From Casimir Forces to Black-Body Radiation: Quantum and Thermal Fluctuations

2017 ◽  
Author(s):  
Alejandro W. Rodriguez ◽  
Adolfo Plasencia
Keyword(s):  
Driving Force ◽  
Black Body ◽  
Thermal Fluctuations ◽  
Black Body Radiation ◽  
Casimir Forces ◽  
Princeton University ◽  
Virtual Photons ◽  
Recent Developments ◽  
The Subject ◽  
Relationship Of

This dialogue with physicist Alejandro W. Rodríguez is in two parts. The first part, which took place in the MIT campus, reflects on how theory has been overtaking experimentation in recent developments in science. It also addresses the subject of the Casimir forces and their effects by using devices which benefit from them in everyday life. Later, Alejandro explains why the vacuum is not empty; and, what are the "virtual photons". In the second part, Alejandro explains his current research in the Department of Electrical Engineering of Princeton University, focusing on the black body; and quantum and thermal processes of electromagnetic fluctuations at the nanoscale, where the rules of quantum mechanics now hold sway. He is now studying quantum fluctuations and how the forces and energy exchanged between objects work. This all-important area is the current driving force for development in the field of thermovoltaic energy and thermal panels for capturing light; an area with a revolutionary potential capable of changing the existing relationship of humans with energy, technology and the environment, in other words, with the planet.

scholarly journals The Puzzling of Zero-Point Energy Contribution to Black-Body Radiation Spectrum: The Role of Casimir Force

2017 ◽  
Vol 16 (04) ◽  
pp. 1771002 ◽  
Author(s):  
L. Reggiani ◽  
E. Alfinito
Keyword(s):  
Casimir Force ◽  
Radiation Spectrum ◽  
Mechanical Stability ◽  
Zero Point ◽  
Direct Consequence ◽  
Black Body ◽  
Thermal Fluctuations ◽  
Black Body Radiation ◽  
Point Energy ◽  
Nyquist Noise

The role played by zero-point contribution in black-body radiation spectrum is investigated in connection with the presence of Casimir force. We assert that once mechanical stability for the physical system is established, there is no further role for zero-point contribution to the spectrum in full agreement with experimental evidence. As a direct consequence, Johnson–Nyquist noise in dissipative conductors, should be interpreted just in terms of thermal fluctuations only, thus neglecting quantum fluctuations predicted by [H. Callen and T. Welton, Irreversibility and generalized noise, Phys. Rev. 83 (1951) 34]. Casimir force between opposite metallic plates can be independently measured by its equilibration through application of a mechanical force and measuring it at a mechanical equilibrium.

scholarly journals The complete photo-electric emission from the alloy of sodium and potassium

1917 ◽  
Vol 93 (652) ◽  
pp. 359-372 ◽  
Keyword(s):  
Temperature Variation ◽  
Unit Area ◽  
Thermionic Emission ◽  
Black Body ◽  
External Source ◽  
Black Body Radiation ◽  
The Subject ◽  
The Law ◽  
Work Done ◽  
Sodium And Potassium

The experimental work described in the present paper suggested itself to the writer in connection with an earlier investigation on the law governing the temperature variation of the complete photo-electric emission from a hot body, i. e . the photo-electric emission from a body in equilibrium with the full (black body) radiation corresponding to its temperature. By making use of hypotheses contained in the quantum theory, the writer obtained the following expression for the current per unit area C = AT (1+2 k T/ Ф +2 k 2 T 2 / Ф 2 ) e -Ф / k t, where Ф is the work done in removing an electron from the hot body, and is equal to hv, v being the lowest frequency of the radiation capable of producing a photo-electric emission, and h being Planck’s constant. The quantity k is the "gas constant” reckoned for one molecule, and A is a quantity independent of T, and characteristic of the substance. As the expression inside the brackets in the above formula does not differ appreciably from unity, the latter is substantially of the same type as Richardson’s equation C = AT λ e -Ф / k T , (1) for the thermionic emission. Richardson* has also shown that it follows, from thermodynamic considerations, that this law governs the complete photo-electric emission. There is reason to believe that the thermionic emission is not wholly photo-electric in origin, but it is clear that some portion of it is the complete auto-photo-electric emission of the substance concerned, and that the law governing its temperature variation should be the same as that for the whole thermionic emission. We are thus led to expect that, when a body is exposed to an external source of full radiation, the same law will govern the variation of its complete photo-electric emission with the temperature of the source of the radiation. This expectation has been confirmed by experiments on the alloy of sodium and potassium, the description of which constitutes the subject of the present paper.

scholarly journals The mathematical representation of a light pulse

1914 ◽  
Vol 89 (612) ◽  
pp. 399-404
Keyword(s):  
Light Pulse ◽  
White Light ◽  
Black Body ◽  
Black Body Radiation ◽  
Mathematical Representation ◽  
Light Quantum ◽  
Concrete Case ◽  
Know How ◽  
New Class ◽  
The Subject

In recent years, owing to the work of Rayleigh, Schuster, and others, our views as to the nature of white light have undergone a change, and it is now universally accepted that white light consists of irregular pulses which are transformed into trains of sine waves by their passage through a prism. But the method of this transformation is not clearly understood, as the reasoning on the subject is unfortunately somewhat general, the only concrete case well known being the pulse Rayleigh represented by e - c 2 t 2 . Had the nature of a light pulse been better understood, there might possibly never have been any talk of the “Light Quantum” or unit theory of light. The object of this note is to call attention to a new class of expressions representing the initial form and dispersion of a light pulse. They are both simple and elegant, and one of them gives the energy distribution required by Wien’s law for black body radiation. They have been suggested by one of Kelvin’s hydrodynamical papers. They do not depend on the Fourier analysis and this is an advantage, for we never know how much of the latter is subjective.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Light and Sensitivity: Love in the Time of the Daguerreotype

2015 ◽  
Author(s):  
Katarzyna Czeczot
Keyword(s):  
Male Gaze ◽  
History Of Photography ◽  
Sensitive Material ◽  
History Of ◽  
The Subject ◽  
Definition Of ◽  
Relationship Of ◽  
Point Of Departure ◽  
Passive Object

The article deals with the love of Zygmunt Krasiński to Delfina Potocka. The point of departure is the poet's definition of love as looking and reads Krasiński's relationship with his beloved in the context of two phenomena that fascinated him at the time: daguerreotype and magnetism. The invention of the daguerreotype in which the history of photography and spiritism comes together becomes a pretext for the formulation of a new concept of love and the loving subject. In the era of painting the woman was treated as a passive object of the male gaze; photography reverses this scheme of power. Love ceases to be a static relationship of the subject in love and the passive object – the beloved. The philosophy of developing photographs (and invoking phantoms) allows Krasiński - the writing subject to become like a light-sensitive material that reveals the image of the beloved.

Casimir forces and vacuum energy

2017 ◽  
Author(s):  
Serge Reynaud ◽  
Astrid Lambrecht
Keyword(s):  
Casimir Force ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Thermal Fluctuations ◽  
Model Systems ◽  
Vacuum Field ◽  
Force Measurements ◽  
Casimir Forces ◽  
Current State ◽  
Field Fluctuations

The Casimir force is an effect of quantum vacuum field fluctuations, with applications in many domains of physics. The ideal expression obtained by Casimir, valid for perfect plane mirrors at zero temperature, has to be modified to take into account the effects of the optical properties of mirrors, thermal fluctuations, and geometry. After a general introduction to the Casimir force and a description of the current state of the art for Casimir force measurements and their comparison with theory, this chapter presents pedagogical treatments of the main features of the theory of Casimir forces for one-dimensional model systems and for mirrors in three-dimensional space.

The Physical World

2017 ◽  
Author(s):  
Nicholas Manton ◽  
Nicholas Mee
Keyword(s):  
Quantum Mechanics ◽  
Particle Physics ◽  
Variational Principles ◽  
Black Body ◽  
Black Body Radiation ◽  
Physical World ◽  
Atomic Scale ◽  
Solid State Physics ◽  
Least Action ◽  
Dimensional Spacetime

The book is an inspirational survey of fundamental physics, emphasizing the use of variational principles. Chapter 1 presents introductory ideas, including the principle of least action, vectors and partial differentiation. Chapter 2 covers Newtonian dynamics and the motion of mutually gravitating bodies. Chapter 3 is about electromagnetic fields as described by Maxwell’s equations. Chapter 4 is about special relativity, which unifies space and time into 4-dimensional spacetime. Chapter 5 introduces the mathematics of curved space, leading to Chapter 6 covering general relativity and its remarkable consequences, such as the existence of black holes. Chapters 7 and 8 present quantum mechanics, essential for understanding atomic-scale phenomena. Chapter 9 uses quantum mechanics to explain the fundamental principles of chemistry and solid state physics. Chapter 10 is about thermodynamics, which is built around the concepts of temperature and entropy. Various applications are discussed, including the analysis of black body radiation that led to the quantum revolution. Chapter 11 surveys the atomic nucleus, its properties and applications. Chapter 12 explores particle physics, the Standard Model and the Higgs mechanism, with a short introduction to quantum field theory. Chapter 13 is about the structure and evolution of stars and brings together material from many of the earlier chapters. Chapter 14 on cosmology describes the structure and evolution of the universe as a whole. Finally, Chapter 15 discusses remaining problems at the frontiers of physics, such as the interpretation of quantum mechanics, and the ultimate nature of particles. Some speculative ideas are explored, such as supersymmetry, solitons and string theory.

Constructing Quantum Mechanics

2019 ◽  
Author(s):  
Anthony Duncan ◽  
Michel Janssen
Keyword(s):  
Quantum Mechanics ◽  
Quantum Theory ◽  
Stark Effect ◽  
Zeeman Effect ◽  
Black Body ◽  
Black Body Radiation ◽  
Wave Mechanics ◽  
Specific Heats ◽  
Old Quantum Theory ◽  
Upper Level

This is the first of two volumes on the genesis of quantum mechanics. It covers the key developments in the period 1900–1923 that provided the scaffold on which the arch of modern quantum mechanics was built in the period 1923–1927 (covered in the second volume). After tracing the early contributions by Planck, Einstein, and Bohr to the theories of black‐body radiation, specific heats, and spectroscopy, all showing the need for drastic changes to the physics of their day, the book tackles the efforts by Sommerfeld and others to provide a new theory, now known as the old quantum theory. After some striking initial successes (explaining the fine structure of hydrogen, X‐ray spectra, and the Stark effect), the old quantum theory ran into serious difficulties (failing to provide consistent models for helium and the Zeeman effect) and eventually gave way to matrix and wave mechanics. Constructing Quantum Mechanics is based on the best and latest scholarship in the field, to which the authors have made significant contributions themselves. It breaks new ground, especially in its treatment of the work of Sommerfeld and his associates, but also offers new perspectives on classic papers by Planck, Einstein, and Bohr. Throughout the book, the authors provide detailed reconstructions (at the level of an upper‐level undergraduate physics course) of the cental arguments and derivations of the physicists involved. All in all, Constructing Quantum Mechanics promises to take the place of older books as the standard source on the genesis of quantum mechanics.

Electromagnetic fluctuations from energetic particles in plasmas

1988 ◽  
Vol 40 (3) ◽  
pp. 407-417 ◽  
Author(s):  
Cheng Chu ◽  
J. L. Sperling
Keyword(s):  
Distribution Function ◽  
Velocity Distribution ◽  
Charged Particles ◽  
Velocity Distribution Function ◽  
Black Body ◽  
Black Body Radiation ◽  
Specific Model ◽  
Magnetized Plasma ◽  
Plasma Power ◽  
Correlation Techniques

Electromagnetic fluctuations, induced by energetic charged particles, are calculated using correlation techniques for a uniform magnetized plasma. Power emission in the ion-cyclotron range of frequencies (ICRF) is calculated for a specific model of velocity distribution function. The emissive spectra are distinct from that of the black-body radiation and have features that are consistent with experimental observation.

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