Free Astronomy Magazine March-April 2024 ARABIC VERSION

the contributions of Camille Flam- marion, Giovanni Virginio Schiapar- elli, Percival Lowell and other sci- entists contributed not only to dis- seminating the themes of extrater- restrial life to the public, but also to giving a boost to science fiction liter- ature. And so we reach the middle of the twentieth century, when a ques- tion asked by Enrico Fermi to some colleagues turns into the famous par- adox that bears his name: “If the uni- verse is teeming with aliens, where is everybody?” From the 1950s to today, thinkers from the most varied fields of human knowledge have given dozens of reasonable answers to that question, and some of them entail the disturbing consequence that aliens would be aware of our ex- istence, due to unnatural features recognizable on the surface of our planet. An example could be the con- tinental areas of the nocturnal hemi- sphere, where artificial lighting frames out coastlines and other major population centers alike. This type of technosignature, however, would be visible to aliens located at a distance from Earth of no more than 100 light years (or probably fewer). The same limit applies to radio waves. Considering that in the ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ 11 - ﻣﺎﺭﺱ ﺃﺑﺮﻳﻞ 2 0 2 4 أﻣﺎ ﰲ اﻟﻘﺮﻧ اﻟﺘﺎﺳﻊ ﻋ ﻌﴩﻳﻦ ـﴩ واﻟ ـ ﻓﻘﺪ ﺳــﺎﻫﻤﺖ ﻣﺴــﺎﻫﻤﺎت ﻛﺎﻣﻴ ـﻞ ﻓﻼﻣــﺎر ﻳﻮن وﺟﻴﻮﻓﺎﻧﻲ ﻓ ﺟﻴﻨﻴﻮ ﺷﻴﺎﺑﺎرﻳﲇ وﺑ ﺳـﻴﻔﺎل ﻟﻮﻳﻞ وﻋﻠﻤﺎء آﺧـﺮﻳﻦ ﻟـﻴﺲ ﻓﻘـﻂ ﰲ ﻧـ ﴩ ـ ﻣﻮﺿـﻮﻋﺎت اﻟﺤﻴــﺎة ﺧـﺎرج ﻛﻮﻛ ـﺐ اﻷرض ﻟﻠﺠﻤﻬﻮر وﻟﻜﻦ أﻳﻀًﺎ ﰲ إﻋﻄـﺎء دﻓﻌـﺔ ﻷدب اﻟﺨﻴﺎل اﻟﻌﻠﻤﻲ وﻫﻜﺬا ﻧﺼﻞ إﱃ ﻣﻨﺘﺼﻒ اﻟﻘﺮن اﻟﻌ ﴩﻳﻦ ﻋﻨﺪﻣﺎ ﻳﺘﺤﻮل ﺳﺆال ﻃﺮﺣﻪ إﻧﺮﻳﻜـﻮ ﻓ ﻣﻲ ﻋﲆ ﺑﻌﺾ زﻣﻼﺋﻪ إﱃ ا ﻔﺎرﻗﺔ اﻟﺸﻬ ة اﻟﺘﻲ ﺗﺤﻤـﻞ اﺳـﻤﻪ :" إذا ﻛـﺎن اﻟﻜـﻮن ﻳﻌـﺞ ﺑ ﺎﻟﻜﺎﺋﻨﺎت اﻟﻔﻀـﺎﺋﻴﺔ ﻓـﺄﻳﻦ اﻟﺠﻤﻴـﻊ؟ ﻣﻨـﺬ اﻟﺨﻤﺴﻴﻨﻴﺎت وﺣﺘﻰ اﻟﻴﻮم، ﻗﺪم ﻣﻔﻜﺮون ﻣﻦ ﻣﺨﺘﻠﻒ ﻣﺠﺎﻻت ا ﻌﺮﻓﺔ اﻹﻧﺴﺎﻧﻴﺔ ﻋـ ﴩات ـ ا ﻹﺟﺎﺑﺎت ا ﻌﻘﻮﻟﺔ ﻋﲆ ﻫﺬا اﻟﺴﺆال وﺑﻌﻀـﻬﺎ ﻳﻨﻄـﻮي ﻋـﲆ ﻧﺘﻴﺠـﺔ ﻣﺰﻋﺠـﺔ ﺗﺘﻤﺜــﻞ ﰲ أن اﻟﻜﺎﺋﻨ ـﺎت اﻟﻔﻀــﺎﺋﻴﺔ ﺳ ـﺘﻜﻮن ﻋــﲆ ﻋﻠــﻢ ﺑﻮﺟﻮدﻧﺎ، ﺑﺴﺒﺐ اﻟﺴﻤﺎت ﻏ اﻟﻄﺒﻴﻌﻴﺔ اﻟﺘـﻲ ﻳﻤﻜﻦ اﻟﺘﻌﺮف ﻋﻠﻴﻬﺎ ﻋﲆ اﻟﺴﻄﺢ . ﻣﻦ ﻛﻮﻛﺒﻨﺎ ـــــ ﻣﻦ اﻷﻣﺜﻠﺔ ﻋﲆ ذﻟﻚ ا ﻨﺎﻃﻖ اﻟﻘﺎرﻳﺔ ﻣﻦ ﻧﺼﻒ اﻟﻜﺮة اﻷرﺿﻴﺔ اﻟﻠـﻴﲇ ﺣﻴـﺚ ﺗﻌﻤـﻞ اﻹﺿـﺎءة اﻻﺻﻄﻨﺎﻋﻴﺔ ﻋﲆ ﺗﺤﺪﻳﺪ اﻟﺨﻄﻮط اﻟﺴـﺎﺣﻠﻴﺔ وﻏ ﻫﺎ ﻣﻦ ا ﺮاﻛﺰ اﻟﺴﻜﺎﻧﻴ ﺔ اﻟﺮﺋﻴﺴـﻴﺔ ﻋـﲆ ﺣﺪ ﺳﻮاء وﻣﻊ ذﻟﻚ ﻓﺈن ﻫﺬ ه اﻟﻌﻼﻣﺔ اﻟﺘﻘﻨﻴـ ﺔ ﻮن ﻣﺮﺋﻴ ﻜﺘﺳ ﺔ ﻣﻦ ﻗﺒﻞ اﻟﻜﺎﺋﻨـﺎت اﻟﻔﻀـﺎﺋﻴﺔ ا ﻮﺟﻮد ة ﻋﲆ ﻣﺴﺎﻓﺔ ﻻ ﺗﺰﻳﺪ ﻋـﻦ 100 ﺳـﻨﺔ ) ﺿﻮﺋﻴﺔ أو رﺑﻤﺎ أﻗـﻞ ( ﻣـﻦ اﻷرض وﻳﻨﻄﺒـﻖ ﻧﻔﺲ اﻟﺤﺪ ﻋﲆ ا ﻮﺟﺎت اﻟﺮادﻳﻮ .ﻳﺔ ر ﺘﺸﺎرد أوفﻣ ﺪﻟﺘﻮن ﻫ ى اوفﺟ ﻨﺖ ﺗﻮﻣﺎ اﻹ ﻮ ر ﺘﺸﺎرد أوفﻣ ﺪﻟﺘﻮن ﻏﺎﻟ ﻠﻮ ﻏﺎﻟ ﻠﻲ ﻳﻮﻫﺎﻧﺲﻛ ﻠﺮ ﻧﻴ ﻮﻻس ﻮﺑﺮﻴ ﻮس