Four dimensions are the only mathematically possible way for anything in our universe to be detected.
April 20, 2026
Original Paper
Complete Detectable Spacetime Geometry: Unified Emergence of Matter, Gravity, and Quantum Dynamics
SSRN · 6598576
The Takeaway
Physicists have long wondered why space has three dimensions and time has one. This framework argues that these properties emerge necessarily from the geometric requirements of observation. If the universe had a different number of dimensions or a different mathematical signature, systems would contain hidden defects that make them impossible to detect. This theory unifies gravity and quantum mechanics by showing they are both side effects of this fundamental detectability. It suggests that the laws of physics are hard-wired into the very concept of existence itself. This finding implies that any universe we could ever observe would have to look exactly like ours.
From the abstract
A framework of Complete Detectable Spacetime Geometry (CDSG) is developed in which admissibility is defined by detectability (absence of hidden defects) and closure under probe-complete evolution. It is shown that a completed probe algebra separating admissible configurations forces a minimal four dimensional realization and excludes both lower-dimensional underdetermination and higher-dimensional hidden-direction extensions. Lorentzian signature arises as the unique metric structure compatible