Of all the mid-flight past times out there, querying the shape of windows perhaps isn’t top of the list.
Having said that, delving deeper into the seemingly mundane can often unearth meaning. And if nothing else it gives you something useful to discuss with your friends, or a random nugget of information to pull out during a pub quiz.
In the 190s, when plane travel was starting to become mainstream, the de Havilland Comet came into fashion. With a pressurised cabin, the plane was able to fly higher and faster than other aircrafts.
The plane had square windows. And tragically in 1953, two planes fell apart in the air, killing 56 people in total. It was because of the windows.
With corners comes weak spots. Thus a square window, with four corners, has four potential weak spots. Making them far more likely to crack under huge stress – such as air pressure.
Rounded corners help alleviate such stresses by distributing it around the circumference of the window, as opposed to having it concentrated in the corner of a square window.
So there you have it.