[ExI] Reinventing SETI: Why Our Alien-Hunting Playbook Needs an Upgrade

[Adrian Tymes]

Wouldn't a 2,000 ly radius over 3,000 years be 2/3 c, not 1/3?

On Mon, Sep 29, 2025, 2:53 PM Keith Henson via extropy-chat <
extropy-chat at lists.extropy.org> wrote:

> I make the case that we have seen aliens.
>
> Of course, I could be wrong. I was, for a number of years, among the
> people who thought the blinking of Tabby's star had to be natural.
> But finding a couple of dozen blinking stars in a 2000 ly radius
> around that star convinced me that it is not natural.  Assuming it is
> aliens, you can conclude a few things, like FTL does not exist, or
> they would be here.
>
> The AIs say they have been in space for 3000 years; if so, they have
> spread out at around 1/3 of c.
>
> Independent of what we are looking at, it seems that our long-term
> fate is to exist as uploads in data centers out in the computational
> zone, far out from the habitable zone where the cold makes computing
> less error-prone.
>
> YMMV
> Best wishes,
>
> Keith
>
> On Mon, Sep 29, 2025 at 7:00 AM BillK via extropy-chat
> <extropy-chat at lists.extropy.org> wrote:
> >
> > On Mon, 29 Sept 2025 at 12:55, spike jones via extropy-chat
> > <extropy-chat at lists.extropy.org> wrote:
> > >
> > > Disagree.  Our first good strong radio signals are only about a
> century old.  A hundred year radius sphere is not that big, about ten
> thousand stars in that range, and even then, only those 50 years out (a
> coupla thousand) would have had time to return a possibly malignant
> signal.  We can’t dismiss the Dark Forest notion yet.
> > >
> > >  <big snip>
> > >
> > > spike
> > > _______________________________________________
> >
> >
> > The author mentions that the whole galaxy could already have 'watcher'
> > robots in every system.
> > Even at sub-light speeds, in theory, Von Neumann replicating probes
> > could be everywhere within a few million years.
> > The 'watching' could be for contact or destruction.
> > Thinking on that scale however, I have to wonder about the problem of
> > keeping the robot programming up-to-date. The originating civilization
> > could be so far away and may no longer exist. Even if it still exists,
> > it may have changed its mind about the Von Neumann robot objectives or
> > technology. That is a huge problem to try to fix!
> >
> >
> > BillK
> >
> > _______________________________________________
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> > extropy-chat at lists.extropy.org
> > http://lists.extropy.org/mailman/listinfo.cgi/extropy-chat
>
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