After the departure of his father, Gohan reflects on the power he wields and so devotes himself to scholarly research on the source of that strength, ki. Gohan begins researching the martial arts of the past, organizing them in his book Groundbreaking Science in Age 804. The book quietly gains popularity and one of the articles, "Katchin Can Be Cut!", has an immense influence on the birth of the Swordsman class, as it leads to the creation of Trunks and Goten's Kikoukenjutsu Sword School in the year following the book's release. It also leads to Krillin and Tien Shinhan starting up their own training schools in Age 821, the New Turtle School and the New Crane School, respectively. As a result, by Age 1000, many Earthlings have taken up advanced martial arts and understand ki control.
- In the first promotional video for Dragon Ball Online, the Unnamed Martial Artist (1) is shown reading a book that may be Groundbreaking Science (as it is a popular book among Earthling martial artists like himself).
- Gohan's book being responsible for introducing the concept of ki to the general population of Earth leading to a martial arts renaissance on Earth that lead to the foundation of the Kikoukenjutsu Sword School, New Turtle School, New Crane School, and Pan Fighting Network, is quite a fitting tribute to both his chosen occupation as a scholar (which allowed him to study ki and the martial arts from a scientific and scholarly perspective) and his own history as a martial artist who was the true winner of the Cell Games responsible for defeating Cell.