This podcast has me wondering why we would even assume that life forms on other planets would need to exist with the visible spectrum or any of the spectrums we can perceive. What if they don't reflect visible light and instead reflect, emit and perceive gamma rays or in ranges of the light spectrum. I never really thought about the fact that even if we were to run into aliens we might not even have the machinery to perceive them and maybe likewise them to us. Interesting that we may have to understand life on a far deeper level before we even know what it actually is we're supposed to be looking for.