if light and radio waves are all the same phenomenon, why cant my phone use one component as both the camera and the antenna?

Question

As above

In: Physics

Answer 1

I read this the other day:

“Scientists have transformed WiFi routers into ‘cameras’ capable of seeing people through walls.
Researchers at Carnegie Mellon University have discovered a method for detecting the 3D shapes and movements of individuals in a room using only WiFi routers-no cameras or
LiDAR required.
According to the researchers, WiFi signals ‘could serve as a universal substitute’ for traditional RGB cameras in ‘sensing’ people in a room.
They noted that using WiFi bypasses issues like poor lighting and occlusion that conventional camera lenses encounter. Intriguingly, they claim that this advancement actually enhances privacy rights. ‘In fact, they state,
‘most households in developed countries already have WiFi at home, and this technology could potentially be scaled to monitor the wellbeing of the elderly or to identify suspicious activities at home.”