 In some ways this technique was superior to wind tunnel study, as it allowed for the direct measurement of real-world influences on the trajectory, as a test of theoretical calculations.On the downside, reducing the collected data to a mathematical trajectory for checking against the theoretical calculations is difficult.Bull was at CARDE briefly before returning to the university to defend his thesis in March 1951, at 23 years old becoming the youngest PhD graduate in the Institute's history—a record that remains to this day.