{"id":796849,"date":"2025-06-24T06:04:04","date_gmt":"2025-06-24T11:04:04","guid":{"rendered":"https:\/\/spaceweekly.com\/?p=796849"},"modified":"2025-06-24T06:04:04","modified_gmt":"2025-06-24T11:04:04","slug":"where-is-the-center-of-the-universe","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=796849","title":{"rendered":"Where is the center of the universe?"},"content":{"rendered":"<p> <br \/>\n<\/p>\n<div>\n<figure id=\"attachment_513660\" aria-describedby=\"caption-attachment-513660\" style=\"width: 800px\" class=\"wp-caption alignnone\"><figcaption id=\"caption-attachment-513660\" class=\"wp-caption-text\">This is the center of our galaxy, the Milky Way. But where is the center of the universe? Infrared image via NASA\/ JPL-Caltech\/ Susan Stolovy (SSC\/Caltech) et al.<\/figcaption><\/figure>\n<ul>\n<li><strong>Where is the center of the\u00a0universe?<\/strong> The center of our solar system is the sun. And the center of our galaxy is a supermassive black hole. So where\u2019s the universe\u2019s center?<\/li>\n<li><strong>The language of mathematics makes it confusing.<\/strong> We\u2019re more familiar with two- and three-dimensional space. But our universe has four dimensions, interwoven in space-time.<\/li>\n<li><strong>The Big Bang did not happen in a single place.<\/strong> And as the universe expands, it\u2019s not expanding outward from a single point. Essentially, there is no center of the universe.<\/li>\n<\/ul>\n<p>  <span>By Rob Coyne, University of Rhode Island<\/span><\/p>\n<h3>Where is the center of the\u00a0universe?<\/h3>\n<p>Only a century ago, scientists were struggling to reconcile what seemed a contradiction in Albert Einstein\u2019s theory of general relativity. <\/p>\n<p>Published in 1915, and already widely accepted worldwide by physicists and mathematicians, the theory assumed the universe was static. As in, that it was 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<p>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. That it was, instead, expanding. <\/p>\n<p>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. <\/p>\n<p>I\u2019ve spent decades trying to understand general relativity, including in my current job as a physics professor teaching courses on the subject. I know wrapping your head around the idea of an ever-expanding universe can feel daunting. 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<figure>\n            <iframe loading=\"lazy\" title=\"The Expanding Universe | National Geographic\" width=\"1110\" height=\"624\" src=\"https:\/\/www.youtube.com\/embed\/BBKV2N550XE?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><figcaption>The universe gets bigger every day. Video via National Geographic.<\/figcaption><\/figure>\n<h3>The space between galaxies<\/h3>\n<p>First, let\u2019s define what\u2019s meant by <em>expansion<\/em>. On Earth, <em>expanding <\/em>means something is getting bigger. And in regard to the universe, that\u2019s true, sort of. Expansion might also mean <em>everything is getting farther from us<\/em>, which is also true with regard to the universe. Point a telescope at distant galaxies and they all do appear to be moving away from us. <\/p>\n<p>What\u2019s more, the farther away they are, the faster they appear to be moving. Those galaxies also seem to be moving away from each other. So it\u2019s more accurate to say that everything in the universe is getting farther away from everything else, all at once.<\/p>\n<h3>The Big Bang was not a single point<\/h3>\n<p>This idea is subtle but critical. It\u2019s easy to think about the creation of the universe like exploding fireworks: Start with a Big Bang, and then all the galaxies in the universe fly out in all directions from some central point. <\/p>\n<p>But that analogy isn\u2019t correct. Not only does it falsely imply that the expansion of the universe started from a single spot, which it didn\u2019t, but it also suggests that the galaxies are the things that are moving, which isn\u2019t entirely accurate. <\/p>\n<p>It\u2019s not so much the galaxies that are moving away from each other. It\u2019s the space between galaxies, the fabric of the universe itself, that\u2019s ever-expanding as time goes on. In other words, it\u2019s not really the galaxies themselves that are moving through the universe. It\u2019s more that the universe itself is carrying them farther away as it expands. <\/p>\n<p>A common analogy is to imagine sticking some dots on the surface of a balloon. As you blow air into the balloon, it expands. Because the dots are stuck on the surface of the balloon, they get farther apart. Though they may appear to move, the dots actually stay exactly where you put them, and the distance between them gets bigger simply by virtue of the balloon\u2019s expansion. <\/p>\n<p>Now think of the dots as galaxies and the balloon as the fabric of the universe, and you begin to get the picture. <\/p>\n<p>Unfortunately, while this analogy is a good start, it doesn\u2019t get the details quite right either.<\/p>\n<figure class=\"align-center zoomable\">\n            <img decoding=\"async\" alt=\"split screen of a green balloon with red dots and a squiggle on the surface, lightly inflated and then much more blown up\" src=\"https:\/\/images.theconversation.com\/files\/672328\/original\/file-20250604-74-2xt71o.jpg?ixlib=rb-4.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;fit=clip\" srcset=\"https:\/\/images.theconversation.com\/files\/672328\/original\/file-20250604-74-2xt71o.jpg?ixlib=rb-4.1.0&amp;q=45&amp;auto=format&amp;w=600&amp;h=338&amp;fit=crop&amp;dpr=1 600w, https:\/\/images.theconversation.com\/files\/672328\/original\/file-20250604-74-2xt71o.jpg?ixlib=rb-4.1.0&amp;q=30&amp;auto=format&amp;w=600&amp;h=338&amp;fit=crop&amp;dpr=2 1200w, https:\/\/images.theconversation.com\/files\/672328\/original\/file-20250604-74-2xt71o.jpg?ixlib=rb-4.1.0&amp;q=15&amp;auto=format&amp;w=600&amp;h=338&amp;fit=crop&amp;dpr=3 1800w, https:\/\/images.theconversation.com\/files\/672328\/original\/file-20250604-74-2xt71o.jpg?ixlib=rb-4.1.0&amp;q=45&amp;auto=format&amp;w=754&amp;h=424&amp;fit=crop&amp;dpr=1 754w, https:\/\/images.theconversation.com\/files\/672328\/original\/file-20250604-74-2xt71o.jpg?ixlib=rb-4.1.0&amp;q=30&amp;auto=format&amp;w=754&amp;h=424&amp;fit=crop&amp;dpr=2 1508w, https:\/\/images.theconversation.com\/files\/672328\/original\/file-20250604-74-2xt71o.jpg?ixlib=rb-4.1.0&amp;q=15&amp;auto=format&amp;w=754&amp;h=424&amp;fit=crop&amp;dpr=3 2262w\" sizes=\"(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px\"\/><figcaption>It\u2019s the space between the dots that\u2019s growing. Image via NASA\/ JPL-Caltech.<br \/><\/figcaption><\/figure>\n<h3>The 4th dimension<\/h3>\n<p>Important to any analogy is an understanding of its limitations. Some flaws are obvious: A balloon is small enough to fit in your hand, not so the universe. Another flaw is more subtle. The balloon has two parts: its latex surface and its air-filled interior. <\/p>\n<p>The language of mathematics would describe these two parts of the balloon differently. The balloon\u2019s surface is two-dimensional. If you were walking around on it, you could move forward, backward, left or right, but you couldn\u2019t move up or down without leaving the surface. <\/p>\n<p>Now it might sound like we\u2019re naming four directions here \u2013 forward, backward, left and right \u2013 but those are just movements along two basic paths: side to side and front to back. That\u2019s what makes the surface two-dimensional: length and width. <\/p>\n<p>The inside of the balloon, on the other hand, is three-dimensional. So you\u2019d be able to move freely in any direction, including up or down \u2026 length, width and height. <\/p>\n<p>This is where the confusion lies. The thing we think of as the <em>center<\/em> of the balloon is a point somewhere in its interior, in the air-filled space beneath the surface. <\/p>\n<p>But in this analogy, the universe is more like the latex surface of the balloon. The balloon\u2019s air-filled interior has no counterpart in our universe, so we can\u2019t use that part of the analogy. Only the surface matters.<\/p>\n<p>So asking, \u201cWhere\u2019s the center of the universe?\u201d is somewhat like asking, \u201cWhere\u2019s the center of the balloon\u2019s surface?\u201d There simply isn\u2019t one. You could travel along the surface of the balloon in any direction, for as long as you like, and you\u2019d never once reach a place you could call its center because you\u2019d never actually leave the surface.<\/p>\n<h3>There is no center of the universe<\/h3>\n<p>So, in the same way, you could travel in any direction in the universe and would never find its center because, much like the surface of the balloon, it simply doesn\u2019t have one.<\/p>\n<p>Part of the reason this can be so challenging to comprehend is because of the way the language of mathematics describes the universe. The surface of the balloon has two dimensions, and the balloon\u2019s interior has three. But the universe exists in four dimensions. Because it\u2019s not just about how things move in space, but how they move in time.<\/p>\n<p>Our brains are wired to think about space and time separately. But in the universe, they\u2019re interwoven into a single fabric, called space-time. That unification changes the way the universe works relative to what our intuition expects.<\/p>\n<p>And this explanation doesn\u2019t even begin to answer the question of how something can be expanding indefinitely. Scientists are still trying to puzzle out what powers this expansion.<\/p>\n<p>So, in asking about the center of the universe, we\u2019re confronting the limits of our intuition. The answer we find \u2013 everything, expanding everywhere, all at once \u2013 is a glimpse of just how strange and beautiful our universe is.<!-- Below is The Conversation's page counter tag. Please DO NOT REMOVE. --><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/counter.theconversation.com\/content\/252695\/count.gif?distributor=republish-lightbox-basic\" alt=\"\" width=\"1\" height=\"1\" style=\"border: none !important; box-shadow: none !important; margin: 0 !important; max-height: 1px !important; max-width: 1px !important; min-height: 1px !important; min-width: 1px !important; opacity: 0 !important; outline: none !important; padding: 0 !important\" referrerpolicy=\"no-referrer-when-downgrade\"\/><!-- End of code. If you don't see any code above, please get new code from the Advanced tab after you click the republish button. The page counter does not collect any personal data. More info: https:\/\/theconversation.com\/republishing-guidelines --><\/p>\n<p><span>Rob Coyne, Teaching Professor of Physics, University of Rhode Island<\/span><\/p>\n<p>This article is republished from The Conversation under a Creative Commons license. Read the original article.<\/p>\n<p>Bottom line: Where is the center of the universe? The center of our solar system is the sun. And the center of our galaxy is a supermassive black hole. So where\u2019s the universe\u2019s center?<\/p>\n<p><span class=\"cp-load-after-post\"\/><\/div>\n<p><br \/>\n<br \/><a href=\"https:\/\/earthsky.org\/space\/where-is-center-of-the-universe\/?rand=772280\">Source link <\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>This is the center of our galaxy, the Milky Way. But where is the center of the universe? Infrared image via NASA\/ JPL-Caltech\/ Susan Stolovy (SSC\/Caltech) et al. Where is&hellip; <\/p>\n","protected":false},"author":1,"featured_media":796850,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[46],"tags":[],"class_list":["post-796849","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-earth-sky"],"_links":{"self":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/796849","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=796849"}],"version-history":[{"count":0,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/posts\/796849\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=\/wp\/v2\/media\/796850"}],"wp:attachment":[{"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=796849"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=796849"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spaceweekly.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=796849"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}