# Time travel question: **URL:** \ **Category:** Factual Questions\ **Created:** [June 5, 2002, 2:48pm UTC](https://boards.straightdope.com/t/time-travel-question/112493 "2002-06-05T14:48:12Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Aro](https://avatars.discourse-cdn.com/v4/letter/a/b3f665/32.png) [@Aro](https://boards.straightdope.com/u/Aro)\ **Post date:** [June 5, 2002, 2:48pm UTC](https://boards.straightdope.com/t/time-travel-question/112493/1 "2002-06-05T14:48:12Z")
This is going to be hard to explain… Yet again, sorry if this thread should be elsewhere… I feel part of the question may have a factual answer… In general (in films) they assume time travel will be relative to the earth in some way. If you move forward in time you will appear in the same place on earth only in the future or the past. (As in the ‘Time Machine’). Has anyone wrote / talked about absolute co-ordinates in the Universe, not just with respect to Earth in time travel? I mean, if you moved forward in time 150 days, the earth would be on the other side of the sun whilst you remained in open space, in real trouble. In fact, due to the expansion of the Solar system, Galaxy and Universe, should all forms of time travel not land you miles into open space, if you are to remain in the same exact co-ordinate you started in? Would it be possible to work out how far you moved from the earth, from your original position, whilst remaining in the same co-ordinates? Would one second back in time leave you in a void in space? ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [June 5, 2002, 3:04pm UTC](https://boards.straightdope.com/t/time-travel-question/112493/2 "2002-06-05T15:04:52Z")
In the book [Bearing an Hourglass](http://www.amazon.com/exec/obidos/ASIN/0345313151/ref=pd_ser_asin_2/002-9141812-9406433) by Piers Anthony (book two of the Incarnations of Immortality series) the main character holds the office of Time (ala Father Time…the first book was about the guy who takes over the office of Death). His method of travel is to speed up and slow down time for himself such that everything moves around him in the fashion you mention so he gets to where he is going. Looked at closely it doesn’t seem to be very workable bet hey…it’s fiction. ---
**Author:** ![Tranquilis](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tranquilis/32/3639_2.png) [@Tranquilis](https://boards.straightdope.com/u/Tranquilis)\ **Post date:** [June 5, 2002, 3:15pm UTC](https://boards.straightdope.com/t/time-travel-question/112493/3 "2002-06-05T15:15:12Z")
Excellent question! Dunno the answer, but I’ve been wondering the same thing myself. Why didn’t the time machine gouge an enourmous hole through the city/earth as the planet rotated/orbited out from under it? For that matter, even if the machine stood still WRT the earth’s surface, why didn’t the pigerons crap all over it, or some such…? Sure, to the time traveller, we all look to be moving really damn fast, but to us, he’d bemoving more slowly than mollasas in a deep-freezer. ---
**Author:** ![Tranquilis](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tranquilis/32/3639_2.png) [@Tranquilis](https://boards.straightdope.com/u/Tranquilis)\ **Post date:** [June 5, 2002, 3:16pm UTC](https://boards.straightdope.com/t/time-travel-question/112493/4 "2002-06-05T15:16:59Z")
Time travel would allow me to fix my typos… 😛 ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 5, 2002, 3:43pm UTC](https://boards.straightdope.com/t/time-travel-question/112493/5 "2002-06-05T15:43:39Z")
[Python]Just remember that you’re standing on a planet that’s evolving And revolving at nine hundred miles an hour, That’s orbiting at nineteen miles a second, so it’s reckoned, A sun that is the source of all our power. The sun and you and me and all the stars that we can see Are moving at a million miles a day In an outer spiral arm, at forty thousand miles an hour, Of the galaxy we call the ‘Milky Way’.[/Python] It’s not possible to know whether you are at absolute rest, only whether you are at rest relative to some object or other. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [June 5, 2002, 7:38pm UTC](https://boards.straightdope.com/t/time-travel-question/112493/6 "2002-06-05T19:38:46Z")
The OP is an issue that has been around the SF community for decades. Most writers simply ignore it, because otherwise they couldn’t write the story they wanted to write. But for the answer to your question, I recommend, as I did in another recent time travel thread, [Time Machines : Time Travel in Physics, Metaphysics, and Science Fiction by Paul J. Nahin](http://www.amazon.com/exec/obidos/ASIN/0387985719/qid=1023305665/sr=1-1/ref=sr_1_1/103-7525518-1061451), which discusses every conceivable variation on the subject. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [June 5, 2002, 8:27pm UTC](https://boards.straightdope.com/t/time-travel-question/112493/7 "2002-06-05T20:27:51Z")
> [@](#): > > \*Originally posted by Tranquilis \* > \*\*Dunno the answer, but I’ve been wondering the same thing myself. Why didn’t the time machine gouge an enourmous hole through the city/earth as the planet rotated/orbited out from under it? > > For that matter, even if the machine stood still WRT the earth’s surface, why didn’t the pigerons crap all over it, or some such…? Sure, to the time traveller, we all look to be moving really damn fast, but to us, he’d bemoving more slowly than mollasas in a deep-freezer. \*\* You answered your own first question with your last sentence. We assume the time traveller is whizzing into the future as if heis somehow actually in motion. However, it is just as reasonable to suppose that he his sitting in a bubble of extremely slow time. If you view it that way then it is easy to see why he doesn’t go flying through the earth. He’s planted nicely on terra-firma and is just hanging out for several thousand years. Howeever, that doesn’t explain why there isn’t pigeon crap all over him (maybe from his perspective the time between the crapping and the crap disappearing naturally may be too quick for him to notice or maybe his time bubble has anti-crap properties). Going backwards in time is a more dicey proposition and I’m not sure how to explain that.