Scientists have long theorized that life can only exist in universes with three dimensions. However, new research challenges this view and suggests that life is theoretically possible in a two-dimensional world. The research was published in the magazine Physical Review Review.
Traditionally, universes with more than three dimensions were believed to be unstable and unpredictable, devoid of life and observers. The three-body problem is unpredictable in the 3D world, but even the two-body problem (predicting the orbit of two bodies) becomes too chaotic in higher dimensions and stable orbits are not possible.
“This means that such a world cannot contain time-stable objects, and therefore probably cannot contain stable observers either. In a space with more than three dimensions, there can be no traditional atoms and perhaps no stable structures either,” the researchers write in the paper.
There are suggestions that life could not have arisen in a two-dimensional (plus time) universe due to insufficient complexity. The main argument against life in two-dimensional universes is that they have no gravity, making it impossible to create the conditions necessary for life.
However, physicist James Scargill of the University of California, Davis, has shown that scalar gravitational fields can exist in two dimensions.
In addition, Scargill has examined biological networks and created planar graphs that are thought to demonstrate properties important for the formation of complex brains. This suggests that complex life forms could exist in a two-dimensional world.
Gravity and stable orbits are not the only requirements for the emergence of life, as life itself in a two-dimensional world may not look the same as we imagine. For example, an animal of this world may not have a digestive tract.
Scargill’s theory is based on the idea of a ‘brane world’ (membrane), where a hypothetical massless graviton is not localized, allowing two-dimensional life to take advantage of four-dimensional gravity.
Although the study’s results are hypothetical, they raise questions about where and how life could exist in the universe.
