This may be a stupid question, but I've been wondering this for a while and haven't yet found a solid answer. I'm worried the answer will be something along the lines of "of course not, you dummy" but it's bothering me and I haven't found the answer so I figured I'd take the risk. Is it possible for matter to ONLY be visible in an area of the spectrum other than visible light? For instance, can any matter be invisible to us but visible in the UV or IR range?
While individual atoms or molecules can emit energy at discrete or narrow ranges of wavelengths, once you have larger chunks of matter (and they are above absolute zero) they will emit, at least, a continuous black body spectrum. While black body radiation can be observed at all wavelengths, far away from the peak wavelength it may be below our ability to detect its emission.