{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,8]],"date-time":"2026-02-08T09:37:57Z","timestamp":1770543477715,"version":"3.49.0"},"reference-count":20,"publisher":"IOP Publishing","issue":"2","license":[{"start":{"date-parts":[[2019,1,10]],"date-time":"2019-01-10T00:00:00Z","timestamp":1547078400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/publishingsupport.iopscience.iop.org\/iop-standard\/v1"},{"start":{"date-parts":[[2019,1,10]],"date-time":"2019-01-10T00:00:00Z","timestamp":1547078400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/iopscience.iop.org\/info\/page\/text-and-data-mining"}],"content-domain":{"domain":["iopscience.iop.org"],"crossmark-restriction":false},"short-container-title":["Eur. J. Phys."],"published-print":{"date-parts":[[2019,3,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>The emission\/absorption of a photon and the launch\/capture of a massive particle in special relativity Einstein-like boxes are studied, using the four-vector formalism. The study demands the introduction of the centre-of-inertia concept, the relativistic equivalent of the classical centre-of-mass of a system. Then, using Einstein\u2019s principle of the inertia of the energy and the conservation of energy and momentum, we show explicitly, in both cases, that the centre-of-inertia velocity does not change during the processes that take place inside the boxes. We argue that the centre-of-inertia is a useful concept in special relativity as counterpart of the centre-of-mass, and we suggest that it should be explored in the classroom to stress the similarities and the differences between the classical and the relativistic descriptions of mechanical systems.<\/jats:p>","DOI":"10.1088\/1361-6404\/aaf44c","type":"journal-article","created":{"date-parts":[[2018,11,27]],"date-time":"2018-11-27T17:16:19Z","timestamp":1543338979000},"page":"025601","update-policy":"https:\/\/doi.org\/10.1088\/crossmark-policy","source":"Crossref","is-referenced-by-count":4,"title":["Four-vector description of the photon-in-a-box problem"],"prefix":"10.1088","volume":"40","author":[{"given":"J","family":"G\u00fc\u00e9mez","sequence":"first","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6636-9957","authenticated-orcid":false,"given":"M","family":"Fiolhais","sequence":"additional","affiliation":[]}],"member":"266","published-online":{"date-parts":[[2019,1,10]]},"reference":[{"key":"ejpaaf44cbib1","doi-asserted-by":"publisher","first-page":"841","DOI":"10.1119\/1.10134","type":"journal-article","article-title":"Inertia of energy and the liberated photon","volume":"44","author":"Antippa","year":"1976","journal-title":"Am. 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All rights, including for text and data mining, AI training, and similar technologies, are reserved.","name":"copyright_information","label":"Copyright Information"},{"value":"2018-10-04","name":"date_received","label":"Date Received","group":{"name":"publication_dates","label":"Publication dates"}},{"value":"2018-11-27","name":"date_accepted","label":"Date Accepted","group":{"name":"publication_dates","label":"Publication dates"}},{"value":"2019-01-10","name":"date_epub","label":"Online publication date","group":{"name":"publication_dates","label":"Publication dates"}}]}}