摘要:

A new expression is found for the perturbation energy, with the principle feature that it is in remainder form. The remainder is first applied or manipulated to obtain the familiar infinite series of perturbation theory. Secondly, an iterative procedure for solving the Schrödinger equation is proposed. It is shown, by making use of the remainder, that this procedure leads to results equivalent, in the small perturbation limit, to the results of perturbation theory.

ISSN:0002-9505    

DOI:10.1119/1.1972264

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

The principle of relativity applied to purely length-time considerations is shown to lead rigorously to either the Lorentz or the Galilean transformations, but to no other. No reference is made to properties of light or of mass. The derivation itself leads to the appearance of an invariant and ultimate speedkas a constant of integration.

ISSN:0002-9505    

DOI:10.1119/1.1972268

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

The relativistic equation of motion with a resistance force of Newtonian type cannot be simply given byFr = m0dvr/dτ+λvr. It is shown that the relativistic form corresponding to the classical equation of motion with a resistance force proportional to thenth power of the velocity is given byFr = m0dvr/dτ+λ(zvr − ur)[(zvs − us)(zvs − us)](n−1)/2, whereur, is the four-velocity of the fluid andz = −vsu3/c2. This equation may be considered as “physical,” because it can be reduced to particular exact (i.e., relativistic) equations describing real motions. Other mathematically correct (i.e., relativistically covariant) equations which reduce, for low velocities, to the same classical expression, cannot.

ISSN:0002-9505    

DOI:10.1119/1.1972271

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

The art of masers and lasers is founded on Einstein's discovery of stimulated emission. This discovery led to a search for methods for establishing population inversion in a suitable material and hence to the construction of a radiation amplifier. In 1954 Townes and his students constructed the first microwave amplifier and oscillator based on the stimulated emission principle. Three-level solid masers followed quickly and speculations began on extending the art into the optical region. The first ruby laser was built in 1960 by Maiman. It was quickly followed by the four-level lasers of Sorokin and Stevenson and the He-Ne laser of Javan. Large scale search for additional laser materials and more effective laser techniques began in 1961. This fascinating and frantic effort is still in progress. Its highlights are briefly described.

ISSN:0002-9505    

DOI:10.1119/1.1972275

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

In conventional thermodynamics, the two most important consequences of the second law of thermodynamics, namely, the existence of an absolute temperature scale and the existence of an entropy function are deduced from the Kelvin-Planck statement or its equivalent, the Clausius statement, with the aid of the Carnot engine and Carnot refrigerator. In the Caratheodory method, a new statement of the second law is made; the Carnot cycle is dispensed with and purely analytical methods are used to derive the absolute temperature and the entropy. It is shown in this paper how the analytic methods of Caratheodory may be used without replacing the traditional statements of the second law by a new axiom. Both the Caratheodory statement of the second law and the Caratheodory theorem on Pfaffian differential forms are unnecessary.

ISSN:0002-9505    

DOI:10.1119/1.1972279

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

It is shown that the net mechanical impulse one must exert to change one static system of currents and charges slowly into another such system is independent of the method used, and is given by the change inΣqiAT(xi,t), whereAT(xi,t)is the transverse vector potential, evaluated at the positionxiof the chargeqi. The linear momentum stored in a quasistatic electromagnetic field is thus given byΣqiAT(xi,t). These considerations show that it is possible to give the transverse vector potentialATof a static system a physical meaning. Namely, thatAT(x)is the net mechanical impulse one must exert to bring a unit point charge slowly from infinity to the pointx.

ISSN:0002-9505    

DOI:10.1119/1.1972282

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

A natural science course for nonscience majors used the digital computer in teaching classical mechanics. The advantages of using the computer in physics courses for both science and non-science majors are discussed.

ISSN:0002-9505    

DOI:10.1119/1.1972286

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

The vector method for obtaining the Lorentz transformations of special relativity is shown to have several apparent variants. Investigation of these reveals that equivalence prevails whether or not the exact form of related operators is preserved. A simple scheme for analyzing the defining dyadic, vector, and scalar functionals forms the basis of the present study.

ISSN:0002-9505    

DOI:10.1119/1.1972291

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

The kinematics of processes involving four different particles is discussed. The boundaries of the physical region for the various processes are established one at a time, using explicitly energy and momentum conservation. Then follows a joint description of all processes where all four-momenta formally are considered to be ingoing. The description is given explicitly in terms of two independent variables (s,t), in contrast to the usual symmetric (s,t,u) description.

ISSN:0002-9505    

DOI:10.1119/1.1972297

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

Spinors have in recent years become an important mathematical tool in special and general relativity. After a general review of the status of physical laws, it is shown why spinors are the “basic building bricks” of any Lorentz invariant law. The properties of spinors are briefly discussed and it is shown why it sometimes pays to translate a tensor problem into spinor language, solve it therein, and finally translate back.

ISSN:0002-9505    

DOI:10.1119/1.1972301

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP