[ExI] tabby's star dimming again

[BillK]

On 21 May 2017 at 15:51, Stuart LaForge  wrote:
> The only evidence ruling out aliens is the supposed lack of a heat
> signature and radio waves. But seriously, you and Keith have both made the
> point that vectoring waste heat would be the most efficient form of
> entropy exaust. What if they don't have their exhaust pointed along the
> galactic plane. That seems to make sense from an interplanetary security
> stand point.
>
> Furthermore, like you mentioned, perhaps they have some ingenious
> technology that enables them to harness heat energy too. If their
> thermodynamic efficiency approached 1.0 then, we might have to look for
> radiation with frequencies downshifted to near CMB levels.
>

<http://www.popsci.com/alien-megastructure-star-dimming-again>
Quotes:
If it's dust that's blocking the light, the spectra should show big
dips in the blue and ultraviolet wavelengths. If it's other stuff
orbiting the star, like a family of huge comets, then the observations
should show extra heat being radiated off of this stuff. So far, that
excess infrared has remained elusive, but Jason Wright, an astronomer
from Penn State, said that the observations that will start tonight
could provide the first evidence of that.

If it's an alien megastructure, or some kind of internal process, all
of the wavelengths should get dimmer equally. A bizarre signature,
such as Tritium or artificial elements would be a pretty strong hint
for aliens, although it would take an extraordinary amount of evidence
to prove such an extraordinary claim.


> More important than going there is hedging against them coming here. They
> might already be on the way. I sure hope Trump or whoever else thinks they
> are in charge of this rock at least has a plan for dealing with the
> possibility.  I can't help but think of the Aztecs that saw Cortez's ships
> from miles off and refused to believe in them until they were "taken by
> surprise".
>

Tabby's star is 1,480 light-years away. I think we can safely not
worry about visitors.
(Unless we see the ships on the horizon, of course).  :)

BillK