The Comment1 on my paper2 has many flaws, which I list below:

  1. They attack my rejection of the center-of-energy theorem, but ignore the fact that I present a counterexample to this theorem in the last paragraph of the introduction of my paper. Further, they ignore the fact that I demonstrate a flaw in the proof of the center-of-energy theorem in Sec. V of my paper, starting at the top of p. 874.

  2. They agree that their “simplest example of hidden momentum” is “an unrealistic model for a current-carrying wire,” and they agree that it has no hidden momentum. But they then refer to papers “by Vaidman and Hnizdo, who showed that there is no electromagnetic momentum either, in this case.” Perhaps the authors did not read Sec. VI of my paper, where I show that the conclusions in those papers are wrong, and a current in a conducting wire does lead to EM momentum. Indeed, it must, since a current in a wire has a magnetic moment and, as I show in Eq. (18) of my paper, such a magnetic moment has electromagnetic momentum in the presence of an external electric field.

  3. The authors then bring up an even more unrealistic model, “in which the current is represented as an incompressible fluid in a nonconducting tube.” But I show in the last four paragraphs of Sec. VI of my paper that this model does not lead to hidden momentum either.

  4. I find it interesting that their purely mechanical “ping-pong-ball” model for hidden momentum described in the last paragraph of their Comment contradicts the center-of-energy theorem because there is no electromagnetic momentum to cancel.

I trust that discerning readers are capable of reading my paper and this Comment and deciding for themselves who is correct.

1.
D. J.
Griffiths
and
V.
Hnizdo
,
Am. J. Phys.
83
,
279
(
2015
).
2.
J.
Franklin
,
Am. J. Phys.
82
,
869
875
(
2014
).