# Existence of Life in 2 + 1 Dimensions

## TL;DR

This paper explores the theoretical possibility of life in 2+1 dimensions by examining gravitational theories and neural network structures, challenging previous assumptions about the limitations of lower-dimensional universes.

## Contribution

It demonstrates how scalar gravity theories can bypass gravitational limitations and analyzes planar graph structures similar to biological neural networks in 2+1 dimensions.

## Key findings

- Scalar gravity can evade gravitational limitations in 2+1 dimensions
- Planar graphs exhibit properties similar to biological neural networks
- Potential for life-supporting structures in 2+1 dimensions

## Abstract

There are anthropic reasons to suspect that life in more than three spatial dimensions is not possible, and if the same could be said of fewer than three, then one would have an anthropic argument for why we experience precisely three large spatial dimensions. There are two main arguments levelled against the possibility of life in 2 + 1 dimensions: the lack of a local gravitational force and Newtonian limit in 3D general relativity, and the claim that the restriction to a planar topology means that the possibilities are 'too simple' for life to exist. I will examine these arguments and show how a purely scalar theory of gravity may evade the first one, before considering certain families of planar graphs which share properties which are observed in real-life biological neural networks and are argued to be important for their functioning.