Abstract: The past decade has seen a massive boom in theoretical and experimental work to detect elusive light scalar particles known as axions. In this talk, I give an overview of the recent revolution. Firstly, I provide a modern perspective of the axion detection program. I will then apply these ideas to describe the effort to detect axions from the early universe making up either dark matter or dark radiation. Focusing on nucleon interactions, I show how the upcoming experiments will see new particles or dramatically shape the axion landscape. If a positive signal is detected, axions will provide a new method of looking back into the early universe and have profound implications for particle physics and cosmology.