"Encouragement, mentoring and affordable child care are probably the least expensive elements associated with research in physics or chemistry, yet they are critical to the success of women scientists today," Dava Sobel writes. wapo.st/3NczcKM

Opinion | Women win a fraction of scientific Nobels. Marie Curie offers fixes.

The missing elements in science? Mentorship, encouragement and child-care support for aspiring women scientists.