The Women in Science 2020 Wall Calendar is based on Rachel Ignotofsky's New York Times best-selling book, Women in Science: 50 Fearless Pioneers Who Changed the World. Each full-color monthly spread showcases one of the women from Rachel's book, including Wang Zhenyi, the astronomer who, in the 1700s, figured out how an eclipse occurs, or Nettie Stevens, the geneticist who discovered that the sex of a baby is determined...