Symmetric and conserved energy-momentum tensors in moving media

A symmetric and conserved energy-momentum tensor for a scalar field in a moving medium is derived using the Gordon metric. When applied to an electromagnetic field, the method gives a similar result. This approach thus points a way out of the old Abraham-Minkowski controversy about the correct energy-momentum tensors for the electromagnetic field in a material medium. The new tensor describes the properties of the field while the Abraham tensor contains information about the field coupled to the medium.Comment: 5 pages, LaTeX, two references added with commentar

How I got to work with Feynman on the covariant quark model

In the period 1968 - 1974 I was a graduate student and then a postdoc at Caltech and was involved with the developments of the quark and parton models. Most of this time I worked in close contact with Richard Feynman and thus was present from the parton model was proposed until QCD was formulated. A personal account is presented how the collaboration took place and how the various stages of this development looked like from the inside until QCD was established as a theory for strong interactions with the partons being quarks and gluons.Comment: LaTeX, 20 pages, 2 figures. Contribution to "50 Years of Quarks", to be published by World Scientifi