Navigation and the Map of the Multiverse: How to Find A₁, ₁ and Not Get Lost

The article "Navigation and the Map of the Multiverse: How to Find A₁, ₁ and Not Get Lost" is the second in the "Practical MBM" series. It addresses the central challenge of inter-universal expeditions: how to determine the direction and distance to a neighboring universe without being able to observe it directly. A clear notation system A₊, ₌ is introduced, where the first index denotes the extra dimension wₖ, and the second denotes the universe number in that chain, counting from ours. Our Universe is designated as U₀. It is shown that multiverse navigation is fundamentally different from ordinary navigation: stars, radio beacons, and GPS are useless because neighboring universes lie not in three-dimensional space but along extra dimensions. The primary navigation tool proposed is anisotropy of fundamental constants — weak but measurable variations in the fine-structure constant and other constants across different sky directions. The dipolar anomaly indicates the direction to the nearest universe A₁, ₁, and its amplitude (intensity I₁, ₁) allows distance estimation. The article includes a hypothetical map of the universe chain A₁, ₁ A₁, ₅ with evolving constants and types — from habitable to singular. The scientific foundation draws on real studies of constant variations (Ghosh et al. , 2025; Su et al. , 2025), brane geometry (Guo et al. , 2026; Benakli, 2026; Pinheiro & Almeida, 2026), and probabilistic approaches to the multiverse (Garriga & Vilenkin, 2008). Risks are also examined: wrong direction, incompatible constants, backward infiltration, and loss of coordinates. The article concludes with a rhetorical question: what if the observed variations in constants are not instrument errors but an imprint of a neighboring universe — a signal we have not yet learned to read?