I was watching a physics lecture. The professor stated that there is no light in intergalactic space because it is so vast, no matter what you do, you cannot see the light of any stars. I know that light gets dimmer by a factor of 1/4πr^2 from the source. I thought in theory you can detect electromagnetic radiation from any distance, even visible light. Is this with all electromagnetic radiation of just light? I also know that the farther you go out, the lesser amount of photons will hit your detector. It seems that all electromagnetic radiation dims out as r goes to infinity.