Some Factors Affecting Achievement in Physics in a Survey Course in the Physical Sciences

A study was made of the gains in physics achieved by different groups. Those who presented high school credit in physics for college entrance made a greater average gain than those who did not, but a smaller percentage of gain. Those whose intelligence rating was in the upper fifty percentile made a greater gain than those in the lower fifty percentile, but a smaller percentage of gain

Two Experiments for First Year Students of Physics

In the first of these the acceleration due to gravity is measured by timing by means of an electrically driven tuning fork the descent of a small metal ball. The start and finish of the fall are recorded electrically on a rotating drum on which the fork is also making a trace. In the second experiment the average velocity of air molecules is measured by finding the volume per second of the gas emerging from a region of higher pressure (usually atmospheric) into one of low pressure, through a small orifice of measured diameter

The Single Precipitation of Calcium Oxalate in the Presence of Magnesium

It has been known for a long time that when calcium is precipitated as the oxalate in the presence of magnesium some magnesium is likely to be found in the precipitate. Therefore, it is customary to perform a double precipitation whenever the content of magnesium amounts to more than a few milligrams. With a view toward eliminating the time-consuming second precipitation whenever possible, it is the purpose of the present work to determine to what extent reliable results may be obtained for calcium using merely a single precipitation

Joseph Henry

Have you ever asked your pupils the question, what American has contributed most to the development of electrical science? Very likely a great majority would answer without hesitation, Edison, the inventor of the incandescent light. Some might answer, Bell, the inventor of the telephone. A few, the radio fans, might say De Forest, the inventor of the three electrode tube. An occasional one might even answer Franklin, the first great American scientist, who drew electricity from the clouds, and showed that lightning and the electric fluid are the same. Not one, I am sure, would ever mention Joseph Henry

Motivation in Physics

In recent years there has been a decided trend in high schools the country over toward general science, and away from the particular sciences, physics, chemistry, biology, etc. The proponents of general science seem convinced that this is due to a better choice of subject matter in their field, and to better methods of presentation. However this may be, it will certainly be well for those of us who have to do with the teaching of the special sciences to subject our own work to critical examination. We should aim to discover our faults of whatever kind, and eliminate them

A Great American Scientist

Dr. Albert A. Michelson, 78, discoverer of the speed of light, and one of the greatest scientists of modern times, died here at 3 :10 p.m. Saturday. Death came quietly to the man whose work made it possible to know the distance of the stars. It came on the eve of success of what he called his \u27last experiment,\u27 the most precise and extensive in physics-the exact determination of the speed of light. So ran the opening paragraphs of a long and appreciative front page article in the Des Moines Sunday Register of May 10, 1931. And in a similar strain the press of the entire country told of the passing of this modest man of science, one of the greatest of modern times

Permanent Achievements of Science

A very delightful man whom I once knew often said that he was deeply grateful to science for all its invaluable gifts to humanity, but that he would have more confidence in scientists if only they would change their minds less frequently. His indictment of science for its instability was a long one, and took a wide range

The New State Course of Study in Physics

The new state course of study in general science was reviewed by Dr. Lantz in the April number of the Science Bulletin. The state course in physics, also just recently published by the State Department of Public Instruction, is likewise an important contribution to science teaching

Science Changes Its Mind

In an interesting book bearing the title Architects of Ideas Trattner tells us that in every age previous to our own there was supposed to exist a body of knowledge final and infallible. Frequently people thought of this knowledge as having been revealed directly from heaven. Embodied in rigid tradition and held sacred by all authorities, it was considered heresy to question any time-honored belief. The great development in human culture that Mees has called the Helix of History began somewhere in the eastern hemisphere five or six millennia ago. For many centuries advancement was slow. Succeeding turns of the helix fell very close together. It was not until relatively very recent times that Kepler, Galileo, da Vinci, Vesalius and other kindred spirits succeeded in liberating the mind of man from the bondage of tradition, and in starting the advance that has placed Science in the honored position among human activities and achievements that it occupies today

Something from Nothing

Matter made while you wait-hydrogen, helium, oxygen, iron or what will you have? No, it has not quite come to this! But the time-honored law of conservation which states that matter is neither destructible nor creatable is no longer accepted as unquestionably and universally true