<story><title>Age of universe at 26.7B years, nearly twice as old as previously believed</title><url>https://phys.org/news/2023-07-age-universe-billion-years-previously.html</url></story><parent_chain><item><author>gmmeyer</author><text>The question is &amp;quot;how long has it been since the big bang.&amp;quot; It&amp;#x27;s an important and relevant question for cosmology and physics. It isn&amp;#x27;t really a stance on the &amp;quot;beginning of time,&amp;quot; which may have started long before this moment, but it is the start of the universe as far as physics is concerned.</text></item><item><author>kleene_op</author><text>IANAP, but as a mathematician it seems extremely inelegant that there would be a start to the time dimension of the space-time object we live in, when we don&amp;#x27;t even know if the spatial dimensions are finite themselves.&lt;p&gt;It is my understanding that the density of the universe billions of years ago was radically different from the one we now observe, and since density is intrinsically tied to our perception of space and time, wouldn&amp;#x27;t it make more sense that time actually stretches infinitely the further back we go, thus nullifying the concept of a beginning?&lt;p&gt;I guess I&amp;#x27;m having a hard time with the idea that space-time could be discontinuous.</text></item></parent_chain><comment><author>chinabot</author><text>How I work it out in my head that time effectively did not exist before the big bang is that; If everyone agrees that time slows as the gravity increases, and we assume at the time of the big bang that all the mass of the universe was in an infinitely small space, the conclusion is we had an infinitely large gravity and time would be effectively be stopped. Take it with a grain of salt.</text></comment>
<story><title>Age of universe at 26.7B years, nearly twice as old as previously believed</title><url>https://phys.org/news/2023-07-age-universe-billion-years-previously.html</url></story><parent_chain><item><author>gmmeyer</author><text>The question is &amp;quot;how long has it been since the big bang.&amp;quot; It&amp;#x27;s an important and relevant question for cosmology and physics. It isn&amp;#x27;t really a stance on the &amp;quot;beginning of time,&amp;quot; which may have started long before this moment, but it is the start of the universe as far as physics is concerned.</text></item><item><author>kleene_op</author><text>IANAP, but as a mathematician it seems extremely inelegant that there would be a start to the time dimension of the space-time object we live in, when we don&amp;#x27;t even know if the spatial dimensions are finite themselves.&lt;p&gt;It is my understanding that the density of the universe billions of years ago was radically different from the one we now observe, and since density is intrinsically tied to our perception of space and time, wouldn&amp;#x27;t it make more sense that time actually stretches infinitely the further back we go, thus nullifying the concept of a beginning?&lt;p&gt;I guess I&amp;#x27;m having a hard time with the idea that space-time could be discontinuous.</text></item></parent_chain><comment><author>fnordpiglet</author><text>Maybe I guess. Many models stipulate that time began with the Big Bang. Many propose the Big Bang was a local event that obliterated our ability to observe time before it.  We have models where the universe rips apart, collapses, or just evolves forever and always has and always will. I think what’s crucial to understand is we have a lot of different possible explanations for what we see, some of them discuss beginnings and ends, some do not. Perhaps as a mathematician with a relatively closed set of possibilities for explanations that’s unsettling. But, I’ve always found the various paradoxes in math to illustrate similar problems in formulating a closed and coherent anything, including the universe.</text></comment>