Officers for 1930

• Publisher: Elsevier Science
• Year: 1930
• Tongue: English
• Weight: 48 KB
• Volume: 210
• Category: Article
• ISSN: 0016-0032
• DOI: 10.1016/s0016-0032(30)90767-3

✦ Synopsis

CURRENT ToPics. [J. F. I. by failing through some dozens of volts is of the same order as the lengths of x-rays. Hence it seemed worth while to test the correctness of the equivalence of electrons to waves by seeing whether crystals would diffract electrons. Davisson and Germer in New York were the first to observe this effect. G. P. Thomson of Aberdeen has established the diffraction of electrons by thin films of metal. Still further confirmation came by the use of diffraction gratings. Compton and J. Thibaud were able to use these with x-rays in spite of the largeness of the rulings in comparison to the length of the waves by the device of letting the rays fall on the grating at grazing incidence. When Rupp in Germany substituted electrons for x-rays he obtained similar results and was thus enabled to measure the lengths of the electroni c waves, just as the lengths of visible light waves are got from the diffraction grating. "To describe the properties of matter as well as those of light it is necessary to speak at the same time of waves and of corpuscles.

The electron can no longer be regarded as a simple little grain of electricity. We must associate a wave with it and this wave is not a myth because we can measure its length and predict its interference effects. A whole class of phenomena have thus been foreseen before they were actually disco~cered."