We examine “de Broglie-Bohm” causal trajectories for the two electrons in a nonrelativistic helium atom, taking into account the spin-dependent momentum terms that arise from the Pauli current. Given that this many-body problem is not exactly solvable, we examine approximations to various helium eigenstates provided by a low-dimensional basis comprised of tensor products of one-particle hydrogenic eigenstates.First to be considered are the simplest approximations to the ground and first-excited electronic states found in every introductory quantum mechanics textbook. (...) For example, the trajectories associated with the simple 1s(1)1s(2) approximation to the ground state are, to say the least, nontrivial and nonclassical.We then examine higher-dimensional approximations, i.e., eigenstates Ψ α of the Hamiltonian in this truncated basis, and show that ∇ i S α =0 for both particles, implying that only the spin-dependent momentum term contributes to electronic motion. This result is independent of the size of the truncated basis set, implying that the qualitative features of the trajectories will be the same, regardless of the accuracy of the eigenfunction approximation.The electronic motion associated with these eigenstates is quite specialized due to the condition that the spins of the two electrons comprise a two-spin eigenfunction of the total spin operator. The electrons either (i) remain stationary or (ii) execute circular orbits around the z-axis with constant velocity. (shrink)

The famous astronomer Fred Hoyle started his research career as an atheist. Hoyle’s most important contribution to astrophysics is the theory of nucleosynthesis, i.e. the idea that chemical elements such as carbon can form in stars on the basis of hydrogen and helium. Essentially here was his prediction that the carbon core has a state with a specific energy which is precisely adapted to the basic fusion process. This result was one of the most important breakthroughs in modern astrophysics, (...) and the so called Hoyle state has become a cornerstone for state-ofthe-art nuclear theory. The calculations he made, eventually revealed a fine-tuning of the universe. Hoyle’s work in this area supported the anthropic principle that the universe was fine-tuned so that intelligent life would be possible. It is said that what really made him conclude that creation demanded intelligence, were his calculations of the special properties of the carbon atom. This shook his atheism fundamentally [1, p. 57]. In this paper we describe this discovery. (shrink)

The two-electron atom is the simplest nontrivial quantum system not amenable to exact solutions. Today, its relevance in the development of quantum mechanics and its pedagogical value within the realm of atomic physics are widely recognized. In this work, an historical review of the known different methods and results devised to study such a problem is presented, with an emphasis to the calculations of the ground state energy of helium. Then we discuss several, related, unpublished results obtained around (...) the same years by Ettore Majorana, which remained unknown till recent times. Among them a general variant of the variational method appears to be particularly interesting, even for current research in atomic and nuclear physics: it takes directly into account, already in the trial wavefunction, the action of the full Hamiltonian operator of a given quantum system. Further relevant contributions, specialized to the two-electron problem, include the introduction of the remarkable concept of an effective nuclear charge different for the two electrons (thus generalizing previous known results) and an application of the perturbative method, where the atomic number Z was treated effectively as a continuous variable. Finally a survey of results, relevant mainly for pedagogical reasons, is given; in particular we focus on simple broad range estimates of the helium ionization potential, obtained by suitable choices for the wavefunction, as well as on a simple alternative to Hylleraas’ method, which led Majorana to first order calculations comparable in accuracy with well-known order 11 results derived, in turn, by Hylleraas. (shrink)

We consider the status of quantum information in the quantum theory and based on the correspondence principle, we propose an interpretation of the wave function as a mathematical representation of quantum information. We consider Clauser’s analysis of incompatibility formulations of quantum theory in laboratory space and configuration space in the context of local realism. Then, we introduce the hypothesis of quantum space of directly unobserved relations, which precede quantum correlations, and are compatible with the Reichenbach common cause principle. The possible (...) implications of the hypothesis are discussed in the context of the latest experimental and theoretical results on the dynamics of entanglement formation in helium atoms. Finally, we present the Chyliński model as an example of quantum relational continuum space, which predicts potentially measurable effects for the bound states. (shrink)

The article begins with a response to a recent contribution by Jensen, in which he has criticized several aspects of the use of triads of elements, including Döbereiner’s original introduction of the concept and the modern use of atomic number triads by some authors including myself. Such triads are groups of three elements, one of which has approximately the average atomic weight of the other two elements, as well as having intermediate chemical reactivity. I also examine Jensen’s attempted reconstruction Mendeleev’s (...) use of triads in predicting the atomic weights of three hitherto unknown elements, that were subsequently named gallium, germanium and scandium. The present article then considers the use of atomic number triads, in conjunction with the phenomenon of first member anomaly, in order to offer support for Janet’s left-step periodic table, in which helium is relocated into group 2 of the table. Such a table features triads in which the 2nd and third elements of each group, without fail, fall into periods of equal length, a feature that is absent in the conventional 18-column or the conventional 32-column table. The dual sense of the term element, which is the source of much discussion in the philosophy of chemistry, is alluded to in further support of such a relocation of helium that may at first appear to contradict chemical intuition. (shrink)

The known facts of quantum physics and biology strongly suggest the following hypotheses: atoms and the fundamental particles have a rudimentary degree of consciousness, volition, or self-activity; the basic features of quantum mechanics are a result of this fact; the quantum mechanical wave properties of matter are actually the conscious properties of matter; and living organisms are a direct result of these properties of matter. These hypotheses are tested by using them to make detailed predictions of new facts, and then (...) by showing that the predictions can be verified. The hypotheses are used to predict successfully that the quantum wave properties of matter are strongly predominant in proteins, to explain the presence and relative abundance of carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur in proteins, and to explain diffraction phenomena, the behavior of helium II, the exclusion principle, and causality and determinism in modern science, thus closely relating physics and biology. (shrink)

Some recent work in mathematical chemistry is discussed. It is claimed that quantum mechanics does not provide a conclusive means of classifying certain elements like hydrogen and helium into their appropriate groups. An alternative approach using atomic number triads is proposed and the validity of this approach is defended in the light of some predictions made via an information theoretic approach that suggests a connection between nuclear structure and electronic structure of atoms.

It is with good reason that the name Rutherford is closely linked with the early history of the alpha particle. He discovered them, determined their nature, and from 1909 used them to probe the structure of the atom. From 1898 to 1902 Rutherford construed alpha radiation as a type of non-particulate Röntgen radiation. On his theory of the locomotion of radioactive particles Rutherford proposed that alpha radiation consisted of negatively charged particles. During 1902 he confirmed the particulate nature of (...) alpha radiation but discovered that these alpha particles were positively charged. Although Rutherford suspected from 1903 that these alpha particles were related somehow with helium, the proof required six long years of investigation. By mid-1908 it seemed certain that the alpha particle possessed two units of the elementary charge. Since the e/m ratio had already been determined for alpha particles, this evidence enhanced the suspected connection with helium. However, this gain and loss of charge was still construed as an ionization effect. Since as late as 1908 gaseous ionization was assumed to involve the gain or loss of a single unit of charge, Rutherford's alleged case of doubly ionized alpha particles was presumably an exception. Yet helium was known to be an inert gas and thus hardly a likely candidate for such exceptional ionization behaviour. To establish the connection, therefore, Rutherford resorted to a spectroscopic test. He collected spent alpha particles shot into a thin glass tube and gradually observed the spectrum of helium. Rutherford had thus been correct in his assumption, but a proper explanation was possible only after the confirmation of the nuclear structure of the atom. (shrink)

The Bohr formulation—the original one—is now largely a matter of history. The usual career of a theory was its fate. It explained much, but it failed at the first signs of complication, even for the simplest molecules as hydrogen and helium. Some results were either only approximate in a loose or incomplete fashion, e.g. in the application of the correspondence principle to intensities, the only reliable predictions being only for an absence of certain lines, or they quite disagreed with (...) experiment, e.g. in the case of the hydrogen molecule and the hydrogen molecule ion, the normal and excited states of helium, the anomalous Zeeman effect, the Ramsauer effect, and in the treatment of problems where more than one electron was involved. In the last mentioned cases the perturbation method, so successful in solving “many-body” problems in celestial mechanics, failed completely because systems of several electrons, possessing frequencies of the order of light waves, cannot interact classically. A bit of much forced pragmatism was practiced in treating the many electron atom as a variation of the hydrogen atom. Besides, there were technical oddities, like ½ quantum numbers, and impenetrated anologies between visible and X-ray spectra. (shrink)

In this paper we study some of the methodological problems associated with the development of the various theoretical schema devised to explain the phenomenon of superfluidity. The physical behaviour of supercooled helium defied explanation in terms of the known atomic laws for helium and their ‘natural’ extrapolations. We show that the basic conceptual difficulties involved were circumvented by the development of intermediate intermediaries through a process of contextual reinterpretation.

In a recent paper in this Journal, one of us argued against placing He above Be in Mendeleiev’s system of the elements. In it the goal was to dispute the notion that in Mendeleiev’s system of the elements the location of He should in fact lie above Be, which has a very similar electronic configuration, rather than above the noble gas column. That paper was based on rather old, Hartree–Fock limit studies on the strikingly limited non-additive contributions in the He3 (...) and He4 systems in contrast with the much larger non-additivity obtained for the Be3, Be4 and Be5 oligomers. In a recent benchmark multireference Averaged Quadratic Coupled Cluster results on Be2 and Be3 we showed that the delocalized non-additive contribution comprises 94 % of the binding energy of Be3. Here we use this and other pertinent information (drawn from the same paper) to conclude that He may not be associated with Be in Mendeleiev’s Table, despite their quite similar spectroscopic ground states. Furthermore, we use the new results to show that the large non-additivity implies that less than 2 % of the Be3 binding is located in each Be pair contained within the Be trimer. The rest of the interaction energy is necessarily delocalized over all three Be atoms. This might actually announce the bulk properties (i.e. “the electron gas”) that in solid-state physics explain the large electric and heat conduction for the solid Be metal. Thus, in the case of beryllium the metallic characteristics are already evident in Be3, a far cry from the monoatomic helium gas. (shrink)

Introductory survey -- Atomic theory and mechanics -- The quantum postulate and the recent development of atomic theory -- The quantum of action and the description of nature -- The atomic theory and the fundamental principles underlying the description of nature.

Helium and neon, the two lightest noble gases, have been traditionally positioned by IUPAC in the Group 18 of the Periodic Table of Elements, together with argon, and other unreactive or moderately reactive gaseous elements (krypton, xenon, radon), and oganesson. In this account we revive the old discussion on the possible placement of helium in the Group 2, while preserving the position of neon in Group 18. We provide quantum-chemical arguments for such scenario—as well as other qualitative and (...) quantitative arguments—and we describe previous suggestions in the literature which support it or put it into question. To this author’s own taste, He should be placed in Group 2. (shrink)

We apply an online optimization process based on machine learning to the production of Bose-Einstein condensates. BEC is typically created with an exponential evaporation ramp that is optimal for ergodic dynamics with two-body s-wave interactions and no other loss rates, but likely sub-optimal for real experiments. Through repeated machine-controlled scientific experimentation and observations our ’learner’ discovers an optimal evaporation ramp for BEC production. In contrast to previous work, our learner uses a Gaussian process to develop a statistical model of the (...) relationship between the parameters it controls and the quality of the BEC produced. We demonstrate that the Gaussian process machine learner is able to discover a ramp that produces high quality BECs in 10 times fewer iterations than a previously used online optimization technique. Furthermore, we show the internal model developed can be used to determine which parameters are essential in BEC creation and which are unimportant, providing insight into the optimization process of the system. (shrink)

These articles and speeches by the Nobel Prize-winning physicist date from 1934 to 1958. Rather than expositions on quantum physics, the papers are philosophical in nature, exploring the relevance of atomic physics to many areas of human endeavor. Includes an essay in which Bohr and Einstein discuss quantum and_wave equation theories. 1961 edition.

The intention of Atomic Order is to encourage and contribute to the dialogue between philosophers and scientists by discussing a concrete example of scientific discovery according to a method acceptable and understandable to both sides. This discussion takes simultaneously into account the scientific and philosophical methodologies and mentalities. By regarding "pure" science or "pure" philosophy as limiting cases, it becomes evident that basic questions are best posed and answered by emphasiz ing the deeply embedded complementary relationship between the two. The (...) example chosen is atomic physics, and a systematic method is developed to illuminate the philosophical structure of this science--and science generally--from within.The book consists of two parts. The first part is devoted to the problem of atomic order as discovered and verified by physics, from the speculations of Dalton to the consequences of modern quantum mechanics. These chapters will afford a telescopic, historical review to the scientific reader and a reliable, understandable account of the physical discoveries and theories to the nonscientist. The second part analyzes the presuppositions, guiding principles, and implications that made possible the development of atomic physics and that impart a humanistic meaning to it. In separate chapters are discussed the epistemological structure of atomic physics, the new conception of matter implicit in the quantum theory, and the ontological implications of atomic order. It is seen that, in this area, science and philosophy are inextricably interpenetrated. A philosophic problematic is immanent in creative atomic science, as is evidenced by the numerous reflections and speculations of scientists that are quoted in the book. Conversely, an interest in scientific research is indispensable for a modern philosopher, and the philosopher may well be surprised and encouraged on recognizing the role already being played by philosophy in the supposedly pragmatic world of science.Dr. Cantore brings an ecumenical cast Lof mind to the healing of the bjcultural split between the humanists and the scientists. The recipient of a doctorate in physics and another in philosophy, he has drawn from both fields in a book dedicated to "making the educated public more aware of the need and method for a new synthesis between the two cultures.". (shrink)

Senior molecular geneticists were interviewed about their perceptions of the ethical and social implications of genetic knowledge. Inductive analysis of these interviews identified a number of strategies through which the scientists negotiated their moral responsibilities as they participated in generating knowledge that presents difficult ethical questions. These strategies included: further analysis and application of scientific method; clarification of multiple roles; negotiation with the public through public debate, institutional processes of funding, ethics committees and legislation; and personal responsibility.

Let EOA be the elementary ontology augmented by an additional axiom S (S S), and let LS be the monadic second-order predicate logic. We show that the mapping which was introduced by V. A. Smirnov is an embedding of EOA into LS. We also give an embedding of LS into EOA.

Although continued investments in nanotechnology are made, atomically precise manufacturing (APM) to date is still regarded as speculative technology. APM, also known as molecular manufacturing, is a token example of a converging technology, has great potential to impact and be affected by other emerging technologies, such as artificial intelligence, biotechnology, and ICT. The development of APM thus can have drastic global impacts depending on how it is designed and used. This paper argues that the ethical issues that arise from APM (...) - as both a standalone technology or as a converging one - affects the roles of stakeholders in such a way as to warrant an alternate means furthering responsible innovation in APM research. This paper introduces a value-based design methodology called Value Sensitive Design (VSD) that may serve as a suitable framework to adequately cater to the values of stakeholders. Ultimately, it is concluded that VSD is a strong candidate framework for addressing the moral concerns of stakeholders during the preliminary stages of technological development. (shrink)

It is shown that the Kapitza-Dirac effect with atoms, which has been considered to be evidence for their wavelike character, can be interpreted as a scattering of pointlike objects by the periodic laser field.