<p>We propose Waves as Space-Time (WST) as a conceptual framework for understanding how the brain may utilize subthreshold travelling waves of the membrane potential to flexibly link spatial and temporal dimensions of neural activity. Rather than presenting a complete biological model, WST is intended to serve as a simplified lens for investigating how wave dynamics can enrich neural coding. The core proposition is that subthreshold membrane potential oscillations constitute a substrate capable of transforming as well as transmitting neural activity, enabling temporal spike patterns to be recast as spatially differentiated signatures and spatial patterns to be unfolded into temporally structured sequences. This perspective highlights how such bidirectional transformations offer the brain a versatile encoding strategy that can support functions such as memory, propagation, and dynamic reconfiguration of information. By considering WST travelling waves as a powerful mechanism for neural computation, it encourages further theoretical, computational and experimental work on their potential role in complex cognitive processes.</p>