physical experiments (c. 1936 — ); the invention of the 

 klystron (Varian, 1937), of the magnetron (c. 1938), and 

 the development of radar for navigation (1940 — ); the in- 

 vention of the cine camera (Friese-Green, 1889) and of 

 the tape recorder (Poulsen, 1889); the invention of the 

 airborne magnetometer (about 1945); the invention of the 

 hovercraft (Cockerell, c. 1953) and hydroplane (Ricochet, 

 1906) surface vehicles; the use of nuclear power in sub- 

 marines capable of long and deep submersion, and to power 

 surface ships. 



The rate of advance of science and technology together 

 since 1900 has indeed been very great, and is increasing 

 continually. There seems little doubt that as men come to 

 realize even more fully the ability of science to achieve 

 great things, so the world will become willing to accept a 

 basically scientific outlook for the future. The fact is simply 

 that, from the earliest human attempts at an understanding 

 of the world, it has been made ever more clear to man that 

 this world, including man himself, is objectively real, and 

 that things happen according to definite rules — called phy- 

 sical laws. In any given set of circumstances the same event 

 will be repeated — that is, the same causes produce the same 

 effect. Although parts of modern physics would deny strict 

 cause-and-effect relations as always prevailing, one should 

 note the extreme conceptual difficulty of rejecting the 

 cause-and-effect hypothesis, which is basic to our present- 

 day science, and without which Man would not have 

 gained the control of natural forces which he has gained. 



34 



