Crazy thought I has was what if you could make a supercooled wall to the point you could see through it then you could realistically only see it if you perturbe

Crazy thought I has was what if you could make a supercooled wall to the point you could see through it then you could realistically only see it if you perturbed it and what you'd be able to see is the "wave" as the energy travels from the perturbation. Kinda like those anime shields. Maybe a little too crazy of a thought.