In this project 'Radiation and Us: Making the Invisible Visible' we will develop interactive exhibits and shows to be situated in Northern Ireland's premier interactive science centre, W5. This will be done through a partnership of researchers into the medical uses of radiation from Queen's University and science communications experts from W5. The title of the project has a double meaning: radiation is often used to make visible of our insides which would otherwise remain invisible. Additionally, in this project, through the interactive simulations we will make the detailed behaviour of the invisible radiation visible to all.People generally have a negative view of radiation, considering it to be a mysterious entity. It is usually associated with negative things like bodily harm, destruction, danger and nuclear war. These negative associations can be a barrier to people's understanding and learning. However radiation has many interesting and positive uses including medical applications.Radiation is invaluable for medical diagnosis techniques ranging from the X-rays we all know from the dentist to more sophisticated ways of making three dimensional images of the insides of our bodies. Radiation is also invaluable in the treatment of cancer, being the second most common form of therapy after surgery. By illustrating the science behind these positive uses of radiation we hope to engage the audience and encourage some of the pupils to study the relevant sciences further.Because of radiation's invisibility and the safety concerns associated with it, it is not possible for school pupils or members of the general public to learn by doing activities involving radiation directly. However researchers into its medical uses have sophisticated computer simulations which show how the radiation travels through our bodies either for making X-ray images or for the treatment of cancer.We will use some of these simulations to develop an interactive exhibit to be situated in Northern Ireland's premier interactive science centre, W5 supported by shows covering the same topic. The interactive simulations will also be distributed using the World Wide Web and CD ROMs.These simulations will be designed to have an educational benefit for pupils from 12 years upwards but also to be of interest to the general public. They will present the user with challenges such as making a radiotherapy plan, avoiding a patient's sensitive organs with the radiation while getting enough of it into the patient's tumour. Radiation tracks will be displayed to demonstrate the science of radiation as well as its medical applications. The user will be presented with a scientifically accurate view of the creation and stopping of some of the X-rays and particles as it would occur inside a patient's body. This will take the form of an ever-changing animated display of the tracks created by the particles. The users will be able to interact with the simulations by sending in radiation from different directions and see how the X-rays and particles interact differently with different parts of the body. For example the bones stop more of the X-rays as we all know from X-ray photographs but in these simulations we can all see it happening before our eyes, making the behaviour of the invisible radiation visible.