Here is a thread in which I posted some of the numbers I found when considering you type of question.
http://www.learningstrategies.com/forum/ubb/Forum8/HTML/002809.html Oh and just a note on Science. It is the discipline of trying to create a consistant model of the physical world based on observations. If the observation is that Photoreading works, them it's Sciences job to ensure that it's model(s) can explain the observation.
Science doesn't say what can and can't be achieved it just tries to understand what can and can't. The value of a model it can predict what "may" be possible even if it hasn't been observed yet.
