future. To shape the science of the film, Boyle and Garland hired scientific advisers, including NASA employees and astrophysicists. Brian Cox, a professor of particle physics at the University of Manchester, was hired to advise the cast and crew after the director had seen Cox on the science TV series Horizon. Cox gave regular lectures to the film's cast members about solar physics, and also advised the filmmakers to scale down the nuclear device in the film from the mass of the Moon to the size of Manhattan. In the film's backstory, a Q-ball enters and is caught in the Earth's Sun, and begins to eat it away. According to Cox, the Sun would not be dense enough in real life to stop a Q-ball, but filmmakers took creative licence in writing the backstory. Cox noted in the DVD commentary that several inaccuracies were permitted to allow for plot. He also dismissed criticisms of the film by scientists: "Sunshine is not a documentary. It's trying to just, in an hour and forty minutes, get across a feeling of what it's like – not only to be a scientist, because obviously there's much more in it than that. So, I found it interesting to watch the kind of people that get upset because the gravity is wrong." Boyle originally included romantic subplots, including a sex scene planned between the characters Capa (Murphy) and Cassie (Byrne) in the ship's oxygen garden. However, the director considered the attempt for relationships in space too "embarrassing" and excluded the subplots. Boyle further distanced the characters from possible relationships by ensuring that the cast members wore little to no make-up to avoid any romantic overtures. The director also avoided including humour in the script with the exception of a few gags, believing that humour was a difficult fit for the story. "You get intensity of experience in space movies but not joy. So there's not much room for comedy or sex – everything is waiting to destroy you", explained Boyle. Slow motion during weightlessness was inaccurately portrayed; the director had discovered this when riding the Vomit Comet, but he kept the slow motion to meet audiences' expectations. Another purposeful inaccuracy was the "whooshing" of the ship, despite there actually being no sound in the vacuum of space; Cox later mentioned in the BBC's Stargazing Live programme in January 2011 that this was simply because without accompanying