When waiting for the subway, why should you stand within the yellow line?

Let me introduce the origin first

When passengers are waiting for the train on the platform, they must stand outside the safety white line one meter away from the edge of the platform. How did this safety line emerge?

According to railway history records, this safety line originated from a tragedy nearly a hundred years ago. In the winter of 1905, at a small station in Russia called Olodok, the station director led all 38 employees of the station, dressed in costumes and holding flowers, to stand on both sides of the railway line to wait for the imperial envoy sent by Tsar Nicholas II to inspect. Minister. However, unfortunately, the train did not enter the station slowly, but rushed into the "Human Alley" like a violent wind. In an instant, the "Human Alley" collapsed. Dozens of employees seemed to have been shoved in the back and involuntarily rushed to the station. Fall forward. As a result, 34 people lost their lives and 4 people were disabled for life.

Due to the limited technological level at that time, people could not explain this. Only later did people figure out the truth of the tragedy. It turned out that a partial vacuum was formed when the train passed quickly, and the nearby airflow filled the vacuum, thus forming a strong thrust, causing the "man alley" to collapse and a tragedy occurred. Since then, in order to ensure personal safety, a safety white line has been drawn on all platforms around the world. Passengers are not allowed to cross this white line while waiting for the train.

The explanation of pressure is also very simple

First of all, you have to understand that the faster the air flows, the smaller the pressure of the gas. When a train is speeding past, the air near the train moves quickly and the pressure is low. If a person stands very close, he or she will be easily squeezed in by the atmospheric pressure and die.

Helicopters also use this principle to take off, and the two sides of the car are designed to be symmetrical to avoid accidents caused by pressure differences caused by different air flow rates.