The precarious rights of senior citizens, especially those who are highly educated and who are expected to counsel and guide the younger generations, has stimulated the creation internationally of advocacy associations and opinion leader groups. The strength of these groups, however, varies from country to country. In some countries, they are supported and are the focus of intense interest; in others, they are practically ignored. For this is reason we believe that the creation of a network of all these associations (...) is essential. The proposed network would act as a support for the already-existing policies of the United Nations’ High Commission for Human Rights, of independent experts, and of the Global Alliance for the Rights of Older People. All three have long ago recommended the creation of a recognized instrument for uniting presently scattered efforts. The proposed network, therefore, will seek to promote the international exchange of relevant expertise, and it will reinforce the commitments and actions that single countries are currently taking to meet these objectives. For example, informative public events can be organised to promote particular support initiatives and to provide an opportunity for new members of the network to be presented. The network will promote health for senior citizens, disease prevention, senior mobility, safe free time for seniors, alimentary education, protection against new risks and dangers, as well as equity in the services necessary for seniors to adopt new information and communication technologies. In the case of retired academic members, the network will promote equality with respect to continuing use of digital technologies (particularly email), continuing access to research libraries, and the guaranteed ability for seniors to fund their own research programs and to deliver free seminars. (shrink)

The paper examines different ways of using historical resources in teaching refraction related subjects. Experimental procedures can be taught by using Ptolemy’s and Al Haytham’s methods. The student can check the validity of the approximations or rules which were presented by different people. The interpretation of the relations is another subject. Refraction phenomena were interpreted either by the principle of least time or by particles or by waves. The law of refraction can be used as an example of a law (...) which was discovered but put aside. The use of the law to construct lenses can be seen in Ibn Sahl’s hyperbolical lenses. Al Farisi’s method of “cones” is used for the interpretation of the rainbow. Al Farisi’s model was discovered again by Descartes. These models were not able to explain the supernumerary arcs. For this reason a simple wave model is presented. The models proposed by Al Haytham of atmospheric refraction can be used to show that refraction actually cannot be considered as the cause of the change of the size of the moon. Finally Huygens model of refraction in the atmosphere is used to introduce the wave fronts as more fundamental than rays. (shrink)