Sciencemadness Discussion Board

problem with time travel

xxxxx - 29-1-2007 at 15:43

i like science fiction as much as the next guy, but i am having a problem with time travel, mainly the rotation of the earth and the motion of the earth around the sun, for starters. it seems like if someone was to travel even a few seconds through time that they would be in outer space.

Waffles - 29-1-2007 at 16:17

you mean the same way that GPS satellites, within a few weeks or even days after they are launched, should give coordinates kilometers off because of the relativistic effect of gravity on the flow of time?

these problems can be accounted for without too much difficulty. remember, in the context of time travel, you don't just 'travel through time.' you're traveling through SPACE-TIME. if you can find a mechanism to transport information (and hopefully matter) through time, accounting for the motion of the earth's spin, the earth's rotation, the solar system's travel, the galaxy's travel, and the universe's expansion should be a minor issue in tweaking the 'space' aspect of your space-time travel.

you should read the book 'the light of other days' by clarke, it talks some about this and its a pretty sweet read. :)

Aurum - 4-2-2007 at 06:13

Quote:
Originally posted by xxxxx
i like science fiction as much as the next guy, but i am having a problem with time travel, mainly the rotation of the earth and the motion of the earth around the sun, for starters. it seems like if someone was to travel even a few seconds through time that they would be in outer space.


That would only be a problem if the earth was not the center of the universe.:D:D

BTW, time travel is easy. I do it all the time, unfortunately only in one direction.

unionised - 4-2-2007 at 12:41

That works fine if you are at the centre of the earth or at the poles. Those of us here on the rest of the surface are stuffed.

edmo - 14-9-2008 at 23:45

The atomic particles aren't concerned with the orbit of the earth and they travel faster/slower through time, so why would you care?

Sauron - 15-9-2008 at 04:20

Plot devices like time travel and FTL propulsion are not intended as anything but necessary fabrications requiring suspension of disbelief. Without these, much science fiction simply becomes impossible to write.

chemoleo - 24-9-2008 at 19:23

I think the xxxxxx meant that since the earth moves around the sun, time travel for a few seconds backwards (while NOT travelling in space), would mean that you'd end up in an empty space where earth formerly was (while as in NOW it is at the present location)? The fallacy in this is, if it was true time travel, the location of earth would be that of a few seconds ago, too, so you'd NOT end up in space.
Time travel is principally possible assuming faster than light travel is available, i.e. through wormholes: Take a spaceplane, and jump through a wormhole to a location 65 light years away. Then, upon arrival, erect an enormous telescope and focus on earth: You'll then be able to watch all the happenings around the year 1943, perhaps the end of the battle of Stalingrad? Your choice. Provided the cloud cover isn't too bad :)

Baphomet - 24-9-2008 at 20:39

chemoleo that would work but is not time travel either.. simply exploiting the fact that light travels at a particular velocity

If you went back through the wormhole you'd still be on earth in 2008 (or maybe later depending upon relative gravity), not 1943, for instance.

FTL through wormholes is quite plausible and does not break any rules..

chemoleo - 25-9-2008 at 15:29

Well of course it isn't true time travel - but the closest to it that is conceivably feasible today.
Think of it - our ENTIRE past is out there, in the form of radiation - all it needs is someone to collect it in time.
Would love to drop back some 2000 years and really see what Christianity is about, or perhaps the dinosaurs?

By the way, serious physicists have speculated or even designed time travel machines, there are a couple of books to read on the matter:
The elegant universe (Brian Greene)
Hyperspace (Michio Kaku)
and of course the Hawking books.
And books by John A Wheeler.

Some give nice explanations on relativity, even with some math in it to get some deeper understanding (i.e. Hyperspace, the elegant universe).
Hawkings books are sometimes, in my opinion, too popular sciencey, too dumbed down...

Ephoton - 4-10-2008 at 17:29

I wonder if in the future we could use the reflection of such light off distant objects
to save us from the worm hole jump.

ye to prove religion this way or disprove would be awesome.

though it would probably start the final war that ends the earth.

chief - 5-10-2008 at 03:44

Those who wonder about religion are gonna, scientifically, like this video (I bet):
http://www.youtube.com/watch?v=TjGkRFFBd0A

phlogiston - 5-10-2008 at 12:22

[QUOTE] i like science fiction as much as the next guy, but i am having a problem with time travel, mainly the rotation of the earth and the motion of the earth around the sun, for starters. it seems like if someone was to travel even a few seconds through time that they would be in outer space.[/QUOTE]

It appears to me that when most people say "I want to travel back in time", they actually mean: "I want the entire universe to travel back in time, with me staying the way I am right now".
If -you- travel back in time with respect to the universe, it would mean getting younger rather than older.

12AX7 - 5-10-2008 at 12:45

Quote:
Originally posted by phlogiston

"...with me staying the way I am right now".


Ah, the most important statement of all! What importance is time travel if you don't know why you're travelling? If memory scales with time (presumably, literally "turning the clock back" undoes memories just as it undoes other events), then who's to say we haven't travelled back in time any number of times and simply don't remember it? Time, on average, must be flowing forward, because entropy is rising, but that says nothing of the instantaneous flow of time! Time travel seems as interesting from a psychological angle as physical.

Tim

Sauron - 6-10-2008 at 03:42

Faster than light travel is just as much of an artificial plot devise as time travel, neither exist, they are just devices for setting the stage for a yarn that otherwise would not be remotely plausibe.

One simply has to suspend one's disbelief in such things when reading such SF. It is unnecessary and undesirable to try to reconcile such artifices with the laws of nature or science or the cosmos. It's just storytelling.When Wells wrote THE TIME MACHINE he was not propsing that such an engine could be made. He was writing a thinly disguised allegory about class struggle's logical extrapolation, from a rather marxist or fabian-socialist viewpoint of course. Wells didn't care a fig for science.

ScienceSquirrel - 6-10-2008 at 04:09

SF is an extreme example but all fiction, particularly of the escapist or adventure type, requires a little artifice to get it to work.
You might as well criticise romantic fiction for its girl gets boy and lives happily ever after endings.

[Edited on 6-10-2008 by ScienceSquirrel]

FrankRizzo - 6-10-2008 at 19:16

http://www.stonemakerargument.com/2.html

zed - 16-10-2008 at 23:04

Are we all presupposing that one must travel through space to get from one place to another?

How primitive.

On my planet, when we want to take a long trip, like say...to visit Earth, we just create an anti-gravity field around our "ships". Then off we go.

The anti-grav sequesters us from the normal space-time field of the so-called physical universe. Once outside the confines of normal "space", we can pretty much go anywhere we want to, as fast as we want to. Since we aren't in "space", we aren't limited by that "speed of light" stuff.

When we get where we want to be, we just turn off the anti-grav, and there we are.

Oh,oh....I hear my mom calling. I think maybe I'm not supposed to talk about stuff like this when I'm off planet.