Physics Commons^™

Diffraction Of Spherical Scalar And Vector Waves At Axial Points Of A Circular Aperture And Disk, Keith Leon Mcdonald

Faculty Publications

The following work treats Kottler's saltus problem of diffraction of electromagnetic waves emitted by a Hertzian oscillator source and the analogous Kirchhoff's scalar problem of waves emitted by a point source. The medium is a homogeneous isotropic dielectric. In the vector case a new exact solution of the basic integrals is presented, at axial points only, (a) behind a circular aperture in a "black'' screen, and (b) behind its complementary "black'' disk. The relative time-averaged intensity of energy flow is plotted for the disk only. It is shown that the scalar theory predicts considerably larger values than the electromagnetic theory …

Using A Density Gradient Column To Determine Wheat Density, Wendell R. Peters, Robert Katz

Robert Katz Publications

A wheat kernel placed in a density gradient column will sink until it reaches the level where its average density is equal to that of the liquid at that level. Knowing the density of the liquid as a function of height, one can measure accurately the density of the kernel to three decimal places in about 1 to 2 minutes per kernel. Kernel density ranged from a maximum of 1.416 at 7.5% moisture to a minimum of 1.255 g./cm.³ at 18.5% moisture, for the samples tested. Kernels of a homogeneously selected sample of hard spring wheat (Lee) varied in …

The Magnetic Pole In The Formulation Of Electricity And Magnetism, Robert Katz

Robert Katz Publications

The use of the magnetic pole in the development of the concepts of electricity and magnetism leads unambiguously to a relativistic formulation of the field vectors which is well within the grasp of the sophomore student. The development is wholly consistent with Maxwell's equations and leads to clear and understandable definitions of the field vectors both in vacuum and in the material medium, as well as to the relations defining the transformations of the field vectors.

Glass-To-Sapphire End Window Seals, Edward E. Stepp, Richard A. Anderson

Physics Faculty Research & Creative Works

SAPPHIRE windows have been used in laboratory devices where radiation from the ultraviolet through the infrared must be transmitted. Sapphire windows have been valuable in chambers which contain the alkali metals, for the alkali metals are known to react with Pyrex 7740 glass and quartz leaving them pitted and darkened. This paper is a report on an improved glass-to-sapphire end window seal.

Transverse Mass And Gravitational Mass, Robert Katz

Robert Katz Publications

A problem suggested by Professor Gamow deals with the relationship between the transverse mass and the gravitational mass: A steamroller of mass m moves horizontally, in the +x direction, with velocity v, in a region of space in which there is a gravitational field intensity g vertically downward. Find the weight of the moving steamroller.

A Note On K-Commutative Matrices, D. W. Robinson

Faculty Publications

Let A and B be square matrices over a field in which the minimum polynomial of A is completely reducible. It is shown that A is k commutative with respect to B for some non-negative integer k if and only if B commutes with every principal idempotent of A. The proof is brief, simplifying much of the previous study of k-commutative matrices. The result is also used to generalize some well-known theorems on finite matrix commutators that involve a complex matrix and its transposed complex conjugate.

Hardness And Moisture Content Of Wheat Kernels, Robert Katz, N. D. Collins, A. B. Cardwell

Robert Katz Publications

The hardness of kernel sections of hard red winter and soft white winter wheat and durum wheat decreased with increasing moisture content. Small variations in hardness with variety and test plot location were detected.

A Movement West, Robert Katz

Robert Katz Publications

I did not discover that I had any interest in teaching or in academic life until late in my twenties, and then only through a sequence of unrelated circumstances.
I was born in 1917. My parents were Russian-Jewish immigrants who came to New York City at about the turn of the century.
At sixteen I enrolled in Brooklyn College, a recently organized, tuition-free, municipal college, then housed in rented office buildings in downtown Brooklyn. It took an hour to get to or from school on the subway. I managed to choose this inconvenient location because this school seemed most likely …

Yakir Aharonov Dissertation, Yakir Aharonov

Faculty Collections

Yakir Aharonov's Dissertation entitled "Some Problems in the Quantum Theory of Measurements."

Two Proposed Experiments For The Detection Of The Dirac Monopole, Robert Katz, Darrell R. Parnell

Robert Katz Publications

A magnetic monopole may be detected by its deflection in an electric field or by the character of the ionization it produces. The electric deflection experiment may be performed in a helium bubble chamber where helical (or spiral) tracks whose axes are parallel to the D-lines would be certain evidence for the discovery of the monopole. Previous studies of the ionization have emphasized that the Bragg tail would be missing from a monopole track, as compared to a charged particle. This conclusion must be modified because of the thin-down of tracks of heavy nuclei. The tracks of heavy nuclei …

A New Grain Hardness Tester, Robert Katz, A. B. Cardwell, N. D. Collins, A. D. Hostetter

Robert Katz Publications

A hardness tester, especially adapted for grain, was constructed by modifying a commercial portable soft metal tester known as the Barcol Impressor. A preloaded stylus is forced into grain sections prepared by means of a microtome. The displacement of the stylus, measured by a dial micrometer, is used as a hardness index. This has been related to the Vickers diamond pyramid hardness which is a standard metallurgical test. A number of hardness measurements may be made on a single transverse kernel section. The tester may be used for all wheat varieties. Significant variations in hardness within a single wheat kernel …

Effect Of Change In Moment Of Inertia On Line Intensities Of Parallel Vibration-Rotation Bands Of Symmetric Top Molecules, Gordon A. Gallup, J.L. Koenig

Gordon Gallup Publications

Effect of Change in Moment of Inertia on Line Intensities of Parallel Vibration-Rotation Bands of Symmetric Top Molecules

Ua3/3/1 Proposed National Science Foundation Summer Institute, Ward Sumpter, Wku President's Office

WKU Archives Records

Proposal for National Science Foundation summer institute to be held at WKU during the summer of 1959.

Structure Of Ch2, Gordon A. Gallup

Gordon Gallup Publications

Gray has criticized the calculation of the ground state multiplicity of the CH₂ fragment by the author. In answer, I would like to make two comments.
1. Regardless of the energies of ionization of a carbon atom, CH₂ may be considered as a system composed of two protons, a carbon kernel, and four electrons. The proper amount of configuration interaction should arise naturally and depend on relative energies of orbitals and overlap values. It appears that there is too much configuration interaction in the calculation in reference since the equilibrium angle arrived at is 160° instead of 140° …

5. Newton, Robert L. Bloom, Basil L. Crapster, Harold A. Dunkelberger, Charles H. Glatfelter, Richard T. Mara, Norman E. Richardson, W. Richard Schubart

Section VIII: The Development of Modern Science

Isaac Newton (1642-1727) was born and educated in England. He attended Trinity College, Cambridge, and there found the inspiration for his prodigious work that was to synthesize and extend the labors of Copernicus, Galileo, Kepler, and others beyond the wildest dreams of any of them. Newton was the intellectual giant who set the direction of the physical sciences on the paths they were to follow undeviatingly into the twentieth century. [excerpt]

Xx. Meaning In The Physical Sciences, Robert L. Bloom, Basil L. Crapster, Harold L. Dunkelberger, Charles H. Glatfelter, Richard T. Mara, Norman E. Richardson, W. Richard Schubart

Section XX: Meaning in the Physical Sciences

The twentieth century has seen two major revolutions in our theories of physics concerning nature, and these have made us change many of our concepts about the terms in which nature can be described. The new theories born in these revolutions are the theory of relativity and of quantum mechanics. The biological sciences had their revolutions in the nineteenth century, and while remarkable progress has been made since, nothing comparable to that upheaval has occurred in this century. Of the two massive changes in the concepts of the physical sciences, we can discuss but one here. [excerpt]

1. The Problem, Robert L. Bloom, Basil L. Crapster, Harold L. Dunkelberger, Charles H. Glatfelter, Richard T. Mara, Norman E. Richardson, W. Richard Schubart

Section XX: Meaning in the Physical Sciences

Newton's laws of motion and their associated definitions encountered their first difficulty near the middle of the nineteenth century.

Newton had designed his theory to describe the behavior of matter in space and time by inventing a relationship between the force on a body and the resulting change in motion of the body. Such a description of nature came to be called mechanical, and a large part of physicists' efforts were directed toward reducing all aspects of physics to mechanics. These efforts were rewarded magnificently in the fields of heat, electricity, and sound, in addition to astronomy and other more …

2. The Theory Of Special Relativity, Robert L. Bloom, Basil L. Crapster, Harold L. Dunkelberger, Charles H. Glatfelter, Richard T. Mara, Norman E. Richardson, W. Richard Schubart

Section XX: Meaning in the Physical Sciences

Albert Einstein (1879-1955) published his first work on relativity in 1905, the same year in which he published remarkable papers on Brownian motion and the photoelectric effect. At the time he did this work, he was a patent examiner in the Swiss Patent Office. He was awarded the Nobel Prize for physics in 1921 "for his services to the theory of physics, and especially for his discovery of the law of the photoelectric effect." He became a professor of physics at several German universities, and in 1916, he took a position at the Kaiser Wilhelm Institute in Berlin.

As the …

Physics, Contents, Henry Semat, Robert Katz

Robert Katz Publications

Table of contents

Physics, Chapter 1: Fundamental Quantities, Henry Semat, Robert Katz

Robert Katz Publications

Physics is a fundamental science dealing with matter and energy. By convention, the subject matter of physics has been divided into such topics as mechanics, heat, sound, light, and electricity. In addition to these general classifications, present-day physics includes atomic physics, nuclear physics, solid-state physics, chemical physics, biophysics, and many other subdivisions. It is impossible to include all aspects of physics in a single definition or paragraph, and to distinguish physics clearly from its nearest neighbors, the other physical sciences-astronomy., chemistry, and geology.

Physics, Chapter 7: Work And Energy, Henry Semat, Robert Katz

Robert Katz Publications

An extremely important concept that has been developed in physics is that of the work done on a body by the action of some external agent which exerts a force on this body and produces motion. For example, whenever someone lifts a body, he does work by exerting a force upward on it and moving it upward. Whenever a steam locomotive pulls a train, a series of processes takes place in the steam engine of the locomotive which enables it to exert a force on the train and move it in the direction of the force. The term work, as …

Physics, Chapter 5: Force And Motion, Henry Semat, Robert Katz

Robert Katz Publications

All of us have many times had the experience of setting a body in motion. If we analyze any of these experiences, we readily recall that in each case some force was required to start the object moving. In throwing a ball, moving a piece of furniture, or pulling a sled, the force needed to start the object moving is supplied by one's muscular effort as a push or a pull. In more complex cases, such as setting a car or an airplane in motion, the analysis, although more complicated, will also show that a force is required to start …

Physics, Chapter 6: Circular Motion And Gravitation, Henry Semat, Robert Katz

Robert Katz Publications

Our earlier discussion of the kinematics of a particle was developed principally from the point of view of being able to describe that motion easily within a rectangular coordinate system. Thus the most complex case with which we dealt was that of a projectile motion, in which the acceleration was constant and was directed along one of the coordinate axes. A more convenient framework within which to discuss rotational and circular motions is provided by a set of polar coordinates. In the present discussion we will restrict ourselves to motion in which the polar coordinate r is constant, or fixed; …

Physics, Chapter 8: Hydrostatics (Fluids At Rest), Henry Semat, Robert Katz

Robert Katz Publications

From our everyday experience, we have become familiar with the fact that matter occurs in three different forms-solid, liquid, and gas. Under ordinary conditions stone, iron, copper, and chalk, for example, are solids; water, oil, and mercury are liquids; air, hydrogen, and carbon dioxide are gases. Each one of these forms is called a phase. At times it is difficult to distinguish clearly between the solid and the liquid phases, as in a material such as tar which flows under the action of a force at ordinary temperatures. Metals at high temperatures flow or "creep" under the action of a …

Physics, Chapter 10: Momentum And Impulse, Henry Semat, Robert Katz

Robert Katz Publications

An extremely important concept in the development of mechanics is that of momentum. The momentum of a body is defined as the product of its mass by its velocity. We shall use the symbol p to denote the momentum of a body. The momentum of a body is a vector quantity, for it is the product of mass, a scalar, by velocity, a vector. While momentum and kinetic energy are compounded of the same two ingredients, mass and velocity, they are quite different concepts, and one aspect of their difference may be seen in the fact that momentum is …

Physics, Chapter 13: Properties Of Matter, Henry Semat, Robert Katz

Robert Katz Publications

When a system is subjected to external forces, it generally undergoes a change in size or shape or both. We have thus far touched very lightly on such changes; for example, we have considered the change in length of an elastic spring and the change in volume of a gas when such systems were subjected to varying pressures. The changes produced in a system by the action of external forces depend upon the physical properties of the material of which the system is composed. A study of the properties of matter leads to information which is of practical value to …

Physics, Chapter 14: Temperature, Henry Semat, Robert Katz

Robert Katz Publications

Temperature is one of the fundamental concepts of physics. We are all able to recognize that some bodies are hotter than others, but our temperature sense is qualitative rather than quantitative and is capable of only a limited range. The sense of touch can frequently be used to distinguish between hotter and colder objects, provided that these lie in a temperature range consistent with the stability of human tissue. Even within this range the sense of touch is often unreliable as a measure of temperature.

The metal bracket holding a wooden rail may feel much colder to the touch than …

Physics, Chapter 17: The Phases Of Matter, Henry Semat, Robert Katz

Robert Katz Publications

A substance which has a definite chemical composition can exist in one or more phases, such as the vapor phase, the liquid phase, or the solid phase. When two or more such phases are in equilibrium at any given temperature and pressure, there are always surfaces of separation between the two phases.

In the solid phase a pure substance generally exhibits a well-defined crystal structure in which the atoms or molecules of the substance are arranged in a repetitive lattice. Many substances are known to exist in several different solid phases at different conditions of temperature and pressure. These …

Physics, Chapter 18: Transfer Of Heat, Henry Semat, Robert Katz

Robert Katz Publications

The methods by which heat is transmitted can be classified into three distinct types known as convection, conduction, and radiation. In any actual case of heat transmission, a combination of these methods may be operating simultaneously, and the principal problem is to determine the rate at which heat flows from the source at higher temperature to the source at lower temperature.

We may distinguish between the three processes of heat transfer by considering whether a medium is required for the transfer of heat, and whether that medium is at rest or in motion. In the process of conduction, …

Physics, Chapter 19: Heat Engines, Henry Semat, Robert Katz

Robert Katz Publications

In this chapter we shall consider the physical principles underlying the operations of heat engines because of the intrinsic importance of these principles and because of the part they have played in the development of fundamental physical ideas. Heat engines are designed and built to convert heat into work. In most cases the heat is obtained from the combustion of a common fuel such as coal, oil, gasoline, or natural gas. An important new source of heat that is just beginning to be used, and will be used more extensively in the future, is the mass which is converted into …