I don't know if everyone has ever opened a van. If you open another car before you drive, isn't there a "faster" feeling for a van?
For example, when the speed reaches 100km/h, the van driver and the passengers in the copilot can feel the wind and electricity. If you drive a car, there is no such feeling. Even if you drive to 120km/m, you feel very slow. ". Of course, it is not the van that is faster than the car in actual speed. For this phenomenon, the old driver explained the effect of “deceleration glass”.
However, this is not the case. The reason why the older generation of drivers would say the word “reduction glass” may be that they had opened large trucks or small trucks in the early years and later came into contact with the cars, obviously feeling different speeds. Sense, but they can not explain this phenomenon, so he thought that foreigners (the cars were foreign goods at that time) in the use of what technology on the glass can slow down, "the deceleration of glass" was born. In fact, the so-called "deceleration glass" is nothing more than safety glass. It consists of two pieces of high-purity quartz crystal material glass. It can be insulated and soundproofed. A vacuum is applied between the two pieces of glass to force the entire glass No serious breakage will occur. In any case, such a glass cannot have the function of deceleration. This is contrary to the laws of nature. It can explain the speed of a van, and the reason why a sedan has a slow glass is only visual error.
This is actually very simple physical knowledge. For example, the moon moves about one kilometer on average in one second. In our eyes, it is very slow and almost immobile, which means that when you watch objects of the same speed in different positions, it will be very different. The speed is different for different cars. This is the case with buses and cars that we are familiar with. The front glass of the bus is almost vertical, the driver's seat is high, and you can see it very close to the front of the bus. The surface of the road, the fleeting road will make the driver feel the speed of the car quickly. Conversely, the car not only has a long front, but also a sloping front glass, the seat is low, and there is a large section of the road vision is blocked. At the same speed, it looks like there is no bus so fast.