Aroplane window is never bogged, why know?

Calcutta: shell or oval. Aircraft windows are usually the same. Never be rounded. Just the square? There is never even a sharp edge in the plane's window. This incident has been going on for almost half a century. But no one is aware of the reason. The mystery remains on the screen. But there is a very common reason behind this.
In 1949, the world's first commercial jetline De Havilland Comet was launched. But within a year, two airplanes in the middle of the sky collapsed. The investigation begins A strange information revealed in the investigation. Investigators said, as per the fate of the planes, the windows of the planes They were square. Naturally the edges were edgy.
Now the incident is that commercial aircraft usually fly 30,000 feet above the ground. Because, there is very little wind concentration. As a result the air can not prevent the aircraft there. Although its effects are very low. As a result, aviation is also advantageous. But in these circumstances passengers may have respiratory problems. Air pressure is increased in the cabin to solve that problem. As a result, there is a difference between air pressure and internal air pressure.
If there is a square window, it has four corners. Extra air pressure is likely to break down broken edges. That was what happened during the comet crash. Biman crashed in mid-sky
Since then, the structure of aircraft windows has been changed. Instead of edges, the edges are round or oval. If the edges are round, it is possible to keep the balance of the plane outside and the air pressure. As a result, the possibility of degradation of the aircraft is greatly reduced.