Brown was introduced to electronics by his father, who worked as a television and radio repair technician. He began building his own amplifiers and would buy transformers from Tubby's Dromilly Road studio, and while there would keep asking Tubby to give him a chance at mixing. He was taken on at Tubby's as an assistant, performing tasks such as winding transformer coils, and began working as a mixer in the mid-1970s, initially creating dubs of reworked Studio One riddims for Don Mais' Roots Tradition label, given his chance when Prince Jammy cut short a mixing session for Mais because he was too tired to continue. His name originated from a joke between Tubby and Bunny Lee. Having noticed Brown's forward thinking ideas and technical aspirations, Tubby remarked "Damn, this little boy must be a scientist."
He left King Tubby's studio at the end of the 1970s and became the principal engineer for Channel One Studio when hired by the Hoo Kim brothers, giving him the chance to work on a 16-track mixing desk rather than the four tracks at Tubby's.
He came to prominence in the early 1980s and produced many albums, his mixes featuring on many releases in the first part of the decade. In particular, he was the favourite engineer of Henry "Junjo" Lawes, for whom he mixed several albums featuring the Roots Radics, many based on tracks by Barrington Levy. He also did a lot of work for Linval Thompson and Jah Thomas. In 1982 he left Channel One to work at Tuff Gong studio as second engineer to Errol Brown. He then emigrated to the Washington, D.C. area in 1985, again to work in studios as a sound engineer.
He made a series of albums in the early 1980s, released on Greensleeves Records with titles themed around Scientist's fictional achievements in fighting Space Invaders, Pac-Men, and Vampires, and winning the World Cup. The music on these albums was played by Roots Radics, his most frequent collaborators. Scientist has alleged in court that Greensleeves sold these albums without his consent, according to his interview with United Reggae online magazine.
Five of his songs from the album Scientist Rids the World of the Evil Curse of the Vampires were used as the playlist songs on the K-Jah radio station in the 2001 video game Grand Theft Auto III. Scientist has alleged in court that these songs were used without his consent.