Star Trek talked about transparent aluminum (which is possibly possible now), but something different can also be done with the light metal. Foam aluminum is lighter than regular aluminum, naturally, and also better in crashes. Simple variations on existing resources can have a large effect. Aluminum is recyclable, allows for more energy efficient vehicles, and foamy aluminum can replace resin-intense materials like fiberglass. Strange and useful stuff.
“New Aluminum Foam Makes Trains Stronger, Lighter, Safer” – Wired
Pretending Not To Panic 