Comment on ‘Covariant formulation of electrodynamics in isotropic media’

IF 0.6 4区教育学 Q4 EDUCATION, SCIENTIFIC DISCIPLINES

European Journal of Physics Pub Date : 2023-12-13 DOI:10.1088/1361-6404/ad0de9

Jerrold Franklin

{"title":"Comment on ‘Covariant formulation of electrodynamics in isotropic media’","authors":"Jerrold Franklin","doi":"10.1088/1361-6404/ad0de9","DOIUrl":null,"url":null,"abstract":"A recent paper Pal (2022 <italic toggle=\"yes\">Eur. J. Phys.</italic>\n<bold>43</bold> 015204) puts into covariant form an extension of relativistic classical electromagnetism from free space to a linearly polarizable medium. The paper is based on the assumption that the relativistic tensor, <italic toggle=\"yes\">F</italic>\n\n<italic toggle=\"yes\">μ</italic>\n<italic toggle=\"yes\">ν</italic>\n, which is a tensor in free space, will also be a tensor in a linear medium. Pal constructs a proposed covariant formulation that gives <inline-formula>\n<tex-math>\n<?CDATA ${F}^{\\mu \\nu }$?>\n</tex-math>\n<mml:math overflow=\"scroll\"><mml:msup><mml:mrow><mml:mi>F</mml:mi></mml:mrow><mml:mrow><mml:mi>μ</mml:mi><mml:mi>ν</mml:mi></mml:mrow></mml:msup></mml:math>\n<inline-graphic xlink:href=\"ejpad0de9ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\n</inline-formula> for a medium moving with constant velocity, <bold>v</bold>, in terms of <italic toggle=\"yes\">F</italic>\n\n<italic toggle=\"yes\">μ</italic>\n<italic toggle=\"yes\">ν</italic>\n for the medium at rest. However, although <italic toggle=\"yes\">F</italic>\n\n<italic toggle=\"yes\">μ</italic>\n<italic toggle=\"yes\">ν</italic>\n has been proven to be a relativistic tensor in free space, we show that it is not a tensor in a linear medium. This means that the covariant extension proposed by Pal fails.","PeriodicalId":50480,"journal":{"name":"European Journal of Physics","volume":null,"pages":null},"PeriodicalIF":0.6000,"publicationDate":"2023-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"European Journal of Physics","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1088/1361-6404/ad0de9","RegionNum":4,"RegionCategory":"教育学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"EDUCATION, SCIENTIFIC DISCIPLINES","Score":null,"Total":0}

引用次数: 0

Abstract

A recent paper Pal (2022 Eur. J. Phys. 43 015204) puts into covariant form an extension of relativistic classical electromagnetism from free space to a linearly polarizable medium. The paper is based on the assumption that the relativistic tensor, F ^μ
ν, which is a tensor in free space, will also be a tensor in a linear medium. Pal constructs a proposed covariant formulation that gives

Fμν

for a medium moving with constant velocity, v, in terms of F ^μ
ν for the medium at rest. However, although F ^μ
ν has been proven to be a relativistic tensor in free space, we show that it is not a tensor in a linear medium. This means that the covariant extension proposed by Pal fails.

查看原文本刊更多论文

关于 "各向同性介质中电动力学的共变公式 "的评论

最近的一篇论文 Pal (2022 Eur. J. Phys.43 015204) 以共变形式将相对论经典电磁学从自由空间扩展到线性可极化介质。论文基于这样一个假设：相对论张量 Fμν 在自由空间中是一个张量，在线性介质中也是一个张量。Pal 提出了一种协变公式，用静止介质的 Fμν 来表示以恒定速度 v 运动的介质的 Fμν。然而，尽管 Fμν 已被证明是自由空间中的相对论张量，但我们证明它在线性介质中并不是张量。这意味着帕尔提出的协变扩展失败了。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

European Journal of Physics 物理-物理：综合

CiteScore

1.70

自引率

28.60%

发文量

128

审稿时长

3-8 weeks

期刊介绍： European Journal of Physics is a journal of the European Physical Society and its primary mission is to assist in maintaining and improving the standard of taught physics in universities and other institutes of higher education. Authors submitting articles must indicate the usefulness of their material to physics education and make clear the level of readership (undergraduate or graduate) for which the article is intended. Submissions that omit this information or which, in the publisher''s opinion, do not contribute to the above mission will not be considered for publication. To this end, we welcome articles that provide original insights and aim to enhance learning in one or more areas of physics. They should normally include at least one of the following: Explanations of how contemporary research can inform the understanding of physics at university level: for example, a survey of a research field at a level accessible to students, explaining how it illustrates some general principles. Original insights into the derivation of results. These should be of some general interest, consisting of more than corrections to textbooks. Descriptions of novel laboratory exercises illustrating new techniques of general interest. Those based on relatively inexpensive equipment are especially welcome. Articles of a scholarly or reflective nature that are aimed to be of interest to, and at a level appropriate for, physics students or recent graduates. Descriptions of successful and original student projects, experimental, theoretical or computational. Discussions of the history, philosophy and epistemology of physics, at a level accessible to physics students and teachers. Reports of new developments in physics curricula and the techniques for teaching physics. Physics Education Research reports: articles that provide original experimental and/or theoretical research contributions that directly relate to the teaching and learning of university-level physics.