The Case Against the Nuclear Atom
Reviews and Reactions
Isaac Asimov
As an iconoclastic work, Larson’s book is refreshing. The scientific community requires stirring up now and then; cherished assumptions must be questioned and the foundations of science must be strenuously inspected for possible cracks. It is not a popular service and Mr. Larson will probably not be thanked for doing this for nuclear physics, though he does it in a reasonably quiet and tolerant manner and with a display of a good knowledge of the field.
Discovery, July, 1963
The Case Against the Nuclear Atom, by Dewey B. Larson (North Pacific Publishers)
Since the beginning of the twentieth century we seem to have accepted, quite blindly sometimes, all experimental observations, whether they fitted into the general framework of Bohr and Rutherford, or not. Whenever they do not, present practice is to try and save the theory by adding further extensions and qualifications.
What Larson does, and with alarming simplicity, is to show that most of the “physical and chemical evidence” to which textbook writers refer, is equally consistent with many other hypotheses besides the theory of the nuclear atom, and is therefore no proof to any hypothesis. Where do we go from here? Bohr’s work was a marriage of Rutherford’s theory of the nuclear atom with Planck’s theory of the quantum. The decree that makes the divorce final is the abandonment of the last vestiges of Rutherford’s theory. All that is left is what came originally from Planck. We must go on from here, and the new atomic theory that replaces the nuclear atom must embody the quantum concept in some manner.
To all of us, steeped in the unquestioning adoration of the contemporary scientific method, this is a rude and outspoken book, which sometimes hurts. The frightening thing about it is that it rings true.
Not Guilty, Chemical Engineering, July 22, 1963
The Case Against the Nuclear Atom, by Dewey B. Larson, North Pacific Publishers, Portland, Oregon (1963)
Reviewed by R. D. Redin, Dept. of Physics, South Dakota School of Mines and Technology, Rapid City, S.D.
The thesis of this book is that when the evidence is “critically” examined, the model of the atom consisting of a small nucleaus surrounded by a cloud of electons has no real justification. The alternative proposed is that what is now though of as the nucleus is in reality the entire atom.
Mr. Larson shows himself to be well-informed on the current status of physics research and there is very little in the book that is factually wrong. However, the main criticism against his argument is that he has chosen to regard every weak point and apparent failure of the accepted theory as evidence against the nuclear model and to avoid very much discussion of its far greater number of successes.
Much of this book is devoted to deriding scientists for their narrow-mindedness in not recognizing the great errors they are making, and this lack of objectiveness detracts greatly from this argument. There is little doubt that our model of the atom will be modified as new knowledge is obtained, but it is highly unlikely that the modifications will be as radical as Mr. Larson proposes.
Response by D. B. Larson,
published in the Nov. 25, 1963 issue of Chemical Engineering:
In view of the importance of the issue, from the standpoint of the direction that our research effort ought to take, I feel that I ought to point out that your reviewer, Mr. Redin, like many others that have reviewed my book The Case Against the Nuclear Atom, has tacitly conceded the validity of my basic argument, apparently without realising that he has done so. Mr. Redin’s “main criticism”, he says, is that I have emphasized “every weak point and apparent failure” of the nucear theory and have paid little attention to its successes. But only the weaknesses and failures are relevant to the point at issue. The mere fact that they exist, which Mr. Redin concedes, is sufficient to verify my contention.
I have no quarrel with those who take the stand that the nuclear theory is the best theory now available, nor with those who say that it has made important contributions to the advance of physical science. My point is that, despite all that can be said in its favor, it is wrong. In the final analysis, the validity of a theory cannot be judged by what it has done, the acid test is what, if anything, it fails to do. The whole structure of Relativity, for example, owes its existence to the fact that Newton’s Laws, despite their impressive record of successes, failed at one point.
The present almost universal belief that the nuclear theory is an established fact-that we are dealing with nuclear physics-strikes a double blow against scientific progress. First, it wastes an enormous amount of time and effort in futile attempts to establish the nature and properties of features of the atomic model that have no counterparts in the real world-the purely hypothetical force that holds the hypothetical nucleus together, for example. Second, it places an almost insurmountable obstacle in the way of a better theory, even if this might be the correct theory.
A Crack at the Nuclear Theory,
From Chemical and Engineering News, July 29, 1963
The Case Against the Nuclear Atom, Dewey B. Larson. vii + 139 pages. North Pacific Publishers, Portland, Oregon (1963). Reviewed by Dr. Isaac Asimov.
As an iconoclastic work, Larson’s book is refreshing. The scientific community requires stirring up now and then; cherished assumptions must be questioned and the foundations of science must be strenuously inspected for possible cracks. It is not a popular service and Mr. Larson will probably not be thanked for doing this for nuclear physics, though he does it in a reasonably quiet and tolerant manner and with a display of a good knowledge of the field.
His thesis is that Rutherford, in deducing the existence of the atomic nucleus from his bombardment of metal films with alpha particles, made a possibly incorrect deduction. Rather than a tiny, massive nucleus at the center of a frothy, electron-filled atom, Larson suggests that the experiment could be equally well interpreted as indicating a tiny atom surrounded by nothing except energy fields. Larson thus suggests a return to the Daltonian atom, a featureless sphere of the size we associate with what we call the atomic nucleus.
With Rutherford’s assumption (false, according to Larson) quickly elevated to unquestioned fact, it became necessary to pile assumption upon rickety assumption to account for observed phenomena in terms of an internal atomic structure that did not really exist. The prime architects of this supposedly fallacious mass of atomic theory and the villains of Larson’s drama were Niels Bohr, who quantized the nonexistent electrons within the atom, and Werner K. Heisenberg who dragged in Uncertainty to account of everything that could not otherwise be taken care of.
The book is reasonable and reasoned enough to be worth reading if only because it offers the healthful mental exercise of searching for a refutation. To me, it seems that this can be found in the nub of Larson’s “case,” which is that there are no electrons, as such, within the atom. (More generally, he maintains that there are no subatomic particles at all within the atom, but that all are easily created and destroyed in the course of atomic interactions. It is the electron, however, which is the prize example.)
The existence of the electron within the atom, he maintains, was predicated originally upon the fact that electrons were emitted as beta particles from radioactive elements. Later, he goes on, it was admitted that the beta particles did not exist within the atom but were formed at the moment of radioactive breakdown. Nevertheless, with their reasoning shot away, nuclear physicists continued, automaton-like, to insist that electrons existed within the atom.
It seems to me, however, that Larson is quite wrong here. The beta particle phenomenon was used to indicate the presence of electrons within the nucleus, a presence which introduced certain complications and paradoxes in nuclear theory. With the discovery of the neutron, the intranuclear electron was, with great relief, dropped.
The existence of electrons in the outer reaches of the atom--a different matter entirely--was deduced chiefly from the photoelectric effect. Here a quantum, as low in energy as that of red light, is able to bring about the ejection of electrons from cesium metal. It is possible to conceive of the creation of an electron in the course of radioactive breakdown, which involves large energies. To suppose an electron can be created by the energy of a quantum of red light is, however, inadmissible if one is to accept Einstein’s mass-energy conversion formula, and this formula even Larson does not seem disposed to question.
If no electrons exist within the atom, as Larson suggests, I do not see how the photoelectric effect can be explained. From this I conclude that however stimulating Larson’s book might be as an intellectual exercise, it need not be taken seriously as anything more than that.
The Mystery of the Atom, Response by Arthur W. Adamson, Chemical and Engineering News, Sept. 9, 1963
I couldn't help but be amused at Isaac Asimov’s review of “The Case Against the Nuclear Atom” by D. B. Larson. Dr. Asimov apparently appreciated Larson’s point that the emergence of a given particle (e.g., an electron) from the nucleus is no proof of its prior existence there. But he then goes ahead and uses that very argument to say that since electrons can be ejected photoelectrically from an atom, the atom therefore contains electrons.
It doesn't matter whether the photon energy that stimulates the photoelectric effect equals the rest mass energy of the electron or not. Returning to the situation with the nucleus, it is perfectly possible that a low energy x-ray could interact with a nucleus, leading to emission of a beta particle and a neutrino. We could not, of course, make the parallel conclusion to Asimov’s that nuclei contained electrons after all, but would look to some other explanation consistent with present ideas. For example, absorption of the x-ray quantum may have raised the nucleus to a low lying excited state from which beta decay was now energically feasible.
Larson does us a service in reminding us that from an operational point of view, we don't know what is in an atom, and that arguments like Asimov’s are specious and, in fact, are never applied consistently but only to serve the desired conclusion. This reminder should also keep us from falling into the entirely nonscientific attitude of saying that any particular model or theory represents some sort of Absolute Truth.
Nonetheless, the present theory of the wave-mechanical nuclear atom, for all its ad hoc nature, does reasonably well and is all we have anyway. It will undoubtedly hold sway until and if some phenomenon is encountered that is far beyond its ken that no amount of patching will make do.