1d, 2d, 4d, and other strange things in the cosmos

[Exapno_Mapcase]

@panache45

The interesting thing is that for anything to be a “life form,” it has to be capable of motion, which means existing in the 4th dimension. So your 1- and 2-dimensional life forms can exist within the 4th dimension, but not necessarily all 3 of the spacial dimensions.

I don’t understand what you’re saying here. You might mean that motion requires a timelike dimension, but time is not “the” fourth dimension. That’s merely a spoken convention for the everyday world. The dimensions are not numbered. If there are two spacelike dimensions and one timelike dimension then no fourth dimension exists at all. If there are ten spacelike dimensions and one timelike dimension, then time in the usual convention would be the eleventh dimension.

[Chronos]

In fact, in the numbering most often used by actual physicists, time is actually the zeroth dimension. Oh, we could call it the fourth, or the first, or the seventeenth, and it would all work out the same way, but zeroth happens to be the terminology that caught on.

[Sailboat]

@Jake

I’ve always wondered if it’s possible to live in ONE dimension.

What would be the point?

[Cartoonacy]

@Sailboat

What would be the point?

That was a clever line.

[Little_Nemo]

@Jake

I’ve always wondered if it’s possible to live in ONE dimension. Would we be able to only move in one direction? Or just be like a photograph and completely still?

You’d really get to know your neighbours.

[Jake]

Thanks all, for your responses!
I get the “Point” of your answers.

[Asympotically_fat]

I don’t get point of these dimension related puns and I think a line needs to be drawn; I’ll be plane: the sheer volume of them is leaving little room four-space for sensible discussion!

[Senegoid]

@aNewLeaf

Mandatory that anybody asking the question read *Flatland *by Edwin Abbot.

Definitely a good read on this subject. Entire text (including original illustrations) is on-line here!

For a good compendium of related puns, view The Dot and the Line, in which a love-struck straight line attempts to win the heart of a dot, who, alas, is in love with an unkempt squiggle.

[Exapno_Mapcase]

As always, people can’t leave well enough alone. Hence Sphereland.

There are combined editions of the two books.

[chorpler]

@OldGuy

Even in a 2D (plus time) world life would probably be impossible certainly intelligent life. There are limited numbers of ways to connect different points with lines when the lines remain on a surface and don’t cross each other. That means it would be very difficult to have circulatory and neural systems that connected to all the body without interfering with each other. There might be some other system, but one might think that connectivity is important for life. I think this also means that it would be very difficult to construct the complex molecules out of which life is made.

A.K. Dewdney’s The Planiverse is the most in-depth book on this topic I’ve seen. There are ways to get signals to cross over each other in two dimensions. The discussion on crossover switches can be found here (see “Logical circuits in Planiverse”). Dewdney’s creatures have exoskeletons and “zipper organs” that allow them to circulate fluids and nutrients.

Also, Ian Stewart (who wrote Flatterland: Like Flatland, Only More So) has also come out with an Annotated edition of Flatland that makes reading the original much more informative for modern readers.

[chorpler]

Oh, and Rudy Rucker’s The Fourth Dimension continues Flatland and Sphereland’s concepts (and the narration using A. Square as the protagonist), and discusses four spatial dimensions in great detail (and using lots of illustrations).