If only we could somehow share a physical entity of known dimensions to reference together with the drawing so that we did not need to use a physics riddle to indicate scale...
> Behind the figures of the human beings, the silhouette of the Pioneer spacecraft is shown in the same scale so that the size of the human beings can be deduced by measuring the spacecraft.
It's good to have redundancy, not just so someone interpreting the plaque can confirm their hypothesis, but also in case one of the messages fail. In this case, the spacecraft could break, but we can assume quantum transitions will always be observable.
Using quantum transitions is quite ridiculous in my opinion due to requiring not only the observer to have a perfectly compatible understanding of physics (even a more advanced understanding might not be compatible - maybe they don't categorize elements by electrons, or even treat elemental particles as a quantifiable entity), combined with the sheer number of deductions required to understand what was meant with two circles and a few lines.
I doubt we would ever have decoded this had we been the recipient rather than author, and that's with a perfectly compatible understanding of physics.
I don't know if aliens would decode it but it's not right that humans wouldn't decode it.
:sigh:
I hope I never live to see Galactic Twitter.
I'd also hold that the only thing this plaque could ever give is clear sign of artificial creation, and by virtue the (possibly past) existence of some entity capable of creating it. Maybe they'll get a vague idea of what we look like, but if "their" culture does not commonly depict themselves in 2D as we do, or "they" have vastly different morphologies, even that would be unclear. The context needed to understand our attempt at showing our location might also be lost if the thing went far enough.
Maxwell published in 1873. The double slit experiment was 1803, subatomic theory developed throughout the 1800s, and Planck proposed quanta in 1900. The first radio transmission across the Atlantic came approximately 2 years after Planck's theory.
I doubt it is plausible to develop anything resembling industrial technology without stumbling across certain fundamental truths in the process because doing so requires a sufficiently accurate model of physics.
The inventor of the arc converter was 18 at the time radio waves were discovered, 34 at the time he invented the arc converter, but 56 and with only 17 years left till his death when the era of modern quantum mechanics started with the invention of wave mechanics. It's a lifetime apart.
Some discoveries were made during that period that are of course still relevant.
The only way this doesn't work is if the aliens who retrieve the plaque from deep space somehow stabilize in the long term at a point where they've developed rocketry and general space travel but not radio or an understanding of quantum mechanics.
However the above would seem to imply that they don't do radio astronomy, don't have a very good understanding of light (since it's all photons), and don't have high frequency electronic circuits (since designing those requires accounting for RF interference). I guess their understanding of optics is also lacking and their understanding of chemistry is rudimentary and stagnant over the long term.
In other words, aliens permanently stuck at a late 1800s technology level that have nonetheless developed the ability to travel across interstellar distances. And spotted voyager (a very small cold object in deep space). And retrieved it intact.
That's undoubtedly a very cool premise for a scifi story but as far as real life goes I think your time would be better spent worrying that voyager might be eaten by a species of space fairing wale.
RF equipment is not built or designed by people working with or having understanding of quantum mechanics. Understanding waves could come from observing liquids, or if audio exists to them, that. Designing around noise can be done empirically as we do. Quantum mechanics in this area only matter due to our current chip manufacturing process, but who says they use semiconductors?
On the other hand they could also have a better understanding of light and photons and never build RF into their core technology stack, thereby not having people observe and analyze the hydrogen line.
The only strict order is that we know now that our previous theories were complete garbage, and we are still waiting to discover why our current theory is complete garbage.
It's easy to imagine that another species might have never conceptualized electrons as little balls orbiting around a nucleus. They are neither balls nor are they flying in circles, those are simply abstractions we like because they appeal to the way we perceive reality. The way we conceptualize electrons leads to issues like the wave-particle duality, so it's likely just a local optimum we got stuck in. Another species might not even think of Electrons as being distinct entities, maybe they think of the electron field as one large ocean with some waves in it, or they subscribe to the single electron theory, or something we have never thought of and might never imagine from our perspective.
It is also very highly constrained by how _we_ observe the universe. Beings with different sensory/cognitive capacities could develop very different models.
> equivalences between apparently dissimilar modes of presentation
If there was some mathematical equivalence between their models and ours, which is already a leap to assume, there is still a question about whether the specific measure used would be translated to something equivalent to our object length measure in their model, which gets much stronger than just some equivalence assumption. And it’s even stronger to assume that this equivalence could just be inferred without any other information apart from the disk.
For some extra-solar civilization to examine the probe and its plaque intact, it will have to rendezvous with it in space. It seems to me to be the greater leap of faith to suppose this can be done without having knowledge that is isomorphic or equivalent to our formulation of orbital mechanics. Do you have any concrete ideas about how this might be so?
How could we ever be certain than another intelligence (whatever that means) would be capable of understanding the intended message? Unless of course we are already starting off with the major assumption that the only things that can be intelligent are things like us. I'm not even sure that intelligent has any meaning aside from denoting behavior "similar to us".
Or to them, an atom is as large an arbitrary macro structure as proteins are to us, and so they would never consider two empty circles with a single line to represent something so big and chaotic. Or maybe they had the crazy idea of building everything of vibrating strings!
Who knows what the abstractions and approximations would be when the foundation of it all isn't "getting hit on the head by an apple".
Now if you go the other way, referenced 21 cm as a well known quantity (say, by making the plaque 21cm wide and referencing its diameter) and used that to describe the hydrogen spin flip in order to teach or communicate our level of physics understanding rather than depend on a shared understanding, then I'd say it makes more sense.
Or even future human data archeologists digging through a mix of 20 & 21 century data heavily polluted by AI slop. ;-)
In one unused shelter here in Brno the numbered stones of a medieval chapel are stored since it was demolished long ago. In another shelter in Prague you can find the complete archive records of the Prague 4 city administration.
Any aliens discovering this would inevitably reach the conclusion that humans had a lot of respect to both honoring their past & for comprehensive bureaucracy. So much indeed, that when the end came, they decided to forego the temporary safety of their shelters and let this legacy of their culture survive instead!