Complex sentence: He was the originator of the "rivet theory" to explain the rapid sinking of the Titanic, which was greatly expanded upon by Dr. Jennifer Hooper McCarty in her PhD thesis work at Johns Hopkins University.
Split into simpler sentences: He was the originator of the "rivet theory" to explain the rapid sinking of the Titanic. This was greatly expanded upon by Dr. Jennifer Hooper McCarty in her PhD thesis work at Johns Hopkins University.