What Was “Carbonite Freezing” actually for in Cloud City?

On my bajillionth viewing of Empire I realized that they tested it on Han Solo - even offering to pay Boba if it killed Solo - so they would know if it would work on Luke. So...what the hell was it actually for and why did Vader want to freeze Luke in the first place? via /r/StarWars https://ift.tt/2CZwozK