Here is a story i knew. I have been an aviation enthusiast for 9 years (And counting) so my younger self knew this stuff too. Once like 7 or 8 years we saw 2 contrails in the sky and it looked like they were gonna hit. all the little kids were saying "Omg those idiots they are gonna hit each other if they do not turn" They intersected like the contrails looked like they hit but then kept going (As obvious as their contrails now forming an X shape) And all those little kids were like "WHAT???" and they turn to me because they knew i know this kind of shit. and im like "IDIOTS. It's obvious they are at different Altitude. If they were really gonna hit, a collision warning system would have warned them LONG before it happened"