[ExI] Gaian Bottleneck
avantguardian2020 at yahoo.com
Wed Jan 27 08:34:06 UTC 2016
> From: John Clark <johnkclark at gmail.com>
>To: ExI chat list <extropy-chat at lists.extropy.org>
>Sent: Monday, January 25, 2016 9:55 AM
>Subject: Re: [ExI] Gaian Bottleneck
>I agree, I think it's probably something odd but natural. It's a F3 star that is brighter than our G2 sun and as a result it has a shorter lifetime. The sun will remain on the main sequence for about 10 billion years but a F3 will leave the main sequence in only about 2.5 billion years and become unstable. If the sun were a F3 and the Earth were in a larger orbit around it in the habitable zone Evolution would have had enough time to produce bacteria but then the sun would have vaporized the bacteria and the entire planet as well a billion years before the Cambrian Explosion even started.
Yes, I agree that the lifespan of F3 stars is problematic for the ET hypothesis. But interestingly enough there is an overlooked data point that isn't being reported in the media. If you look on page 7 of the original article, the authors are 99% confident that KIC 8462852 has a small companion star. The original article can be found here:
They say it is a class M3 red dwarf of about 0.4 solar masses and is located 1.95" ~ 885 AU ~ 0.014 LY from the F3 star.
While it may contributing to a "natural" explanation by perturbing objects orbiting the F3, I bring it up for a different reason. Red dwarfs are some of the longest lived stars in the universe with lifespans of trillions of years, therefore the companion star could be older than our sun. It is possible that a civilization could have evolved in the red dwarf system and then made the short hop to the F3 for big energy. After all an 885 AU crossing would be relatively easy for any civilization capable of Dyson technology.
>And if it's a Dyson Sphere it's odd we can't pick up any intelligent radio signals from it; the star is only 1,480 light years away and the Arecibo Observatory could detect a similar instrument 50,000 light years away but we don't hear a peep. People have looked with optical telescopes
>for flashes of LASER light coming from the vicinity of the star and haven't found those either.
If they exist, why would they have pointed their transmitters at us? We have only had radio for about a century, so they can't possibly have heard us yet. I agree ET is an unlikely scenario here, but it is certainly fun to think about. I for one am looking forward to May 2017 when the Kepler will again be aligned with Tabby's Star. Until then, I imagine astronomers are going to "science the shit out of this" to quote The Martian.
"We speak for Earth. Our obligation to survive is owed not just to ourselves but also to that Cosmos, ancient and vast, from which we spring." - Carl Sagan
More information about the extropy-chat