It was once thought that vacuums–like the vacuum of space–contained nothing. No particles, no sound, just empty darkness. But it has since come to light, thanks to discoveries in quantum physics, that virtual sub-atomic particles constantly and spontaneously appear and disappear, even in the void. Which doesn’t mean a whole lot unless you’re trying to build the ultimate random number generator.

Tapping this spontaneous cascade of sub-atomic particles within vacuums, scientists at the Australian National University have built the world’s fastest random number generator by listening in on the action. Using lasers, the team has created a device that can listen to the random noise in the vacuum and use it to generate truly random numbers, which have myriad uses in encryption, information technology, computer modeling, and other complex tasks.

Most existing random number generators work off of some kind of computer algorithms. Those algorithms are pretty good, but if you know the inputs you can figure the outputs. In other words, the numbers aren’t truly random, they are just correlated in a way that is unknown to the user. But Vacuum noise is truly random–quantum theory ensures the numbers are truly unpredictable. By measuring the noise in a vacuum, the team can generate billions of random numbers per second. The only thing limiting them in their ability to flood the world with random numbers is the capacity of their Web connection.

But that doesn’t mean you can’t get your very own sequence of unique random numbers off the Web. Access ANU’s randomness generator here.