We present a cosmic perspective on the search for life and examine the likely number of Communicating Extra-Terrestrial Intelligent (CETI) civilizations in our Galaxy by utilizing the latest astrophysical information. Our calculation involves Galactic star formation histories, metallicity distributions, and the likelihood of stars hosting Earth-like planets in their habitable zones, under specific assumptions which we describe as the Astrobiological Copernican Weak and Strong conditions. These assumptions are based on the one situation in which intelligent, communicative life is known to exist—on our own planet. This type of life has developed in a metal-rich environment and has taken roughly 5 Gyr to do so. We investigate the possible number of CETI civilizations based on different scenarios. At one extreme is the Weak Astrobiological Copernican scenario—such that a planet forms intelligent life sometime after 5 Gyr, but not earlier. The other is the Strong Astrobiological Copernican scenario in which life must form between 4.5 and 5.5 Gyr, as on Earth. In the Strong scenario (under the strictest set of assumptions), we find there should be at least 36(-32/+175) civilizations within our Galaxy: this is a lower limit, based on the assumption that the average lifetime, L, of a communicating civilization is 100 yr (since we know that our own civilization has had radio communications for this time). If spread uniformly throughout the Galaxy this would imply that the nearest CETI is at most 17,000 (-10,000/+33,600) ly away and most likely hosted by a low-mass M-dwarf star, likely far surpassing our ability to detect it for the foreseeable future, and making interstellar communication impossible. Furthermore, the likelihood that the host stars for this life are solar-type stars is extremely small and most would have to be M dwarfs, which may not be stable enough to host life over long timescales. We furthermore explore other scenarios and explain the likely number of CETI there are within the Galaxy based on variations of our assumptions.
_________________ ˄28 The term "troll" refers to internet users–in this context, paid operatives–who post inflammatory or otherwise disruptive content on social media or other websites.
SpaceX is targeting Tuesday, June 30 for a Falcon 9 launch of the GPS III Space Vehicle 03 mission from Space Launch Complex 40 (SLC-40) at Cape Canaveral Air Force Station in Florida. The 15-minute primary launch window opens at 3:55 p.m. EDT, 19:55 UTC, and a backup opportunity is available on Wednesday, July 1 with a 15-minute launch window opening at 3:51 p.m. EDT, 19:51 UTC.
Following stage separation, SpaceX will land Falcon 9’s first stage on the “Just Read the Instructions” droneship, which will be stationed in the Atlantic Ocean. The spacecraft will deploy approximately 1 hour and 29 minutes after liftoff.
Täna 22:55 Eesti aja järgi või homme kell 22:51. _________________ “Always remember that the crowd that applauds your coronation is the same crowd that will applaud your beheading. People like a show.” - sir Terry Pratchett
Pics Or It Didn't Happen
Pics Or It Didn't Happen
4 July UTC / 5 July NZT
21:19 - 22:03 UTC / 09:19 - 10:03 NZT
Launch Complex 1
00:19-01:03 homme. Video lives 1h pärast. _________________ “Always remember that the crowd that applauds your coronation is the same crowd that will applaud your beheading. People like a show.” - sir Terry Pratchett
Nurgas oli juba numbritest näha et asi hakkab kukkuma, umbes pool vajalikust kiirusest oli alles käes ja kõrgus langes pea kilomeeter sekundis. _________________ Ma ei saa sellest aru, järelikult on see vale.
SpaceX is targeting Wednesday, July 8 at 11:59 a.m. EDT, 15:59 UTC, for launch of its tenth Starlink mission, which will include 57 Starlink satellites and 2 satellites from BlackSky, a Spaceflight customer. Falcon 9 will lift off from Launch Complex 39A (LC-39A) at Kennedy Space Center in Florida, and a backup opportunity is available on Friday, July 10 at 11:16 a.m. EDT, 15:16 UTC.
Falcon 9’s first stage previously supported Crew Dragon’s first demonstration mission to the International Space Station, launch of the RADARSAT Constellation Mission, and the fourth and seventh Starlink missions. Following stage separation, SpaceX will land Falcon 9’s first stage on the “Of Course I Still Love You” droneship, which will be stationed in the Atlantic Ocean.
18:59 täna (08.07) või reedel (10.07) kell 18:16. _________________ “Always remember that the crowd that applauds your coronation is the same crowd that will applaud your beheading. People like a show.” - sir Terry Pratchett
sa ei või postitada uusi teemasid siia foorumisse sa ei või vastata selle foorumi teemadele sa ei või muuta oma postitusi selles foorumis sa ei või kustutada oma postitusi selles foorumis sa ei või vastata küsitlustele selles foorumis sa ei saa lisada manuseid selles foorumis sa võid manuseid alla laadida selles foorumis
Hinnavaatlus ei vastuta foorumis tehtud postituste eest.