While many scientists have shied away from explicitly political actions in recent decades, the community throughout history has spoken publicly on a wide variety of social, technological and ideological issues.

That has included everything from opposing fascism, nuclear proliferation and the Vietnam War to sitting on government panels that advise elected leaders on stem-cell research involving human embryos.

In U.S. history, scientists have been vocal about fascism, nuclear proliferation, the Vietnam War, stem cells and more.