For a galaxy that’s supposed to be humming with alien radio waves, space seems eerily quiet. A new study suggests it might be because aliens can see that we don’t have the quantum hardware to hear them—at least not yet.

Of course, there are plenty of plausible explanations for why years of searching have failed to find even a hint of a nonhuman intelligence among the stars. Maybe they’re all too scared. Maybe they’re all dead a long time ago. Maybe we’re just too boring. Maybe we just need to be patient. Maybe we really are alone.

Or, according to theoretical physicist Latham Boyle of the University of Edinburgh, aliens may be too cool for the old school because they’ve discovered the benefits of using qubits to increase bandwidth.

“The possibility of interstellar quantum communication is intriguing because it fundamentally expands the concept of interstellar communication,” Boyle explains in his paper, which you can download from the arXiv peer-review server.

If quantum communication does exist, it would be a triumph for advanced technology on our planet, but the process would be impossible to detect without major hardware upgrades. Classical communication uses the basic properties of electromagnetic waves to send messages.

Tuning the properties of photons, such as their number or frequency, could transmit information that remains readable across vast regions of interstellar nothingness, allowing a technological species like us to transmit sounds, images, and text at the speed of light. As humans have discovered in the last century, there is more to a light wave than its size and length.

Quantum mechanics is where classical physics meets gambling, combining the mathematics of probability with the laws that determine how particles work.

Based on this peculiar way of thinking about the universe, light waves can exist in blurry states, their fates entangled, so that the sum of their properties can be used to calculate, observe, transmit, and even teleport information, just as individual photons can. do it yourself

The experiments showed that the fuzzy state of a photon’s probability remains unchanged over quite impressive distances, making the concept of interstellar quantum networks possible in principle.

To consider how aliens might use the quantum nature of light instead of classical communication technology, Boyle compared the information capacity of each and the different ways errors could disrupt classical, quantum, and combined transmissions.

Accurately sending a radio signal over any distance depends on the receiver receiving at least a small fraction of the light waves. Theoretically, a single photon could carry meaningful information, causing many unnecessary light waves to be lost in space along the way.

This is not the case in quantum communication, where multiple photons are involved in a single transmission; many of them must be received in a precise state for the message to be interpreted correctly.

According to Boyle’s calculations, any transmitting and receiving antennas would need to be wider than 100 kilometers (more than 60 miles) to accommodate enough quantum states to sustain the trip. This is also a best-case scenario, optimistically picking up the highest-frequency waves from our nearest galactic neighbor that can easily pass through Earth’s atmosphere.

Smaller dishes can collect shorter wavelengths, but they would need to be above our atmosphere, like on the Moon, to have any hope of collecting enough photons. Or smaller dishes could be used in a two-way loop where quantum signals accompany classical signals, softening the error correction process enough to allow a few more photons to be lost along the way.

That said, any alien willing to quantum-shout at us would probably have the technology to see our planet in enough detail to conclude that it wouldn’t hear them. So they didn’t even try. The work is available on the pre-release server arXiv.