Funny how in a lot of sci-fi movies humans are threatened by dangerous aliens yet if an alien viewed the Earth it would see brutal wars, terrorism,etc

@SW-User good point!

My college professor told me ( a long time ago) about a theory that no alien race could ever travel outside its solar system because once a planet discovered nuclear power it would destroy itself first!

@4thdimensiondream Eh, perhaps, though there could also be instances where they don't destroy their civilization when they discover nuclear power and continue on developing into a space-faring civilization.