Yet they can't explain what happened to the BLUE sky. They can't explain the gap between trails. They can't explain why one jet leaves a normal dispersing trail while another leaves a massive long trail at the same altitudes, They can't explain why if they saw them before the 1990s, they did not discuss them back then. They can't explain why some days there are no trails. Guess flights were cancelled that day. They can't tell you their age because they were not alive back then. So how would they know what the sky looked like? They can't explain..........