Starlight Could Really Be a Vast Alien Quantum Internet, Physicist Proposes

What if the universe is a giant alien chatroom, and we just can't understand it?
Starlight Could Really Be a Vast Alien Quantum Internet, Physicist Proposes
Image: Carlos Fernandez via Getty Images

Humanity has been attempting to make contact with aliens for decades, whether that means sending a golden record with our greatest hits into space aboard Voyager or searching the cosmic microwave background radiation for hints of life


But according to a new hypothesis proposed by Terry Rudolph, a professor of quantum physics at Imperial College London, alien communications might’ve been hidden right under our noses the whole time in the starlight.

“What I show is that alien civilizations can, in principle, run their own quantum internet in such a way that to the creatures excluded from the conversation (us!) we will only ever see thermal electromagnetic radiation,” Rudolph says in an email. “All we would see, if they did use the effect I propose, is some very random looking thermal light.”

In other words, Rudolph is suggesting that interstellar light could actually be harnessed by space faring aliens to form an encrypted quantum internet.

This may sound like the stuff of science fiction, but Rudolph says it was actually a natural extension of what he does as co-founder of PsiQuantum, a Silicon Valley-based company on a mission to build a scalable photonic quantum computer. He laid out his idea in a paper recently published on the arXiv preprint server.

Rudolph said the idea for the paper on aliens communicating with quantum starlight flowed from his work on quantum computers. Unlike the quantum computers being pursued by the likes of Google or Intel that use superconducting circuits or trapped ions at incredibly cold temperatures to create qubits (the quantum equivalent of a computer bit), photonic computers use light to accomplish the same thing. While Rudolph says this kind of quantum design is unconventional, it does also have advantages over its rival—including being able to operate at room temperature and easy integration into existing fiber optic infrastructure.


“It was while I was stuck trying to deeply understand one of those advantages that I decided to push my analysis to an extreme limit, a limit which I thought would end up being ridiculous and would definitely not work,” said Rudolph. “Instead I found things still worked, and the end result was the realization that certain incredibly simple photonic quantum effects are in principle usable by circumspect aliens (or humans!) for the quantum internet.”

The primary way the aliens would create this kind of quantum internet is through a quantum mechanics principle called entanglement, explains Rudolph. In a nutshell, entanglement is a phenomena in which the quantum states of particles (like photons) are linked together. This is what Einstein referred to as “spooky action at a distance” and means that disturbing one particle will automatically affect its partner, even if they’re miles apart. This entanglement would allow aliens—or even humans—to send encrypted signals between entangled partners, or nodes. Now, scale that single computer system up  to a network potentially spanning the entire cosmos. 

Aliens aside, Rudolph says that his paper demonstrates that building a photon-based quantum internet here on Earth might be “much easier than we expected.”

As for the aliens, even if they were using this kind of technology to transform waves of light into their own personal chat rooms, we’d have no way of knowing, says Rudolph. And even if we could pick out these light patterns in the sky, we still wouldn’t be able to listen in.

“A distinct but important point is that even if your adversary can intercept and listen in on your communication, the quantum internet is provably securable,” says Rudolph. 

This is due to the incredibly shy nature of quantum particles—any attempt to observe them by an outside party would alter their state and destroy the information they were carrying.

“So even if the aliens slip up somehow, and we do work out that they are communicating using the scheme I proposed, the amazing quantum effects which make the quantum internet secure would still prevent us having any hope of working out what they are saying,” he said.

“Kinda depressing for those of us who would like to listen in.”