# Spacetime Of Flatland

• I
I started this post on physics.stackexchange but it's too vague for that site, so here I am! :)

I'm trying to really get the intuition of spacetime.

This video explains how Minkoswki was the first to think that maybe our universe does not consist of a 3d space which evolves in time, but rather a 4d non-euclidean mathematical space, Minkowski spacetime.

Not even to say this made no sense for me.
Head hurts when I think of non-euclidean spaces and 4,or more, dimensions.

So, I made some more caotic researches, watched other videos and I bumped into this explanationwhich resulted more intuitive and understandable.

This video, showed how spacetime whould have looked for a 2d event, as time passes. It blew my mind.

As soon as I finished this video I remembered about this book I read "FlatLand", which is about some 2d creatures who live in a 2d world, and so, I started wondering what would have spacetime looked like for this 2d space world, hoping it would help to clarify the concept, or to make it more "accesible".

In any way, I've just a small background in special relativity and some videos, and some spare readings behind my back, so I don't know if I can really dig into this with my current knowledge.

In the end, I'm just curious if anyone else have used this kind of help to initially understand this concept and if it can be a good way to start.

Can spacetime be thought for a flat world? How much would resemble the idea behind our 4d spacetime? What would light look like there? and, Could I ideally graph spacetime from a 2d big-bang to a certain time?
I don't expect these questions to be answered, I'm just asking if is lecit and useful to discuss about something like that and maybe to open a discussion.

## Answers and Replies

Dale
Mentor
2021 Award
In the end, I'm just curious if anyone else have used this kind of help to initially understand this concept and if it can be a good way to start.
Yes, most spacetime diagrams are drawn with 1 dimension of space and 1 dimension of time. However diagrams with 2 dimensions of space and 1 dimension of time are also common. It is a very good approach to start!

nearc
Gold Member
since we are using "flatland" as the reference point you might want to explicitly restrict interactions to only the 2D. since in the book a 3D object was allowed to interact. if that is possible then the gravity of an object outside the the 2D land could change the physics of the world