Science
Related: About this forumThe strangest star in the galaxy is acting up again.
Its a news story 1,280 years in the making. Thats about how many light years from Earth sits KIC 8462852, also known as Tabbys Star, whose bizarre pattern of dimming and brightening is so unusual that some scientists have theorized its behavior could be accounted for by an alien structure periodically occluding its light source.
Aliens should always be the very last hypothesis you consider, but this looked like something you would expect an alien civilization to build, Penn State astronomer Jason Wright told The Atlantic in 2015. The Atlantic published a follow-up asking whether the megastructure in question could be a Dyson Sphere, a large array designed to absorb massive amounts of solar energy from Tabbys star, an idea that appears in several popular science fiction novels. Wrights statement and the buzz around it prompted a small backlash from critics (myself included) who considered the assumption that one would expect alien societies to emulate Western science-fiction novels to be a bit anthropomorphic.
But back to Tabbys star: A periodically-dimming star is not an unusual occurrence in the universe. From our Earthly perspective, a star may suddenly dim for many reasons: if it is in a binary or trinary system, its companion star may briefly eclipse it from our perspective, temporarily reducing the amount of light reaching us. Some stars, such as Cepheid variables, periodically brighten and dim at regular intervals as the stellar atmosphere pressure builds and releases. Others still may dim very slightly when planets pass them from our perspective.
Yet Tabbys star fits no known model. The star rose to prominence for being inexplicable to science after its brightness suddenly dipped 20 percent within the span of a day. For reference, a planetary transit across a star generally causes a dip of less than 1 percent. Such a drastic dip implied that whatever was crossing the path of Tabbys star was bigreally big. In fact, in order to account for a 20 percent dip in brightness, the transiting object orbiting Tabbys star would have to be around 5 times the radius of our sun, according to Columbia University astronomy professor David Kipping.
More at:
http://www.salon.com/2017/05/24/the-strangest-star-in-the-galaxy-is-acting-up-again/
dhill926
(16,339 posts)PLEASE HELP US!!!!
HAB911
(8,892 posts)PLEASE!
LongTomH
(8,636 posts)So it's far from just "an idea that appears in several popular science fiction novels."
Russian astrophysicist Nikolai Kardashev thought along similar lines with his idea of a Kardashev scale. A civilization that builds a Dyson sphere would be a Kardashev type II civilization, one that harnesses the total energy of their star.
Much earlier, the spaceflight pioneer Konstantin Tsiolkovsky predicted that: "Man will not always stay on Earth; the pursuit of light and space will lead him to penetrate the bounds of the atmosphere, timidly at first, but in the end to conquer the whole of solar space."
longship
(40,416 posts)That is what all the pertinent scientists are saying. (I.E., astronomers, cosmologists, etc.)
In other words: No aliens.
Javaman
(62,530 posts)if they are building a Dyson sphere's they don't want anything to do with us.