None of the fundamental experiments on which the restricted principle of relativity is based requires for their explanation that the classical concept of absolute time be modified; the present experiment was devised to test directly whether time satisfies the requirements of relativity. It depends on the fact that if a pencil of homogeneous light is split into two components which are made to interfere after traversing paths of different length, their relative phases will depend on the translational velocity of the optical system unless the Lorentz-Einstein transformation equations are valid. Hence, such a system at a point on the earth should give rise to an interference pattern which varies periodically as the velocity of the point changes in consequence of the rotation and revolution of the earth. The effect to be expected for a small velocity is so very small that it has been necessary to devise a special source of light, an interferometer of great stability and a refinement of the technic of measuring displacements in the interference pattern. With the apparatus finally employed, we have shown that there is no effect corresponding to absolute time unless the velocity of the solar system in space is no more than about half that of the earth in its orbit. Using this null result and that of the Michelson-Morley experiment we derive the Lorentz-Einstein transformations, which are tantamount to the relativity principle.
A nepheloid layer has been observed by optical means in the lower part of the water column on the continental slope and rise. By sampling it has been found to be a suspension of lutite, apparently in sufficient quantity to induce downslope flow. Sediment transported in the nepheloid layer may be a major component of deep-sea sediment bodies.
Between 1965 and 1969, fifty-one profiles of light scattering were made in the central Arctic Ocean from Fletcher's Ice Island (T-3). The profiles, taken with an in situ photographic nephelometer extend from just below the surface to the bottom. Two distinctly different types of profiles were observed. At all stations the strongest scattering occurs near the surface, decreasing with depth in the upper layers. Over the Canada abyssal plain, light scattering is almost constant below 2000 meters, decreasing slightly with depth all the way to the bottom so that the bottom water is the clearest. Over the ridges and rises surrounding the Canada basin, however, scattering increases with depth below an intermediate scattering minimum. The zone of deep light scattering on the ridges and rises is called the bottom nepheloid layer. The bottom nepheloid layer is evidently caused by fine material that is maintained in suspension by the turbulent flow. Four spot measurements of bottom currents on the Mendeleyev ridge gave speeds of 4 to 6 cm/sec. One spot measurement over the Canada abyssal plain gave a speed of less than 1 cm/sec. This indication of swifter current speeds over the ridges is supported by bottom photographs in which animal tracks are much less evident on the ridges than on the Canada abyssal plain in spite of a greater abundance of life on the ridges. This is attributed to the higher current speeds, which obliterate the tracks. The observations suggest a counterclockwise deep circulation in the Canada basin with the currents confined primarily to the sloping margins of the basin. This pattern of deep circulation is in agreement with ideas and experiments on deep circulation with a concentrated source and distributed surface sink. Deep water enters the basin over a sill and leaves by upward diffusion through the halocline into the surface water, which then flows out of the basin.
Baited traps and a camera lowered through the Ross Ice Shelf, Antarctica, at a point 475 kilometers from the open Ross Sea and to 597 meters below sea level revealed the presence of fish, many amphipods, and one isopod. Biological or current markings were not evident on a soft bottom littered with subangular lumps. A fish was caught through a crevasse 80 kilometers from the shelf edge.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.