Abstract
IRVINE, CALIFORNIA --New observations described at a National Academy of Sciences colloquium here suggest that giant walls of galaxies, hundreds of millions of light-years long, may have crisscrossed the universe when it was just 15% of its present age. Such structures are similar to what we see today, which raises a problem for theorists: If gravity hasn't radically resculpted the universe over time, that implies that it may have far less mass than theorists prefer. That is in line with evidence of a scarcity of mass in the nearby universe but at odds with one measurement of how fast the cosmic expansion rate is changing, which hints at a much higher density of matter ( see p. 37 ).
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
