Scientists and Mathematicians Online
Many web sites post expert articles. Some even answer submitted questions. Here's a sample of what's out there.

Ask Dr.Math
The Math Forum at Drexel University enjoys an excellent reputation. Not only are their lessons sound but the site was designed for online access so it is interesting and easy to use. Dr. Math provides clear explanations; students can search the archives or email a new math conundrum.

Mad Scientist Network
The Mad Scientist Network at Washington University in St.Louis is maintained by graduate and medical students. Questions from more than 20 different fields can be submitted to 200 scientists or so. Links and archives of past questions are available, too. The site managers have a good sense of humor.

Science Hobbyist
Bill Beaty has a wide ranging collection of science projects and observations, everything from "safe" high voltage generators to highway traffic "waves" (how car traffic behaves like a fluid) to Science Fair ideas.

RefDesk
RefDesk lists experts in science from A-Z--birds, bugs, chemistry what-have-you. At times it appears that an expert site was identified and a question devised rather than vice verse. You can meet several Dr.Sciences. This collection is still a more manageable approach than using most search engines.

Ask DrUniverse
Ask Dr. Universe will answer questions like "Why don't spiders stick to their own webs?" and "Do frogs sleep?"

Ask A biologist
Ask a Biologist looks at all things biological, from Parts of the Cell and The Nervous System to How Animals See Color and Viral Attack.

Science4Fun
Abdul Wahab Malik, from Pakistan, has assembled a very accessible web site for a wide range of science topics. He encourages people to use his Contact Us link to ask questions or get ideas.
Access to experts is handy as specific topics and queries arise serendipitously. It is best to seek an expert primarily for unusual questions to conserve this resource for special occasions.

American Association for the Advancement of Science
AAAS provides a wide range of resources, from STEM volunteers to hundreds of standards based lesson plans to films and publications.
Related Topics ...
Other Areas To Check Out ...
● Simulation & Modeling Tools
● Science Education Groups
● Teacher Training: Math, Science and Technology Sampler
● Ethics in Science
● Biographies
● Handheld Devices: Smartphones and Tablets