# Grandfather Killing The Grandson (Time Travel Question) **URL:** \ **Category:** In My Humble Opinion\ **Created:** [March 9, 2011, 8:31am UTC](https://boards.straightdope.com/t/grandfather-killing-the-grandson-time-travel-question/574022 "2011-03-09T08:31:17Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Markxxx](https://avatars.discourse-cdn.com/v4/letter/m/5daacb/32.png) [@Markxxx](https://boards.straightdope.com/u/Markxxx)\ **Post date:** [March 9, 2011, 8:31am UTC](https://boards.straightdope.com/t/grandfather-killing-the-grandson-time-travel-question/574022/1 "2011-03-09T08:31:17Z")
OK it’s late but I was trying to think this through We all know of the [Grandfather Paradox](http://en.wikipedia.org/wiki/Grandfather_paradox) > [@](#): > > suppose a man traveled back in time and killed his biological grandfather before the latter met the traveler’s grandmother. As a result, one of the traveler’s parents (and by extension the traveler himself) would never have been conceived OK fine, makes sense But supposing this time traveler goes back and meets his biological grandfather and the grandfather decided to kill the grandson FIRST and actually kills the grandson in the past. So what kind of problems does this create? Outside of the fact the grandfather is now a murder and may be arrested. I was thinkin of how it woud effect the future? Or doesn’t it? ---
**Author:** ![ColdPhoenix](https://avatars.discourse-cdn.com/v4/letter/c/6bbea6/32.png) [@ColdPhoenix](https://boards.straightdope.com/u/ColdPhoenix)\ **Post date:** [March 9, 2011, 8:36am UTC](https://boards.straightdope.com/t/grandfather-killing-the-grandson-time-travel-question/574022/2 "2011-03-09T08:36:43Z")
It wouldn’t affect the future any more than if anyone else killed the grandson. ---
**Author:** ![One\_And\_Only\_Wanderers](https://avatars.discourse-cdn.com/v4/letter/o/838e76/32.png) [@One\_And\_Only\_Wanderers](https://boards.straightdope.com/u/One_And_Only_Wanderers)\ **Post date:** [March 9, 2011, 8:59am UTC](https://boards.straightdope.com/t/grandfather-killing-the-grandson-time-travel-question/574022/3 "2011-03-09T08:59:36Z")
causality is not affected in your stated scenario, as long as the grandfather still progresses to meet and impregnate grandma, as he did in the unaltered timeline. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [March 9, 2011, 9:01am UTC](https://boards.straightdope.com/t/grandfather-killing-the-grandson-time-travel-question/574022/4 "2011-03-09T09:01:16Z")
The education film [Roswell That Ends Well](http://en.wikipedia.org/wiki/Roswell_That_Ends_Well) addresses the Grandfather Paradox and demonstrates that a [Restricted Action Resolution](http://en.wikipedia.org/wiki/Grandfather_paradox#Restricted_action_resolution) will occur in such circumstances. The greater danger is demonstrated in a [more comprehensive scientific documentary](http://en.wikipedia.org/wiki/Futurama:_Bender%27s_Big_Score) where the [Destruction Resolution](http://en.wikipedia.org/wiki/Grandfather_paradox#Destruction_resolution)comes into play. ---
**Author:** ![heathen\_earthling](https://avatars.discourse-cdn.com/v4/letter/h/13edae/32.png) [@heathen\_earthling](https://boards.straightdope.com/u/heathen_earthling)\ **Post date:** [March 9, 2011, 12:25pm UTC](https://boards.straightdope.com/t/grandfather-killing-the-grandson-time-travel-question/574022/5 "2011-03-09T12:25:34Z")
Okay, suppose that a guy goes back in time and ends up _attempting_ to kill his grandfather for whatever reason, but the grandfather kills him in self-defense first. Based on the time traveler’s odd dialect and clothing, the grandfather strongly suspects that he was from the future, and even manages to convince a few other people of this. Photos of the dead time traveler are widely reproduced in paranormal/conspiracy books. The grandfather sticks to his story over the years, and even tells his grandson all about it. The grandson grows up, and eventually recognizes himself as the man in the famous “dead time traveler” photo that his grandfather showed him. When time travel is invented, he decides not to risk going back to that era. Paradox? ---
**Author:** ![RTFirefly](https://avatars.discourse-cdn.com/v4/letter/r/c77e96/32.png) [@RTFirefly](https://boards.straightdope.com/u/RTFirefly)\ **Post date:** [March 9, 2011, 5:10pm UTC](https://boards.straightdope.com/t/grandfather-killing-the-grandson-time-travel-question/574022/6 "2011-03-09T17:10:37Z")
> [@Markxxx](#): > > So what kind of problems does this create? None. Cite: [CalMeacham’s greatest sig line hits](http://boards.straightdope.com/sdmb/showpost.php?p=6696082&postcount=93) ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [March 9, 2011, 5:14pm UTC](https://boards.straightdope.com/t/grandfather-killing-the-grandson-time-travel-question/574022/7 "2011-03-09T17:14:03Z")
Awwww…Thanks for remembering > [@](#): > > “Of course,” said my grandfather, pulling a gun from his belt as he stepped from the Time Machine, “There’s no paradox if I shoot You!” Physicist and science fiction author Robert Forward said that he wouldn’t believe the Grandfather Paradox unless someone could prove it to him mathematically. His own take was that there was only one, self-consistent past, and that anything you did travelling back in time was unalterably part of it. His novel **Timemaster** was his way of putting this into a story. But he didn’t address (or ignored) the issues of Free Will and what would happen if someone very precisely and actively tried to alter the past.