摘要:

The gedanken experiment of Elitzur and Vaidman showing wave‐particle duality was realized as a demonstration at a scientific exposition. Presence or absence of a mirror in one arm of an interferometer was measured while detecting one photon at a time. A reasonable fraction of events was ‘‘interaction‐free,’’ which means that the conclusion that there was a mirror in the beam could be drawn from the signal of a photon that had not interacted with the mirror. The demonstration was found to be thought‐provoking.

ISSN:0002-9505    

DOI:10.1119/1.18413

出版商:American Association of Physics Teachers    

年代:1996

数据来源: AIP

摘要:

Pedagogic niceties in the treatment of unconventional thermodynamic cycles, especially those involving (negatively sloping) diagonal linear transitions in aP/Vstate diagram and/or those implying supposedly superefficient heat‐engine operation, are discussed as a means of stimulating student interest and comprehension, as well as promoting fresh insights, correcting erroneous notions, and provoking further enquiry. In particular, a novel (ostensibly all‐adiabatic) engine usingtwoidealgasesof mutually differing atomicities as working substance is analyzed qualitatively and quantitatively. Emphasis is placed on the crucial role of thesecondlaw of thermodynamics in a determination of heat‐engine operation.

ISSN:0002-9505    

DOI:10.1119/1.18414

出版商:American Association of Physics Teachers    

年代:1996

数据来源: AIP

摘要:

The calculation of the primordial hydrogen and helium abundances in the big‐bang cosmology is presented in an oversimplified model accessible to university physics students who have had no physics beyond an elementary modern physics course.

ISSN:0002-9505    

DOI:10.1119/1.18415

出版商:American Association of Physics Teachers    

年代:1996

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.18403

出版商:American Association of Physics Teachers    

年代:1996

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.18416

出版商:American Association of Physics Teachers    

年代:1996

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.18417

出版商:American Association of Physics Teachers    

年代:1996

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.18479

出版商:American Association of Physics Teachers    

年代:1996

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.18182

出版商:American Association of Physics Teachers    

年代:1996

数据来源: AIP