
3. Mercury Vapor Bulb
Growing up, we might’ve used mercury vapor bulbs in science class. That’s not their only use. They’re used as movie props, too. In ‘The Saint,’ a hydrogen power device is a mercury vapor bulb. We never would’ve spotted that one, so thankfully, this Reddit user pointed that out. It might even bring back horrible memories if science class was your least favorite subject. It wasn’t our favorite (via SavingsTask).