The commenter who identified that we're now able to eliminate radiowave-broadcast communications, via lasers ( & fiberoptics, etc ), is spot-on.
There is another angle, though.
Imagine a simplified-model of civilization...
a batch of 7 newborn-babies, instead of hundreds of genetically-distinct populations in Africa...
those 7 babies live in "eden".
they learn that they can consume everything they want, that doesn't harm them.
they learn that they have to be somewhat self-moderating, because others fight them when one crowds the other, too much.
etc.
they move away from each-other, & some lose their skin-pigment, others change it...
an empire forms, in-which industry is the rule ( the Roman empire ).
Now a momentum is set in-place, that is making the sequence of the Industrial-Revolutions inevitable...
at the time of the Roman Empire, the children are, say, 11yo.
at the time of the Industrial Revolutions, they are in puberty, their brains forced into chaos, & ALL sorts of new force-multiplying technologies landing in their hands...
So, what is The Great Filter?
What happens when it is unconscious-toddler-mind, or unconscious-adolescent-who-never-got-challenged, who has all the world-snuffing technologies that we now have, but who has the global-responsiblity-level of .. drunk & drugged narcissistic children...
Say you have 7 kids going into The Great Filter, representing the whole populations-sea of our world...
Say only 1 of them survives The Great Filter...
Are they going to be CAREFUL in what they do, technologically, from then on??
Obviously.
I don't expect more than about 1.5% of this planet's population to survive this century's TANTRUM/POGROM that has narcissism-roots, politics-roots, religion-roots, food-insecurity-roots ( like total collapse of the terrestrial & marine food-webs, later this century ), etc.
Will the remnant who survive this century, if any do, be as careless with technology as we currently are??
How could they be?
If The Great Filter is an automatic force-growing-up consequence of EVERY world-overwhelming-species, who mixes accommodated-immaturity with ecosphere-destroying technology, then whatever portion of worlds who reach The Great Filter have survivors of it, .. it'd be inherent in the survivors' experience that they have been made careful.
Same as you don't find incapable-of-self-discipline in career-military-officers, you don't find our murderous carelessness/ideological-rabies in any survivor of The Great Filter:
Universe automatically force-extinguishes populations who won't grow up, who gain the technological-leverage that we've gained.
So, silence depicts a lack-of-carelessness AND an absence-of-need to be throwing-away-energy through radiowave broadcast, both.
When combined, galactic silence makes much fundamental sense.
We're in our species' "puberty" stage, and haven't survived our force-growing-up Great Filter, yet.
If we do, well, then finding others who also did, will make sense.
If we won't, .. then our epitaph will be that we wouldn't grow-up, at ANY cost.
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Language forms one's mind, and, then, one's formed-mind is reflected in the language one uses.
"Collaborative Intelligence" is a book on working-with 3 of the 4 kinds of innate-mind-language:
are the 4 kinds that I know-of.
The AbstractShapeCognition kind ( my kind ) apparently makes up a significant fraction of physicists.
The book only deals-with the other-3, however.
Why does that have any significance, whatsoever?
Translating EVERYTHING from AbstractShapes into English .. gets exhausting & frustrating.
Temple Grandin has a couple of TED Talks.
She thinks in movies.
then translates what the variant-movies showed her into words, to communicate.
Language is confining.
Languate is enabling between people, and also between oneself & one's thoughts, but it is crippling.
Douglas Hofstadter's "Godel Escher Bach: An Eternal Golden Braid" is on how self-consistent-formal-systems are INHERENTLY mind-blind to all that the formation of the formal-system doesn't/won't see.
Leonard Shlain's "The Alphabet Versus The Goddess" book identifies that women's-rights simply doesn't get much of anywhere, in language/cultures which speak more-gendered language.
ie Anglo cultures have more women's-rights than Latin cultures, with their gendered-language.
That is consistent, & durable.
It gave me dispair for human potential, when I discovered that many language-families program people into genderizing everything, & locking "validity", in establishment's eyes, from "female".
That isn't going to change.
Which means that humankind is less-likely to endure The Great Filter, this century.
The "shackles binding our Potential" are too strong, and too strongly-valued, for humankind to break, enough?
It looks more & more like this is the case.
See the fallacy of wrong-framing, and understand that all human languages are wrong-framing something.
Each language is better at some things, but worse at others, and incapable of some concept-expressing...
That alters our viability, planet-scale.
In "The Design Of Everyday Things", it noted that we've a species-wide mental-defect:
When we do something, and it doesn't work, instead of agilely changing-what-we're-doing, we do what we already-were-doing, MORE FORCEFULLY.
That is why I ditched Emacs for Vim: Vim keeps hitting one on the head with one's not-changing-levels, thereby conditioning one's mind into the habit of changing-levels, counter to that innate species-wide ignorance/incompetence.
Morass-of-capability ( emacs ) was fun, but I NEED to be able to see what need be seen, need to be able to think what need be thunk, etc, and not-changing-levels is an already-known-incompetence?
And I'm autistic? ( making that much worse, with woodenheadedness/monotropism )
Vim forces the change in mental-habit.
Some equivalent is going to be required, species-wide, to force-change our language, in order to make our viability more-likely, XOR our conditioned mental-habit is going to sink a greater percentage of our species' life, this century.
Oh, & Temple Grandin's thinking in movies nuked the entire "without language, thinking cannot happen" school of philosophy, didn't it?
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