136 The Electron Microscope 



scope, but the fundamental plan on which nature seems to be 

 built. It is perhaps more correct to say that individual atoms 

 have blurred features than to assume that they are blurred by 

 taking photographs of them. Sharp features come out only when 

 they are investigated in milHons. This is just the opposite of 

 what we would expect if mass-photographs were taken of 

 humans, or even of sheep, and it conveys an idea how ill-suited 

 our everyday concepts are for the understanding of the funda- 

 mentals of atomic physics. 



Very recently Louis de Broglie * has advanced an interesting 

 argument which, it appears, destroys all hope of ever seeing an 

 atomic lattice with an electron or proton microscope. He starts 

 from the consideration that in order to see a particle it is not 

 sufficient to probe it with one beam corpuscle, but with several. 

 Will the next corpuscle find the object in the same place? De 

 Broglie's result is that in order to locate an atom with sufficient 

 accuracy it is necessary to knock it sideways, thus imparting to 

 it a motion which will necessarily blur the picture. But what is 

 worse, in the case of atoms the energy imparted by the first 

 collision will be sufficient to knock it out of the lattice. Thus it 

 appears that while the lattice as a whole is a solid piece of 

 physical reality, the single atom in the lattice belongs into meta- 

 physics rather than into physics ! 



* Louis de Broglie, Comptes rendus, 222, 1017 and 223, 490-493, 1946. 



