Scientists from Oxford published a book called "Mona Lisa: People and Pictures", where they tried to reveal the secret of the mysterious smile of Lisa Gherardina, depicted in the popular painting of the artist Leonardo da Vinci.
According to scientists, the mysterious and simultaneous smile of Mona Lisa is associated with the history of her life. It is reported that Lisa Gerardina married at the age of 15 to a 30-year-old Florentine businessman named Francesco del Giocondo. According to the preliminary version, he could engage in the slave trade and kept a large number of slaves as maids. A British art critic named Jonathan Jones has stated that the woman's smile may have been caused by her illness of syphilis.
According to information from sources, during the painting of the painting, Leonardo da Vinci invited people playing the lyre and jesters who provided Lisa Gerardina with gaiety. Some researchers have questioned the fact that the woman depicted in the portrait is the wife of Giocondo. Their guesses are confirmed by the widow's mourning veil on the head of Mona Lisa, although her husband lived a rather long life. Also, experts are at a loss in conjecture why the author of the work created it for four years and could not part for the rest of his life.