‘A hidden connection is stronger than an obvious one’. – Heraclitus of Ephesus
The study of buildings, and in particular indoor air science, has great intellectual merit. Buildings are highly heterogeneous, with steep spatial gradients in materials, environmental conditions, and occupant activities. Buildings are dynamic, changing over timescales that range from seconds (e.g., as HVAC systems cycle or wind velocities that affect ventilation change) to decades (e.g., as buildings age or are renovated). Buildings are complex systems comprising interconnected and complex subsystems. Given these attributes of buildings, one might conclude that the indoor air sciences are ripe for cross‐disciplinary research. Yet indoor air scientists all too often work in narrow trenches, interacting primarily with those they have interacted with for years, content to dig more deeply into that of which they already have significant knowledge, and unaware of the connections that their work may have to those who dig in other trenches. In these ‘hidden’ connections lie opportunities for significant discoveries, new ways of solving problems, and—in a nutshell—strong advancement of the indoor air sciences. Perhaps paraphrasing Heraclitus, Friedrich Nietzsche wrote that, ‘Invisible threads are the strongest ties’. Maybe answers to problems that have stumped our community for years lie nearby, but we have missed their presence because of the narrow blinders that we choose to wear. Failure to recognize the hidden threads jeopardizes the vitality of our field. Cultivating connections ought to be a priority as we strive to advance knowledge in our field.