Free Astronomy Magazine January-February 2024 ARABIC VERSION

13.8 billion years ago, an age that appears too recent to justify the morphology and stellar content of the galaxies born in the first billion years. For those galaxies to have de- veloped so rapidly, it would be nec- essary for all the gas in the universe to have transformed into stars with an efficiency close to 100%, which is a scenario that does not seem re- alistic. For a few years now, astronomers have been trying to find a reason- able solution to the problem of pre- cocious galaxies. Of all the proposed solutions, the most surprising one states that the universe could have been born not 13.8 billion years ago, but 26.7 billion years ago! This disconcerting hypothesis was pro- posed last summer by Rajendra Gupta (Faculty of Science at the Uni- versity of Ottawa) in an article pub- lished in the Monthly Notices of the Royal Astronomical Society . Initially, the article did not have a great re- sponse, but with the multiplication of discoveries of precocious primor- dial galaxies, it has begun to arouse more and more interest. To better understand Gupta’s claims, we must go back to 1929, when Fritz Zwicky (famous for having pro- posed the existence of dark matter, as well as the origin of gravitational lenses and neutron stars) formu- lated the concept of “tired light” to explain the redshift-distance of galaxies relationship within a sta- tionary universe. Zwicky’s model was intended to be an alternative to that of the expanding universe, pro- posed shortly before by Georges ﻓﺴ ﻔﺴـﺎء ﺗـﻢ إﻧﺸـﺎؤﻫﺎ ﺎﺳـﺘﺨﺪامﺻــﻮر ــﺔ ﻣــﻦ ــﺐ اﻟﻔﻀــﺎﺋﻲ ﻟﻤﻨﻄﻘــﺔ ﻗﺮ ﻣــﻦ ﺗﻠﺴــ ﻮبﺟــ ﻤﺲو ــﺪة ﺎﻧــﺖ ﻣﻮﺟــﻮدة ﻌــﺪ ﻣــﺎ ﺑـــ اﻟــﺪب اﻷﻛــ ، ﻣــﻊ إدراﺟــﺎت ﺗﻮﺿــﺢ ﻣﻮﻗــﻊﺳــﺖ ﻣﺠــﺮاتﺟﺪ 500 و 800 ﻣﻠﻴــﻮنﺳــﻨﺔ ﻣــﻦ ﻌــﺪ ﺣـــﺪوث اﻻﻧﻔﺠــﺎر اﻟﻌﻈــ ﻢ . ﺗﺤﺘــﻮيﻫــﺬﻩ اﻟﻤﺠـــﺮات ﻋﻠــﻰﻋــﺪد ﻣﻤﺎﺛــﻞ ﻣــﻦ اﻟﻨﺠـــﻮم ﻟﻤﺠﺮة در اﻟﺘ ﺎﻧﺔ، وﻟﻜﻨﻬﺎ ﻣﻌ ﺄة ﻓﻲﻣﺴﺎﺣﺔ أﺻﻐﺮ ﻜﺜ ﺗﻌﺘﱪ ﺗﻠﻚ ﻓﱰة زﻣﻨﻴﺔ اً ﺟﺪ ﺔﺣﺪﻳﺜ ﺑﺤﻴﺚ أن ذﻟـﻚ ﻻ ﻳـﱪر اﻟﺸـﻜﻞ وا ﺤﺘـﻮى اﻟﻨﺠﻤــﻲ ﻟﻠﻤﺠﺮات اﻟﺘﻲ ﺗﺸﻜﻠﺖ ﺧﻼل ا ﻠﻴـﺎر ﺳـﻨﺔ اﻷوﱃ ﻣﻦ ﻋﻤﺮ اﻟﻜﻮن . ﻟﺬﻟﻚ ﻟﻜ ﻲ ﺗﺘﻄﻮر ﺗﻠﻚ ا ﺠﺮات ﺑﻬﺬه اﻟﴪﻋﺔ ﻓﻘﺪ ﻛﺎن ﻣﻦ اﻟﴬوري أن ﻳﺘﺤـﻮل ﺟﻤﻴـﻊ اﻟﻐﺎز ا ﻮﺟﻮد ﰲ اﻟﻜـﻮن إﱃ ﻧﺠـﻮم ﺑﻜﻔـﺎءة ﺗﻘﱰب ﻣﻦ 100% وﻫﻮ اﻟﺴﻴﻨﺎرﻳﻮ اﻟـﺬي ﻻ ﻳﻌﺘﻘﺪ اﻟﻌﻠﻤﺎء ﺑﺄﻧﻪ ﻳﺒﺪو واﻗﻌﻴﺎ . ﻳﺤﺎول اﻟ ﻌﻠﻤﺎء ﻣﻨﺬ ﻋﺪة ﺳﻨﻮات إﻳﺠﺎد ﺣـﻞ ﻣﻌﻘﻮل ﻟﻠﻐﺰ ا ﺠﺮات اﻟﻨﺎﺿﺠﺔ ا ﺒﻜﺮ . ة إن ﻣﻦ ﺑ ﺟﻤﻴﻊ اﻟﺤﻠـﻮل ا ﻘﱰﺣـﺔ اﻟﺤـﻞ اﻷﻛﺜﺮ إﺛﺎرة ﻟﻠﺪﻫﺸﺔ ﻫﻮ اﻟﺬي ﻳﻨﺺﻋﲆ أن اﻟﻜﻮن ﻛﺎن ﻣﻦ ا ﻤﻜﻦ أن ﻳﻮﻟـﺪ ﻟـﻴﺲ ﻗﺒـﻞ 13.8 ﻣﻠﻴﺎر ﺳﻨﺔ وﻟﻜـﻦ ﻗﺒـﻞ 26.7 ﻣﻠﻴـﺎر ! ﺳﻨﺔ ﺗﻢ اﻗﱰاح ﻫﺬه اﻟﻔﺮﺿﻴﺔ ا ﺜ ة ﻟﻠﻘﻠﻖ ﰲ اﻟﺼﻴﻒ ا ﺎﴈ ﻣﻦ ﻗ ﺒﻞ راﺟﻴﻨﺪرا ﺟﻮﺑﺘـﺎ ) ﻛﻠﻴﺔ اﻟﻌﻠﻮم ﰲ ﺟﺎﻣﻌﺔ أوﺗﺎوا ( ﰲ ﻣﻘﺎل ﻧﴩ ﰲ اﻹﺷﻌﺎرات اﻟﺸﻬﺮﻳﺔ ﻟﻠﺠﻤﻌﻴـﺔ اﻟﻔﻠﻜﻴـﺔ ا ﻠﻜﻴﺔ . ﰲ اﻟﺒﺪاﻳ ﺔ ﻟﻢ ﻳﺤﻆ ا ﻘﺎل ﺑﺎﺳﺘﺠﺎﺑﺔ ﻛﺒ ة وﻟﻜﻦ ﻣﻊ ﺗﻜﺎﺛﺮ اﻛﺘﺸﺎﻓﺎت ا ﺠـﺮات اﻟﺒﺪاﺋﻴﺔ ا ﺒﻜﺮة ﻓﻘﺪ ﺑﺪأ ﻳﺜ ا ﺰﻳـﺪ وا ﺰﻳـﺪ ﻣﻦ ﻣﻦ اﻻﻫﺘﻤﺎم وﻟﻔﻬﻢ ادﻋﺎءات ﺟﻮﺑﺘﺎ ﺑﺸﻜﻞ أﻓﻀﻞ، ﻳﺠﺐ أن ﻧﻌﻮد إﱃ ﻋﺎم 1929 ﻋﻨـﺪﻣﺎ ﺻﺎغ ﻓﺮﻳﺘﺰ زو ا ﺸـﻬ ) ﻳﻜـﻲ ﻮر ﺑﺎﻓﱰاﺿـﻪ وﺟﻮد ا ﺎدة ا ﻈﻠﻤﺔ وﻛﺬﻟﻚ أﺻـﻞ ﻋﺪﺳـﺎت اﻟﺠﺎذﺑﻴـﺔ واﻟﻨﺠـﻮم اﻟﻨﻴﻮﺗﺮوﻧﻴـﺔ ( ﻣﻔﻬـﻮم » اﻟﻀﻮء ا ﺘﻌﺐ ـﻟ. « ﴩح ﻋﻼﻗﺔ ا ﺴﺎﻓﺔ ﺑ ا ﺠﺮات واﻻﻧﺰﻳـﺎح اﻷﺣﻤـﺮ داﺧـﻞ اﻟﻜـﻮن اﻟﺜﺎﺑﺖ . ﻛﺎن ا ﻘﺼﻮد ﻣﻦ ﻧﻤﻮذج زوﻳﻜﻲ أن ﻳ ﻜﻮن ﺑﺪﻳﻼً ﻟﻨﻤﻮذج اﻟﻜﻮن ا ﺘﻮﺳـﻊ اﻟـﺬي إ ﻗﱰﺣﻪ ﺟﻮر ﻴﺲﺟ ﻟﻴﻤﺎﺗﺮ وإدون ﻫﺎﺑﻞ ﻗﺒﻞ وﻗﺖ ﻗﺼ . أ رﺻـــــﺎد ـــــﺔ اﻟﻤﺘﻌـــــﺪدة ﻟــــــ اﻷﻃـــــﻮال اﻟﻤﻮﺟ Ceers-2112 وﻫــــــــــﻲﻣﺠــــــــــﺮة ــــــــــﺔ ذات ﺣﻠﺰوﻧ اﻧﺰ ـــﺎح أ ﻤـــﺮ z = 3 ﺎﻧـــﺖ واﻟـــ ﻣﺘﺸـــ ﻠﺔ ـﻮن ﺎﻟﻔﻌﻞ ﺸ ﻞ ﻣﺪﻫﺶﻋﻨﺪﻣﺎ ﺎن ﻋﻤـﺮ اﻟ ﻣﻠ ﺎريﺳﻨﺔ . ﻓﻘﻂ - ﻳﻨﺎﻳﺮ ﻓﺒﺮﺍﻳﺮ 2 0 2 4 [NASA, ESA, CSA, I. Labbe (Swinburne University of Technol- ogy). Image processing: G. Brammer (Niels Bohr Institute’s Cosmic Dawn Center, University of Copenhagen)]