
Sorry, but this content is reserved for subscribers only.
Why do I charge for this site?
This is how I earn a living. Your subscription helps me pay for production costs, web hosting, bandwidth charges, etc.
While other sites generate money by making you watch ads before each video, putting ads on every page, or constantly trying to sell you things, those are the things that annoy me when I visit a website. I find that many parents and teachers prefer an educational site with no ads or sales pitches, even if it means paying a small fee to help cover costs.
Please check out some of my Free videos, experiments, and other resources.
Even better, Subscribe Now, and get full access to hundreds of videos and other science resources. The $29.95/year subscription helps cover the costs of producing new videos, writing curriculum units, site development, and hosting. Without that support, this site would not be possible.
If you are already a subscriber, and having problems logging in, please check the Help Page.
