Today a respected Physicist was on the radio discussing dark matter and the possibility of what she had lightheartedly referred to as “dark light”, among other things. Asking why should the light we perceive be the only light in the universe and concluding there was no reason at all. What if other forms of radiation interact with other arrangements of matter differently, beyond our perception or measurement, but still “as light”, she asked. Not only is it fascinating as a subject of itself, but it also fascinating that someone can be so deeply learned within their own area and at the same time able to make it accessible and understandable (within certain bounds) for those of us who are completely un-versed. Inspiring others is a rich talent. The interviewer wondered if there wasn’t a danger in positing on things we don’t know, to which the Physicist replied (and I’m paraphrasing) that it was OK to speculate, that is after all how scientific enquiry starts every time, but that you have to base your findings and hence your knowledge on the facts you find as you move through the process. Much in the Sherlock Holmes manner of discarding the impossible until what you are left with, however improbable, must be the fact of the matter.