Never before in history have we collected so much data with such detail to better understand our world and ourselves. Advances in tools and measurements now allow us to observe the previously unobservable. Our collective understanding of the world expands despite its complexity, but engaging learners into these new types of inquiry remains a challenge to educators worldwide. How do I engage with the invisible? What is this data telling me? How do I trust an observation I can’t make myself? The App Lab is an ongoing project at the Exploratorium (based in the Creative Applications group that I lead), dedicated to prototyping apps and tools to model 21st century learning experiments.