More accurately - it dimmed at an incredible rate ~1480 years ago and we are just now seeing the light from that event.
Tabby's star is dimming at an incredible rate
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Re: Tabby's star is dimming at an incredible rate
#102Link to paper: https://arxiv.org/pdf/1608.01316v1.pdf
Re: Tabby's star is dimming at an incredible rate
#103Earlier quoted context omitted.
Reddit user sigbjoernwilderness's idea is pretty wild... can it be easily ruled out? > Is this the last remaining explanation after Montet/Simon? > The dimming comes from the shadow of a spaceship traveling on an (almost) straight line from KIC8462852 to Earth. The slow continuous dimming results from the increase of the apparent size of the approaching ship while Earth/Kepler is in the penumbra. The irregular dips h…
can it be easily ruled out? Yes: parallax breaks it. If something's colinear with a star today (and occults it), it won't be colinear 6 months later, when the Earth's on the other side of the sun. At 2 light years for instance, that spacecraft would trace an apparent ellipse 3.3" in diameter, while Tabby's star (1,480 ly) would be stationary (0.004" parallax). In comparison, the star's apparent disk is just 30 μas wi…
Excellent point... that answers my question. Thanks!
Re: Tabby's star is dimming at an incredible rate
#104It's obviously being eaten by black monoliths [1].
Re: Tabby's star is dimming at an incredible rate
#105It's not like this is right on our doorstep but I'd still be more comfortable if this was happening more than 1480 light years away.
Well whatever it is, we probably have 1000+ years to save ourselves right? If whatever caused it comes at us at 50% light speed, which sounds unlikely given how fast that already is, we'd still have 700 years. I'm pretty sure that if human's resources were suddenly all turned towards getting the hell out of here, we could certainly pull it off for a good part of the population in a few hundred years. Whether we'd eve…
700 years would be twice light speed; at 0.5c it would be 3000 years.
Re: Tabby's star is dimming at an incredible rate
#106Earlier quoted context omitted.
The mass of the star before it went and formed a black hole. The bigger a star, the hotter it is, and the more evaporates from the surface, and the shorter it lives. Large blackholes grow through things falling into them.
Oh I read the parent comment as black holes having a soft upper boundary. Is that the case? Or if more stuff falls in they just get bigger (minus Hawking radiation)?
So there is a complication, which is space is filled with vast amounts of nothingness. For a black hole to get bigger objects need to be on a collision course with it, which is somewhat unusual. A black hole doesn't behave any differently from the same mass as something not a black hole. So once a star turns into a black hole, the accretion disk is usually remnants/maybe more if it is in a nebula. Once that's gone, that's it for growth.
Re: Tabby's star is dimming at an incredible rate
#107Good ol' PV on Kinja (from the linked gizmodo article: http://gizmodo.com/the-so-called-alien-megastructure-just-go... ) has some interesting thoughts, as usual. > The biggest axe against it being an alien megastructure project is the fact its an F-type star. F-types only live a couple billion years, depending on mass. > But the drop in the radiant flux... a sustained drop. That could be something far more interestin…
I'm sorry, I must've missed something important because I've seen pointers to this post elsewhere. Who exactly is "PV on Kinja?"
Re: Tabby's star is dimming at an incredible rate
#108Sunspots, debris and/or a distant cloud are not completely ruled out: https://arxiv.org/abs/1608.01316 Wiki: The leading hypothesis, based on a lack of observed infrared light, is that of a swarm of cold, dusty comet fragments in a highly eccentric orbit.[12][13][14] Many small masses in "tight formation" orbiting the star have also been proposed.[9] The changes in brightness could be signs of activity associated wit…
Safe to say that a civilization that can build a Dyson structure isn't using any 20th-century coherent modulation types that SETI could detect. SETI is only useful for catching civilizations in the ~100 Earth year-equivalent span between their development of wireless tech and information theory. There's nothing to listen to but white noise after that.
This is speculation. There are all kinds of examples we have of "ancient" technology that are still in everyday use today - knives, for example.
There's no reason to think that something else would abandon using EM as a transfer of communication.
Re: Tabby's star is dimming at an incredible rate
#109Pancreator deliver us, the suns fade.
Re: Tabby's star is dimming at an incredible rate
#110Earlier quoted context omitted.
Ah, but this is only true about we, humans rather than earth/solar system. It cannot be excluded that other sources of radio have been around here in the past :)
It also assumes that outside observers have the same difficulty understanding the make-up and probable evolution of a system as we do. If they were able to observe that Earth would have some properties they were interested in, or would be a likely candidate for such, then they wouldn't need us to announce our presence to guess it.
IMHO the aliens will not be specifically seeking life that is intelligent. Singularities and interstellar traveling alien civilizations share a problem. If one is in essence immortal the only purpose that can endure forever is the pursuit of new knowledge. Even if alien entities are able to learn all there is to know about all the other sciences, biology will be inexhaustible as the novel patterns that can be produced by evolution are effectively infinite. The biosphere of just our planet where the latest estimates are that there are a trillion species if you count all the microorganisms, probably contains more information than all the lifeless planets and stars in the galaxy combined. The aliens will value biodiversity more than we do. And if they arrive they will oppress us "only" to the extent required to counteract our propensity to cause species extinctions (including our suicidal alteration of the planet's climate). I actually would prefer that the Singularity or the aliens arrive sooner rather than later as I have less and less hope of our species getting its act together on its own.