A favorite editor of mine long ago told me never to begin an article with a question, but do I ever listen to her? Sometimes. Today’s lead question, then, is this: Can we expand communications over interstellar distances to include quantum methods? A 2020 paper by Arjun Berera (University of Edinburgh) makes the case for quantum coherence over distances that have only recently been suggested for communications:
…We have been able to deduce that quantum teleportation and more generally quantum coherence can be sustained in space out to vast interstellar distances within the Galaxy. The main sources of decoherence in the Earth based experiments, atmospheric turbulence and other environmental effects like fog, rain, smoke, are not present in space. This leaves only the elementary particle interactions between the transmitted photons and particles present in the interstellar medium.
Quantum coherence is an important matter; it refers to the integrity of the quantum state involved, and is thus essential to the various benefits of quantum communications. But let’s back up by tackling a new paper from another University of Edinburgh researcher, Latham Boyle. Working at the Higgs Centre for Theoretical Physics there, Boyle cites Berera’s work and moves on to explore quantum communications at the interstellar level and their application to SETI questions.
Traditional communications involve bits in one of two states, 0 or 1. Quantum bits, or qubits, can exist in superposition, meaning that a qubit can represent a 0 or a 1 simultaneously. Here I pause to remind all of us of the famous Richard Feynman quote: “I think I can safely say that nobody understands quantum mechanics.” Which is in no way to play down the ongoing work to explore the subject, given its mathematical precision and the fact that experiments involving quantum physics produce results. Thus another famous quote attributed to David Mermin: “Shut up and calculate.”
In other words, use quantum mechanics to get results because it works, and stop getting distracted by the philosophical issues it raises. I am trying to do this now, but philosophy keeps rearing its head. The specter of George Berkeley wanders by…
But back to quantum methods and interstellar information exchange. The Berera paper makes the case that at certain frequency ranges, photon qubits can maintain their quantum coherence over conceivably intergalactic distances. Fully understood or not, quantum communications opens up a wide range of effects that are interesting in the interstellar context. Boyle notes that protocols based on quantum communication offer exponentially faster performance for specific ranges of problems and tasks.
Let’s drill further into quantum benefits. From the paper:
First, it is already known to permit many tasks that are impossible with classical communication alone, including quantum cryptography [10, 11], quantum teleportation [12], superdense coding [13], remote state preparation [14], entanglement distillation/purification [15–17], or direct transmission of (potentially highly complex, highly entangled) quantum states (e.g. the results of complex quantum computations). Second, protocols based on quantum communication are exponentially faster than those based on classical communication for some problems/tasks [18], in particular as measured by the one-way classical communication complexity [19–21] (the number of bits that must be transmitted one-way, from sender to receiver, to solve a problem or carry out a task – possibly the notion most pertinent to interstellar communication).
Boyle explores these advantages and associated problems through the quantum capacity of a quantum communication channel, constraining this by examining the properties of the interstellar medium in light of what are known as quantum erasure channels, which model error correction and channel carrying capacity. The question is: How much information can be reliably carried over a quantum channel even if some photons are lost in the process? And it turns out that these constraints mean that the choice of frequency bands is critical.
Image: This is Figure 1 from the paper. Caption: Quantum communication with Q > 0, over distance L, is impossible at wavelengths where the horizontal line corresponding to L lies within the blue shaded region (summarizing the Milky Way ISM’s extinction curve). Gray regions are off limits from the ground. Adapted from [23, 26], with data from [30–37]. Credit: Latham Boyle.
The interstellar quantum communications channel Boyle studies is one in which photons can be erased in three different ways, the first being their absorption or scattering due to the interstellar medium between sender and receiver. Thus the pink line in the figure, indicating the frequency that a sender on Proxima Centauri would need to select to reach the Earth. A second problem is extinction within the Earth’s atmosphere, demanding a wavelength that avoids the gray bands of Figure 1 (hence the benefit of a receiver in space as opposed to Earth’s surface). Finally, photons can be lost due to the spreading of the photon beam as it moves between sender and receiver.
To avoid depolarization by the cosmic microwave background, the wavelength of our photon channel must be less than 26.5 cm (the frequency is about 1.13 GHz), but for communication between stars Boyle calculates that we need to get into the ultraviolet range, with wavelengths as short as 320 nm. Doing this makes our communications channel far more efficient, for we can work with a narrower beam, but having said that, we now run into trouble. Let me quote Boyle on one of several elephants in the room:
This third erasure constraint is the hardest to satisfy! Whereas classical communication (C > 0) can take place even if the receiver only receives a tiny fraction of the photons emitted by the sender, forward quantum communication (Q > 0) requires large enough telescopes that the sender can put the majority of their photons into the receiver’s telescope (Fig. 2b)! Even in the best case, taking the nearest star (Proxima Centauri, L = 1.30 parsec) and the shortest wavelength available from the ground (λ = 320nm, see Fig. 1), this implies D > 100 km!
We can pause here to note, as Boyle does, that the largest telescope currently under construction (ESO’s Extremely Large Telescope) has an aperture of 39 meters. To reach the staggering 100 km suggested by the author, we would have to explore coherently combined smaller dishes using optical interferometry. Boyle notes that quantum teleportation involving photons has been demonstrated at 100-kilometer baselines at sea level and 1000 km baselines from Earth to a satellite. Thus a ‘coherent dense array of optical telescopes over 100 km distances’ may be ultimately feasible. A great deal of research is ongoing on the subject of manipulating quantum states. The author notes work on quantum repeaters and quantum memories that may one day be enabling.
Why would a civilization want to use quantum communications methods given problems like this? For one thing, sending complex quantum calculations becomes possible in ways not available through classical communications. Remember that each qubit can exist in a superposition of states, manipulated by algorithms impossible on classical computers. Quantum error correction and quantum cryptography are among the other advantages of a communications channel based on quantum methods. In addition, extraordinarily high resolutions could be obtained by telescopes using astronomically long baseline interferometry (ALBI) via quantum repeaters.
An intriguing thought concludes the paper.
…we have seen that (setting aside the loopholes mentioned above) the sending and receiving telescopes must be extremely large, satisfying the inequality in Eq. (1); but this same inequality implies that, if the sender has a large enough telescope to communicate quantumly with us, they necessarily also have enough angular resolution to see that we do not yet have a sufficiently large receiving telescope [49], so it would make no sense to send any quantum communications to us until we had built one. Thus, the assumption that interstellar communication is quantum appears sufficient to explain the Fermi paradox.
So there you are. This method of information exchange demands such large telescopes that if an extraterrestrial civilization had them, they could quickly determine whether we had them. And because we don’t, there would certainly be no reason to send a signal to us if quantum methods were deemed necessary for a worthwhile exchange.
The paper is Boyle, “On Interstellar Quantum Communication and the Fermi Paradox” (preprint). The Berera paper is “Quantum coherence to interstellar distances,” Physical Review D 102 (9 September 2020), 063005 (abstract / preprint).
1. If the telescope must be large, why cannot a solar gravity lens telescope work as the collecting lens? IOW, a small telescope at the SGL could be used to receive and transmit quantum signals.
2. The logic of ETI not sending as they can see we do not have a suitable telescope is false. ETI at Proxima could send us classical signals with instructions on how to build a quantum telescope. We build it and then more efficient quantum signalling can be achieved.
3, Does quantum teleportation allow, in principle, the teleportation of larger objects including people? If so, a galactic travel network could exist to allow embodied minds to travel between stars at light speed rather than using spaceships. P K Dick wrote “The Unteleported Man” about teleporting colonists.
4. If quantum signals are very information-dense, wouldn’t ETI signals be very transient “blips”? Along a similar line, James Blish wrote a sci-fi novel The Quincunx of Time (1973) about a device that could receive all signals ever sent across time and received as a “beep”. [ For Paul’s reference, the novel was based on a short story “Beep” published in Galaxy Science Fiction, February 1954.]
Thanks, Alex. I’m going to pull that issue and read ‘Beep’ today. I recall the novel, though that was an even longer time ago!
I read that novel so long ago, that I can hardly remember much more than the title, which did stick in my mind. If I read it when it was published as a paperback in 1976, that was nearly 50 years ago! The Quincunx of Time (cover art by Chris Foss) I’m guessing this was the ppbk version I bought at a W H Smith’s in London.
Andrei, the distance to Proxima Centauri is approx 264,000 AU. That’s 4.24 light years x 63,241 AU per light year. Stay safe. J D 9
“The Quincunx of Time” by James Blish
I already had read this one, and found it intriguing. And quite staggering to consider the possibility of an ongoing exchange of information between various stellar systems that we’re unable to tap into or see. A message would have to be sent directly at us for it to be known, eavesdropping on what other civs are telling each other is simply not possible. Which means this is not a feasible new direction for SETI, even if we could build that +100 km or larger dish required.
So while interesting, this is a hypothesis we neither will be able to confirm or disprove which make the matter quite a bit hypothetical.
II think you are correct about communication with ETIs. However, it has relevance for human interstellar communication with probes to the nearer stars as it’s a way around the low power transmission issues with error-correcting signal frequencies. Just think how long a single megapixel image of Proxima b would take with a tiny Breakthrough Starshot probe transmitting the data back to Earth.
Thank you for your reply Alex.
You’re right that the idea of sending image information with a mobile phone transmitter operating on a fraction of a Watt (Or in best case a few watts) will not be possible. The New Horizons demonstrate this in a clear way, where it took weeks and months for images to arrive at earth at distance of a mere 32,9 AU. While the distance to Proxima B is around 13000 AU.
If we somehow could place NH in the Proxima system we’d be happy to even get a ‘bip’ that confirm that it’s there and healthy.
But here the proposal is for photons in the ultraviolet range, which require a quite capable laser – so I really don’t know how that would fit in the proposed setup for Breakthrough Starshot probes.
@Andrei
I look at these proposals from economics and performance perspectives.
For example, using the same power source for the transmitter, what is the receiving equipment needed and what is the cost of receiving the signal.
Or given the same 100km size receiver, what is the transmitted power needed to receive the signal at the same bitrate.
Lastly, what is the minimum cost of sending the transmitter to the target to receive a “useful signal” given existing receivers
we already have.
The tradeoffs in feasibility, performance, and cost need to be evaluated to decide on an approach. With the comment you made, does the transmitter mass rule itself out given the size of the BS probe?
Hello again Alex.
Yes indeed, economics will always be a limiting factor, regardless if its funding, resources or qualified people willing to work on the project.
The entire electronic package for the Breakthrough Starshot probes would be counted in grams only, and even if some variety of small semiconductor diode lasers could be added, and such certainly can be made to work in the needed ultraviolet range. The strength fall far short of what is needed for sending messages over the distance involved. There simply will be too few photon packages arriving since the entangled state is actually quite fragile, and then there’s polarization drift. The final blow to me is the required 100 km dish / reflector when one consider how hard it got to get the JWST telescope up – and it very nearly got cancelled.
I would cheer as much as anyone if they could get this to work, so I will stand corrected if someone tells us that such laser communication actually could be made to work on such limited power and in such a lightweight package.
I don’t know, in fact, I have no way of knowing, if this sort of instantaneous type of communication is possible (I visualize it as something akin to the ‘ansible’ as described in Le Guin’s “The Left Hand of Darkness”. On the other hand, if such a technology is possible, and easily achieved by any civilization with a physics based technology, then one big question related to the notorious Fermi Paradox is immediately resolved!
Instantaneous communication between interstellar communities becomes convenient. Slow, expensive, highly inefficient transmission of electromagnetic radiation need not be necessary to talk to our pen pals. As for those civilizations that are incapable of, or have not achieved the tech yet, they can simply be dismissed as ‘uncivilized’ or ‘primitive’. Why bother trying to raise the yokels when there may be plenty of advanced folk out there ready to talk?
All those SF tropes, the Encyclopedia Galactica, the Galactic Club, Empires, Zoo Hypothesis, etc not only become possible, but we have a perfectly good excuse for not having stumbled onto any of them yet.
As in FTL, the ability to communicate instantaneously may violate our understanding of physics, but we are humble enough to realize our knowledge of the universe may be highly incomplete. We cannot rule it out of our speculation.
I cannot prove it conclusively, but I suspect there is no FTL, and no ansible. And I also suspect (again, without conclusive evidence) that no, or very few, other intelligent species occur in our Galaxy at this point in time (lets be honest, the tenure of genus Homo is only a tiny instant in Deep Time).
God has a cruel sense of humor. I would not be too surprised he created us with an insatiable curiosity and yet made it impossible for us to ever fully satisfy it.
I don’t think the article mentions speed of transmission as a benefit. As far as i know, there is still no hypothesized way of sending information faster than C.
Exactly so. The speed of light remains the limit. This always gets difficult to explain because of entanglement, and I may have to write something up about this in the near future. Entanglement is real but it does not allow for faster than c communication. Another way to say it is that entanglement alone cannot be used to send a message.
I don’t get that the author is saying that FTL communication is possible. It is only that quantum states allow for the superimposition of many states – the reason why there is research into quantum computers. Success would crack current cryptographic methods using large primes and potentially solve several np hard problems, or at least make them feasible to be useful. My sense is that the advantages are the information density. The disadvantage is the size of the telescope. Even using gamma rays with 1000x smaller wavelengths only reduces the telescope size to 2.7 km! Economics seems to trump this idea, although I do wonder whether a gravity lens would solve the telescope size problem, even Kipping’s TerraScope” would provide the needed size if it allowed the capture of enough of the quantum photons.
Henry, it’s not instantaneous, the information intangled or not can only propagate at the speed of light and no faster.
Quantum communication is not instantaneous. It is bound by c as any other type of communication. The entangled photons still need to travel the distance.
I stand corrected on the instantaneous transmission toodle-oo.
But isn’t there some kind of idea of entangled particles being shipped to another location (by spaceship, say) and then their entangled particles modulated and the message instantaneously appearing at the second location.
It was my understanding that each particle had a “brother” particle of the same state, and that any change occurring in one was instantaneously reflected in the other, regardless of the distance between the two.
IOW, the ansible is carried by a vehicle of some sort to another location, perhaps many light years away. The other unit remains behind. But the two units are quantum-entangled, so a message entered on one immediately is transmitted to the second.
At any rate, if its not instantaneous communication, what’s the benefit of this technology?
Henry, I’m hardly an expert on this, but I do know that entanglement features as a key part of quantum cryptography, where the entangled particles create security because any attempt to intercept them disturbs their entangled state. Entanglement allows qubits to be in superposition and solve problems much faster than with classical computing methods. Maybe some of the readers can expand on how teleporting quantum states can feed into the growth of quantum networks. So there’s a lot going on here.
When two particles become entangled it means that no mater how far they are separated they will always display a particular property, such as spin direction, whenever an observation is carried out. The weird bit is that this property is not decided when the entanglement occurs but only when the observation is made. So, if I have a pair of entangled particles and send one to you, we will both have a particle but won’t know what its spin is until one of us makes an observation. If I make an observation on my particle before you do, and it comes up spin up, then I know that when you look at yours you will also see spin up. But – there is no way of forecasting what the particle state will be, and the particle cannot travel to you at FTL speed. It’s a very interesting phenomenon but I can’t see how it offers any opportunities for faster communication.
Yes, the change between the entangled particles occurs instantaneously, but we cannot control the change. It is entirely random. So it cannot be used to send information. For example, if we measure our particle to have spin up, we can be certain that its entangled partner 10 parsecs away will show spin down at the same time, but we have no way to make our particle to have spin down. It’s spin is random up or down. So we cannot use it to code a binary message. That’s the state of QM for now. In the future someone may be able to find a trick to do it, but at present it’s forbidden.
VIY, its the energy or taking of energy to carry out the observation of its state that disturbs the state, at the atomic level practically any energy influences the system. Perhaps the spin of the particles can be divided into their different states at the beginning and then entangle those as we should know with high certainly what they are without observing them.
Sez the billion year old civilization of us?
For the photon that leaves this solar system and arrives at the other end of a galactic cluster, the instant of departure is the instant of arrival after a journey of millions of light years: the perceived instant here and now is the perceived instant at such a vast remove elsewhere and
elsewhen.
The non-Abrahamic God in some instances barely exists, in others does not exist and in yet others has an existence (“Self of all selves”) in a paradigm shift that excludes from reality any difference between the individual and the Source.
In my view quantum communications is not the solution to the Fermi Paradox. I think the solution to the Fermi Paradox is that there is no paradox. It is and always was based on the flawed assumption that “there is no evidence…” which is used to justify programs like SETI as the only scientific approach to the question while dismissing out of hand taking a serious look at what’s happening in our own skies and historical records especially in light of the fact that our own physics has cracked the door at least theoretically on faster than light travel. Add to that recent whistleblower testimony from military and government sources of evidence covered up from the public and it strongly suggests there is ample evidence but also an intransigent and persistent official coverup.
You lost me at “intransigent and persistent official coverup”. I don’t think “the authorities” are competent enough to successfully cover up a story that big for so long.
I was born in 1947, the same year the term “flying saucer” was coined. I was formally trained as an astronomer and I’ve spent my entire career working in related fields and as an active amateur, one well informed on astronomical issues and controversies. I’ve spent my whole life looking up at the universe, with my naked eye or through the eyepiece, or through libraries and periodicals, or through debate with like-minded, informed folks.
I certainly have seen things in the sky I could not identify, but nothing I could definitely say was evidence of an extrasolar species or alien technology. And I’ve never heard testimony of any such sighting that I could believe was genuine. In fact, most of those accounts lack credibility because they fail to communicate how totally strange and bizarre a legitimate encounter with alien technology would have to be.
I just don’t believe any of it. Do I think ETI its impossible? No, that’s why I frequent responsible web sites and chat groups like this one. I consider myself an amateur astrobiologist and sincerely hope that someday I learn of the existence of alien life, and even better, of alien extraterrestrial intelligence. But do I believe any of the accounts I see on Youtube or Congressional committees or the History Channel? No. Those people are either mistaken or they are lying.
I don’t believe a word of it. I don’t believe in Bigfoot, Nessie, Yeti or UFOs. I don’t believe they are impossible, after all, they do not violate any of the laws of physics so I cannot rule them out altogether. I just don’t believe the people
who claim to have seen them, up front, up close are believable. They are either mistaken or they are lying.
Henry, I merely said it suggested a coverup not that that proves there is one. But I think because of the very nature of the issue, a coverup is easy. As long as there is never any official acknowledgement, anyone who does reveal information will be ridiculed by people who are not even part of the conspiracy. I suspect government denials such as the very recent denial by the Pentagon of information released by Luis Elizondo who worked for them is a case in point. I believe the office and individuals issuing the denial are themselves likely sincere and not involved in any conspiracy. They are just doing what public agencies do, defending their credibility against the perception of nonsense.
As for me, I don’t know what’s true or not but the military admits it is dealing with an unknown in these encounters.
What is much more likely, if there is indeed a sinister government cover-up, is that the UFO story has been fabricated in order to distract prying minds from some OTHER clandestine operation or technology, one with a much more conventional terrestrial origin.
What better way is there to confuse or obscure some secret project than to divert journalists and hobbyists into an alternative universe of UAPs, BEMs, and LGMs? The supposed official ‘confirmations’ of these whistleblower revelations and congressional witnesses has always been from low level officers of dubious identity and rank. If the military had indeed wanted to lend any credence to these stories, it would come from the Secretary of Defense, at a real press conference, not a terse press release from some obscure official, complete with some (possibly) photoshopped data from secret DOD sensors.
To pick an example from safely in the past…if it was necessary, at all costs, to prevent the Soviets from learning we were using high altitude balloons to sample the isotopic residues of their nuclear testing, the knowledge of these devices could be leaked deliberately as flying saucer crashes, complete with deceased alien crewmen of suspicious humanoid anatomy. It should be noted the ‘official’ balloon explanation of the Roswell incident only came well after our knowledge of Russian bomb testing was old news. I’m not saying that’s what happened, just that it is a plausible explanation.
Anyone who has ever worked in the spook community is familiar with stories like this. Trying to follow up on them invariably leads to dead ends.
Of course, that’s the whole point. And it stands to reason, even if you do get lucky and stumble onto the truth, no one will believe you.
In WWII disinformation was used to claim that RAF pilots eating carrots was the reason for their superior performance in downing German aircraft, to hide the development of radar technology.
A WWII Propaganda Campaign Popularized the Myth That Carrots Help You See in the Dark
I find it interesting that people can believe that large numbers of people, e.g., government agencies, the military, and large corporations, can keep secrets indefinitely when the evidence is abundant that they cannot.
Alex, the whole point is they don’t have to keep it, they just discredit those who talk. It isn’t even the same ‘they’. The misconception is there is a large ‘they’ in the know. If such a conspiracy exists, it relies on the natural skepticism of the establishment and of the scientific community at large.
Hello Henry
It would be interesting for your generation to tell how you lived this madness of the “flying saucer” of the 50’s and the retreat that you have today. I was born 6 days after the man on the moon…it’s exasperating:)
As a youngster I was a believer, my confirmation bias kicked in and I ignored every bit of evidence against, and treasured every positive opinion or report. But as with Santa Claus, I soon lost my faith. As a child fascinated by science, and particularly astronomy, I couldn’t help but notice I never saw one! Keep in mind, I was brought up in an era of dark skies, and I was always outdoors at night with my planisphere, my 7×50 monocular, and my Norton’s Star Atlas. If ‘they’ were out there, surely I would be the first to know.
After many hours looking up without seeing anything, I also noticed how my friends who occasionally accompanied me mistook plenty of celestial phenomena–aircraft, meteorological, and astronomical–as alien craft. I also noticed how easily and quickly they exaggerated and embellished sightings of ordinary objects and events to fit what they wanted to believe, not what they actually saw.
By the time I approached adolescence I understood that there was strong evidence to suggest that interstellar civilizations were possible, but that even the crudest knowledge of astronomy led to the inescapable conclusion that it was highly unlikely they were visiting us with any regularity.
One anecdote out of many:
One night while driving to visit my friend Bill, I watched a rocket taking off from the Cape (I lived in Tampa, about a hundred miles from the Space Center, and both day and night launches were easily visible to the naked eye). After arriving at Bill’s his family told me he had gone off looking for me because he had just seen a UFO! It soon became obvious we had both witnessed the same event, but he being from a northern state, he was not familiar with rocket launches from Cape Canaveral. I had time to devise a bit of a practical joke.
When Bill returned, he described what he had seen (and fairly accurately, he was a police officer and had been trained to accurately notice details and evidence). Since I had witnessed the same event, I was able to corroborate his description and quickly convince him I had seen the same thing! However, I then started gradually elaborating on my description, adding additional details, some quite outrageous, which he immediately agreed with. Before long, I had him enthusiastically remembering impossible maneuvers, outlandish visual eruptions, spectacular colors and other manifestations which were purely artifacts of my own imagination.
It was a textbook example of suggestion. I knew Bill was an honest, level-headed and skeptical man of some intelligence, but he WANTED to believe. The evening was a lesson to both of us. To this day, I am not convinced by eyewitness testimony, and I am even wary of my own.
Thank you, Henry. The question was rather how your generation perceived the 50s and early 60s in full “space race” and so how did you perceive the “UFO wave” ? but would be a vast subject.
It is obvious that the American society – then European – was “prepared” I would say almost formed in this sense, that is to say, it had to adhere to the idea of this “space race”. Just look at the toys of the time or movies like “space conquest”.
I would say that the populations – many peoples – accept the idea of leaving the earth (and to finance the budgets). The idea is rather recent even if Icarus and some other scientists were to fly
It was positive since it should raise vocations but I have the impression that in all this “breanstorming” we deliberately sowed a bit of doubt then let time do…
One of the big problems about UFOs is precisely the sociological aspect that is linked to the quality of the testimonies: the language barrier or words are powerless to describe many things ; it’s obvious when we read these testimonies. The emotion in the face of perceived real or subjective emotion; the cultural environment in which one has bathed and possibly the doubt deliberately sown…make it very difficult to relate facts (your police friend must know) There is always a part of subjectivity.
It is very difficult to remain objective in the face of the unknown precisely because the unknown offers a multitude of solutions…true or false.
An anecdote: in 2015, a neighbor retired, building engineer, 80 years old, a well-educated guy, serious, amateur and passionate about local history, saw 2 km from my home some “triangles”.
he testified to the police, the newspapers came and he even wrote a small book reporting the facts and offering explanations that he autographed me. For me who looks at the sky at night, this testimony was important because I know the country and man so I could compare some thing. Everything seemed true in what he described. I’m not saying he didn’t see anything, but it took me more than five years to think about the character and understand that ultimately he just wanted his name to stay in local history…I must say it’s pretty subtle (or twisted). He will be remembered as the guy who saw UFOs. Pierre is a nice guy and I do not make any criticism but I let you meditate about this story…
the paper : https://www-leparisien-fr.translate.goog/oise-60/liancourt-60140/liancourt-certains-m-appelaient-l-extraterrestre-29-05-2017-6995520.php?_x_tr_sl=auto&_x_tr_tl=en&_x_tr_hl=fr&_x_tr_pto=wapp
Let us not forget neutrino beams, if you want to talk fancy interstellar communications available only to the galactic elite:
https://www.centauri-dreams.org/2019/05/17/a-neutrino-beam-beacon/
and here…
https://www.centauri-dreams.org/2012/04/18/neutrino-communications-an-interstellar-future/
The author posits a space faring people that, knows we exist, wants to communicate and can build a conventional transmitter. Even if we assume there are messages that can only be communicated via quantum communication, they could send instructions for building a quantum receiver. To be an answer to the Fermi question, we would need to assume that understanding the quantum message could not be taught. That is not a completely absurd assumption.
Answering Fermi’s question requires we understand the cosmic environment. The known unkowns of general relativity like dark matter and singularities seem puny when compared to the known unkowns of quantum mechanics. What lifestyles does mastery of the measurement problem allow?
https://www.youtube.com/watch?v=4mcoCs6E3xc&t=359s
As a thought experiment, consider a beam splitter that sends entangled pairs of particles in diametrically opposite directions. Suppose polarization is the entangled property, random at particle pair origin. For any pair, to repolarize one particle near Proxima instantaneously repolarizes the other near Sol, but until you Solsters know its original polarization, you cannot know if we Proximals repolarized it.
The logic would seem to suggest that a physical installation halfway between two stars, like Sol and Proxima, could send a record of prior particle polarizations in both directions, along with the paired particles themselves, of which some could be repolarized via Bell nonlocality in either Sol space or Proxima space to send interstellar messages.
If so, and once you could disregard the time required to place the beam splitter halfway between the two stars because the placement was already done, thenceforth you might think quantum entanglement should make communication at roughly twice the speed of light theoretically possible.
In practice, calibration problems will forever prevent such 2c interstellar comlinks from happening. However, there may be less dramatic, more marginal improvements over c as the speed limit for communication that quantum entanglement can make possible (as anticipated by James Blish in the *Cities in Flight* references to ultrawave).
The idea of recording the state of the particle and the relay between the sun and Proxima is interesting but I don’t understand how we could have 2c? In addition, it seems to me that it complicates the process of transmission in an environment where the slightest state of energy (cosmic background) is disruptive for the particle which would require to encapsulate the message in crypto as in the article. In short: it is not the easy solution but why not…
Claire Isabel Webb, “Technologies of Perception: Searches for Life and Intelligence beyond Earth” (PhD diss., Massachusetts Institute of Technology, 2020
https://dspace.mit.edu/handle/1721.1/129021
The full paper in PDF format is in the above link.
Abstract
Scientists in the late 1950s in the United States gained technological capabilities to test for signs of extraterrestrial life. While exobiologists developed visual techniques to detect whether sites beyond Earth might harbor microbes, “biosignatures,” radio astronomers searched for extraterrestrial intelligence (SETI) in the form of “technosignatures.”
This dissertation explores how scientists since the Space Age have constructed experimental assemblages to imagine, relate to, and investigate the alien and exotic microbes — unknown, indeed, as-yet-imperceptible, objects — through familiar sensory metaphors of seeing (exobiologists) and listening (SETI scientists).
From historical material gathered at various D.C. archives, the American Philosophical Society, and the National Library of Medicine, I show how exobiologists’ technologies of vision rendered anew images of the Moon, Mars, Venus, and the Earth from afar and at surface, affording scientists the ability to conceptually anticipate relationships between their world and others.
Through a epistemic practice I call “gaze-scaling,” they yoked the concept of “island” to “planet,” casting extraterrestrial sites as fragile laboratories of life that beckoned exploration. I next draw from immersive participant observation since 2016 to engage ethnographic sonar on the SETI group Breakthrough Listen based at U.C. Berkeley, California. I analyze how they construct criteria of intelligence through “experiments of anticipation” that are parametrized to hear from a commensurable subject.
I theorize “figures of listening” in both observational protocols and as a preemptive attunement to Other intention, acts that configure an alien who would be not just perceptible, but relatable.
If exobiologists envisioned universal standards of biochemistry that would map life’s common origins, SETI astronomers have traded on imagined superhuman characteristics of the alien — more benevolent, wiser, and technologically superior — to suggest human futures. I outline how the alien has been imagined through three potent analogical figures: as artifacts, animals, and angels.
Furnished by feminist epistemologies and queer theories of care around multispecies becomings — traditions that have persistently challenged ontological stability across species, gender, race, and spacetime — I theorize those analogies as acts of “reflexive alienation”: a mode of worldmaking in which scientists imagine Others imagining them. Future-oriented extraterrestrial objects held in abeyance cultivate Earthly concepts of being.
Description
Thesis: Ph. D. in History, Anthropology, and Science, Technology and Society (HASTS), Massachusetts Institute of Technology, Program in Science, Technology and Society, September, 2020
Page 229 blank. Cataloged from PDF version of thesis.
Includes bibliographical references (pages 217-228).
Date issued
2020
URI
https://hdl.handle.net/1721.1/129021
Department
Massachusetts Institute of Technology. Program in Science, Technology and Society
Publisher
Massachusetts Institute of Technology
>Can we expand communications over interstellar distances to include quantum methods?
It seems to me that yes in the measure where we have a universal “tool” which is the energy state of a particle (one can also choose its spin) which can be positive or negative. In other words, we have a binary system that we know how to use to create messages.
The idea would be to polarize a series of particles in one direction and then in the other according to OUR choice for creates the message. Let’s remember the Morse code. We could then constitute something that is NOT natural in space and could be our identifiable technosignature. The difficulty is that we do not master the polarity of the particle on its arrival: it is the surprise package ! So there’s a 50% chance that E.T will immediately understand the message and a 50% chance that he’ll hear something like this Beatles song or the soundtrack was turned upside down…diplomatically, it’s not great for a first contact :)
The thing is complicated with the quantum ones since, if I have understood correctly, they play the ghost as soon as we try to see them or catch them. What reduces us, to work on statistical bases: how many photons do I have to send for my message to be intelligible knowing that >50% will be lost or more ?
The article says that you should “encapsulate” the message which would mean you should deliver the instruction manual with? This complicates things.
The alternative would be to record or “freeze” several levels of particle energy and polarity at various T-moments, then assemble these records in a certain order to create a message. The particle A is + (positive) a T1; B is + a T2; C is – a T3 etc…. would be our alphabet. It would be left to create the message and …the instruction manual. This could work if an ETI is in the same space-time referential to reconstruct the message. Usually, at this point, serious people say : “well my dear, you are in full science fiction :)”
However imagine the telegrapher of the future who presses on his manipulator (of quantum) he sends “A+ B+ C- D- E+” * and hop ! Instantly across the galaxy, the same thing appears on the paper of his colleague with three tentacles and four eyes.
* translation: “don’t forget to bring the bread tonight, darling”:D
Joke aside, what would this technology bring us ? it would free us from distances but wouldn’t it be frustrating for our species which is curious by nature ? if contact is established with a higher ETI, what will be the upheavals for the human species? will we be able to bear them?
I see another advantage with the quantum : the wavelength of 26.5cm which would be the minimum to avoid interference by the cosmic microwave background, corresponds to a 1131.3 Mhz in microwave. It is interesting to note that this frequency is relatively close to the frequency of Hydrogen 1420.4 Mhz/ 21.11cm. Could we use this property?
In theory, I think we could communicate like this over interstellar distances. In practice, we do not yet master on earth the mechanics of materials (size of telescopes) nor the control of the very low energy level of particles both at emission and reception.
Forgive me if I say something silly, as the subject is so complex. In France we say “I walk on eggs”to say that we are proceeding with caution.
A CNRS article (to be translated) and a linked document :
https://www.inp.cnrs.fr/fr/cnrsinfo/preserver-lintrication-quantique-de-la-diffusion
https://journals.aps.org/prxquantum/abstract/10.1103/PRXQuantum.4.010308
An alternative explanation to those spooky “Pentagon UAP” videos.
https://www.youtube.com/watch?v=Le7Fqbsrrm8
Alternative but not very credible. One would have to discount visual evidence and assume the Navy does not know it’s own equipment. That is hardly credible. Pilots have seen and interacted with these objects with their own eyes. It can’t all be dismissed as quirks of the equipment in my view.
You mean video not videos. The video you posted: Breakdown of the Pentagon UFO videos with Mick West is problematical because the aircraft’s remote sensing capability is not cutting edge or sensitive. It also does not explain the Omaha UFO encounters video. Try the Navy Omaha UFO video. The Navy Omaha was a stealth ship with state of the art, cutting edge sensors including infra red and Sea Giraffe 3D surface/air radar. “Giraffe is designed to detect low-altitude, low cross-section aircraft targets in conditions of severe clutter and electronic countermeasures.” The UFO’s were six feet in diameter according to radar scans Doppler radar range finder, and one object moving at 150 mp much faster than the wind. Infra red shows not any warm exhaust of any type.
It would be helpful to post a link to the video. The one I found was from The History Channel, hardly a reliable source.
https://www.youtube.com/results?search_query=ufo+ohmaha+video+2021+
This includes the Omaha video. It shows the radar. The two spheres which disappeared from radar is easily explained by their submergence underwater where radar and infra red can see them, but only sonar which is sound waves through the water. The fact that the rest of the nine objects could not be tracked might be explained by stealth technology which has a range limit. This range limit would only be around seven miles where once the objects were far enough away they would vanish from radar. This would explain Henry Cordova’s UFO sighting not appearing on radar, but only it if the radar on his ship was not that sensitive a set and the Omaha radar is pretty sensitive and good enough to detect stealth at close range. There large, land based search and detect radar which are used for early warning and long range surveillance designed for detecting stealth, but those are low frequency radar. Russia has some which are in the VHF and L band.
I ‘saw’ a UFO when I was in the Navy, in 1968.
I saw it on my ship’s surface search radar, it was doing several thousand knots less than two hundred feet above the water. It came flying out of the North Vietnam (about 50 miles away) and headed straight out to sea, passing within a few miles of our ship.
The lookouts saw nothing, and there was no sonic boom. No doubt it had visual cloaking tech and anti-shock wave baffling.
Our air defense radar saw nothing, so it must have been flying close to the water.
The funny thing is when I related that story to another QM several years later over a few beers, he remarked he had seen something very similar, in the same area, on HIS destroyer’s surface search radar, just a few months earlier.
Did we both see an alien spacecraft? I’ve convinced myself it was a radar malfunction, or some kind of radar jamming or spoofing technology employed by either us, or Charlie.
But what do I know? I am just a victim of my conservatism and my orthodoxy.
I see we have gotten into the UAP/UFO flying saucer issue which I prefer to call Alien Spacecraft. Now if I tell you the truth you will immediately try to discredited it even if you know nothing about it. The paradox is simple, that there only has to be one that is real. Now my view of the current situation is 99.99 percent BS and a lot of idiots that have no clue what they are looking at. I’m not going to try to convince you and you have your right to your opinion. The problem from both sides is the stigma or more like stink that may have been why this tactic was used in the latter 1940’s. It is a very small world in a huge universe with very very many small minded people crawling on it surface, so I hope someone will stand up and stop the BS.
Interesting info from the Pentagon that relates directly to this “Quantum Communications”
The All-domain Anomaly Resolution Office (AARO), which studies incidents involving what the military now calls Unidentified Anomalous Phenomena (UAP), announced on Monday that Dr. Jon T. Kosloski has been selected as its new full-time director.
“Dr. Kosloski brings extensive experience working in multiple scientific fields, including quantum optics and crypto-mathematics, as well as leading mission-oriented research and analysis teams,”
But where are the images/videos/artifacts of the 0.1% that are actual UAPs? Are we to believe we are misled by means of misdirection, coverups, etc.? Why do “alien spacecraft” mostly get reported in just a few countries, and why not elsewhere? Given the vast increase in portable cameras and video recorders in smartphones, shouldn’t it be more likely that someone, somewhere has captured a clear, non-fuzzy image of a spacecraft or alien by now?
Arguments from authority – the observer was a policeman/pilot/[other professional] so the sighting must be real. Henry’s prank is very instructive in this regard. It is important to realize that memory is not like a camera recording, it is constantly updated and changed. We see what we expect to see. False memories are also easily implanted. How many psychology experiments does one need to verify the fallibility of memory, even relating what one thought the radar showed when relating the memory over a beer?
When James Randi was alive and debunking various claims of ESP, not just by showing how a claim could be done by a magician, but doing experiments with the claimant, he never needed to award the huge prize for a demonstrated claim as a genuine ESP talent. IIRC, he also demonstrated how supposedly objective scientists were fooled by ESP claims. I watched URI Gellar do his “spoon bending” on tv and he did a remarkable job of fooling a tv studio in front of cameras.
Those 0.1% “unexplainable sightings” are just that. Reaching for an “alien spacecraft explanation” is unwarranted. IMO, it is not unlike the motivated reasoning of Creationists whenever they think they have a “gotcha” for evolution.
As for crashed spacecraft, we know Boeing didn’t manufacture them. One might expect that Galactic Engineering GLC has more robust engineering capabilities. ;-)
I appreciate this is so dismissive, but hard evidence is important. Verbal reports, fuzzy images and videos, and claims of coverups don’t cut it.
@Alex
The difference between a fairy tale and a sea story is that the former starts off; “Once upon a time…” and the latter begins with; “Now this is no shit, you guys…”.
Its interesting to note that my drinking buddy’s account of a similar observation under similar circumstances can corroborate two entirely different interpretations of the same phenomenon.
1) UFO aliens are interested in human conflicts (no doubt because they are evaluating our suitability for membership in the Galactic Club) and are often seen lurking about war zones.
2) In a combat zone, both combatants are likely to be employing radars and their electronic countermeasures.
—
At least it can be said that neither of us was required to resort to imagining sinister government conspiracies desperately trying to hide the Truth.
“I appreciate this is so dismissive, but hard evidence is important. Verbal reports, fuzzy images and videos, and claims of coverups don’t cut it.“
Alex, what then would you accept as hard evidence? If the president said “Aliens exist and we have their craft but we can’t show you yet” what would you say? Would you accept that argument from authority?
What evidence would you accept of possible alien visitations? Could you be a little specific of what an acceptable “disclosure” would look like to you. Thanks.
BTW I’m not saying I’m convinced at this point.
If the president of teh US, or the Primeminister of England/Australia, or the Chancellor of Germany said they had an alien spacecraft, then I think I would believe it. I would still like independent scientists to examine the evidence and write a report.
If a UAP “flies” over a city, there should be multiple images and videos from various people. A few years ago a number of “black helicopters” flew over Sacramento. It was reported on the news, and a number of people managed to capture decent videos of the flight. Therefore I think that more independent witnesses recording the event is a good start. It isn’t possible for everyone to fake the same video without making lots of mistakes. But best of all is hard evidence. When I lived in Bermuda, there were reports of pieces falling of the civil aircraft and being left on the runway. I never saw this, even though I was taking monthly flights to New York at the time. But if such pieces were falling off the aircraft, they could be examined. That is the sort of evidence that would be important to validate an ET artifact.
If reputable scientists say they have be given artifacts and tell the public that the artifacts are clearly not of terrestrial origin, I think I would accept that.
I am still waiting after 60+ years for anything like that to happen…
Just a remark after having thought at length about the problem as we have a specific service in France “le GEPAN” (I like even read the famous Kelly-Hopkingville report – You have to look at everything to get an idea :) Things called “UFO” are usually human scale. Is there not a paradox with the vastness of the universe?
https://www.cnes-geipan.fr/en/home
The turn this conversation has taken reminds me of a posting by a very accomplished and quiet spoken engineer who once posted in another technical forum. It might seem irrelevant until you give it some thought. I am paraphrasing what he said at the time.
You are a paramedic responding to a mass disaster. You must triage a multitude of victims and separate them into groups. In the first group are those that will die no matter what you do. In the second group are those that are almost certain to die before you can get them to the hospital emergency team. In the third group are all the rest.
Your wise engineer has come up with a subtly different definition of the medical term “triage”. Whether it was deliberate or accidental is not clear.
Traditionally, the triage separates the accident victims into three groups.
1) Those who are going to die anyway, no matter what you do.
2) Those who will probably survive and do not require immediate treatment.
3) All the rest.
In first aid, I was always told: “Don’t worry about the one who yells; he’s alive; take care of the one who says nothing :D
“Given the vast increase in portable cameras and video recorders in smartphones, shouldn’t it be more likely that someone, somewhere has captured a clear, non-fuzzy image of a spacecraft or alien by now?”
I think they do. But why would we believe it’s the real deal? Don’t we tend to assume the clearer the image the more likely it’s a fake? I think an image is worthless unless it’s provenance is known and the source is trustworthy.
As with anything else that we want to seriously scrutinize, we need to use the proper tools of science.
In this case in particular, we need solid physical evidence that can be examined by multiple experts in various relevant fields. Stories and substandard images are not good enough. Neither is someone swearing on a stack of Bibles that they saw something they cannot identify.
I also find it amazing how none of these aliens supposedly visiting us (or is it time travelers from the future this week?) never seem to slip up, or when they do, our various human governments are masters at covering it up. Maybe it isn’t so hard to trick us, but unless they are infallible gods, I am not so sure.
And the fact that NASA and the US Government have opened offices to investigate UAPs/UFOs/UAOs, etc. – the readers of this blog should be smart enough to know they are just dog-and-pony shows designed to placate the masses. NASA doesn’t really care about alien spaceships and most politicians are the opposite of qualified when it comes to just about any field of science. Most of them are lawyers, remember that.
Boy, did this thread go way off the original subject matter. So what’s the verdict on ETI using quantum communications after all?
@Robert
Interesting argument: we now live in a world of images. Their incredible multiplication over the last 30 years and the ease of editing any digital photo by anyone who knows how to turn on a computer has contributed greatly to blur the tracks. It was already more difficult with a photo film; you had to know how to manipulate the lab and make up a shot which always left clues for who could look. Today it is impossible with digital without having at the minimum original photo and EXIF information. BTW the fact that we no longer see the world directly but see it through screens more or less unconsciously distorts our vision of reality.
For this subject that always makes a lot of “buzz”, I do not think the image is a “proof” sufficient (same thing for videos that a good graphic designer can always manipulate to give it the meaning he wants – the history of photography is full of such examples). The right question is therefore perhaps: “what is proof?”
In addition, it is necessary to be already on 100% of the source which is also very often almost impossible. And if we are the author of the photo or video, we must be able to prove to others that we are telling the truth…which is also extremely difficult.
“We cut the real in the viewfinder to show what we want to show” which by default hides what is on the side.
I’ll give you my perspective on the subject so you can see my viewpoint:
https://www.tapatalk.com/groups/altpropulsion/larry-reed-s-quantum-wave-mechanics-t27.html
A very similar object that was reported by Falconbridge Canadian Forces
Radar Station, Sudbury, Ontario on November 11, 1975. But there is more to the story:
https://pbs.twimg.com/media/F-vX63vbQAAAxfC?format=jpg&name=medium
“November 7 — 3:00 p.m.–November 8, 9:53 p.m. Remote electronic sensors trigger an alarm at Malmstrom AFB, Great Falls, Montana, indicating that something is violating security at several missile launch sites. Underground, in the launch control facility, two officers note the signal, but there is no TV surveillance topside. A missile security helicopter checks the area and Sabotage Alert Teams consisting of 4–6 men are ordered to proceed to the areas. One SAT team drives down the highway and onto a dirt road that leads to the K-7 area near Judith Gap, Montana. About a mile away, the team sees an orange, glowing object. As they close to within half a mile, they can see that the object is tremendous in size. They radio to the launch control facility that, from their location, they are viewing a brightly glowing, orange, football field-sized disc that illuminates the missile site. The SAT team is ordered to proceed into the K-7 site. However, they refuse to go any farther, clearly fearful of the intimidating appearance of the object. It begins to rise, and at about 1,000 feet, NORAD picks up the UFO on radar. Two F-106 jet interceptors are launched from Great Falls and head toward the K-7 site. The UFO continues to rise. At about 200,000 feet, it disappears from NORAD’s radar. The F-106s are never able to get a clear sighting of the several UFOs, which play cat-and-mouse with the aircraft, extinguishing their illumination when they approach, and re-illuminating after the fighters return to base. All members of the SAT team are directed to the base hospital, where they are psychologically tested. No one can identify the object, but the members of the SAT team obviously have been through a traumatic experience. Targeting teams, along with computer specialists, are brought to the launch site to examine the missile and the computer in the warhead. When the computer is checked, they find that the tape has mysteriously changed target numbers. The reentry vehicle is then taken from the silo and brought back to the base. Eventually the entire missile is changed out. Radar and visual sightings continue for the next 31 hours. (NICAP, “Malmstrom AFB Incident (1975)”; ClearIntent, pp. 27–29; Richard Sigismond, “Four Huge Orange Discs and the Case for the UFO,” IUR 8, no. 2 (Mar./Apr. 1983): 7–8; UFOEv II 90–92; Thomas E. Bullard, “Defending UFOs,” IUR 34, no. 2 (Mar. 2012): 11–12; Nukes 358–361)
November 10 — 10:15–11:20 p.m. A bright light passes over Minot AFB, North Dakota, moving west to east at 1,000–2,000 feet. (ClearIntent, p. 48)
November 11 — 6:15 a.m. A spherical object is observed from Canadian Forces Station Falconbridge [now closed] in Valley East, Ontario. The object appears to be rotating and has a surface similar to the moon. The object ascends and descends. The object is observed on height-finder radar at altitudes from 42,000–72,000 feet intermittently for 6 hours. Two F-106 jets are sent from Selfridge AFB [now Selfridge Air National Guard Base] near Mount Clemens, Michigan, but report no visual or radar contact. Other lights are seen periodically over the next few days, including at least seven members of the Ontario Police in Sudbury. (NICAP, “Spherical Object Tracked on Height Finder Radar”; ClearIntent, pp. 46–47; Yurko Bondarchuk, UFO Sightings, Landings, and Abductions, Methuen, 1979, pp. 152–156; Bob Gribble, “Looking Back,” MUFON UFO Journal, no. 271 (November 1990): 19–22; UFOEv II 92–94; Chris Rutkowski and Geoff Dittman, The Canadian UFO Report, Dundurn Press, 2006,”
From: https://cufos.org/PDFs/pdfs/UFOsandIntelligence.pdf
Projections of Earth’s Technosphere. I. Scenario modeling, Worldbuilding, and Overview of Remotely Detectable Technosignatures
https://astrobiology.com/2024/09/projections-of-earths-technosphere-i-scenario-modeling-worldbuilding-and-overview-of-remotely-detectable-technosignatures.html