For a generation, cosmologists have mapped the cosmos onto a framework built not from measurement but from philosophical convenience — the assumption that the universe looks the same in every direction. Now, researchers at the Tata Institute of Fundamental Research have presented evidence that this assumption may be false, and that the acceleration of cosmic expansion, the very phenomenon that gave birth to dark energy theory, may be an illusion born of where we stand in the universe. If the cosmos is lopsided rather than uniform, the dominant ingredient thought to fill seventy percent of exis