The reason we can't easily make a camera that sees radio waves is primarily due to the fundamental differences between radio waves and visible light waves.
Radio waves and visible light waves belong to different regions of the electromagnetic spectrum, which is a continuum of electromagnetic radiation that spans from radio waves with long wavelengths and low frequencies to gamma rays with short wavelengths and high frequencies.
Cameras that are designed to detect visible light work based on the principles of optics, utilizing lenses or other light-gathering mechanisms to focus and direct the incoming light onto a photosensitive sensor such as a CCD or CMOS sensor. These sensors are specifically designed to detect the wavelength range of visible light.
On the other hand, radio waves have much longer wavelengths compared to visible light. They are typically on the order of meters to millimeters in length. These long wavelengths pose significant challenges for capturing and detecting them in a camera-like device.
To effectively detect radio waves, specialized antennas or receivers are required. These antennas are designed to capture the radio waves and convert them into electrical signals that can be processed by dedicated radio receivers. The properties of radio waves, such as their low energy and longer wavelength, make it difficult to capture and focus them using traditional camera optics.
Moreover, the spatial resolution of a camera is limited by the wavelength of the light it detects. Since radio waves have much longer wavelengths compared to visible light, achieving fine spatial resolution with a radio wave camera would be extremely challenging.
There are specific devices, such as radio telescopes, that are designed to capture and study radio waves. These instruments use large antennas and sophisticated receiver systems to detect and analyze radio wave signals from celestial objects. However, these devices are fundamentally different from traditional cameras used for capturing visible light.
In summary, the fundamental differences in wavelength, energy, and detection mechanisms between radio waves and visible light make it challenging to create a camera that can directly "see" radio waves using conventional optical techniques.