If you have fast internet, enjoy documentaries and haven’t found this site yet, the site Documentary Storm ( https://www.documentarystorm.com/ ) has a large selection of 100% free documentary films in various categories, all publicly available, embedded from a variety of video hosting servers including, but not limited to, YouTube, The National Film Board of Canada, National Geographic, Vimeo, and others.
There an entire section for Science, which I’m looking forward to exploring. Other topic areas for documentaries are:
The Mocumentaries section has only a few entries but I’m watching the “LEAKED: The Internet Must Go” tonight and it’s good.