Unlike Greek astronomers who tried to explain all motions as circular, Shen proposed that planets moved in a willow leaf motion composed with circular motion round the earth.
Hindi tulad ng Greek astronomers na tried sa ipaliwanag ang lahat ng motions bilang pabilog, Shen iminungkahi na planets inilipat sa isang wilow dahon galaw binubuo sa pabilog na kilos sa paligid ng daigdig.