Scientists have for the first time sent a message using a beam of neutrinos, through 240 meters of solid stone.
The team's not telling us how long the message - which said, simply, 'Neutrino', took to arrive.
"Using neutrinos, it would be possible to communicate between any two points on Earth without using satellites or cables," says Dan Stancil, professor of electrical and computer engineering at North Carolina State University.
"Neutrino communication systems would be much more complicated than today's systems, but may have important strategic uses."
The most intriguing thing about using neutrinos to communicate is that they can penetrate almost anything they encounter. This could be a particularly useful feature for submarines, for example, or for sending messages in space, allowing them to travel straight through a planet.
Because of their neutral electric charge and almost non-existent mass, neutrinos aren't affected by magnetism or gravity, so can travel almost unimpeded.
The experiment was carried out at Fermilab, using its particle accelerator and a multi-ton detector called MINERvA, located in a cavern 100 meters underground.
The message consisted of the word 'Neutrino' in binary format. The neutrinos needed to be fired in large groups, because they're so hard to spot that, even with a multi-ton detector, only about one in ten billion is detected.
After the neutrinos were detected, a computer on the other end translated the binary code back into English.
"Of course, our current technology takes massive amounts of high-tech equipment to communicate a message using neutrinos, so this isn't practical now," says University of Rochester physics professor Kevin McFarland.
"But the first step toward someday using neutrinos for communication in a practical application is a demonstration using today's technology."