摘要:

Stillman Drake has argued that Galileo believed that inertial motion is rectilinear motion, and that certain of Galileo's references to uniform circular motion were part of a strategy against the Aristotelian geocentrists. Drake's arguments are examined and are found to be unconvincing.

ISSN:0002-9505    

DOI:10.1119/1.1973014

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

Visible light from a helium-neon laser was directed onto a white-card surface capable of rotation, and the granularity characteristics of the scattered light were observed. Photographs are given showing the degree of granularity observed under various rotational speeds. It is indicated that the visible granularity, due to the extremely high degree of coherence of the laser light, disappears from view as a consequence of persistence of vision when the light is scattered by a moving surface. Additional observations relating to the phenomenon of granularity are also presented and discussed.

ISSN:0002-9505    

DOI:10.1119/1.1973015

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

The solution of a particular elementary boundary value problem is presented. A new set of orthogonal functions is needed. Their properties are discussed briefly. A comment is made about the number of independent solutions of arthorder equation in anndimensional space. The number isrnand notr·n.

ISSN:0002-9505    

DOI:10.1119/1.1973016

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

Although there is widespread recognition that near-field (Fresnel) diffraction can occur with laser light, this fact seems not to have led to previous systematic study of near-field diffraction at simple apertures. Near-field diffraction at circular apertures is studied in detail. The number of Fresnel zones present in the diffraction pattern is given byn = ca2/λX, whereais the radius of the circle,λis the wavelength,Xis the distance from the aperture, andcis a numerical factor which is unity for collimated light, less than unity convergent light, and greater than unity for divergent light. The near-field beam for collimated light diverges noticeably only forλX/a2 > 0.25and reaches the far-field divergence forλX/a2 > 0.7. Several practical applications of near-field diffraction are suggested.

ISSN:0002-9505    

DOI:10.1119/1.1973017

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

摘要:

An electromagnetic wave incident on the common surface between two isotropic dielectrics must satisfy Maxwell's boundary conditions at the surface. The existence of these boundary conditions results in a reflected wave and a transmitted wave into the second medium. The ratio of the amplitudes of the electric vectors of the reflected and transmitted waves to that of the incident wave is given by Fresnel's equations. In order to derive these equations from the boundary conditions one generally takes two separate idealized cases. For the first case the electric vector of the incident wave is taken to be perpendicular to the plane of incidence and for the second case the incident vector is considered to lie in the plane of incidence. The general case when the electric vector makes an arbitrary angle with the plane of incidence is then treated by resolving the incident vector into parallel and normal components.

ISSN:0002-9505    

DOI:10.1119/1.1973018

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1973019

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1973021

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1973023

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1973024

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1973027

出版商:American Association of Physics Teachers    

年代:1966

数据来源: AIP