[ExI] NASA doubts Dyson megastructures will ever be necessary

[Keith Henson]

On Sun, Aug 18, 2024 at 9:20 PM Robert G. Kennedy III, PE via
extropy-chat <extropy-chat at lists.extropy.org> wrote:
>
> I think this is an extremely parochial point of view, even by human
> standards.
>
> A simple math illustration:
> A manual laborer adequately nourished in good physical condition can
> generate about 75 watts of mechanical power over an 8-hour work shift.
> For a typical desk jockey like myself, this figure is closer to 10
> watts.  That may be too generous - most of my colleagues broke a sweat
> and had to switch arms after only a minute of this when I made them lift
> a liter bottle of water through 1 meter to illustrate 10 watts in a way
> that they would remember.
> The average member of the human race already consumes 300X this amount
> of primary power 24/7.  (20 TW divided by 8 billion.)  The average
> member of the developed world consumes an order of magnitude more than
> that.  (20 TW divided by a billion.)

Thinking about this, 20 TW does not include the sunlight energy used
to grow food.

There are about 50 million square km used for food.  The peak is close
to a GW/km^2 and the average is perhaps 1/3 GW/km^2 making the solar
energy input for growing food ~20,000 TW or 1000 times the accounted
energy use.

Hmmm.

Keith


> We put cold beer in cans of thin metal that was worth more than gold
> less than two centuries ago.  And then throw the cans away, mostly.  We
> have Netflix to stream pron, computer games to p*ss away p a large
> nation-state's worth of brainpower, and at least half of us carry
> supercomputers-cum-transceivers in our pockets which are principally
> used to endlessly scroll useless s**t AFAICT.  We light up our
> skyscrapers in colors at night for urban art.  You could think of a
> zillion more examples, virtually any one of which would have been
> absolutely magical/ incomprehensible to our Neolithic ancestors, only
> ~10K years ago.  Even Columbus would be gobsmacked by GPS, though he'd
> probably appreciate its utility in short order.  D'ya think Alexander
> Graham Bell ever imagined his invention would by used for 1 (900) phone
> sex?
>
> Right off the top of my head, I can think of worthwhile constructive
> activities that would require six to twelve orders of magnitude more
> power than what we use now:
> - Fast Interstellar flight with machines.  (Having won a NIAC Phase I
> grant, my colleagues and I will be presenting our work on an
> interstellar probe swarm to Proxima Centauri to NASA at the Pasadena
> Hilton in September.  I'll be turning 65 whilst there.  Can't think of a
> better way to celebrate a milestone birthday than not acting my age.)
> - Terraforming Lite, using techniques you already know about.
> - Terraforming Heavy using Shell Worlds, which I also helped pioneer.
> - Slow Interstellar Heavy with Worldships or Fast with some other
> small-ish craft with a live crew.
>
> That's just the actually useful stuff.  For humility, I like one of the
> background plot elements in one of David Brin's "Uplift" novels - that
> the big intragalactic war was essentially a difference of opinion
> between art critics.  Vernor Vinge (may he RIP) touched on this too in
> "A Fire Upon the Deep".
>
> We have absolutely no idea what aliens would find interesting, fun, or
> compelling to do.  We'd be like ants to them, and that's being generous.
>
> Hooey.
>
> K3
>
> On 2024-08-18 16:15, extropy-chat-request at lists.extropy.org wrote:
>
> > Date: Sat, 17 Aug 2024 13:21:31 -0700
> > From: Keith Henson <hkeithhenson at gmail.com>
> > To: ExI chat list <extropy-chat at lists.extropy.org>,
> >       extropolis at googlegroups.com
> > Cc: BillK <pharos at gmail.com>
> > Subject: Re: [ExI] NASA doubts Dyson megastructures will ever be
> >       necessary
> > On Sat, Aug 17, 2024 at 4:24?AM BillK via extropy-chat
> > <extropy-chat at lists.extropy.org> wrote:
> >>
> >> NASA Scientists on Why We Might Not Spot Solar Panel Technosignatures
> >> William Steigerwald      August 2, 2024.
> >>
> >> <https://science.nasa.gov/science-research/planetary-science/astrobiology/nasa-scientists-on-why-we-might-not-spot-solar-panel-technosignatures/>
> >>
> >> Quotes:
> >> Now a recent paper published May 24 in the Astrophysical Journal
> >> postulates that if advanced extraterrestrial civilizations exist, one
> >> reason they might be hard to detect with telescopes from our vantage
> >> point is because their energy requirements may be relatively modest.
> >> If their culture, technology, and population size do not need vast
> >> amounts of power, they would not be required to build enormous
> >> stellar-energy harvesting structures that could be detected by current
> >> or proposed telescopes. Such structures, based on our own Earthly
> >> experience, might be solar panel arrays that cover a significant
> >> portion of their planet?s surface or orbiting megastructures to
> >> harness most of their parent star?s energy?both of which we might be
> >> able to spot from our own solar system.
> >
> > Tabby's star and the 24 other blinking stars around it we can see with
> > existing telescopes.
> >
> > The biggest dip corresponds to an object equal to over 400 times the
> > area of the Earth.  Even though it is way out from the star, it
> > intercepts 1.4 million times the total energy humans use.
> >
> > snip
> >
> >> Hmmm.  Yes, it does seem likely that advanced civs could have better
> >> methods of power generation than building huge Dyson space structures.
> >> And that makes the assumption that they would even require such
> >> vast amounts of power utilisation.
> >
> > How big does a structure need to get to be considered a Dyson
> > structure?
> >
> > Keith
> >
> > PS amusing, my great great grandmother was Mary Virginia Dyson.
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