[ExI] SETI reviews the Drake equation

[BillK]

On Mon, 4 Feb 2019 at 17:52, Stuart LaForge <avant at sollegro.com> wrote:
>
> Quoting myself (again):
>
> > Yet when we examine living organisms, whether they be humans or the
> > lowliest bacterium, their biomolecules are always just one of the
> > mirror images and not both. For example all glucose recovered from
> > living cells has left-handed chirality and all amino acids from cells
> > are right-handed.
>
> Quick correction, I have these exactly reversed biologically-active
> glucose is right handed and biological amino acids are left-handed.
>
> > And this is where Sgr A*, the 4 million solar-mass black hole at the
> > center of our galaxy comes into play: At some point in our galaxy's
> > evolution, two black holes collided in the center of our galaxy, in
> > such a way that by complete random chance the resultant super-massive
> > black hole (SMBH) Sgr A* was tilted on it's side like the planet
> > Uranus, precessing like a gyroscope with its radio-jet, which is
> > essentially a gigantic circularly-polarized broad-spectrum laser/maser
> > in just such a fashion to track our sun's orbit around the disk.
>
> The math on this doesn't seem to be working out. Namely I don't know
> where the torque would come from to cause SgrA* to precess like that.
> So being in the path of the black hole's radio jet might just be a
> rare occurrence that happens twice every 230 million years when the
> sun's orbit crosses the radio jet's path and we just happened to be
> crossing the beam path when we looked at it.
>
> That still would have given SgrA* plenty of opportunities to kick
> start abiogenenesis on earth, but make it a lot less of an existential
> threat going forward.
>
> Stuart LaForge
>

Yes, I wondered about the likelihood of the radio jet remaining
constantly pointed at the Earth.

Also it isn't a gamma ray burst. It's only a radio jet from
26,000 light years away with a lot of interstellar dust and gas
between. So much dust that we can't see the source in the optical
band. Doesn't that mean the radio jet would have little effect on the
Earth?



BillK