Earth’s Core: Inge Lehmann

Inge Lehmann

I am working on some content research online today when I notice Google Doodle with a split globe. Inge Lehmann is celebrating her 127th birthday today. I am a bit intrigued as to who is this woman. For Google to give a big attention to her with a Google Doodle, she must be someone very important in history that people should remember her.

I quickly typed her name on the Google word box to see who she was. In a matter of millisecond, I discovered that she discovered the earth’s inner core.

She was a seismologist and geophysicist from Denmark. She grew up in Østerbro, one of the ten official districts of Copenhagen. According to Lehmann, the biggest influences of her academic studies were her father Alfred Lehmann, who was an experimental psychologist, and Hanna Adler, her high school teacher.

Mathematics was the focus of her education in the University of Copenhagen and University of Cambridge. However, because of weak physical condition, her schooling became irregular. After a year in Cambridge, she went home to rest for a while. In the succeeding years, she was able to work in an actuary office (actuary is a person who compiles and analyzes statistics and uses them to calculate insurance risks and premiums- google) where she developed her computing skill. Eventually, she went back to Copenhagen University and finished her magisterii in mathematics and physical science in just two years. Later, she became an assistant to the professor of actuarial science in the University of Copenhagen.

After her stint in the insurance business, she worked as an assistant to geodesist Eric Norlund who assigned her to set up seismic observatories in Denmark and in Greenland. Later, after passing the exam in geodesy, she became the state geodesist and head of the seismology department of the Geodetic Institute of Denmark. Among the leading seismologists, that time was Charles Richter.

She became popular in the field of seismology by her observation of a seeming discontinuity in seismic waves at depths of 220±30 km beneath, continents although not usually under oceans and are not appearing in internationally averaged studies immediately. Seismologists called this Lehmann Discontinuity.

In 1936, she proposed, according to her study and observation of seismic data that the earth has as an inner core, which is distinct in properties from the outer core. She concludes that the earth's core is not a solitary liquefied sphere.

She died at the age of 104.

People with such superior mathematical ability are amazing. They are gifted. Lehmann was gifted with mathematical skill and she used it for the benefit of science and seismology. I wish everyone would use their gifts too for the benefit of earth and people living on it, not to earn a Google Doodle for ourselves, but to make our life meaningful. At least, we walk on earth not just as passing shadows that are unperceived and unnoticed but with big and wide footsteps that are worth remembering and following.

Image Credit: Wikipedia.Org