Sometimes we encounter an experience that feels so profound and unexpected that it defies our expectations of the rational, physical world. Different religious traditions offer varying frameworks for interpreting these experiences, but all agree that these experiences seem to connect us with an expanded consciousness, higher power, or a fundamental truth about existence. They can feel like a moment where previous mysteries are clarified, and deep existential questions are answered with firmness and simplicity. They frequently seem to come “out of nowhere,” or are at least beyond our control or expectation, and rarely last very long. What—if anything—can cause or stimulate these experiences is of great interest to seekers and scientists alike. We’ve started gathering valuable information on this topic, but haven’t yet curated the findings.