Hi, I'm not a physicist although I've studied it to first year degree level in the UK many many years ago. I was just reading an article today on the BBC about a new image that's been captured of the visible universe. The following quote got me thinking and I wondered if your expert knowledge may be able to answer a question for me. "The CMB is the "first light". It is the light that was finally allowed to move out across space once a post-Big-Bang Universe had cooled sufficiently to permit the formation of hydrogen atoms. Before that time, scientists say, the cosmos would have been so hot that matter and radiation would have been "coupled" - the Universe would have been opaque." http://news.bbc.co.uk/1/hi/science_and_environment/10501154.stm It begs the question has anyone tried to capture some sort of image of this coupling? I know it sounds like a crazy suggestion. Can a sort of matter image can be constructed in some way, might any such theoretical particles be detectable? I mean matter is energy (De Broglie particle waves etc). The Universe may be opaque but only to light. Apologies as my knowledge of physics is absolutely terrible at the moment. It's been about 20 years since I studied anything and I didn't go beyond special relativity and newtonian mechanics.