As the Dark Energy Survey (DES) releases its final results, we caught up with two physicists who have been involved in the project from its early days. Those two effects motivated the Dark Energy Survey and other cosmology surveys we are pursuing now. How did the idea for the Dark Energy Survey come about? There are now signs that dark energy may not be the cosmological constant or this fixed vacuum energy. Some of that connects to dark energy, like finding many more supernovae, but much of it goes beyond that.