Powerpoint
... This is on page 2 of your OSE sheet. Do not use until later! (Unless you really know what you are doing.) ...
... This is on page 2 of your OSE sheet. Do not use until later! (Unless you really know what you are doing.) ...
TAP 409-3: Uniform electric fields
... In an experiment to measure the charge on an oil drop, the potential difference between two parallel metal plates 5 mm apart was 300 V. a) Calculate the electric field strength between the plates. ...
... In an experiment to measure the charge on an oil drop, the potential difference between two parallel metal plates 5 mm apart was 300 V. a) Calculate the electric field strength between the plates. ...
1 D.2. Energetic quantities: kinetic energy, work, total energy Force
... Try to demonstrate the same relation for n bodies. Faceti va rog demonstartia asta Remark. In (D9) W12 is the work on the path from the point (1) to the point (2). In 2D or 3D this work depends in general on the actual pathway. In the particular case when work does not depend on the actual path, on ...
... Try to demonstrate the same relation for n bodies. Faceti va rog demonstartia asta Remark. In (D9) W12 is the work on the path from the point (1) to the point (2). In 2D or 3D this work depends in general on the actual pathway. In the particular case when work does not depend on the actual path, on ...
A spherical capacitor has two different layers of
... A spherical capacitor has two different layers of dielectrics between its plates. Their permittivities are ϵ1 for a < r < r0 and ϵ2 for r0 < r < b. Find the capacitance of this system by finding the total energy of the fields between the plates. Let the charge on the innermost plate is Q. The field ...
... A spherical capacitor has two different layers of dielectrics between its plates. Their permittivities are ϵ1 for a < r < r0 and ϵ2 for r0 < r < b. Find the capacitance of this system by finding the total energy of the fields between the plates. Let the charge on the innermost plate is Q. The field ...
icnfp_2015_v5
... classical body in weak gravitational field is well known from school textbooks: ...
... classical body in weak gravitational field is well known from school textbooks: ...
Quantum-electrodynamical approach to the Casimir force
... Here our aim is to show that in the special case of zero temperature the right result is obtained without the detour through the extensive temperature Green’s function formalism [5]. In doing so, we evaluate Maxwell’s stress tensor by means of specific quantum-electro-dynamical cavity modes which to ...
... Here our aim is to show that in the special case of zero temperature the right result is obtained without the detour through the extensive temperature Green’s function formalism [5]. In doing so, we evaluate Maxwell’s stress tensor by means of specific quantum-electro-dynamical cavity modes which to ...
A Simply Regularized Derivation of the Casimir Force
... regularization. In the dimensional regularization method, although there isn’t an explicit subtraction for the regularization of the problem, as is clear from its name, the calculation is regularized dimensionally by going to a complex plane with a mathematically complicated/ambiguous approach. In t ...
... regularization. In the dimensional regularization method, although there isn’t an explicit subtraction for the regularization of the problem, as is clear from its name, the calculation is regularized dimensionally by going to a complex plane with a mathematically complicated/ambiguous approach. In t ...
Casimir effect
In quantum field theory, the Casimir effect and the Casimir–Polder force are physical forces arising from a quantized field. They are named after the Dutch physicist Hendrik Casimir.The typical example is of two uncharged metallic plates in a vacuum, placed a few nanometers apart. In a classical description, the lack of an external field means that there is no field between the plates, and no force would be measured between them. When this field is instead studied using the QED vacuum of quantum electrodynamics, it is seen that the plates do affect the virtual photons which constitute the field, and generate a net force—either an attraction or a repulsion depending on the specific arrangement of the two plates. Although the Casimir effect can be expressed in terms of virtual particles interacting with the objects, it is best described and more easily calculated in terms of the zero-point energy of a quantized field in the intervening space between the objects. This force has been measured and is a striking example of an effect captured formally by second quantization. However, the treatment of boundary conditions in these calculations has led to some controversy.In fact, ""Casimir's original goal was to compute the van der Waals force between polarizable molecules"" of the metallic plates. Thus it can be interpreted without any reference to the zero-point energy (vacuum energy) of quantum fields.Dutch physicists Hendrik B. G. Casimir and Dirk Polder at Philips Research Labs proposed the existence of a force between two polarizable atoms and between such an atom and a conducting plate in 1947, and, after a conversation with Niels Bohr who suggested it had something to do with zero-point energy, Casimir alone formulated the theory predicting a force between neutral conducting plates in 1948; the former is called the Casimir–Polder force while the latter is the Casimir effect in the narrow sense. Predictions of the force were later extended to finite-conductivity metals and dielectrics by Lifshitz and his students, and recent calculations have considered more general geometries. It was not until 1997, however, that a direct experiment, by S. Lamoreaux, described above, quantitatively measured the force (to within 15% of the value predicted by the theory), although previous work [e.g. van Blockland and Overbeek (1978)] had observed the force qualitatively, and indirect validation of the predicted Casimir energy had been made by measuring the thickness of liquid helium films by Sabisky and Anderson in 1972. Subsequent experiments approach an accuracy of a few percent.Because the strength of the force falls off rapidly with distance, it is measurable only when the distance between the objects is extremely small. On a submicron scale, this force becomes so strong that it becomes the dominant force between uncharged conductors. In fact, at separations of 10 nm—about 100 times the typical size of an atom—the Casimir effect produces the equivalent of about 1 atmosphere of pressure (the precise value depending on surface geometry and other factors).In modern theoretical physics, the Casimir effect plays an important role in the chiral bag model of the nucleon; in applied physics, it is significant in some aspects of emerging microtechnologies and nanotechnologies.Any medium supporting oscillations has an analogue of the Casimir effect. For example, beads on a string as well as plates submerged in noisy water or gas illustrate the Casimir force.