Antipasto Hardware

The New York Port Authority had egg on its face recently when a stranded jet skier managed to breach JFK International Airport's security perimeter and walk across several runways.

Raytheon, maker of the $100 million Perimeter Intrusion Detection System, has some explaining to do.

But it's not all bad. Inspired by the breach (and Shark Week), Justin Huynh and friends at engineering firm Liquidware have concocted their own intruder alert system for far fewer bucks.

Essentially, it's a simple laser tripwire that sends alerts to Twitter when activated. So far, it works with toy sharks and not hapless jet skiers.

The setup is very simple. A laser pointer is positioned on one side of an aquarium and fired at an Arduino light sensor on the other.

The sensor is hooked up to a BeagleBoard computer paired with a small BeagleTouch OLED display. The system runs Android.

When Bruce the plastic shark swims across the laser light, the kit displays an alert on the display, and can post a warning to Twitter, too. Check it out in the video below.

It's a fun experiment, but assuming the engineering challenges could be met, might a robust underwater version of this actually help prevent real sharks from nibbling on humans? Perhaps, says Huynh.

"Making this work on real sharks would require: a powerful, underwater stationary laser beam (apparently this exists), a receiving photosensor, and a finite distance of water through which the laser would be known to penetrate.

"How far the laser could go would depend on the opacity/diffusion of the water, and you could tune the sensors to go off only if blocked for greater than a certain amount of time, to avoid picking up small fish. It would probably would work better in clear shallow waters (think the Caribbean) than the deep blue sea."

And if real laser-wielding sharks swim by, you could sell the film rights.