[alphapapa]

So is the future wavelength project something like radio waves? It would be fascinating to see an image lit by radio waves. Imagine a wifi router being lit up like a lightbulb, casting shadows around a room, or a room lit by FM radio passing through walls and windows, etc.

[keyme]

Walls are transparent to FM (~100MHz) radio, so you won't see anything.

WiFi is closer. High microwave is probably what you want here.

And of course, this already exists. It's called radar. Haven't seen any radar "photos" though. Interesting if that's indeed possible.

[jakobegger]

The size of the things you can see depends on the wavelength of the light.

FM Radio (100MHz) has 3m wavelength. You'll need a giant camera and will be able to see only very big structures.

Wifi/Microwave/Radar is in the Gigahertz range. 2.5GHz == 12cm wavelength. For radar photos, you'll need a very big camera, and a human would be only a few pixels big.

Some airport scanners are based on millimeter waves (teraherz radiation), and you can find sample photos online. They produce pretty blurry pictures, but clothes become partially transparent.

[alphapapa]

> And of course, this already exists. It's called radar. Haven't seen any radar "photos" though. Interesting if that's indeed possible.

Oh, right, synthetic aperture radar. Duh. Should have thought of that. :)

[ambicapter]

Unfortunately the resolution of your image will decrease with an increasing wavelength so you might end up with a pretty fuzzy radio-picture.