Word: parallaxes
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...distance from the sun is 4.3 light years -about 25 trillion miles. In 1915 Dr. Robert T. A. Innes of Johannesburg discovered, by parallax observations,* that a faint star near Alpha Centauri was only 4.16 light-years away. For 23 years, up to last week, that star, appropriately called Proxima Centauri, held rank as the No. 1 solar neighbor. Last week, from the University of Chicago's Yerkes Observatory in Wisconsin, it was announced that another faint star, Wolf 424† appears to be only 3.7 light-years distant. This is so close that a train traveling a thousand...
...Agriculture in connection with soil conservation work. In a vertical aerial photograph the earth's surface looks perfectly flat. Third dimensional relief can be obtained by the principle employed in the oldtime stereoscope. Pictures of the same area are shot from two slightly different positions, thus providing a parallax in the same way that a person's two eyes do in normal sight. The two pictures are then inserted in a super-glorified stereoscope (built with Zeiss for $50,000). So accurate are the controls, so precise the instruments, that with the aid of another optical illusion...
...Presiding over the congress was a U. S. astronomer, square, heavy-jowled Director Frank Schlesinger of Yale Observatory, whose fame is associated with parallax. Earth's annual orbit around the Sun is 186,000,000 miles across; therefore the direction of stars as observed from Earth on opposite sides of that orbit changes slightly. This change is called parallax. Even the nearer stars are so far off that their parallax is extremely small, and for remote stars it is not discernible at all. Nevertheless since the amount of apparent displacement depends on how far away the star is, parallax...
...Ives has worked out the problems of another method, which requires no special glasses or effort for the observer. He calls it "parallax panoramagram." An object is photographed from many points of view through a grating. The grating deflects and breaks up the image on the negative. The positive print is a blur unless viewed through a grating the duplicate of the camera's. Still pictures made and scanned this way are brilliantly realistic...
...picture. Projection lenses must be of "extraordinary defining power." The films must run through the projectors with microscopic precision. Finally, if all the mechanical requirements are accomplished, there remains one more obstacle. No photographic chemicals are yet known which will register pictures as swiftly as Dr. Ives's parallax panoramagram method requires...