The Long Road

04/30/2005 Archived Entry: "Time Travel in Science Fiction - Part 8: Sliders"

Sliders was a show from the late 90s about a group of friends who became stuck travelling between parallel universes. They jumped from random world to random world hoping that the next jump would bring them home. Some worlds were vastly different from what they knew – Nazis won WWII, sentient fire ruled the earth, etc. Other worlds were identical except for a few minor changes – Elvis was alive, red meant go.

Time is widely considered to be the 4th dimension; but in a multiple timeline universe, time is two-dimensional. It is both the 4th and 5th dimensions. To travel along time’s second dimension is to step sideways through time, and reach parallel universes.

The most important question is what exactly determines that a parallel universe should exist. There are several possibilities; one is that all possible universes exist, the other being that actions create different universes. Do all actions result in a different universe? Do all possibilities exist? For example, is there a different universe in which I write “left” here instead of “right”? If not, then is there some kind of force that dictates which actions deserve their own universe and which don’t?

Also, imagine that there’s an alien civilization in some distant part of the galaxy. This civilization would also cause an infinite number of parallel universes on their own. Even if humans and these aliens never meet, there would be an infinite number of universes where Earth was identical but each had a slightly different version of the alien world. So we end up with X*Y universes where X is the infinite number of different Earths and Y is the infinite number of universes of different Planet of Aliens. We can see then that things get immensely complex really quickly; we have an infinite number of universes which are identical to each other, and an infinitely larger infinite number of universes which are different.

Replies: 5 comments

I used to watch Sliders sometimes, it was a cool show:)

I don't think that there exists an infinite number of universes that are identical to each other.. for all practical purposes, they'd just be one and the same -- what else does "identical" mean? Especially in terms of something so vast and intangible as "the universe." Sure, you can have two paper copies of your resume, but what's it mean to have two identical copies of a universe? (And are they really identical?)

The creation of new universes is exponential... :) At any particular point in time, N objects have M different possibilities for action. And so on. Weeeee!!!

Posted by Arshwana @ 04/30/2005 08:40 AM EST

Well, I guess I didnt mean that there'd be an infinite number of identical universes. Just an infinite number of identical Earths each in a different universe, and there'd probably also be an infinite number of nearly-identical Earths (one in which I wrote "right" instead of "left", for example").

Posted by Rayne @ 05/01/2005 03:08 PM EST

Ah. Well, I suppose at a given slice of time, yes, there'd be several identical Earths.. but maybe time/space has a very efficient way of storing states of objects at various times rather than keeping uber-billion copies around.

Posted by Arshwana @ 05/01/2005 10:44 PM EST

Yeah, I was gonna "pockets" of alternate realities that only "expanded" when new realities were needed..but translating those thoughts into words proved to be too challenging.

Posted by Rayne @ 05/02/2005 02:49 AM EST

Maybe these alternate earths are just in this universe put so far away from us that we'd never be able to reach them, so that they all exist in THIS universe but never have contact with each other.

Posted by Anonymous @ 05/03/2005 10:00 PM EST