Ouch! tough crowd :)
Sorry, I don't mean to cause offence to anyone. I blog things I find interesting. I use my own words, create my own animations, derive my own formulas (and the spelling and grammar mistakes are all mine!)
When I use the photos/images from others, I give credit and link back to sources as much as I can from available data.
I've have on the order of 100 blog articles now. I'm sure over the course of these I've trodden on a few feet (sorry), just as much as I've blazed new trails.
We can all become better by listening to feedback, and I'll try to do better at providing additional sources of information and inspiration.