His daughter Mathilde Carmen Hertz was a well - known biologist and comparative psychologist .
Heinrich Hertz 's nephew Gustav Ludwig Hertz was a Nobel Prize winner , and Gustav 's son Carl Helmut Hertz invented medical ultrasonography .
Heinrich Hertz 's daughter Mathilde Carmen Hertz was a well - known biologist and comparative psychologist .
Heinrich Hertz 's nephew Gustav Ludwig Hertz was a Nobel Prize winner , and Gustav 's son Carl Helmut Hertz invented medical ultrasonography .