[ExI] Tabby's star

[BillK]

On Thu, 31 Oct 2024 at 15:19, Darin Sunley via extropy-chat
<extropy-chat at lists.extropy.org> wrote:
>
> That's not how speed-of-light delay works.
>
> We are seeing their 1470 years ago in real time. If, 200 years after what we're seeing - 1200 years ago, they started expanding towards us, we won't see that for another 200 years.
>
> Anyone who can build a Dyson swarm can build von Neuman probes, which can be accelerated up to large percentages of the speed of light via lasers that remain in the launching system. this would be utterly trivial given the infrastructure we're - per hypothesis - seeing at Tabby's Star.
>
> When and if we see laser flares, that will mean the probes are literally right on top of us.
>
> That's the big problem with relativistic probes or weaponry - you get no warning until hours, maybe days before arrival. A few months tops. Far too little time to do anything about anything moving at 80%+ of C.
>
> See Pellegrino's "A Killing Star" for how this works out for humanity. Spoiler: not good..
> _______________________________________________


Yes, you are correct in describing an exploratory wave travelling out
from Tabby's star towards us with no stops on the way.

But that is not what I'm considering.
I'm thinking that they could have travelled, say 1,000 light years
towards us and begun building structures around that star. So we would
observe these structures appearing 470 years after construction.
If they were stopping to colonise and build around stars nearer to us
than Tabby's star, we would see changes at the stars between us and
Tabby's star.

BillK