#2: Why are blueprints blue? Why did I never wonder why blueprints were blue and not some other color? Now that computer-aided design is all the rage, this is almost like asking why buggy whips were made from whalebone. Crap, why were buggy whips made from whalebone?
Anyway, to answer the question, John Herschel (son of William Herschel, who discovered Uranus) among his many scientific pursuits was involved in early photography (indeed, he coined the term 'photography'). One of his early inventions was the cyanotype. Although the process is pretty simple (coat paper or linen with a solution, expose, and wash with water), it wasn't a super success as a photographic method (though the first book ever published with photographic illustrations was Anna Atkins' book of cyanotypes of seaweeds). However, in the absence of photocopying machines, this simple process became the standard reproduction method for line-drawings, forming the negative image blueprints we know today. Or used to, now that they're dead as the dodo.
#3: The vibrator was "the fifth electric appliance to arrive in the home -- after the sewing machine, the fan, the teakettle and the toaster." Originally designed for use by doctors, the vibrator helped to liberate doctors from the time-consuming chore of having to manually stimulate women to orgasm in order to combat hysteria.
For more info, you can Read the Book or Watch the Movie bow-chika-bow-bow.