How would the Universe change if we grew an extra dimension?

“Imagine what would happen if all-of-a-sudden, the forces binding electrons to nuclei became weaker. If there was a change in how strong that interaction was. You don’t think about it, but at a molecular level, the only thing holding you together is the relatively weak bonds between electrons and nuclei. If you change that force, you change the configurations of everything. Enzymes would denature; proteins would change shape; ligand-gated neurons wouldn’t fit together anymore; DNA wouldn’t encode the molecules it was designed to encode.”

If we take a look at a two-dimensional surface, it’s pretty apparent that we’re pretty omnipotent in comparison. We can draw or erase anything in that dimension, add or remove objects, rearrange their internal structures without leaving them any defense, etc. All of that might lead you to wonder whether there’s the possibility of a fourth spatial dimension out there, and whether that could be part of our Universe? Geometrically, it’s certainly possible. From a historical perspective, there’s no reason a dimension needs to stay the same size over time, either. In 1980, Alan Chodos and Steve Detweiler showed that a Universe that began with four spatial dimensions could have easily evolved into a Universe very much like the one we see today. Building on that, it would be possible for a very small extra dimension to grow large over time. If it did, the consequences would be devastating, but fascinating.