High-speed trains are much faster than trains, but why do they appear to be about the same speed when viewed from the window?

Have you noticed when you are riding a train?

High-speed rail is much faster than train

Why look through the car window?

But the speed is about the same as a train?

turn out to be

There is more than a little knowledge here

Why is the speed outside the high-speed rail window almost the same as that of the train?

When riding on a train with a speed of 300 km/h, the speed of the scenery outside the window is almost the same as that of a regular train, and you won’t feel dizzy. Is the high-speed train glass a deceleration glass? What’s so special about it?

High-speed rail "vehicle safety glass"

The automotive safety glass used in high-speed trains is a laminated glass, with a layer of PVB film sandwiched between two layers of tempered glass.

This kind of glass has good optical properties, no light distortion, can truly reflect the shape and movement of the scene, and the vision is very clear. When light is evenly refracted through the glass, it gives the naked eye a sense of "slowing down".

Viewing angle of the scenery

When a train is running, the speed we see has nothing to do with the linear speed of the train, but is related to the "angular velocity".

The angle of the scenery when looking at it in the direction of the train's travel tends to 0, and the angular velocity becomes very slow. The opposite is true when it is vertical or 180 degrees. This is why high-speed rail seats do not recline, so you feel a slow speed.

In addition, since most high-speed rail lines are built on bridges, there are no obstructions nearby, the windows have a wide field of view, distant scenery can be seen for a long time, and the angular velocity is very small, so there is a feeling of driving slowly.

Why can’t windows be opened on high-speed trains?

The windows cannot be opened on high-speed trains, which is related to the huge air pressure waves generated by the high-speed running of the train.

High-speed trains run at high speeds. When air pressure waves enter the car, the items inside the car will be blown into a mess, and the noise outside the car will also enter the car.

What’s more serious is that this difference in air pressure can cause a feeling of pressure on passengers’ eardrums at the very least, or cause dizziness and nausea, or even rupture of the eardrums at the worst.

In fact, not only the windows of the EMU must be closed, but its doors, carriage connections, etc. must also be kept as airtight as possible to ensure that passengers have a comfortable riding environment.

Why are the corners of high-speed rail windows oval?

Whether it is a conventional train or a high-speed train, the corners of the windows are elliptical.

When the train is running, the windows have to withstand huge pressure waves. Elliptical corners are more evenly stressed than square corners, which can disperse the pressure evenly and greatly reduce the risk of window damage.

When high-speed rail runs at speeds exceeding 300km/h, the air flow rate in the nearby space will increase and the pressure will decrease, creating a pressure difference between the air and the air in the distance, forming an air pressure wave.

When two trains pass each other, a pressure wave is generated. In addition, high-speed trains often pass through tunnels, and the increase in instantaneous pressure waves is also a test for the windows.

The oval design is to evenly distribute the force and improve the pressure resistance of the car window. However, I think the oval corners look more fashionable than the square corners.

I've been sitting on the high-speed train for so long.

I didn't expect there is so much knowledge about high-speed rail windows.

Source: Gaotie Guanjia (ID: gaotieguanjia)