Remember, there are many kinds of light, such as visible light for our naked eyes, and devices like Spitzer's spectacles can see infrared light that people can't see.
The spiral galaxy on the far left may be visible to the naked eye. It is reported that this picture was taken by the telescope of the Kitt Peak National Observatory in Arizona. But the two images on the right show spiral galaxies at different infrared wavelengths displayed by the Spitzer Space Telescope. If you combine infrared and visible light, you can see the image labeled (b) -- arguably the most complete Galaxy image.
It may not sound like the world's greatest technological invention to show invisible dust and gas clouds, but seeing dust and gas clouds at different wavelengths can help astronomers understand the birth and death of stars and other things.