starting gun to react. The sound and flash are the only basis for athletes and timekeepers.
If you are careful, you will find that the starting gun is usually fired on a black round plate. This is actually to allow the timekeeper to observe the flash when the gun is fired, because the light flashes past. , it is easy to be ignored if you are not careful, so with smoke as a supplement, the time for the smoke to leave the muzzle is about 0.05 seconds, but the smoke is only a supplement after all. The most accurate basis is the flash. Currently, many friends including many People in the sports world think that timekeepers rely on smoke to judge, but this is actually wrong.
Of course, it would be even more wrong to think that the timekeeper can also listen to the sound before reacting. The timekeeper can easily make mistakes based on the sound, because the speed of sound propagating in the air is 340M/S. If the distance exceeds 150M will cause a delay of more than .01 seconds, which will seriously affect the timing competition. Therefore, timekeepers generally use the flash of the muzzle as the standard for starting timing, not smoke, let alone sound. .
In fact, it is difficult to be absolutely fair in sports running competitions. We can only guarantee fairness. For example, athletes' running track is related to this sound: Athletes closer to the starting gun have the advantage of shorter starting reaction times.
Based on human instinctive conditioned reflex time, the time to start a false start in sports competitions is defined as faster (less than) 0.1 seconds from the sound of the starting gun to the moment the foot leaves the starting pedal. Because almost no one can achieve a starting time of 0.1 seconds, and the average person's reaction time is between 0.2 and 0.3 seconds. Well-trained and naturally quick athletes have reaction times between 0.1 and 0.2 seconds. Therefore, if the time from the sound of the starting gun to the athlete's feet leaving the starting block is less than one hundredth of a second, it will be judged as a false start.
This difference between trained and untrained athletes shows that trained athletes perform at their best during competition. These results mean that the sound of the starting gun and the distance between the athletes and the starting gun can affect their start. A louder gun sound may make the athletes hear it more clearly, and even though the distance between the athletes and the starting gun is only a few meters or 10 meters (each lane of the track and field track The width is 1.22m, which means that lane 8 is 8.54 meters farther from the starting gun than lane 1), but this may cause a difference in starting reaction time. Because there is a difference in the time it takes for the sound of the starting gun to reach the ears of athletes at different distances, although this difference is extremely small.
For example, the propagation speed of sound in the air is 340 meters per second (at standard atmospheric pressure and 15 degrees Celsius), and the athlete in lane 8 is 8.54 meters farther than the athlete in lane 1. The time he hears the gunshot will be 0.025 seconds later than the athlete in lane 1. Although this is a negligible time, if the athletes in lane 1 and lane s perform the same in other aspects, such as running, sprinting, etc., then the athlete in lane 1 will definitely win.
Prior to this, Liu Xiang’s fastest starting speed was 0.108 seconds. This starting speed allowed him to set a world record of 12.88 seconds. However, Liu Xiang's fastest starting reaction time is not the fastest in the world. The fastest is 0.104 seconds created by the world's 100-meter superstar, Montgomery of the United States. It can be seen that the reaction time is not more than 0.1 seconds, but very close to 0.1 seconds.
From the perspective of physiological limits, some people think that Liu Xiang's 0.105 seconds and Montgomery's 0.104 seconds starting time are actually no longer normal simple reactions, but an intuitive synchronization with or advance of the starting gun. conduct. In other words, before Liu Xiang and Montgomery heard the gunshot, or strictly speaking, before their brains had time to process a signal from the auditory nerve, their brains had already decided to take action. Even when they may not have heard the gunshot, their brains sent out a start signal. Only when this signal ran towards Liu Xiang and Montgomery's powerful thighs, calves, ankles, and soles did their brains know that the gunshot had been fired. After another 0.005 seconds and 0.004 seconds, the soles of Liu Xiang and Montgomery's feet left the starting pedal.
Therefore, many modern large-scale sports games have starting blocks. This is a good basis and can better correct some mistakes. However, it is complicated and I will not go into details here.
It should be noted that there is now something called an electronic starting gun, and there are many kinds of patented products. The earliest one should be in May 1989. Chen Tianshi of Fujian Normal University applied for a patent, which is composed of electronic components. Electronic starting gun with synchronous control and simulated gunshot, flash, power amplifier and other circuits. Of course, there are many electronic starting guns with different patents, but no matter what kind of electronic starting gun, the use of electronic components overcomes the insurmountable problems of traditional gunpowder starting guns, and it also has the ability to amplify and generate "electricity". It has the function of "whistle" and has the effect of multiple uses in one machine. It is a better sports starting equipment. Of course, there is no smoke.