The concept of a horizon from general relativity describes the loss of causal connection. Bose-Einstein condensates, a priori very distinct from cosmological scenarios due to its non-gravitational nature, may remarkably provide a stage to observe relativistic effects. The connection between these two worlds is established by the identification of a matter-wave metric in Bose-Einstein condensates. In this (very
informal and humble) talk, we try to motivate and discuss a little about the underlying analogy. We start by giving a simple overview on BEC physics, covering the basic theoretical tools used in the description of its dynamics. We argue that the existence of an effective space-time metric can be directly associated with the superfluid character of a BEC. Some consequences of the present analogy, such as the emergence of sonic horizons and theoretical evidence of Hawking radiation are discussed.