Astronomical observations show that our universe is expanding faster and faster in all directions due to something we call ‘dark energy’ – but what exactly is it? There are many theories out there, and astrophysicists have an unlikely ally in the search – atomic physicists like myself. As part of my PhD research, I used lasers to trap and cool atoms to use as tiny sensors to search for new physics, including searching for evidence of a specific dark energy candidate, the chameleon field. In this talk I will give an overview of the physics behind dark energy and my experiment, explain how atomic physics experiments have applications across all sorts of fields, and why even though I ended up measuring zero, that’s still moving science forward.