tag:blogger.com,1999:blog-1580378912972065231.post425573756074692322..comments2024-01-04T11:40:48.827-06:00Comments on Dr Michael G Strauss: A Changing Arrow of Time?Michael G Strausshttp://www.blogger.com/profile/11580842374977938870noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-1580378912972065231.post-90914299426727998992019-01-23T21:52:52.634-06:002019-01-23T21:52:52.634-06:00They still require a beginning of our universe.They still require a beginning of our universe.Michael G Strausshttps://www.blogger.com/profile/11580842374977938870noreply@blogger.comtag:blogger.com,1999:blog-1580378912972065231.post-53276905916277183872019-01-16T01:14:26.146-06:002019-01-16T01:14:26.146-06:00As far as I know, these models propose a cauchy su...As far as I know, these models propose a cauchy surface that "separates" both regions, to the point where they have no causal or temporal connection (they are 100% separated). Actually, these models present two or more universes with a first common instant on that cauchy surface (which is inexplicably there).The Crowhttps://www.blogger.com/profile/05413691784316461118noreply@blogger.comtag:blogger.com,1999:blog-1580378912972065231.post-58871925917331870872017-07-23T15:40:28.724-05:002017-07-23T15:40:28.724-05:00I don't know about the time sensitivity of pre...I don't know about the time sensitivity of previous universes since I've not studied that. Since all theories of previous universes have so many unknowns, I don't know if there is an answer to this. We do know that any idea of previous universes has some real problems with thermodynamic considerations as discussed in my post on "Some Proposals about the Beginning of our Universe."Michael G Strausshttps://www.blogger.com/profile/11580842374977938870noreply@blogger.comtag:blogger.com,1999:blog-1580378912972065231.post-64153305319396938612017-02-10T16:58:46.101-06:002017-02-10T16:58:46.101-06:00Thanks Mike, In any ocillating process or evolutio...Thanks Mike, In any ocillating process or evolution leading to our expanding universes how time sensitive would the alternate phases be in order to get the universe we observe. Does such consideration lead to the same sort of semi-infinite improbability as when considering the spectrum of precise physical constants. Thanks KeithKeithhttps://www.blogger.com/profile/16219283160015859565noreply@blogger.comtag:blogger.com,1999:blog-1580378912972065231.post-12548786884167014682017-02-10T07:53:27.263-06:002017-02-10T07:53:27.263-06:00What is "de Sitter space"? Google has an...What is "de Sitter space"? Google has an explanation, but its still a bit technical. Can you break it down? Thanks!Faithful Thinkershttps://www.blogger.com/profile/04089768576413860677noreply@blogger.comtag:blogger.com,1999:blog-1580378912972065231.post-3763501460243896132017-02-07T06:59:28.064-06:002017-02-07T06:59:28.064-06:00Great question. Actually they are both possible s...Great question. Actually they are both possible scenarios. I think I probably left out too many details in this post and didn't make some things clear. In the AG scenario, the universe does seem to appear from a vacuum state and has a "bounce surface" at which point the arrow of time points in opposite directions. Depending on the exact boundary conditions of that surface you can get either one of the pictures. Vilenkin says this about the two options. "The bounce surface in de Sitter space is defined up to boost transformations. The surfaces obtained from one another by such transformations are completely equivalent, but in the limit of infinite boost the surface becomes null." [That limit is the picture on the right.]Michael G Strausshttps://www.blogger.com/profile/11580842374977938870noreply@blogger.comtag:blogger.com,1999:blog-1580378912972065231.post-35109980123019560092017-02-06T22:14:13.711-06:002017-02-06T22:14:13.711-06:00Dr. Strauss, the two figures in the image appear t...Dr. Strauss, the two figures in the image appear to represent two different models. Which one is the AG model? Faithful Thinkershttps://www.blogger.com/profile/04089768576413860677noreply@blogger.comtag:blogger.com,1999:blog-1580378912972065231.post-22583123288457008682017-02-06T21:30:38.699-06:002017-02-06T21:30:38.699-06:00Thank you for you hard work! Thank you for you hard work! rikmidhttps://www.blogger.com/profile/03060007178464116071noreply@blogger.com