An explanation of Berkeley's Idealism in this video, and why he thought the physical world didn't exist. Metaphysics Playlist: https://www.youtube.com/playlist?list=PLvoAL-KSZ32cX32PRBl1D4b4wr8DwhRQ4

Twitter: https://twitter.com/PhilosophyTube

Also, it didn't make it into the video but TheBerkeleyBear recommended the work of a philosopher called Nick Bostrom in the comment section of the previous episode on morality and the future. If you want to read some of what Bostrom thinks then here's a link to it: it's a little dry but section 3 is particularly interesting.

Bostrom: http://www.existential-risk.org/concept.html