Free Astronomy Magazine January-February 2024 ARABIC VERSION

T 8 he image reveals temper- ature fluctuations dating back 13.77 billion years (shown as color differences) that correspond to the seeds that eventually grew into galaxies. The signal from the Milky Way was sub- tracted using multi-frequency data. This image shows a temperature range of ±200 microKelvin. [NASA/ WMAP Science Team] ing Zwicky’s afloat. Nevertheless, starting from the 1990s and also thanks to the entry into the scene of the Hubble Space Telescope, many observations have been made which have unequivocally demonstrated how the tired light hypothesis was not the most suitable to explain the redshift of distant galaxies. In par- ticular, the cosmic background radi- ation, a cornerstone of cosmology based on the Big Bang and precisely mapped between 2010 and 2013 by the Planck space telescope (in mi- crowaves and infrared), cannot be e x - plained in the sta- tionary universe scenario. Furthermore, in this type of universe, if the mecha- nisms of tired light were valid, the surface brightness of stars, and therefore of galaxies, should be constant, in the sense that the fur- ther away an object is, the less light we receive, and since its apparent area decreases, there should be a constant ratio between received light and apparent area. But this is not the case: what is observed is that the surface brightness of ob- jects (essentially galaxies) decreases with distance, a phenomenon com- patible with an expanding universe; as they recede, they appear to emit photons at a reduced rate, since each photon must cover a greater distance to reach the observer than the previous photon. ﺗﻜﺸﻒ اﻟﺼﻮرة ﻋﻦ ﺗﻘﻠ ﺎت درﺟﺎت اﻟ ـ ﺤﺮارة ﻌﻮد ﺗﺎر ﺨﻬﺎ إﻟــــــﻰ ١٣.٧٧ ــــــﺎردوﻻرﺳـــــــﻨﻮات ﻣﻠ ) ﻤــــــﺎ ﻫـــــــﻮ ﻣﻮﺿـــﺢ ﻓــــﻲ اﺧﺘﻼﻓـــﺎت اﻟﻠــــﻮن ( اﻟـــ ﺗﺘﻮاﻓــــﻖ ﻧ ــــﺬوراﻟــــ ﻣــــﻊ اﻟ ــــﺔ اﻟﻤﻄـــــﺎف ﻤــــﺖ ﻓــــﻲ ﻧﻬﺎ إﻟــﻰ اﻟﻤﺠـــﺮات وﺗـــﻢﻃـــﺮح اﻹﺷـــﺎرة ﻣـــﻦ ﻣﺠـــﺮة در اﻟﺘ ﺎﻧـــــــــــﺔ ﺎﺳــــــــــــﺘﺨﺪام ﺑ ﺎﻧــــــــــــﺎت ﻣﺘﻌــــــــــــﺪدة اﻟــــــ دد . ﺗُﻈﻬــــــﺮﻫـــــــﺬﻩ اﻟﺼــــــﻮرة ﻧﻄــــــﺎقدرﺟـــــــﺔ ﺣﺮارة ﻳ ﻠﻎ ±٢٠٠ ﻣ ﻜﺮو ﻠﻔﻦ ﻠﺨـــﺺ ــــﮫ ــــﺪﻳﻮ ﻌــــﺾﻣــــﺎ ﺗﻮﺻــــﻞ إﻟ ﻫــــﺬا اﻟﻔ ﺗﻠﺴـــــــــ ﻮب ﻼﻧـــــــــﻚ اﻟﻔﻀـــــــــﺎﺋﻲ اﻟﺘـــــــــﺎﺑﻊ ﻟﻮ ﺎﻟـــــــــﺔ ــــــــــﺔ اﻟﻔﻀــــــــــﺎء اﻷوروﺑ ) إ ﺴــــــــــﺎ ( ﺧــــــــــﻼل ﻣﻬﻤــــــــــﺔ اﻷرﺻــــﺎد اﺳـــــﺘﻐﺮﻗﺖ اﻟـــــ 4.5 ﺳــــﻨﺔ ـــــﺪءا ﻣـــــﻦ اﻻﻛﺘﺸـﺎﻓﺎت اﻟــ ـ ﺠﺪ ﺪة ﻓــﻲدر اﻟﺘ ﺎﻧــﺔ وﺣــ اﻟﻠﺤﻈــﺎت اﻷوﻟـــﻰ ﻌـــﺪ اﻻﻧﻔﺠــﺎر اﻟﻌﻈـــ ﻢ ﻗﺒـــﻞ 13.8 ﻣﻠ ﺎرﺳﻨﺔ . أﻳﻀ ﺎً ﰲ إﺑﻘﺎء زوﻳﻜﻲ واﻗﻔﺎً ﻋﲆ ﻗﺪﻣﻴﻪ . وﻣﻊ ذﻟﻚ، ﺑﺪء اً ﻣﻦ اﻟﺘﺴﻌﻴﻨﻴﺎت وأﻳﻀًﺎ ﺑﻔﻀﻞ دﺧﻮل ﺗﻠﺴﻜﻮ ب ﻫﺎﺑﻞ اﻟﻔﻀﺎﺋﻲ إﱃ ا ﺸﻬﺪ، ﺗﻢ إﺟﺮاء اﻟﻌﺪﻳﺪ ﻣﻦ اﻻرﺻﺎد اﻟﺘـﻲ أﻇﻬﺮت ﺑﺸﻜﻞ ﻻ ﻟﺒﺲ ﻓﻴﻪ ﻛﻴـﻒ أن ﻓﺮﺿـﻴﺔ اﻟﻀﻮء ا ﺘﻌﺐ ﻟﻢ ﺗﻜﻦ اﻷﻛﺜﺮ ﻣﻼءﻣﺔ ﻟﺘﻔﺴـ اﻻﻧﺰﻳﺎح اﻷﺣﻤﺮ ﻟﻠﻤﺠﺮات اﻟﺒﻌﻴﺪة . ﻋﲆ وﺟﻪ اﻟ ﺨﺼﻮص، ﻓـﺈن إﺷـﻌﺎع اﻟﺨﻠﻔﻴـﺔ اﻟﻜﻮﻧﻴﺔ وﻫﻮ ﺣﺠـﺮ اﻟﺰاوﻳـﺔ ﰲ ﻋﻠـﻢ اﻟﻜـﻮن اﻟﻘﺎﺋﻢ ﻋﲆ اﻻﻧﻔ ﺠﺎر اﻟﻜﺒ واﻟﺬي ﺗـﻢ رﺳـﻤﻪ ﺑﺪﻗـﺔ ﺑ ـ ﻋـﺎﻣﻲ 2010 و 2013 ﺑﻮاﺳــﻄﺔ ﺗﻠﺴــﻜﻮب ﺑﻼﻧــﻚ اﻟﻔﻀــﺎﺋﻲ ) ﰲ ا ﻮﺟــﺎت ا ﻴﻜﺮوﻳﺔ واﻷﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء ﻻ ( ﻳﻤﻜﻦ أن ﻳﻜﻮن ﻫﺬا اﻟﻨﻮع ﻣﻦ اﻟﻜﻮن إذا ﺗﻢ ﺗﺤﺪﻳﺪ آﻟﻴﺎت اﻟﻀﻮء ا ﺘﻌﺐ . ﺻﺤﻴﺢ أن ﺳـﻄ ﻮع ﺳـﻄﺢ اﻟﻨﺠـﻮم وﺑﺎﻟﺘـﺎﱄ ا ﺠﺮات ﻳﺠﺐ أن ﻳﻜﻮن ﺛﺎﺑﺘًﺎ ﺑﻤﻌﻨﻰ أﻧﻪ ﻛﻠﻤـﺎ ﻛﺎن اﻟﺠﺴﻢ ﺑﻌﻴﺪ اً ﻗﻞ اﻟﻀﻮء ﺑﻤﻌﻨﻰ أﻧﻪ ﻛﻠﻤـﺎ ﻛﺎن اﻟﺠﺴﻢ ﺑﻌﻴﺪ اً ﻗﻞ اﻟﻀﻮء اﻟﺬي ﻧﺴـﺘﻘﺒﻠﻪ وﺑﻤﺎ أن ﻣﺴﺎﺣﺘﻪ اﻟﻈﺎﻫﺮة ﺗﺘﻨﺎﻗﺺ ﻓﻴﺠـﺐ أن ﺗﻜﻮن ﻫﻨـﺎك ﻧﺴـﺒﺔ ﺛﺎﺑﺘـﺔ ﺑـ اﻟﻀـﻮء ا ﺴﺘﻘﺒﻞ و ا ﻨﻄﻘﺔ اﻟﻈﺎﻫﺮ .ﺔﻳـ وﻟﻜـﻦ ﻫـﺬا ﻟﻴﺲ ﻫﻮ اﻟﺤﺎل : ﻣﺎ ﻟﻮﺣﻆ ﻫﻮ أن ﺳﻄﻮع ﺳـﻄﺢ اﻷﺟﺴـﺎم ) ا ﺠـﺮات ﺑﺸـﻜﻞ أﺳـﺎﳼ ( ﻳﺘﻨـﺎﻗﺺ ﻣـﻊ ا ﺴﺎﻓﺔ، وﻫﻲ ﻇﺎﻫﺮة ﻣﺘﻮاﻓﻘﺔ ﻣـﻊ اﻟﻜـﻮن ا ﺘﻮﺳﻊ وﻣـﻊ ﺗﺮاﺟﻌﻬـﺎ ﻳﺒـﺪو أﻧﻬـﺎ ﺗﺒﻌـﺚ ﻓﻮﺗﻮﻧﺎت ﺑﻤﻌـﺪل ﻣـﻨﺨﻔﺾ ﺣﻴـﺚ ﻳﺠـﺐ أن ﻳﻐﻄﻲ ﻛﻞ ﻓﻮﺗﻮن ﻣﺴﺎﻓﺔ أﻛـﱪ ﻟﻠﻮﺻـﻮل إﱃ اﻟﺮاﺻﺪ ﺑ ﺎرﻧﺔ ﻣﻘ ﺎﻟﻔﻮﺗﻮن اﻟﺴﺎﺑﻖ . ﻣﺠﻠﺔ FreeAstronomy ﺎﻟﻌﺮ ﺔ - ﻳﻨﺎﻳﺮ ﻓﺒﺮﺍﻳﺮ 2 0 2 4