Inge Lehmann suggested in 1936 that the Earth had a solid core inside the floating core. It was no easy task to find out this when Richard Dicon Oldham had already established in 1906 that the earth had a floating core. Only through careful testing of hundreds of seismograms could Inge Lehmann establish that the Earth's core was fixed.
Inge Lehmann's name is known abroad, but in Denmark it is only a small crowd of geofysicers who know about her groundbreaking research.
Was it because she was one of the few women who worked in research in the 30s or did she share the fate of other Danish scientists?
Her name came again on the lips of the Geofysians, when the Danish Geophylic Association in 1988 celebrated her 100 year anniversary at an event where the 100 year-old herself was present.
Inge Lehmann died in 1992 104 years old.