{"id":14947,"date":"2025-06-18T10:00:00","date_gmt":"2025-06-18T10:00:00","guid":{"rendered":"https:\/\/modernsciences.org\/staging\/4414\/?p=14947"},"modified":"2025-06-13T15:05:08","modified_gmt":"2025-06-13T15:05:08","slug":"universe-expansion-no-center-general-relativity-cosmology-basics-june-2025","status":"publish","type":"post","link":"https:\/\/modernsciences.org\/staging\/4414\/universe-expansion-no-center-general-relativity-cosmology-basics-june-2025\/","title":{"rendered":"Where is the center of the\u00a0universe?"},"content":{"rendered":"\n\n
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\n In space, there are four dimensions: length, width, height and time.\n scaliger\/iStock\/NASA via Getty Images Plus<\/a><\/span>\n <\/figcaption>\n <\/figure>\n\n Rob Coyne<\/a>, University of Rhode Island<\/a><\/em><\/span>\n\n

About a century ago, scientists were struggling to reconcile what seemed a contradiction in Albert Einstein\u2019s theory of general relativity<\/a>. <\/p>\n\n

Published in 1915<\/a>, and already widely accepted worldwide by physicists and mathematicians, the theory assumed the universe was static \u2013 unchanging, unmoving and immutable. In short, Einstein believed the size and shape of the universe today was, more or less, the same size and shape it had always been.<\/p>\n\n

But when astronomers looked into the night sky at faraway galaxies with powerful telescopes, they saw hints the universe was anything but that. These new observations suggested the opposite \u2013 that it was, instead, expanding<\/a>. <\/p>\n\n

Scientists soon realized Einstein\u2019s theory didn\u2019t actually say the universe had to be static; the theory could support an expanding universe as well. Indeed, by using the same mathematical tools provided by Einstein\u2019s theory, scientists created new models that showed the universe was, in fact, dynamic and evolving<\/a>. <\/p>\n\n

I\u2019ve spent decades trying to understand general relativity, including in my current job as a physics professor<\/a> teaching courses on the subject<\/a>. I know wrapping your head around the idea of an ever-expanding universe can feel daunting \u2013 and part of the challenge is overriding your natural intuition about how things work. For instance, it\u2019s hard to imagine something as big as the universe not having a center at all, but physics says that\u2019s the reality.<\/p>\n\n

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