У вашего броузера проблема в совместимости с HTML5
This week we will be going over a little more advanced concept, designing Ruby Objects. We will not be covering specific chapters but a few general concepts from the book
This will be a review of the first half of this book, and will be different from the approach I did in the WGR book series. Reading the book is not required, but an understanding of Ruby or Rails is recommended.
FYI, 12mins in I mention a book, the link is below for that:
https://gumroad.com/l/ruby-science