[http://youtu.be/D6lFGJdwRyo] (YouTube link)What theoretical physicist Stephen Hawking has contributed to our body of knowledge fills many volumes. A good short course is his most popular book, A Brief History of Time. B...

[http://youtu.be/q3MWRvLndzs] (YouTube link)Minute Physics gives an incredibly concise overview of what we know, and what we don't know, about the beginning of the universe. Of course, the most tantalizing part is the po...