LETTERS TO THE EDITOR

REPLY TO Ya. P. TERLETSKY

In his letter to the editorial board of the journal, Ya. P. Terletsky accuses me of having allegedly, in my review (UFN, vol. 48, issue 2), incorrectly attributed to him the view that the interrelation of mass and energy \((E = mc^2)\) is only a particular physical relation, and not a law of nature. In order to substantiate his accusation, Ya. P. Terletsky presents the matter as though, with the aim of distorting his fundamental assessment of the law of interrelation of mass and energy, I had beforehand distorted the formula he cited, as he says, for the four-dimensional energy–momentum vector generalized for several particles.

I consider it necessary to make the following remarks on this matter:

1. The exposition of Ya. P. Terletsky’s speech was made by me from the stenogram, reviewed and corrected by Ya. P. Terletsky.

2. In setting forth Ya. P. Terletsky’s assessment of the law of interrelation of mass and energy, I relied not at all on the above-mentioned formula in any form whatsoever, but on the direct statements of Ya. P. Terletsky. In the text of the stenogram (see copy), reviewed and corrected by Ya. P. Terletsky, there is the direct statement: “The last thing I wanted to say is that the relation \(E = mc^2\) is incorrectly elevated to the rank of a law” (p. 48 of the stenogram). What did I say in the review? In the review I said: “Ya. P. Terletsky also denied the necessity of calling the relation \(E = mc^2\) a law of nature. The relation \(E = mc^2\), he said, is incorrectly elevated to the rank of nature” (see p. 273 of the review). From a simple comparison of what is said in the stenogram with what is written in the review, it is clear that Ya. P. Terletsky’s thought was conveyed by me correctly. True, Ya. P. Terletsky everywhere spoke simply of a law, and not of a law of nature. But this clarification, made by me, does not in the least distort Ya. P. Terletsky’s thought, for a physicist speaks of nature, and he knows of no other laws except the laws of nature. This can be denied only by one who subjectivistically interprets the laws of science. I suppose that, speaking in his address about laws, Ya. P. Terletsky had in mind, of course, the laws of nature.

In order to show that the statement of Ya. P. Terletsky quoted above is not a slip of the tongue, but precisely a definite point of view, I also cited in the review another passage from the stenogram: “Both in the report of Comrade Kuznetsov and in the article of Comrade Vislobokov, the laws of motion for large velocities are not analyzed. Everything is concentrated on the particular relation \(E = mc^2\), but this relation ... does not exhaust and does not reflect the existence of new conservation laws” (p. 47 of the stenogram and p. 273 of the review). It is characteristic that even in his letter to the editorial board Ya. P. Terletsky defends, in essence, the same thought, namely that “the relation \(E = mc^2\) is only (emphasized by me.—I. O.) a particular physical relation...” — a relation, and not a law.

It will also not be superfluous to note that in the published review there is the following exposition of the speech of one of the participants in the discussion: “N. V. Pilishchenko (Academy of Social Sciences) came out with a resolute criticism of those comrades who proposed not to call the relation \(E = mc^2\) a law of nature” (p. 279 of the review). N. V. Pilishchenko had in mind here precisely the point of view of Ya. P. Terletsky.

1. As for the formula published in the review, it appeared as a result of the fact that in Ya. P. Terletsky’s formula, which was contained in the text of the stenogram

\[ \left( \text{namely: } \left(\sum_k p_k\right)^2 + m_0^2 c^2 = \left(\sum_k \frac{E_k}{c}\right)^2 \right), \]

the second term was given without the summation sign, although in it the question is of generalizing

expressions for the case of several particles. Meanwhile, immediately before this, the text of the review contained the expression \(m_0^2 c^2\) in the formula for a single particle. This is what compelled me to change it in the final proofreading, under conditions in which it proved impossible to coordinate the correction with the author, for which I can express my regret. I proceeded from the fact that the equation published in the review is correct, at least for noninteracting particles.

In his letter to the editor, Ya. P. Terletsky, in the formula cited, writes \(M_0^2 c^2\) instead of \(m_0^2 c^2\).

1. Neither I. V. Kuznetsov nor N. F. Ovchinnikov elevate the law \(E = mc^2\) “to the rank of a fundamental, all-embracing law.” This statement by Ya. P. Terletsky is devoid of any basis whatever. My point of view is that \(E = mc^2\) is a law of nature, and not a particular physical relation, as Ya. P. Terletsky maintains.

2. It would be inappropriate and unnecessary here to refute Ya. P. Terletsky’s wholly unfounded statement about the “extreme instability of position” of the author of the review. I leave this to Ya. P. Terletsky’s conscience. I shall note only that anyone who even cursorily looks through my published works, beginning in 1949 (the first work on this question), will easily find that my point of view on this question has remained definite; I have criticized and will continue to criticize views according to which matter is transformed into energy, or mass is transformed into energy, or the concept of energy “encompasses” both the concept of motion and the concept of matter.

N. F. Ovchinnikov