 Percy Williams Bridgman (1882–1961) was a physicist at Harvard University whose pioneering work in the physics of high pressures was rewarded with a Nobel Prize in  1946.[2]  His chief scientific contribution was made possible by technical prowess: in his laboratory Bridgman created pressures nearly 100 times higher than anyone else had achieved before him, and investigated the novel behavior of various materials under such high pressures. But Bridgman was placed in a predicament by his own achievements: at such extreme pressures, all previously known pressure gauges broke down; how was he even to know what levels of pressure he had in fact reached? (see Kemble, Birch and Holton 1970) As he kept breaking his own pressure records, Bridgman had to establish a succession of new measures fit for higher and higher pressures. Therefore it is no surprise that he thought seriously about the groundlessness of concepts where no methods were available for their measurement.