https://peertube.dngr.us/videos/watch/d5eb0130-95a8-43e3-908e-d8532057a22a Want to support this channel and help us preserve old films? Visit https://www.patreon.com/PeriscopeFilm Visit our website www.PeriscopeFilm.com This black and white educational film from the United Kingdom is part four of a five part series entitled “Atomic Physics - An Historical Approach” from 1947. Animations and recreations are used to describe early atomic breakthroughs such as the discovery of the neutron in 1930 and Einstein’s theory of relativity, with Einstein himself making an appearance. Written, directed and narrated by Derek Mayne. Animation sequences made by Gaumont-British Animation Ltd. Produced by Gaumont-British Instructional Ltd. Atomic theory is a scientific description of the nature of atoms and matter that combines elements of physics, chemistry, and mathematics. According to modern theory, matter is made of tiny particles called atoms, which are in turn made up of subatomic particles. Atoms of a given element are identical in many respects and different from atoms of other elements. Atoms combine in fixed proportions with other atoms to form molecules and compounds. In 1919, Lord Ernest Rutherford discovered the proton, a positively charged particle within the atom's nucleus. Rutherford also put out the idea that there could be a particle with mass but no charge. He and William Harkins called it a "neutron", and imagined it as a paired proton and electron. In 1932, the physicist James Chadwick conducted an experiment which led to the discovery of this "neutron". Chadwick bombarded Beryllium with alpha particles from the natural radioactive decay of Polonium. The resulting radiation showed high penetration through a lead shield, which could not be explained via the particles known at that time. 00:06 TITLE CARD 00:14 Scientists use apparatus containing a needle to detect alpha particles 00:43 Animation of experiment 00:55 Lord Ernest Rutherford speaks about experiments 01:12 Improved apparatus, animation of experiment 02:20 Geiger counter explained and demonstrated, oscilloscope shown 03:53 Mass spectrograph explained and demonstrated 04:55 Animation of atomic weights of elements 05:08 Atomic weight of chlorine (Cl) discussed in detail, isotopes discussed 05:43 Scientists conduct experiments 06:06 Discovery of the neutron using polonium and beryllium in 1930, animation 07:23 Billiard balls, rice grains used to demonstrate experiment 07:56 Animations continue 09:09 Animation explaining isotopes in chlorine 10:23 Lord Rutherford speaks about experiments 11:05 High speed particle machines used for experiments at Cavendish Laboratory, Cambridge 12:27 Observation cabinet and accelerator tube at the Science Museum at South Kensington, animation 13:40 Newspaper headlines reporting splitting of atom 14:12 Albert Einstein describes the theory of relativity 15:13 Animation depicting theory of relativity using lithium (Li), hydrogen (H), and helium (He) 19:08 Terrestrial globe with raised reliefs 19:29 Scientists conduct experiment using a synchrotron 20:05 Linear electron accelerator 20:28 Electrostatic generator, Van de Graaff generator 21:10 Million and two million volt generators at the Cavendish Laboratory 21:21 END We encourage viewers to add comments and, especially, to provide additional information about our videos by adding a comment! See something interesting? Tell people what it is and what they can see by writing something for example: "01:00:12:00 -- President Roosevelt is seen meeting with Winston Churchill at the Quebec Conference." This film is part of the Periscope Film LLC archive, one of the largest historic military, transportation, and aviation stock footage collections in the USA. Entirely film backed, this material is available for licensing in 24p HD, 2k and 4k. For more information visit http://www.PeriscopeFilm.com Source: https://www.youtube.com/watch?v=90n6vQIBDD8 Mirrored from Periscope Film (https://www.youtube.com/@PeriscopeFilm) Sat, 13 Jun 2026 13:24:45 GMT https://validator.w3.org/feed/docs/rss2.html PeerTube - https://peertube.dngr.us https://peertube.dngr.us/lazy-static/avatars/41a6fee9-7f57-42d0-a5fc-5db4f1af2e31.png https://peertube.dngr.us/videos/watch/d5eb0130-95a8-43e3-908e-d8532057a22a All rights reserved, unless otherwise specified in the terms specified at https://peertube.dngr.us/about and potential licenses granted by each content's rightholder.