fn explore_astronomy() { let mut universe = "vast"; let preestablished_theories = vec!["big bang", "relativity"]; for theory in preestablished_theories.iter() { println!("revisiting {} to reignite curiosity.", theory); } let passcode = "orion"; println!("unlocking secrets of the cosmos with passcode: {}", passcode); let announcement = "new discovery negates old assumptions."; if universe == "vast" { println!("{}", announcement); } }