Fill the gaps with the words given below

gravity, times, proposed, daydreaming, measurements, relative, sufficed, accuracy, force, equal, asymmetry, leap, a falling stone, acceleration, Newton's law

1) … in his job at the Patent Office in Bern, Switzerland, Einstein considered the case of 2) …, drawn towards the ground by 3) …. The physicists of the day distinguished between the "inertial mass" of the stone, as it appeared in 4) …, which related the 5) … acting on an object to its mass 6) … its 7) …, and the stone's "gravitational mass", which is its mass as described in Newton's law of gravity. Precision 8) … indicated they were probably the same. Why have two masses when one 9) …? It was another 10) …. Ignoring experimental 11) …, Einstein took them to be exactly 12) …, a breathtaking 13).... which led him to realise that acceleration and gravity were 14) … to each other. This was to be the basis for his general theory of relativity − a theory scientists often describe as the most beautiful theory ever 15) ….