Interesting piece from the quantum communications perspective. It can be serious or comical depending on whether the title is kept in mind. With PsiQuantum as a contributor (PsiQuantum just reeled in $400M+) we must ask “Was it all from we Earth bounded beings or is their something extra-terre$trial contributing?” Because Quantum is Coming. Qubit

Perhaps they are everywhere? Undetectable distributed quantum computation and communication alien civilizations can be established using thermal light from stars

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+  We show that free-space diffraction of photons distributes highly useful entanglement: the receivers of the propagated modes can do a distributed quantum computation using only linear optics and photon counting.

+  The distributed computation requires classical communication between receivers, however, similar to standard measurement-based computation, that communication is of purely random outcomes and so can be indistinguishable from noise. The speculation in the title arises from the further observation that the natural way for a circumspect civilization to hide their photonic entanglement distribution is to use the thermal light already being
emitted from the various stars they visit.

+  This requires them knowing the number of photons in the modes they have chosen to use, and as such they would need to perform a quantum non-demolition measurement of photon number. Because the thermal light they are measuring is diagonal in the number basis even this process can be rendered in principle indiscernible to those of us excluded from the conversation.

Source:  PsiQuantum & Imperial College London (Cornell University’s arXiv.org).  Terry Rudoplh,  Perhaps they are everywhere? Undetectable distributed quantum computation and communication alien civilizations can be established using thermal light from stars [PDF]…

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