Now apply Occam’s razor to the following two choices:
1. Aliens have visited Earth. They crashed their spaceships or we shot them down. The US Government (and possibly other governments) retrieved and studied their technology and managed to keep it a secret for decades
1. Aliens have visited Earth. They crashed their spaceships or we shot them down. The US Government (and possibly other governments) retrieved and studied their technology and managed to keep it a secret for decades
2. Aliens have not visited Earth