The invention:
A medically safe alternative to X-ray examination,
ultrasound uses sound waves to detect fetal problems in pregnant
women.
The people behind the invention:
Ian T. Donald (1910-1987), a British obstetrician
Paul Langévin (1872-1946), a French physicist
Marie Curie (1867-1946) and Pierre Curie (1859-1906), the French husband-and-wife team that researched and developed the field of radioactivity
Alice Stewart, a British researcher