This could be an element of a home security system. When an intrusion is detected the blade protruding from the object begins to rotate at high speed; faster than sight.
At faster than sight speed, the blade strikes the intruder's hand when they reach for the shiny item.-- rcarty, Oct 17 2013 Perhaps there's a non-maiming application for this tech? Chopping herbs?-- the porpoise, Oct 17 2013 Not inside a vacuum, they don't.-- Alterother, Oct 17 2013 //Not inside a vacuum, they don't.//
That would also render moot the other detectability problem, being motor sound. Maybe this idea would be viable inside a largish bell jar, preferably with an airlock to permit the thief to enter.-- the porpoise, Oct 17 2013 What would prevent the thief from stealing the bell jar?-- Canuck, Oct 18 2013 Micron thin blades. No blade tilt, no wind.
//At faster than sight speed//
[marked-for-tagline]-- 2 fries shy of a happy meal, Oct 18 2013 "You could tell if you were hiring an experienced Burglar by asking him to hold his hands up." said Bilbo to Gandalf.-- popbottle, Oct 18 2013 //Not inside a vacuum, they don't.//
Items of sentimental value should be stored in outer space, where the cost of going to steal them would exceed their value to a thief. It works well with stars.-- pertinax, Oct 21 2013 My daddy was a fan miner. He died of the windy lung.-- the porpoise, Oct 21 2013 random, halfbakery