How can deaf children acquire a sound basis of concepts in a field like physics? Traditionally, such subjects were not taught to deaf students, as they were considered less than able to grasp the abstract concepts needed. In this work a short presentation of the history of deaf education is given, along with a report of how a group of deaf students overcame these difficulties. As adult deaf teachers they evaluate their former education, focusing on the concentrated work of grasping the concepts, discussing and cooperating, and creating a lexicon of appropriate signs. Included is also a study of conceptions about astronomical phenomena, where deaf Norwegian children are compared to hearing children from Norway and around the world. It is shown that the deaf children do not lack in logical and mental capacity, but there is a lack of experience and general knowledge, which can be attributed to the lack of hearing and exposure to the normal flow of information. From the results, this work recommends that the formation of concepts in a freely communication milieu is placed in focus of education of any child.