The Brief History of Time might be the most (popular) popular science book ever. With 9 million copies sold worldwide, Stephen Hawking's discussion of cosmological phenomenons is widely read outside the scientific community. Who would think that someone from the non-muggle world would be interested in light cones, black holes and the curvature of space?
Harry Potter and The Prisoner of Azkaban (2004), is my favorite theatrical adaptation of the series. Directed by Alfonso Cuaron, he added subtle details to the movie that were never used before by Chris Columbus (director of The Sorcerer's Stone and The Chamber of Secrets). Alfonso Cuaron added crows to the scenes outside Hagrid's hut. As Harry, Hermione and Ron hid behind pumpkins, crows appeared to fly freely around them and resting on the pumpkins. Aside from crows, bats and the shrunken head, The Brief History of Time also made a cameo on HP.
Harry accidentally blows up Aunt Marge at the Dursleys and runs away. He then rides the Knight Bus to the only wizarding place he knows he could stay. As Harry entered the Leaky Cauldron, a guy with a charmed spoon is reading A Brief History of Time.
Reading the books, I've always had the impression that witches and wizards in Rowling's world are ignorant and uninterested in the affairs of Muggles (save for Mr. Weasley). The appearance of TBHoT is a comic relief and gives a continuity from the muggle to the wizarding world.
On a side note, The Girl Who Leapt Through Time (2006), also makes a physics reference with Schrodinger's Cat, complete with the poison, Geiger counter and hammer in a box.