Alternative Dimensions vs. Parallel Universes

Here’s a question that’s always bugged me, and I was hoping that someone on this board would be able to help me with this:

I was watching a show on the “Devil’s Sea” in Japan, which people are calling the second Bermuda Triangle. Now, one guy on there said that people who disappeared in that area were “slipping into an alternate dimension.” Okay, so forgetting for the moment that the likelihood of someone slipping into an alternate dimenion or parallel universe is so extremely unlikely as to be ridiculous, shouldn’t this guy have said that people would slip into a parallel universe instead? Both additional dimensions and parallel universes have been proven in theory. I know that much.

And I know I’m arguing semantics. But I want to know. So I looked up dimension in the dictionary, and it appears that dimensions describe an object in space and time, which is the definition I’ve always assumed applied to dimensions. So why do people say that you can slip into an alternate dimension instead of a parallel universe? What’s the difference?

I think they’re used pretty much interchangeably. In fact, I think most people use them without knowing what the terms actually mean, or where they come from.

I believe that the first story of higher-dimension fiction was Abbott’s Flatland, in which he has intelligent and self-aware geometrical forms in a two-dimensional world speculating about other dimensions – “A romance in Higher Dimensions” is the book’s subtitle, abnd in the course of it we meet or consider life in zero, one, and four dimensions as well as 2- or 3- dimensions. It’s a great read, and it’s inspired a cartoon, a bad episode of Outer Limits, and a slew of sequels. (I strongly recommend Sphereland and The Planiverse.)

The idea got picked up in science fiction, where the idea was used for higher-dimensional beings intersecting our three-dimensional world. But another use was that one might travel in a fourth spatial dimension and find oneself in a parallel universe “next door”. It is this sense in which people use it as you have suggested, and only in this form can “other dimension” and “parallel universe” mean the same thing. As I say, it has become so familiar and such a cliche that most folks probably have no idea why they would use “other dimension” to talk about a parallel universe.
Curiously, in this month’s issue of Scientific American there is a lengthy discussion of Parallel Universes, right down to how far away they are. And in the article, there is no suggestion that they are separated from us in any fourth spatial dimension. So these are “parallel universes” that are not “other dimensions”.

This thread is better suited for General Questions. I’ll move it for you.

Cajun Man ~ SDMB Moderator


Parallel universes are not the same thing as other dimensions. You can theoretically have an infinite number of parallel dimensions which would all be three dimensional in nature.

You might travel through other dimensions or otherwise make some use of them (they have a lot of application in mathematics but that’s just on paper…not reality). Whether higher dimensions actually exist we don’t know. There are lots of cool thing syou could do if you could access the fourth dimension (spatial…not time) and it would appear magical to those of us stuck in 3-D (e.g. no prison cell could hold you as you could walk right out of it). The thing is we cannot perceive things in 4-D or higher. Even if I took you to the fourth dimension you’d see everything in 3-D although what you would see would probably be disconcerting at the least.


Should be “parallel universes”.