Professor Feynman was a gifted physicist who lived in the 20th Century (1918–1988).  The BBC ran a short series featuring Feynman thinking aloud about explanations for various physical phenomena.   Although the concepts he discusses are complex he explains them so well and with such enthusiasm you will no doubt enjoy listening to them.  The video below is the first of the series in a playlist on YouTube (click on the "watch on YouTube" link bottom right of the video screen to see the rest), several of the episodes are also available here: http://www.bbc.co.uk/archive/feynman/.