The teaching of science presents special challenges. At the K-12 level, inadequate preparation of teachers in the sciences, especially in physics, is one of the reasons students often have negative recollection of their physics class in pre-college years.At the college level, different challenges are present. For the teaching of science to non-science majors, it is required to have a course that, besides interesting and motivating students, gives them some basic foundation in scientific literacy, and increases in students' mind the appreciation of the sciences. If we recognize that students taking general science courses come with very different backgrounds, then it is clear that reaching every one in an effective way is no simple task. For students majoring in a technical field (physics, engineering, etc.), it is desirable to give them a deeper comprehension of technical subjects by making use of manipulatives and computer simulations.

Web-based information technology, especially if it supports both synchronous and asynchronous learning, could help us achieve the following goals:

1) Help high school teachers in obtaining a firm grasp of difficult concepts in physics and give them the tools to present material in the most compelling way. For example, Java-type tools can give them the ability to ``dissect'' an experiment or physical demonstration (such as gravitational or Coulomb's law) and to answer ``what if'' questions(for example, related to some peculiar consequences of the fact that these are inverse-square laws);

2) Provide a synchronous learning environment in large enrollment general science courses through the use of Web-based active learning tools (Java applets) and collaboration technology (such as TangoInteractive). For example, in a collaborative environment, students would be able to provide answers to ``what if `` questions in real time and the consequences of erroneous assumptions could be investigated.

3) Provide a set of tools to science majors to allow them to explore difficult and sometimes not very intuitive concepts. The use of Java applets and/or computer simulations, linked with live demonstrations of physical phenomena, could provide an excellent active learning environment.

Web-based technology, up to now mostly in the form of electronic books and of tools for searches of archives of other sources, has shown the power of a distributed information environment. Now, however, we have to do more and better by going beyond the static (and passive?) learning environment phase to a dynamic (either directed or self-paced) one.