- Email: [email protected]
The positively charged earth
RESEARCH
652
NOTES
REFERENCES 1. J. E. KUPPERIAN, E. T. BYRAM, T. A. CHUBB and H. FRIEDMAN, Ranet. Space Sci. 1, 3 (1959). 2. D. C. MORTON and J. D. PURCELL, Plmret.Space Sci. 9,455 (1962).
3. J. C. BRANDT, Space Research I/ (Eds. H. C. van de Hulst, C. de Jager, and A. F. Moore) p. 624. North Holland, Amsterdam (1961). 4. J. C. BRANDT, Astrophys. J. 134, 394 (1961). 5. J. C. BRANDT, Nuture, Lot&. 195, 834 (1962). 6. J. W. CHAMBERLAIN,Plunet. Space Sci. 11, 901 (1963). 7. T. N. L. PATTERSON,F. S. JOHNSONand W. B. HANSON, Planet. Space Sci. 11, 767 (1963). 8. W. I. AXFORD, A. J. DESSLERand B. GOTTLIEB, Astrophys. J. 137, 1268 (1963). 9. M. NEUGEBAUERand C. W. SNYDER, Science 138, 1095 (1962). 10. 3. C. BRAND-C, unpublished research. 11‘ M. B. MCELROY, private ~olnnlunication (1964). 12. C. S. GUM, Observatory 76, 150 (1956). 13. A. SCHL~~TER,Gns Dynamics of Cosmic Clouds, I.A.U. Symposium NO. 2, p. 144. Interscience, New York (1955). 14. L. G. HENYEY and J. L. GREENSTEIN,Astrophys. J. 93, 70 (1941). 15. G. MUNCH, Space Age Astronomy (Eds. A, J. Deutsch, and W. B. Klemperer) p. 213. Academic Press, New York (1962). 16. T. M. DONAKUE, communication to the Fourth International Space Science Symposium, COSPAR, Warsaw (1963). 17. W. B. HANSON and T. N. L. PATTERSON,Planet. Space Sci. 11, 1035 (1963). 18. M. F. INGHAM, Morr. Not. Roy. Astr. Sot. 124, 523 (1962).
Aanet. space Sci. 1964, Vol 12, pp. 652 to 656. PergamonPreSSLtd. Printedin NorthernIreland
THE
POSITIVELY
CHARGED
EARTH
(Received 7 Feb~r~ury 1964) For about two hundred years the concept that the Earth has a normal negative surface charge has been universally maintained. The situation as it seems to exist has been well presented by Gish’“, as well as by other writers in the field of atmospheric physics. However, for many years as the result of certain induction and Earth charge experiments, 1 have been convinced that the conclusion drawn from the famous Wilson@’ experiment is incorrect and that the true nature of the Earth’s normal surface charge is positive. In March of 1962, a primitive and unique instrumental device was designed and constructed, in an attempt to obtain conclusive evidence concerning the sign of the Earth’s normal fair weather surface charge. The method used is an adaptation of the famous Faraday ice-pail experiment. With this device the basic quantity which is measured is electric charge, either positive or negative. The procedure is direct in that no principle of electrostatic induction is involved. Basic prirreiple of design Figure 1 is a three dimensional front view illustrating schematically the Faraday ice-pail, or container, placed on the plate of an electroscope. A narrow slit, S, of dimensions 1 x 10 cm, permits a thin rotating mica sheet, M, dimensions approximately 9 x 9 cm, to partially enter the container of 13 cm dia. The four corners of the mica sheet are covered both top and bottom with copper foil. When the mica sheet is rotated about the point, P, the copper corner segments, 2.6 x 2.6 cm in area, make contact with a grounded copper foil, G. Thus they receive an Earth surface charge which is carried to and given up to the copper foil C, connected to the inside of the container. Since the copper corner sections are in effect completely surrounded by the Faraday container they give up their entire charges to the container. By repeating the process, individual Earth surface charges placed on the corner sections cause the total charge on the Faraday container to increase. Since the Faraday container is placed on the top of an electroscope, the accumulation of charges conveyed into the Faraday container causes the electroscope leaf to deflect. By standard methods the nature of the charge, positive or negative, can readily be determined. Field equipment and experimental procedure A vertical projection of the field equipment used in determining the nature of the Earth’s charge is also shown diagrammatically in working combination in Fig. 2. A box of dimensions 33 x 20 s 20cm, in which the electroscope and Faraday container are also entirely enclosed, is covered with metal foil. In the experimental procedure this foil and also the electroscope case are constantly kept grounded. A copper
RESEARCH NOTES
653
c
\
FIG. 1
FIG. 2
RESEARCH
654
NOTES
foil, G, is mounted in electrical contact with a metal grounded spike to which the box and electroscope case are also connected. The diagrammatical representation of the foil, G, extending to A to B and to ground is only to picture the insertion of a negative battery potential later described. S (Fig. 2) is a spindle, made of wood largely to avoid electric surfaces charges, on which the mica sheet is mounted and which can be rotated manually so that the number of contacts between the copper covered corner sections and the grounded foil, G, is of the order of one per second. This can be operated from a reclined position on the Earth’s surface at the back of the box with hand extended to the lower part of the spindle and also shielded with metal foil to minimize any effect of the body or clothing charge. C is a copper foil connected to the inside of the container, to which the charges are carried. The sensitivity of the electroscope was such that under average conditions a leaf deflection of from one to two centimetres could be obtained with roughly 40-100 contacts. Experimental results While hundreds of tests were made during a period of almost two years, only a few typical results are listed in the following table. The object of this experimental work was to determine the nature of the Earth’s normal fair weather surface charge and no attempts were made to determine the nature of the charge during thunder storms or under extreme weather conditions.
Number of contacts
Date
Location
23 Mar., 1962 26 Mar., 1962 18 April, 1962 5 June, 1962
Boulder, altitude 5300 ft Boulder Golf course, 3 miles east of Boulder Ground, football field Top of stadium seats Trail Ridge, altitude 11,150 ft Trail Ridge Boulder Boulder Golf course Boulder Boulder Boulder
29 June, 1962 9 July, 1962 8 Aug., 1962 7 Dec., 1962 14 Feb., 1963 25 Feb., 1963 28 April, 1963 30 June, 1963
Sign of charge
80 70 50 150 100 50 40 50 60 35 50 SO 70
+ + + + + + + + + + + + +
Design specifications and functional tests In the design of the equipment every known precaution was taken to avoid spurious effects and thus provide functional reliability. All contacts were made between similar metal parts so that any effect of contact potential would be minimized. Also the leading part of the copper corner sections were carefully folded over so that triboelectric effects (e.g. contact between metal and surface oxides) would also be minimized. To test for the presence of any appreciable electrolytic potential between ground and the copper con tact foil, G, a number of tests was made with a negative bias of from about -6 to -45 V introduced between the ground and foil and this still permitted the electroscope to receive a positive charge. That is, in Fig. 2 which shows the optional circuit, the negative terminal of the battery was connected to A and thus to the foil, G and the positive terminal was connected to B and to ground. Two tests typical of many results showing the reversal of sign of charge effect are recorded in the following table TABLE
Date and location 25 Feb. 1963 Boulder 8 Dec. 1963 Boulder golf course
Bias (V) -9 -68 -112 -6 -45 -112 -180
2
Number of contacts
Sign of charge
50 60 600 60 50 60 60 300 50
Positive charge Positive charge No charge Negative charge Good positive charge Good positive charge Fair positive charge No charge Good negative charge
RESEARCH
NOTES
655
As shown in the last results the reversal of sign took place on 8 Dec. 1963, about medium way between -45 and -180 V. This must indicate that the potential gradient was at the time somewhat over 100 V/m. The results establish the very important fact that no appreciable spurious effects are introduced in the experimental method. Another crucial experiment was performed in a shielded room and at different times repeated in a Faraday cage. The complete field equipment consisting of all parts as described was placed on an insulated metal screen. A second screen was placed above the first in order to produce a fairly uniform electric field between the two screens. With first the upper screen at a given negative potential with respect to the lower screen the number of contacts for a specified electroscope deflection was determined. In this case the accumulated charge on the electroscope was positive. The potential was then reversed to change the direction of the electric field and the number of contacts again determined. Within an experimental error of a few contacts the accumulated charge, in the first case positive and the second case negative, was the same for each of the two field directions. An additional test was performed in the shielded research room of the National Center for Atmospheric Research. With a 68 V battery placed in the circuit between A and B (Fig. 2), in one case with the negative terminal leading to the contact foil, G and the positive to ground and the box, and then with the potential reversed the number of contacts for a relative small deflection was 48, the same for each applied, within the accuracy with which the specified deflection could be measured. This experiment was repeated with slightly different Faraday cage conditions, with an automobile inside a grounded building, and similar results were obtained. An apparent warm weather or humidity effect must now be pointed out. During the winter and spring months a positive Earth charge could always be obtained. But during the hot days of July and August this was only intermittently possible and occasionally for days no indication of any charge could be detected. That this is the result of loss of charge due to high humidity is indicated by the fact that on 9 July 1962, at a mountain altitude of 11,150 feet, a strong positive charge was obtained with 40 contacts while less than two hours later on the Boulder plains at an altitude of 5280 feet, even with a large number of contacts no electroscope leaf deflection resulted. To test this in a more direct way, on the morning of 20 Oct. 1963, the equipment was inside the building during the night where the recorded humidity was 33 per cent. Then the number of contacts for a given leaf deflection, using a 112 V battery, was 46. Then a measurement was taken outside, under cover, when there was a fine drizzle indicating high humidity, and the number of contacts to produce the same deflection was 70. Such a test can of course not be very accurate since there must be a certain time required for the apparatus to adjust itself to different humidity conditions. The experimental
comjirmed
To confirm the previous results a slightly different form of apparatus, which involved the same basic principle was used. Instead of the rotating mica sheet with its copper corner sections, a thin copper plate, 6 cm in diameter, was supported by a wooden arm, which was hinged to the metal box containing the electroscope and Faraday container. This plate was carried to and fro to make contact with the grounded foil, G, (Fig. 2), and after receiving an earth charge it was made to enter the same Faraday container and by making contact with the inner foil to release its charge. To avoid any effect of body capacitance and clothing surface charge of the operator during the procedure, a string was attached to operate the device by remote control. Some recent results are listed in the following table. TABLE
3 Dec. 4 Dec. 8 Dec. 8 Dec. 11 Dec. 13 Jan. 13 Jan. 14 Jan. 15 Jan. 16 Jan. 17 Jan.
1963 1963 1963 1963 1963 1964 1964 1964 1964 1964 1964
Boulder Boulder Boulder, Boulder Boulder, Boulder Boulder, Boulder Boulder Boulder Boulder
3
golf course strong wind from mountains golf course 4 in. of snow midnight, zero degrees
golf course
50 contacts 70 50 50 50 50 30 30 30 30 50
Good Good Large Large Large Good Good Good Good Good Good
positive* positive* positive positive positive positive* positive* positive* positive* oositive* iositive*
* A leaf deflection of 30 degrees or more was obtained. A final crucial test
The earlier tests taken over a long period of time may have given the reader acceptable evidence that the Earth’s normal surface charge is positive. However a final crucial test was made which may outweigh the results of the previous tests in its significance.
RESEARCH
656
NOTES
This is simple in its basic nature and can be easily described. At the Boulder golf course there is an iron stake which was extended to a height of 10 ft. At the top of the stake was placed copper foil which by means of electric leads was permanently grounded. Beside the stake is an irrigation ditch about 2 ft deep and 2.5 ft wide. The electroscope with its top Faraday container was placed at the bottom of the ditch with the case of the electroscope grounded. The moveable copper plate described in Section 5 was mounted in a position in front of the Faraday container, so it could be operated from beneath the Earth’s normal surface by remote control. Above the complete apparatus were screens at ground level which were Earth grounded. This presented a situation whereby the equipment was in effect within a grounded Faraday cage. In the operation of the experiment, a copper cylinder 55 in. in length and of 3.5 in. dia. was attached to the end of a wooden pole. This cylinder had appreciable capacitance and with this, contact was made to the copper foil on top of the grounded stake where the Earth charge was fairly great. The copper cylinder was then brought down and from below ground level was made to contact the moveable copper plate within the Faraday cage. In turn by remote control operation, the copper plate was made to enter the Faraday container to give up its charge. By many tests with normal fair weather conditions, only 15-20 contacts were necessary to give the electroscope a good positive charge. In the manipulation of this experiment an Earth charge was brought to a point within the Earth itself. That the nature of this charge when suitably detected was shown to be positive must be accepted as the supreme test. Conclusion
The experiment described is direct and independent of electrostatic induction effects. It gives conclusive evidence that the normal fair weather Earth surface charge is positive. The new positive Earth surface charge concept is in good agreement with the fact that cosmic rays bring predominately positively charged particles to the Earth and lower atmosphere. This constitutes the primary source of the positive Earth and atmospheric charge. A quasi equilibrium status is reached, when the rate of income of cosmic ray positive particles equals the rate at which they are released from the upper fringe regions of the atmosphere. There is thus a combined Earth and lower atmosphere positive charge to provide an electric field in effect radially outward from the Earth’s surface. This new concept offers a new approach to the explanation of atmospheric electrical effects. conclusion I wish to thank my son, W. J. Pietenpol, of the International Business Machines Corporation, for constant encouragement and advice. I also acknowledge the kindness of D. E. Billings, of the Univ. of Colorado Department of Astrophysics, and R. H. Bushnell and J. D. Sartor, of the National Center for Atmospheric Research, for making suggestions and confirming results. Acknowledgemenr-In
Boulder,
W. B. PIETENPOL
Colorado REFERENCES
1. 0. H. GISH, Compendium
of Meteorology, p. 101. American chusetts (1951). 2. C. T. R. WILSON,Proc. Camb. Phil. Sot. 13, 363 (1906).
Meteorological
Society, Boston,
Massa-
Planet. Space Sci. 1964, Vol. 12, pp. 656to 657.Pergamon Press Ltd. Printed in Northern Ireland
THE
ABSORPTION
OF HYDROGEN BY MOLECULAR (Received
LYMAN GAMMA NITROGEN*
11 February
RADIATION
1964)
Photon absorption cross sections obtained theoretically and from laboratory measurements have been used in conjunction with rocket and satellite determinations of the intensity of the Sun’s radiation, to estimate the composition of the Earth’s upper atmosphere. For example, Danilovm has presented evidence for supposing that molecular nitrogen predominates at altitudes above 200 km and is present in considerable quantity to a height of about 400 km. This evidence is partially based upon interpretation of data, obtained by Purcell (2’, for the attenuation due to absorption by molecular nitrogen of the solar hydrogen Lyman gamma line at 972.537 A. The absorption cross section of molecular nitrogen at this wavelength has been * The experimental work was carried out under the auspices of the U.S. Air Force Cambridge Research Laboratories and the analysis was sponsored at the University of Southern California by the U.S. Office of Naval Research.
652
NOTES
REFERENCES 1. J. E. KUPPERIAN, E. T. BYRAM, T. A. CHUBB and H. FRIEDMAN, Ranet. Space Sci. 1, 3 (1959). 2. D. C. MORTON and J. D. PURCELL, Plmret.Space Sci. 9,455 (1962).
3. J. C. BRANDT, Space Research I/ (Eds. H. C. van de Hulst, C. de Jager, and A. F. Moore) p. 624. North Holland, Amsterdam (1961). 4. J. C. BRANDT, Astrophys. J. 134, 394 (1961). 5. J. C. BRANDT, Nuture, Lot&. 195, 834 (1962). 6. J. W. CHAMBERLAIN,Plunet. Space Sci. 11, 901 (1963). 7. T. N. L. PATTERSON,F. S. JOHNSONand W. B. HANSON, Planet. Space Sci. 11, 767 (1963). 8. W. I. AXFORD, A. J. DESSLERand B. GOTTLIEB, Astrophys. J. 137, 1268 (1963). 9. M. NEUGEBAUERand C. W. SNYDER, Science 138, 1095 (1962). 10. 3. C. BRAND-C, unpublished research. 11‘ M. B. MCELROY, private ~olnnlunication (1964). 12. C. S. GUM, Observatory 76, 150 (1956). 13. A. SCHL~~TER,Gns Dynamics of Cosmic Clouds, I.A.U. Symposium NO. 2, p. 144. Interscience, New York (1955). 14. L. G. HENYEY and J. L. GREENSTEIN,Astrophys. J. 93, 70 (1941). 15. G. MUNCH, Space Age Astronomy (Eds. A, J. Deutsch, and W. B. Klemperer) p. 213. Academic Press, New York (1962). 16. T. M. DONAKUE, communication to the Fourth International Space Science Symposium, COSPAR, Warsaw (1963). 17. W. B. HANSON and T. N. L. PATTERSON,Planet. Space Sci. 11, 1035 (1963). 18. M. F. INGHAM, Morr. Not. Roy. Astr. Sot. 124, 523 (1962).
Aanet. space Sci. 1964, Vol 12, pp. 652 to 656. PergamonPreSSLtd. Printedin NorthernIreland
THE
POSITIVELY
CHARGED
EARTH
(Received 7 Feb~r~ury 1964) For about two hundred years the concept that the Earth has a normal negative surface charge has been universally maintained. The situation as it seems to exist has been well presented by Gish’“, as well as by other writers in the field of atmospheric physics. However, for many years as the result of certain induction and Earth charge experiments, 1 have been convinced that the conclusion drawn from the famous Wilson@’ experiment is incorrect and that the true nature of the Earth’s normal surface charge is positive. In March of 1962, a primitive and unique instrumental device was designed and constructed, in an attempt to obtain conclusive evidence concerning the sign of the Earth’s normal fair weather surface charge. The method used is an adaptation of the famous Faraday ice-pail experiment. With this device the basic quantity which is measured is electric charge, either positive or negative. The procedure is direct in that no principle of electrostatic induction is involved. Basic prirreiple of design Figure 1 is a three dimensional front view illustrating schematically the Faraday ice-pail, or container, placed on the plate of an electroscope. A narrow slit, S, of dimensions 1 x 10 cm, permits a thin rotating mica sheet, M, dimensions approximately 9 x 9 cm, to partially enter the container of 13 cm dia. The four corners of the mica sheet are covered both top and bottom with copper foil. When the mica sheet is rotated about the point, P, the copper corner segments, 2.6 x 2.6 cm in area, make contact with a grounded copper foil, G. Thus they receive an Earth surface charge which is carried to and given up to the copper foil C, connected to the inside of the container. Since the copper corner sections are in effect completely surrounded by the Faraday container they give up their entire charges to the container. By repeating the process, individual Earth surface charges placed on the corner sections cause the total charge on the Faraday container to increase. Since the Faraday container is placed on the top of an electroscope, the accumulation of charges conveyed into the Faraday container causes the electroscope leaf to deflect. By standard methods the nature of the charge, positive or negative, can readily be determined. Field equipment and experimental procedure A vertical projection of the field equipment used in determining the nature of the Earth’s charge is also shown diagrammatically in working combination in Fig. 2. A box of dimensions 33 x 20 s 20cm, in which the electroscope and Faraday container are also entirely enclosed, is covered with metal foil. In the experimental procedure this foil and also the electroscope case are constantly kept grounded. A copper
RESEARCH NOTES
653
c
\
FIG. 1
FIG. 2
RESEARCH
654
NOTES
foil, G, is mounted in electrical contact with a metal grounded spike to which the box and electroscope case are also connected. The diagrammatical representation of the foil, G, extending to A to B and to ground is only to picture the insertion of a negative battery potential later described. S (Fig. 2) is a spindle, made of wood largely to avoid electric surfaces charges, on which the mica sheet is mounted and which can be rotated manually so that the number of contacts between the copper covered corner sections and the grounded foil, G, is of the order of one per second. This can be operated from a reclined position on the Earth’s surface at the back of the box with hand extended to the lower part of the spindle and also shielded with metal foil to minimize any effect of the body or clothing charge. C is a copper foil connected to the inside of the container, to which the charges are carried. The sensitivity of the electroscope was such that under average conditions a leaf deflection of from one to two centimetres could be obtained with roughly 40-100 contacts. Experimental results While hundreds of tests were made during a period of almost two years, only a few typical results are listed in the following table. The object of this experimental work was to determine the nature of the Earth’s normal fair weather surface charge and no attempts were made to determine the nature of the charge during thunder storms or under extreme weather conditions.
Number of contacts
Date
Location
23 Mar., 1962 26 Mar., 1962 18 April, 1962 5 June, 1962
Boulder, altitude 5300 ft Boulder Golf course, 3 miles east of Boulder Ground, football field Top of stadium seats Trail Ridge, altitude 11,150 ft Trail Ridge Boulder Boulder Golf course Boulder Boulder Boulder
29 June, 1962 9 July, 1962 8 Aug., 1962 7 Dec., 1962 14 Feb., 1963 25 Feb., 1963 28 April, 1963 30 June, 1963
Sign of charge
80 70 50 150 100 50 40 50 60 35 50 SO 70
+ + + + + + + + + + + + +
Design specifications and functional tests In the design of the equipment every known precaution was taken to avoid spurious effects and thus provide functional reliability. All contacts were made between similar metal parts so that any effect of contact potential would be minimized. Also the leading part of the copper corner sections were carefully folded over so that triboelectric effects (e.g. contact between metal and surface oxides) would also be minimized. To test for the presence of any appreciable electrolytic potential between ground and the copper con tact foil, G, a number of tests was made with a negative bias of from about -6 to -45 V introduced between the ground and foil and this still permitted the electroscope to receive a positive charge. That is, in Fig. 2 which shows the optional circuit, the negative terminal of the battery was connected to A and thus to the foil, G and the positive terminal was connected to B and to ground. Two tests typical of many results showing the reversal of sign of charge effect are recorded in the following table TABLE
Date and location 25 Feb. 1963 Boulder 8 Dec. 1963 Boulder golf course
Bias (V) -9 -68 -112 -6 -45 -112 -180
2
Number of contacts
Sign of charge
50 60 600 60 50 60 60 300 50
Positive charge Positive charge No charge Negative charge Good positive charge Good positive charge Fair positive charge No charge Good negative charge
RESEARCH
NOTES
655
As shown in the last results the reversal of sign took place on 8 Dec. 1963, about medium way between -45 and -180 V. This must indicate that the potential gradient was at the time somewhat over 100 V/m. The results establish the very important fact that no appreciable spurious effects are introduced in the experimental method. Another crucial experiment was performed in a shielded room and at different times repeated in a Faraday cage. The complete field equipment consisting of all parts as described was placed on an insulated metal screen. A second screen was placed above the first in order to produce a fairly uniform electric field between the two screens. With first the upper screen at a given negative potential with respect to the lower screen the number of contacts for a specified electroscope deflection was determined. In this case the accumulated charge on the electroscope was positive. The potential was then reversed to change the direction of the electric field and the number of contacts again determined. Within an experimental error of a few contacts the accumulated charge, in the first case positive and the second case negative, was the same for each of the two field directions. An additional test was performed in the shielded research room of the National Center for Atmospheric Research. With a 68 V battery placed in the circuit between A and B (Fig. 2), in one case with the negative terminal leading to the contact foil, G and the positive to ground and the box, and then with the potential reversed the number of contacts for a relative small deflection was 48, the same for each applied, within the accuracy with which the specified deflection could be measured. This experiment was repeated with slightly different Faraday cage conditions, with an automobile inside a grounded building, and similar results were obtained. An apparent warm weather or humidity effect must now be pointed out. During the winter and spring months a positive Earth charge could always be obtained. But during the hot days of July and August this was only intermittently possible and occasionally for days no indication of any charge could be detected. That this is the result of loss of charge due to high humidity is indicated by the fact that on 9 July 1962, at a mountain altitude of 11,150 feet, a strong positive charge was obtained with 40 contacts while less than two hours later on the Boulder plains at an altitude of 5280 feet, even with a large number of contacts no electroscope leaf deflection resulted. To test this in a more direct way, on the morning of 20 Oct. 1963, the equipment was inside the building during the night where the recorded humidity was 33 per cent. Then the number of contacts for a given leaf deflection, using a 112 V battery, was 46. Then a measurement was taken outside, under cover, when there was a fine drizzle indicating high humidity, and the number of contacts to produce the same deflection was 70. Such a test can of course not be very accurate since there must be a certain time required for the apparatus to adjust itself to different humidity conditions. The experimental
comjirmed
To confirm the previous results a slightly different form of apparatus, which involved the same basic principle was used. Instead of the rotating mica sheet with its copper corner sections, a thin copper plate, 6 cm in diameter, was supported by a wooden arm, which was hinged to the metal box containing the electroscope and Faraday container. This plate was carried to and fro to make contact with the grounded foil, G, (Fig. 2), and after receiving an earth charge it was made to enter the same Faraday container and by making contact with the inner foil to release its charge. To avoid any effect of body capacitance and clothing surface charge of the operator during the procedure, a string was attached to operate the device by remote control. Some recent results are listed in the following table. TABLE
3 Dec. 4 Dec. 8 Dec. 8 Dec. 11 Dec. 13 Jan. 13 Jan. 14 Jan. 15 Jan. 16 Jan. 17 Jan.
1963 1963 1963 1963 1963 1964 1964 1964 1964 1964 1964
Boulder Boulder Boulder, Boulder Boulder, Boulder Boulder, Boulder Boulder Boulder Boulder
3
golf course strong wind from mountains golf course 4 in. of snow midnight, zero degrees
golf course
50 contacts 70 50 50 50 50 30 30 30 30 50
Good Good Large Large Large Good Good Good Good Good Good
positive* positive* positive positive positive positive* positive* positive* positive* oositive* iositive*
* A leaf deflection of 30 degrees or more was obtained. A final crucial test
The earlier tests taken over a long period of time may have given the reader acceptable evidence that the Earth’s normal surface charge is positive. However a final crucial test was made which may outweigh the results of the previous tests in its significance.
RESEARCH
656
NOTES
This is simple in its basic nature and can be easily described. At the Boulder golf course there is an iron stake which was extended to a height of 10 ft. At the top of the stake was placed copper foil which by means of electric leads was permanently grounded. Beside the stake is an irrigation ditch about 2 ft deep and 2.5 ft wide. The electroscope with its top Faraday container was placed at the bottom of the ditch with the case of the electroscope grounded. The moveable copper plate described in Section 5 was mounted in a position in front of the Faraday container, so it could be operated from beneath the Earth’s normal surface by remote control. Above the complete apparatus were screens at ground level which were Earth grounded. This presented a situation whereby the equipment was in effect within a grounded Faraday cage. In the operation of the experiment, a copper cylinder 55 in. in length and of 3.5 in. dia. was attached to the end of a wooden pole. This cylinder had appreciable capacitance and with this, contact was made to the copper foil on top of the grounded stake where the Earth charge was fairly great. The copper cylinder was then brought down and from below ground level was made to contact the moveable copper plate within the Faraday cage. In turn by remote control operation, the copper plate was made to enter the Faraday container to give up its charge. By many tests with normal fair weather conditions, only 15-20 contacts were necessary to give the electroscope a good positive charge. In the manipulation of this experiment an Earth charge was brought to a point within the Earth itself. That the nature of this charge when suitably detected was shown to be positive must be accepted as the supreme test. Conclusion
The experiment described is direct and independent of electrostatic induction effects. It gives conclusive evidence that the normal fair weather Earth surface charge is positive. The new positive Earth surface charge concept is in good agreement with the fact that cosmic rays bring predominately positively charged particles to the Earth and lower atmosphere. This constitutes the primary source of the positive Earth and atmospheric charge. A quasi equilibrium status is reached, when the rate of income of cosmic ray positive particles equals the rate at which they are released from the upper fringe regions of the atmosphere. There is thus a combined Earth and lower atmosphere positive charge to provide an electric field in effect radially outward from the Earth’s surface. This new concept offers a new approach to the explanation of atmospheric electrical effects. conclusion I wish to thank my son, W. J. Pietenpol, of the International Business Machines Corporation, for constant encouragement and advice. I also acknowledge the kindness of D. E. Billings, of the Univ. of Colorado Department of Astrophysics, and R. H. Bushnell and J. D. Sartor, of the National Center for Atmospheric Research, for making suggestions and confirming results. Acknowledgemenr-In
Boulder,
W. B. PIETENPOL
Colorado REFERENCES
1. 0. H. GISH, Compendium
of Meteorology, p. 101. American chusetts (1951). 2. C. T. R. WILSON,Proc. Camb. Phil. Sot. 13, 363 (1906).
Meteorological
Society, Boston,
Massa-
Planet. Space Sci. 1964, Vol. 12, pp. 656to 657.Pergamon Press Ltd. Printed in Northern Ireland
THE
ABSORPTION
OF HYDROGEN BY MOLECULAR (Received
LYMAN GAMMA NITROGEN*
11 February
RADIATION
1964)
Photon absorption cross sections obtained theoretically and from laboratory measurements have been used in conjunction with rocket and satellite determinations of the intensity of the Sun’s radiation, to estimate the composition of the Earth’s upper atmosphere. For example, Danilovm has presented evidence for supposing that molecular nitrogen predominates at altitudes above 200 km and is present in considerable quantity to a height of about 400 km. This evidence is partially based upon interpretation of data, obtained by Purcell (2’, for the attenuation due to absorption by molecular nitrogen of the solar hydrogen Lyman gamma line at 972.537 A. The absorption cross section of molecular nitrogen at this wavelength has been * The experimental work was carried out under the auspices of the U.S. Air Force Cambridge Research Laboratories and the analysis was sponsored at the University of Southern California by the U.S. Office of Naval Research.