Regarding seeing the curve of the earth from the Concorde, it took about 3
seconds to find the explanation.  When you look through curved glass, you
see a curve.  All the photos I saw from the Concorde with the square, flat
windows show a flat horizon.

https://www.telegraph.co.uk/travel/travel-truths/why-do-aircraft-planes-have-round-windows-not-square/