One of the Apple Watch's coolest features was inspired by lightsabers

Apple designers spent over a year perfecting the vibrating function of the Apple Watch, which buzzes your wrist to let you know that there's a notification.

$4, detailing how $4 to the finished product that will start appearing in stores on April 10.

The "taptic engine" on the back of the Apple Watch has a collection of different vibrations that mean different things. Apple vice president of technology Kevin Lynch said that "Some were too annoying. Some were too subtle; some felt like a bug on your wrist."

Apple wanted to experiment with different kinds of vibrations, so it sampled different sounds and turned them into physical movements that the taptic engine could make. Wired says that Apple used the sound of lightsabers, bells and birds to find out which vibrations worked best.

Weirdly, Apple has a history with lightsabers. Its design chief, Sir Jony Ive,$4. They got talking, and Ive turned the discussion to the upcoming Star Wars movie, which Abrams is directing. Ive gave him "very specific suggestions" about how lightsabers should look in the new movie.

Here's what Ive told the New Yorker about his conversation with Abrams:

It was just a conversation ... I thought it would be interesting if it were less precise, and just a little bit more spitty ... [a lightsaber should be] more analog and more primitive, and I think, in that way, somehow more ominous.

We don't know exactly what Abrams did with Ive's advice, but there's a distinctive-looking lightsaber in the Star Wars trailer that certainly matches Ive's description of his advice.