Study of the anisotropy of cosmic rays from the measurement of the daily variation of meson intensity has demonstrated that there are significant day-today changes in the anisotropy of the radiation. New experimental data pertaining to these changes and their solar and terrestrial relationships are discussed.

An interpretation of these changes of anisotropy in terms of the modulation of cosmic rays by streams of matter emitted by the sun is given. In particular, an explanation for the existence of the recently discovered types of daily variations exhibiting day and night maxima respectively, can be found by an extension of some ideas of Alfvén, Nagashima, and Davies. An integrated attempt is made to interpret the known features of the variation of cosmic ray intensity in conformity with ideas developed above.

The daily variation of cosmic ray intensity can arise partly from atmospheric and partly from non-atmospheric effects. There is at present a difference of opinion whether this latter effect is completely due to extra terrestrial causes or not.

The purpose of the present paper is to suggest a method by which the atmospheric effects could be separated from the other variations without any assumptions about the mechanism of the atmospheric influence.

Some recent measurements of the solar daily variation for cosmic rays incident from the east and west directions at 45° to the vertical in London are described. The results do not agree with those to be expected if the variation was due to a non-isotropic flux of primary particles entering the earth's magnetic field. This result is discussed in relation to other evidence and it is concluded that the daily variation is probably due to a modulation of the primary cosmic ray intensity in the earth's magnetic field.

The increase of cosmic radiation on 23 February 1956 by solar radiation exhibited in the first minutes a high peak at European stations that were lying in direct impact zones for particles coming from a narrow angle near the sun, whilst other stations received no radiation for a further time of 10 minutes and more. An hour later all stations in intermediate and high latitudes recorded solar radiation in a distribution as would be expected if this radiation fell into the geomagnetic field in a fairly isotropic distribution. The intensity of the solar component decreased at this time at all stations according to the same hyperbolic law (~t–2).

It is shown, that this decreasing law, as well as the increase of the impact zones on the earth, can be understood as the consequence of an interstellar magnetic field in which the particles were running and bent after their ejection from the sun.

Considering the bending in the earth's magnetic field, one can estimate the direction of this field from the times of the very beginning of the increase in Japan and at high latitudes. The lines of magnetic force come to the earth from a point with astronomical co-ordinates near 12·00, 30° N. This implies that within the low accuracy they have the direction of the galactic spiral arm in which we live. The field strength comes out to be about 0·7 × 10–6 gauss. There is a close agreement with the field, that Fermi and Chandrasekhar have derived from Hiltner's measurements of the polarization of starlight and the strength of which they had estimated to the same order of magnitude.

To construct a model for producing the observed variation in the cosmic ray intensity we consider primarily the Forbush decrease and the general decrease of the cosmic ray intensity during years of solar activity. These are larger variations than the diurnal and 27-day variations and require more drastic assumptions; thus they will better serve to establish a unique model.

It is assumed that the sun does not emit cosmic ray particles except during the time of a solar flare. Thus, decreases in the cosmic ray intensity are to be interpreted as a solar effect which inhibits the arrival of galactic cosmic ray particles at earth. Since the intensity of low rigidity primary cosmic ray particles is observed to vary more than the intensity at higher rigidities, the inhibition has generally been assumed to be caused by magnetic fields.

The necessary depression of the cosmic ray intensity requires both a barrier, to impede their arrival, and a removal mechanism within the barrier, to prevent eventual statistical equilibrium (with uniform particle density). Quantitative development indicates that a heliocentric magnetic dipole, a heliocentric cavity in the galactic field (Davis, Phys. Rev.100, 1440, 1955), and a heliocentric interplanetary cloud barrier (Morrison, Phys. Rev.101, 1397, 1956) all encounter serious difficulties in explaining the observed effects, one reason being the ineffective removal that is available.

It is shown that a geocentric magnetic cloud barrier does not encounter these difficulties: it is proposed that during the years of solar activity the terrestrial gravitational field captures magnetic gas of solar origin from interplanetary space, which is then supported by the geomagnetic field; the removal by absorption by the earth is sufficiently effective that only a relatively thin barrier need be maintained; the occasional capture of new magnetic material accounts for the abrupt onset of the Forbush decreases, and the slow decay (0·5 years) of the captured fields for the smooth variation of the mean cosmic ray intensity with the sunspot cycle.

It has been demonstrated that if a particle is accelerated in an electromagnetic field between two points designated by subscripts (1) and (2), the particle will gain energy in passing from (1) to (2) provided that the quantity J defined by is positive, where ds is an element of path, Us1 and Us2 are the initial and final values of the vector potential along the path, and t is the time. Moreover, if the particle is at rest at the point (1), its energy W2 at the point (2) is such that here e is the charge on the particle.

A point source of cosmic rays at δ = 0°, α = 5h 30m, was reported at the Mexico Meeting of IUPAP in September 1955 (Nature, Lond.177, 35, 1956). The existence of the point source was verified by further observation. This phenomenon suggests the possibility of a direct method of exploring interplanetary space.

A tube has been developed in which the shapes of streams of charged particles moving in the earth's magnetic field can be produced accurately to scale. The tube has been named the Störmertron in honor of Carl Störmer who calculated many such orbits. New developments which have made this tube possible include a method for coating the inside of large glass tubes with a transparent electrically conducting film, and an electron gun producing gas-focused streams in less than ½ micron of mercury vapor, a nearly vapor-free grease joint, and a nearly vapor-free carbon black. The magnetic dipole field of the earth is simulated with an Alnico magnet capped with properly shaped soft iron caps. The stream is deflected using two pairs of yoke coils near the gun.

Eine notwendige Voraussetzung für die Entstehung von thermonuklearen Reaktionen ist eine hohe Temperatur des Stoffes. Die ersten Spuren vom Entstehen solcher Reaktionen können wir bei der Erwärmung des Stoffes (Deuterium oder einer Mischung von Deuterium und Tritium) bis zu T ~ 106 zu entdecken hoffen. Aber nur bei T ~ 108 können die thermonuklearen Reaktionen als eine neue Energiequelle ein Interesse erwecken.

Die Gasentladung im Deuterium bei Stromstärken bis zu 700 tausend Ampere im magnetischen Längsfelde bis zu 12000 Oersted wurde untersucht. Die Einwirkung des Feldes auf den Verlauf der Entladung wurde festgestellt und eine Zunahme des Magnetfeldes im Innern der Entladungssäule entdeckt. Eine Bewertung der Plasmaleitfähigkeit und der Ionisierungszahl wird gegeben.

In der Arbeit[1] wurde die Stabilität eines Zylinders aus vollständig ionisiertem Plasma untersucht, dessen Druck durch die magnetischen Kräfte des längs des Zylinders fliessenden Stromes im Gleichgewicht gehalten wird. Störungen wurden untersucht, bei welchen der Zylinder eine schraubenförmige Gestaltung erhält. Gegenüber diesen Störungen zeigte sich das Gleichgewicht labil. In der vorliegenden Arbeit, gerade wie in[1], wird mit Hilfe der Methode von kleinen Schwingungen und unter der Annahme einer idealen Leitfähigkeit die Stabilität gegenüber beliebigen Störungen in Anwesenheit einer magnetischen Feldkomponente, die längs des Zylinders gerichtet ist (‘Längsfeld’), untersucht. Kriterien der Stabilität werden festgestellt.

The expression ∫∫∫all space ΔH2dv for a change in magnetic energy is shown to be incorrect when applied to a body carrying an electric current and situated in an external magnetic field. A modified expression is derived.

Chandrasekhar's form of the virial theorem in a magnetic field is extended to the case where an external magnetic field is present.

A system of spectral equations of magnetic turbulence in gases differing from that given by Chandrasekhar is suggested. The solution of this system is examined. Correlation and structure functions of the turbulence of interstellar gases, determined according to the data on radial velocities of interstellar clouds from Adams's catalogue, are given. For motions of a scale less than the fundamental one (l less than 80 pc) the spectral function F(k) is about k–1·71, which agrees with the theoretical conclusions.

Recently Nagasawa determined a method of calculation of the electric conductivity in a lowly ionized gas, which leads to more precise results than the formula given by Alfvén. The numerical calculation, however, is much more complicated for the Nagasawa method. This paper simplifies the calculation giving a relation, by means of which the Alfvén values of Nagasawa are obtained in a rather simple way.

As is known, a striking peculiarity of the radio galaxy NGC 4486 is the presence of a small and very bright ‘jet’ in its central part. As it seems to us, the key to the understanding of the nature of the radio galaxy NGC 4486 is the purely continuous spectrum of the above jet, where not even a slightest trace or emission or absorption lines is present.

Extensive progress of radio astronomical methods of investigation during recent years has totally changed our ideas about the nature of the enevelopes ejected during the outburst of super-novae and, consequently, also about the phenomenon of the outburst of the super-nova[1]. The only envelope of a super-nova, investigated in sufficient details by means of optical astronomy, is the Crab nebula (see W. Baade[2], Minkowski[3], Greenstein and Minkowski[4], Barbier[5]. All available explanations concerning the nature of the Crab nebula are based upon these investigations. They were also applied in general to envelopes of other super-novae. Considering the Crab nebula as a typical super-nova remnant let us shortly discuss these statements.

Recent work has suggested very strongly that most non-thermal radio sources emit by the synchrotron mechanism—the radiation of relativistic electrons and positrons in magnetic fields. In this paper a summary of calculations of the total energy in particles and magnetic field in a number of radio sources has been given. Magnetic fields estimated in this way for the Crab, Cassiopeia A, our Galaxy, M 87, NGC 5128, NGC 1316 and Cygnus A are tabulated.

Some effects are examined—the probability of penetration of a part of the flow of particles from the sun to the earth's atmosphere, as a consequence of the compression of the plasma—and formation of an electrical current along the motion of the plasma.

Apparently, the main results of observations cannot be explained by these effects. But the latter may probably cause some secondary phenomena which could perhaps be discovered by means of special observations.