Weber-like interactions and energy conservation

Velocity dependent forces varying as $k(\hat{r}/r)(1 - \mu \dot{r}^2 + \gamma r \ddot{r})$ (such as Weber force), here called Weber-like forces, are examined from the point of view of energy conservation and it is proved that they are conservative if and only if $\gamma=2\mu$. As a consequence, it is shown that gravitational theories employing Weber-like forces cannot be conservative and also yield both the precession of the perihelion of Mercury as well as the gravitational deflection of light.Comment: latex, 11 pages, no figure

Circuit Theory In Weber Electrodynamics

We present a derivation of the equation describing the current flow in a circuit with self-inductance based on Newton's second law plus the Weber force or, alternatively, plus the Lorentz or Liénard-Schwarzschild force. In Weber's approach the self-inductance can be treated as a measure of the effective average inertial mass of the conduction electrons.183241246Assis, A.K.T., (1994) Weber's Electrodynamics, , Dordrecht: KluwerHeald, M.A., Marion, J.B., (1995) Classical Electromagnetic Radiation 3rd Edn, 41, pp. 1-34. , Fort Worth: Saunders problemReitz, J.R., Milford, F.J., Christy, R.W., (1980) Foundations of Electromagnetic Theory 3rd Edn, , (Reading, MA: Addison-Wesley) section 7.7Grover, F.W., (1946) Inductance Calculations - Working Formulas and Tables, 35. , New York: Van NostrandBueno, M.A., Assis, A.K.T., A new method for inductance calculations (1995) J. Phys. D: Appl. Phys., 28, pp. 1802-1806O'Rahilly, A., (1965) Electromagnetic Theory - A Critical Examination of Fundamentals, pp. 215-223. , New York: DoverPearson, J.M., Kilambi, A., Velocity-dependent nuclear forces and Weber's electrodynamics (1974) Am. J. Phys., 42, pp. 971-975Edwards, W.F., Kenyon, C.S., Lemon, D.K., Continuing investigation into possible electric fields arising from steady conduction currents (1976) Phys. Rev. D, 14, pp. 922-938Assis, A.K.T., Weber's law and mass variation Phys (1989) Lett., 136 A, pp. 277-280Assis, A.K.T., Caluzi, J.J., A limitation of Weber's law (1991) Phys. Lett., 160 A, pp. 25-30Assis, A.K.T., Centrifugal electrical force (1992) Commun Theor. Phys., 18, pp. 475-478Assis, A.K.T., Changing (he inertia) mass of a charged particle (1993) J. Phys. Soc. Japan, 62, pp. 1418-142

A commented Portuguese translation of a paper by Maxwell on action at a distance

A commented Portuguese translation of a text by James Clerk Maxwell published in 1873 is offered. In this important paper, Maxwell discusses arguments in favour and against the concept of action at a distance.Apresentamos uma tradução comentada de um importante texto de James Clerk Maxwell publicado em 1873. Neste artigo, Maxwell discute argumentos a favor e contra a ação a distância.27328

Didactic demonstration of the interaction between electric currents

We present the first crucial experiment by Ampère that shows the interaction of two metallic wires carrying steady currents. We discuss its importance in the history of physics. We also present a modern reproduction of the procedures and observations of Ampère with low cost materials.Apresentamos a primeira experiência crucial de Ampère mostrando a interação entre dois fios metálicos conduzindo correntes elétricas. Discutimos sua importância na história da física. Descrevemos uma reprodução moderna dos procedimentos e observações de Ampère com materiais de baixo custo.60561

'Universal' FitzGerald Contractions

The model of a universe with a preferred frame, which nevertheless shares the main properties with traditional special and general relativity theories, is considered. We adopt Mach's interpretation of inertia and show that the energy balance equation, which includes the Machian energy of gravitational interactions with the universe, can imitate standard relativistic formulas.Comment: The version accepted by Eur. Phys. J.

Towards a quantum universe

In this short review we study the state of the art of the great problems in cosmology and their interrelationships. The reconciliation of these problems passes undoubtedly through the idea of a quantum universe.Comment: 7 pages, Accepted for publication in Astrophysics & Space Scienc

On the gravitodynamics of moving bodies

In the present work we propose a generalization of Newton's gravitational theory from the original works of Heaviside and Sciama, that takes into account both approaches, and accomplishes the same result in a simpler way than the standard cosmological approach. The established formulation describes the local gravitational field related to the observables and effectively implements the Mach's principle in a quantitative form that retakes Dirac's large number hypothesis. As a consequence of the equivalence principle and the application of this formulation to the observable universe, we obtain, as an immediate result, a value of Omega = 2. We construct a dynamic model for a galaxy without dark matter, which fits well with recent observational data, in terms of a variable effective inertial mass that reflects the present dynamic state of the universe and that replicates from first principles, the phenomenology proposed in MOND. The remarkable aspect of these results is the connection of the effect dubbed dark matter with the dark energy field, which makes it possible for us to interpret it as longitudinal gravitational waves.Comment: 18 pages, 4 figures. Final version: almost identical to the reference journal; Cent. Eur. J. Phys. 201

Comment On "experimental Proof Of Standard Electrodynamics By Measuring The Self-force On A Part Of A Current Loop"

We discuss the paper of Cavalleri et al. [Phys. Rev. E 58, 2505 (1998)] on the measurement of a force on part of a closed circuit carrying a constant current. ©2000 The American Physical Society.625 B7544Cavalleri, G., Bettoni, G., Tonni, E., Spavieri, G., (1998) Phys. Rev. E, 58, p. 2505Moyssides, P.G., (1989) IEEE Trans. Magn., 25, p. 4313Moyssides, P.G., (1989) IEEE Trans. Magn., 25, p. 4298Moyssides, P.G., (1989) IEEE Trans. Magn., 25, p. 4307Assis, A.K.T., Bueno, M.A., (1996) IEEE Trans. Magn., 32, p. 431Jolly, D.C., (1985) Phys. Lett., 107 A, p. 231Ternan, J.G., (1985) J. Appl. Phys., 57, p. 1743Ternan, J.G., (1985) J. Appl. Phys., 58, p. 3639Christodoulides, C., (1987) J. Phys. A, 20, p. 2037Christodoulides, C., (1988) Am. J. Phys., 56, p. 357Peoglos, V., (1988) J. Phys. D, 21, p. 1055Christodoulides, C., (1989) Phys. Lett. A, 141, p. 383Strnad, J., (1989) Eur. J. Phys., 10, p. 276Strnad, J., (1989) Phys. Lett. A, 137, p. 11Bueno, M., Assis, A.K.T., (1997) Phys. Scr., 56, p. 554Bueno, M., Assis, A.K.T., (1997) Can. J. Phys., 75, p. 357Bueno, M., Assis, A.K.T., (1998) Calcula de Indutância e de Força em Circuitos Elétricos, , Editora da UFSC/Editora da UEM, FlorianópolisDe Bueno, M.A., Assis, A.K.T., (1998) IEEE Trans. Magn., 34, p. 31