Re: How to exit a time machine?
"David Deutsch david.deutsch-LR/[email protected] [Fabric-of-Reality]" <[email protected]> Thu, 27 Nov 2014 11:15:18 +0000
| Newsgroups | gmane.science.physics.fabric-of-reality |
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| Message-ID | <[email protected]> |
--Apple-Mail=_B22F233B-4462-44F4-85F6-A99941C1A171 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="UTF-8" > On 27 Nov 2014, at 08:42, solngawi-/[email protected] [Fabric-of-Reality] <Fabric= [email protected]> wrote: > > > > In the Time Travel chapter o= f The Fabric of Reality, a time machine is imagined to be an exotic sort of= place. Imagine a room with a large opaque cylinder at its centre. The cyli= nder encloses an opaque revolving door and the only way in or out is via a = single entrance cut in the side of the cylinder. When you enter the cylinde= r and go around one or more times and then exit you find yourself in the pa= st. More like a cylinder with an entrance at one end and an exit at anoth= er. Unlike familiar cylinders, this one's exit is not only at a different p= lace from the entrance but a different time. Next, forget the cylinder: its= not solid. It's made of spacetime. > > Once you exit, however, the multiv= erse differentiates and the past you end up in is the past of a different u= niverse to the one you left. > > This poses a problem, however. How does o= ne exit the time machine and stay alive? > > The problem arises because m= acroscopic objects like people are extended in space and so can't exit the = time machine instantaneously. Different planes through your body end up in = different past universes.< /div> > > What is the solution to this? Is ther= e a clever way to get out of a time machine alive? I don't quite see the p= roblem. Every universe in which you step out contains every atom of your b= ody. So the different parts certainly won't end up in different universes. = So are you saying they'd be pulled away from each other in each particular = universe by large forces? From where? -- David Deutsch --Apple-Mail=_B22F233B-4462-44F4-85F6-A99941C1A171 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: 7bit <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> </head> <body style="background-color: #fff;"> <span style="display:none"> </span> <!--~-|**|PrettyHtmlStartT|**|-~--> <div id="ygrp-mlmsg" style="position:relative;"> <div id="ygrp-msg" style="z-index: 1;"> <!--~-|**|PrettyHtmlEndT|**|-~--> <div id="ygrp-text" > <p><br class><div><blockquote type="cite" class><div class>On 27 Nov 2014, at 08:42, <a href="mailto:solngawi-/[email protected]" class>solngawi-/[email protected]</a> [Fabric-of-Reality] <<a href="mailto:[email protected]" class>[email protected]</a>> wrote:</div><br class="Apple-interchange-newline"><div class><br style="font-family: Monaco;font-size: 14px;font-style: normal;font-variant: normal;font-weight: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;" class><br style="font-family: Monaco;font-size: 14px;font-style: normal;font-variant: normal;font-weight: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;" class><div style="font-family: Monaco; font-size: 14px;font-style: normal;font-variant: normal;font-weight: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;" class><span style="word-spacing: normal;" class>In the Time Travel chapter of The Fabric of Reality, a time machine is imagined to be an exotic sort of place. Imagine a room with a large opaque cylinder at its centre. The cylinder encloses an opaque revolving door and the only way in or out is via a single entrance cut in the side of the cylinder. When you enter the cylinder and go around one or more times and then exit you find yourself in the past. </span><br class></div></div></blockquote><div><br class></div>More like a cylinder with an entrance at one end and an exit at another. Unlike familiar cylinders , this one's exit is not only at a different place from the entrance but a different time. Next, forget the cylinder: its not solid. It's made of spacetime.<br class><blockquote type="cite" class><div class><div style="font-family: Monaco;font-size: 14px;font-style: normal;font-variant: normal;font-weight: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;" class><br class></div><div style="font-family: Monaco;font-size: 14px;font-style: normal;font-variant: normal;font-weight: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;" class>Once you exit, however, the multiverse differentiates and the past you end up in is the past of a different universe to the one you left.</div><d iv style="font-family: Monaco;font-size: 14px;font-style: normal;font-variant: normal;font-weight: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;" class><br class></div><div style="font-family: Monaco;font-size: 14px;font-style: normal;font-variant: normal;font-weight: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;" class>This poses a problem, however. How does one exit the time machine and stay alive? </div><div style="font-family: Monaco;font-size: 14px;font-style: normal;font-variant: normal;font-weight: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;" class><br class></div><div style="font-family: Monac o;font-size: 14px;font-style: normal;font-variant: normal;font-weight: normal;letter-spacing: normal;text-align: start;text-indent: 0px;text-transform: none;white-space: normal;" class>The problem arises because macroscopic objects like people are extended in space and so can't exit the time machine instantaneously. Different planes through your body end up in different past universes.< /div><div class><br class></div><div class>What is the solution to this? Is there a clever way to get out of a time machine alive?</div></div></div></blockquote><br class></div><div>I don't quite see the problem.</div><div><br class></div><div>Every universe in which you step out contains every atom of your body. So the different parts certainly won't end up in different universes. So are you saying they'd be pulled away from each other in each particular universe by large forces? From where?</div><div><br class></div><div>-- David Deutsch</div><br class></p> </div> <!--~-|**|PrettyHtmlStart|**|-~--> <div style="color: #fff; height: 0;">__._,_.___</div> <div style="clear:both"> </div> <div id="fromDMARC" style="margin-top: 10px;"> <hr style="height:2px ; border-width:0; color:#E3E3E3; background-color:#E3E3E3;"> Posted by: David Deutsch <david.deutsch-LR/[email protected]> <hr style="height:2px ; border-width:0; color:#E3E3E3; background-color:#E3E3E3;"> </div> <div style="clear:both"> </div> <table cellspacing=4px style="margin-top: 10px; margin-bottom: 10px; color: #2D50FD;"> <tbody> <tr> <td style="font-size: 12px; font-family: arial; font-weight: bold; padding: 7px 5px 5px;" > <a style="text-decoration: none; color: #2D50FD" href="https://groups.yahoo.com/neo/groups/Fabric-of-Reality/conversations/messages/25676;_ylc=X3oDMTJxMm8wbXI1BF9TAzk3MzU5NzE0BGdycElkAzE4ODg2MDAEZ3Jwc3BJZAMxNzA1MDIwNTg1BG1zZ0lkAzI1Njc2BHNlYwNmdHIEc2xrA3JwbHkEc3RpbWUDMTQxNzExNTE2Ng--?act=reply&messageNum=25676">Reply via web post</a> </td> <td>•</td> <td style="font-size: 12px; font-family: arial; padding: 7px 5px 5px;" > <a href="mailto:david.deutsch-LR/[email protected]?subject=Re%3A%20How%20to%20exit%20a%20time%20machine%3F" style="text-decoration: none; color: #2D50FD;"> Reply to sender </a> </td> <td>•</td> <td style="font-size: 12px; font-family: arial; padding: 7px 5px 5px;"> <a href="mailto:[email protected]?subject=Re%3A%20How%20to%20exit%20a%20time%20machine%3F" style="text-decoration: none; color: #2D50FD"> Reply to group </a> </td> <td>•</td> <td style="font-size: 12px; font-family: arial; padding: 7px 5px 5px;" > <a href="https://groups.yahoo.com/neo/groups/Fabric-of-Reality/conversations/newtopic;_ylc=X3oDMTJldWM4NGhqBF9TAzk3MzU5NzE0BGdycElkAzE4ODg2MDAEZ3Jwc3BJZAMxNzA1MDIwNTg1BHNlYwNmdHIEc2xrA250cGMEc3RpbWUDMTQxNzExNTE2Ng--" style="text-decoration: none; color: #2D50FD">Start a New Topic</a> </td> <td>•</td> <td style="font-size: 12px; font-family: arial; padding: 7px 5px 5px;color: #2D50FD;" > <a href="https://groups.yahoo.com/neo/groups/Fabric-of-Reality/conversations/topics/25675;_ylc=X3oDMTM2bWZiOG92BF9TAzk3MzU5NzE0BGdycElkAzE4ODg2MDAEZ3Jwc3BJZAMxNzA1MDIwNTg1BG1zZ0lkAzI1Njc2BHNlYwNmdHIEc2xrA3Z0cGMEc3RpbWUDMTQxNzExNTE2NgR0cGNJZAMyNTY3NQ--" style="text-decoration: none; color: #2D50FD;">Messages in this topic</a> (2) </td> </tr> </tbody> </table> <!------- Start Nav Bar ------> <!-- |**|begin egp html banner|**| --> <div id="ygrp-vital" style="background-color: #f2f2f2; font-family: Verdana; font-size: 10px; margin-bottom: 10px; padding: 10px;"> <span id="vithd" style="font-weight: bold; color: #333; text-transform: uppercase; "><a href="https://groups.yahoo.com/neo/groups/Fabric-of-Reality/info;_ylc=X3oDMTJldDltcjNkBF9TAzk3MzU5NzE0BGdycElkAzE4ODg2MDAEZ3Jwc3BJZAMxNzA1MDIwNTg1BHNlYwN2dGwEc2xrA3ZnaHAEc3RpbWUDMTQxNzExNTE2Ng--" style="text-decoration: none;">Visit Your Group</a></span> <ul style="list-style-type: none; margin: 0; padding: 0; display: inline;"> <li style="border-right: 1px solid #000; font-weight: 700; display: inline; padding: 0 5px; margin-left: 0;"> <span class="cat"><a href="https://groups.yahoo.com/neo/groups/Fabric-of-Reality/members/all;_ylc=X3oDMTJmdGNwcWRjBF9TAzk3MzU5NzE0BGdycElkAzE4ODg2MDAEZ3Jwc3BJZAMxNzA1MDIwNTg1BHNlYwN2dGwEc2xrA3ZtYnJzBHN0aW1lAzE0MTcxMTUxNjY-" style="text-decoration: none;">New Members</a></span> <span class="ct" style="color: #ff7900;">3</span> </li> </ul> </div> <div id="ft" style="font-family: Arial; font-size: 11px; margin-top: 5px; padding: 0 2px 0 0; clear: both;"> <a href="https://groups.yahoo.com/neo;_ylc=X3oDMTJkYzk5bHU4BF9TAzk3NDc2NTkwBGdycElkAzE4ODg2MDAEZ3Jwc3BJZAMxNzA1MDIwNTg1BHNlYwNmdHIEc2xrA2dmcARzdGltZQMxNDE3MTE1MTY2" style="float: left;"><img src="http://l.yimg.com/ru/static/images/yg/img/email/new_logo/logo-groups-137x15.png" height="15" width="137" alt="Yahoo! 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