1.0Sci Phi Journalhttps://www.sciphijournal.orgrich600338<blockquote class="wp-embedded-content" data-secret="MtNUNcnK7Z"><a href="https://www.sciphijournal.org/index.php/2017/08/06/the-philosophy-of-other-worlds/">The Philosophy of Other Worlds</a></blockquote><iframe sandbox="allow-scripts" security="restricted" src="https://www.sciphijournal.org/index.php/2017/08/06/the-philosophy-of-other-worlds/embed/#?secret=MtNUNcnK7Z" width="600" height="338" title="“The Philosophy of Other Worlds” — Sci Phi Journal" data-secret="MtNUNcnK7Z" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" class="wp-embedded-content"></iframe><script> /*! This file is auto-generated */ !function(d,l){"use strict";l.querySelector&&d.addEventListener&&"undefined"!=typeof URL&&(d.wp=d.wp||{},d.wp.receiveEmbedMessage||(d.wp.receiveEmbedMessage=function(e){var t=e.data;if((t||t.secret||t.message||t.value)&&!/[^a-zA-Z0-9]/.test(t.secret)){for(var s,r,n,a=l.querySelectorAll('iframe[data-secret="'+t.secret+'"]'),o=l.querySelectorAll('blockquote[data-secret="'+t.secret+'"]'),c=new RegExp("^https?:$","i"),i=0;i<o.length;i++)o[i].style.display="none";for(i=0;i<a.length;i++)s=a[i],e.source===s.contentWindow&&(s.removeAttribute("style"),"height"===t.message?(1e3<(r=parseInt(t.value,10))?r=1e3:~~r<200&&(r=200),s.height=r):"link"===t.message&&(r=new URL(s.getAttribute("src")),n=new URL(t.value),c.test(n.protocol))&&n.host===r.host&&l.activeElement===s&&(d.top.location.href=t.value))}},d.addEventListener("message",d.wp.receiveEmbedMessage,!1),l.addEventListener("DOMContentLoaded",function(){for(var e,t,s=l.querySelectorAll("iframe.wp-embedded-content"),r=0;r<s.length;r++)(t=(e=s[r]).getAttribute("data-secret"))||(t=Math.random().toString(36).substring(2,12),e.src+="#?secret="+t,e.setAttribute("data-secret",t)),e.contentWindow.postMessage({message:"ready",secret:t},"*")},!1)))}(window,document); //# sourceURL=https://www.sciphijournal.org/wp-includes/js/wp-embed.min.js </script> Other worlds are common in fantasy and science-fiction, but they actually have quite a solid basis in physics as well. Here, I’ll talk about “other worlds” as other universes, not just other planets within our own universe, but places that are not directly connected to us in space and time. Think The Golden Compass, Alice in Wonderland, Narnia, and hundreds of sci-fi books that I don’t know about. 

People have thought about other worlds for centuries. The idea of spirit realms, Heaven and Hell, and purgatory were commonly held beliefs even in times B.C. Even a multiverse was posited byhttp://sci.ismaelosorio.es/wp-content/uploads/2017/07/curled-up-dim.png