- Email: [email protected]
Some problems of cosmical physics, solved and unsolved
434
[J. r;. I.
Up to the present time the highest and lowest values for ozone content recorded are 420 and 172. “The correlation coefficients between the amount of ozone and upper air conditions are among the highest found in meteorology. The correlation with surface pressure is high, but those with the pressure at heights of 9.14 km. are much higher and very high values are found for temperature in the troposphere and for the height of the base of the stratosphere; these are all negative while that for the temperature at 14 km. (in the stratosphere) is positive.” Since ozone is a minimum in the tropics and a maximum in polar regions it seems that sunlight does not change oxygen into ozone, or at best is not solely responsible for the change. The origin of ozone may lie in the aurora and high ozone values occur at times of magnetic disturbance. G. F. S.
Some Problems of Cosmical Physics, Solved and Unsolved. L,ORD RAYLEIGH. (Science, July 26, 1929.) This is the address of the president of Section A, Mathematical and Physical Sciences, of the British Association for the Advancement of Science, at its meeting in Gape Town, July 24, 1929. A review is given of some subjects belonging both to astronomy and to physics. After the first success in identifying the spectral lines of the sun and stars with those produced by terrestrial elements it was seen that there remained certain lines that could be produced in no known way by materials on the earth. The spectral autograph of helium was recognized in the sun about a generation before the gas itself was discovered on the earth. To go further from our planet there are lines in the spectra of nebuke that have never been discovered on the earth, and they are not faint members of complex spectra but “stand out, bold and challenging, on a dark background, presenting a puzzle that was the more intriguing from its apparent simplicity.” Through the work of Hartley, of I. S. Bowen in the United States and of A. Fowler it is now certain that one pair of the nebular lines come from doubly ionized oxygen and that other nebular lines have their origin in singly ionized oxygen and nitrogen. For a long time a main problem was the explanation of the green line in the aurora, first seen by Angstrom in 1868. Nothing else “For some can be seen in any but bright auroras except this line. years I took every available opportunity of looking at this spectrum, and never did so without a deep sense of mystery. The origin of the line was not in this case in the depths of space, but in our own atmosphere at the distance of a short railway journey from the observer. Yet an apparently exhaustive study of the spectra to be obtained
from terrestrial gases by the combined efforts of very many experiAt last McLennan in Toronto menters gave no clue to its origin.” got the line by sending heavy electric charges through mixtures of oxygen and helium or oxygen and argon. The green aurora1 line is without doubt due to the arc spectrum of oxygen but by no means In the sky it appears alone or all is clear about its production. with negative nitrogen lines, whereas in the laboratory it is accomRed panied by other oxygen lines and by lines of argon or helium. auroras are rare but still they do occur and the red line that domiThe strong lines in the nates their spectra awaits explanation. spectrum of the sun’s corona present another unsolved problem. Polar auroras are connected with magnetic disturbances and these have to do with the sun. The theory of Birkeland, extended by Stormer, is held to emit “localized streams of electrically charged This theory presents particles from limited areas of its surface.” advantages in accounting for the occurrence of the aurora but artificial hypotheses have been attached to it. Recently it furnished Hals in the only conceivable explanation of a newly found fact. Holland sent out wireless signals 131 meters in length and after Keeping in mind that the speed 13 sets. received echoes of them. of such signals is ~OO,OOO km. per sec. one sees that the surface reflecting the signals must be farther from the earth than the moon is. The reflector is identified by Stiirmer with the stream of corpuscles from the sun bent around by the earth’s magnetic field. G. F. S. This is a daring conjecture indeed. Stable Solutions of Sodium Thiosulphate. H. W. JONES (Chemist Analyst. 1929, 18, No. 6, p. 5) recommends the addition of 2 grams of chemically pure stick sodium hydroxide to each liter of standard solution of sodium thiosulphate as a stabilizing agent. J. S. H. Occurrence of the Pellagra-Preventive Vitamin in Canned JOSEPH GOLDBERGER AND G. A. WHEELER (Public Health Reports, 1929, 4, 2769-2771) find that canned salmon contains the pellagra-preventive factor or vitamin P-P, and may be used as a fair substitute for meat in the diet in regions where pellagra is endemic and meat is not readily available. J. S. H.
Salmon.
The Ratio of the Electromagnetic to the Electrostatic Unit of Electricity as Compared to the Velocity of Light. H. L. CURTIS. (Bureau of Standards J. of Research, July, 1929.) No determination of the ratio of the electromagnetic to the electrostatic unit of
[J. r;. I.
Up to the present time the highest and lowest values for ozone content recorded are 420 and 172. “The correlation coefficients between the amount of ozone and upper air conditions are among the highest found in meteorology. The correlation with surface pressure is high, but those with the pressure at heights of 9.14 km. are much higher and very high values are found for temperature in the troposphere and for the height of the base of the stratosphere; these are all negative while that for the temperature at 14 km. (in the stratosphere) is positive.” Since ozone is a minimum in the tropics and a maximum in polar regions it seems that sunlight does not change oxygen into ozone, or at best is not solely responsible for the change. The origin of ozone may lie in the aurora and high ozone values occur at times of magnetic disturbance. G. F. S.
Some Problems of Cosmical Physics, Solved and Unsolved. L,ORD RAYLEIGH. (Science, July 26, 1929.) This is the address of the president of Section A, Mathematical and Physical Sciences, of the British Association for the Advancement of Science, at its meeting in Gape Town, July 24, 1929. A review is given of some subjects belonging both to astronomy and to physics. After the first success in identifying the spectral lines of the sun and stars with those produced by terrestrial elements it was seen that there remained certain lines that could be produced in no known way by materials on the earth. The spectral autograph of helium was recognized in the sun about a generation before the gas itself was discovered on the earth. To go further from our planet there are lines in the spectra of nebuke that have never been discovered on the earth, and they are not faint members of complex spectra but “stand out, bold and challenging, on a dark background, presenting a puzzle that was the more intriguing from its apparent simplicity.” Through the work of Hartley, of I. S. Bowen in the United States and of A. Fowler it is now certain that one pair of the nebular lines come from doubly ionized oxygen and that other nebular lines have their origin in singly ionized oxygen and nitrogen. For a long time a main problem was the explanation of the green line in the aurora, first seen by Angstrom in 1868. Nothing else “For some can be seen in any but bright auroras except this line. years I took every available opportunity of looking at this spectrum, and never did so without a deep sense of mystery. The origin of the line was not in this case in the depths of space, but in our own atmosphere at the distance of a short railway journey from the observer. Yet an apparently exhaustive study of the spectra to be obtained
from terrestrial gases by the combined efforts of very many experiAt last McLennan in Toronto menters gave no clue to its origin.” got the line by sending heavy electric charges through mixtures of oxygen and helium or oxygen and argon. The green aurora1 line is without doubt due to the arc spectrum of oxygen but by no means In the sky it appears alone or all is clear about its production. with negative nitrogen lines, whereas in the laboratory it is accomRed panied by other oxygen lines and by lines of argon or helium. auroras are rare but still they do occur and the red line that domiThe strong lines in the nates their spectra awaits explanation. spectrum of the sun’s corona present another unsolved problem. Polar auroras are connected with magnetic disturbances and these have to do with the sun. The theory of Birkeland, extended by Stormer, is held to emit “localized streams of electrically charged This theory presents particles from limited areas of its surface.” advantages in accounting for the occurrence of the aurora but artificial hypotheses have been attached to it. Recently it furnished Hals in the only conceivable explanation of a newly found fact. Holland sent out wireless signals 131 meters in length and after Keeping in mind that the speed 13 sets. received echoes of them. of such signals is ~OO,OOO km. per sec. one sees that the surface reflecting the signals must be farther from the earth than the moon is. The reflector is identified by Stiirmer with the stream of corpuscles from the sun bent around by the earth’s magnetic field. G. F. S. This is a daring conjecture indeed. Stable Solutions of Sodium Thiosulphate. H. W. JONES (Chemist Analyst. 1929, 18, No. 6, p. 5) recommends the addition of 2 grams of chemically pure stick sodium hydroxide to each liter of standard solution of sodium thiosulphate as a stabilizing agent. J. S. H. Occurrence of the Pellagra-Preventive Vitamin in Canned JOSEPH GOLDBERGER AND G. A. WHEELER (Public Health Reports, 1929, 4, 2769-2771) find that canned salmon contains the pellagra-preventive factor or vitamin P-P, and may be used as a fair substitute for meat in the diet in regions where pellagra is endemic and meat is not readily available. J. S. H.
Salmon.
The Ratio of the Electromagnetic to the Electrostatic Unit of Electricity as Compared to the Velocity of Light. H. L. CURTIS. (Bureau of Standards J. of Research, July, 1929.) No determination of the ratio of the electromagnetic to the electrostatic unit of