Why do planes and ships have round windows?

Question

Why do planes and ships have round windows?

In: 152

Answer 1

You know how if you’re opening a snack bag, it’s much easier to open ones with a little notch to tear from?

Well if you’re tearing apart an airplane, it’s much easier to do that if there’s some sort of notch to tear from, like the corner of a rectangle cut in the skin.

If you don’t use any sharp corners, that makes the whole skin much less likely to develop “tears” from all the forces acting on it in flight.