There are a lot of documentaries freely available on YouTube.
Sometimes the producers release them for free, but most often other people upload the films and the copyright owners don't bother with taking them down.
xDocumentaries is a central place where you can easily find these documentaries...
Science, 2008, with Richard Dawkins, 2 hrs 25 mins
A 2008 documentary written and presented by Richard Dawkins looking into Charles Darwin's life work that introduced and explained the theory of evolution. Dawkins insists that evolution is now not just a theory, but scientific fact, and explores why a significant part of today's society is...(show more)
A 2008 National Geographic documentary presenting an imaginary journey starting from Earth and exploring — and learning about — the most important parts of the known universe. It is narrated by Alec Baldwin.
The documentary uses images from the Hubble telescope as a starting point and is...(show more)
A 2013 documentary presenting the events at the Large Hadron Collider at CERN in Geneva from the first firing in 2008 and up to the identification of the Higgs boson in 2012.
The film follows different theoretical and experimental physicists working at or directly interested in the developments...(show more)