This photo shows Albert Einstein teaching relativity to a class at Lincoln University in Pennsylvania in 1946.
It caused a stir because it shows Einstein giving a lecture to an audience made up entirely of African Americans. At the time, racism was still very present.
While some teachers opposed his approach, he saw only potential in these young people.
"Racial separation is not a black disease, but a white disease. And I don't want to be silent about it," the Nobel laureate said.
It is good to remember that for science, human races do not exist.