Core Viewpoint - Scientists from Johns Hopkins University and the University of Chicago have successfully observed polarized microwave signals from the early universe using a ground-based telescope, marking a significant advancement in astronomy by revealing insights into the "cosmic dawn" period, which occurred just a few hundred million years after the universe's birth [1]. Group 1 - The observation was made using a ground-based telescope located in the Andes Mountains of Chile [1]. - This achievement represents the first time that such weak signals, previously thought to be detectable only by space telescopes, have been detected from the ground [1]. - The findings were published in the latest issue of The Astrophysical Journal, highlighting the importance of this research in understanding a critical but poorly understood era in the universe's history [1].