July, 1913. 



KNOWLEDGE. 



243 



case of a body situated near the centre of a hollow 

 sphere, the inner side of whose shell is aglow with 

 light. Consider a particle distant d from the body, 

 where d is infinitesimal compared to the radius of the 

 illumined sphere. Now the diminution of light 

 occasioned by the body as seen from the particle 



is obviously proportional to -p. Now consider a 



similar system in the ether I have postulated. Let 

 the body be A and the particle p. Then the 

 diminution of pressure along Ap occasioned by the 

 interception of waves by the dark bod)- is pro- 

 portional to -75 . But since the waves come in every 



direction and in all/our dimensions, the diminution 

 is also proportional to the length, breadth, thickness, 

 and " fourness " of the body A. Therefore, the 

 pressure along Ap (taking sense into account) is 



(k-^M) 



But the pressure on p from the other side in the 

 opposite direction pA is equal to K. 



Accordingly the particle is being pressed towards 

 the body A with a force equal to 



-("-*) 



XM 

 7' 



when X is a constant. 



a force directly proportional to the mass and 

 inversely proportional to the square of the distance. 

 It is perfectly plain from the foregoing that the 

 ether might be possessed of great density, since it 

 bears the waves which cause gravitation itself, and 

 therefore obviously cannot gravitate. 



This theory also accounts for the instantaneity of 

 gravitation. The most refined observations have 

 failed to disclose any lapse of time between cause 

 and effect where gravitation is concerned, and this 

 would be wholly inconceivable were gravitation an 

 inherent property of matter. 



THE NEW ASTRONOMY. 



MEETING OF THE PHYSICAL SOCIETY. 



Except for the time spent on a paper on wireless detectors, 

 the whole meeting of the Physical Society on Friday, 

 May 30th, was occupied by a lecture by Professor Bickerton 

 and a discussion on his theory of the origin of new stars. 

 The lecturer began by showing that so many agencies tended 

 to bring about stellar impact that these events must be scores 

 of thousands of times more frequent than mere chance 

 encounters would suggest. In fact, the impact of suns must be 

 an important cosmic law. He then showed that all collisions 

 of suns brought about by gravitation must be oblique ; that 

 is, of a grazing character. Some fifty years ago Dr. Johnstone 

 Stoney had deduced this fact. It was accepted by Lord 

 Kelvin, Sir Robert Ball, and Arrhenius. These eminent men 

 had traced out in some detail the results that they thought 

 would ensue. Owing to an oversight their work was valueless. 

 They did not detect the fact that in solar grazes the shearing 

 force available was millions of times greater than that neces- 

 sary to cut the most tenacious of nickel steel, and that 

 consequently grazing suns tear one another and the parts 

 actually meeting coalesce to form a third star of such extreme 

 thermodynamic intensity as to be explosively hot. Hence the 

 problem of the encounter of suns must be taken in two parts : 

 the new third star and the torn bodies of the suns. 



Professor Bickerton then showed that the problems of all 

 cosmic encounters must be divided, whether the collisions be 

 between dense bodies such as suns or rare such as nebulae, 

 meteoric swarms, or interpenetrating sidereal systems. In 

 each case a central furnace, an explosively hot third body, 

 must be formed. It was then shown that in any explanation 

 of novae three most extraordinary criteria had to be satisfied. 

 These were the thermodynamic intensity, the complex light- 

 curve, and the long series of abnormal spectrograms. Every 

 one of the current hypotheses failed in at least two, and most 

 of them failed utterly in all three, criteria. 



The induction that every nova is a third star torn from 

 grazing suns satisfies all three criteria in the utmost minutia 

 of detail. By the process of exhaustion this theory was the 

 only explanation left. The shearing force available might be 

 based on a velocity of two hundred and fifty miles a second, a 

 velocity five hundred times that of a Krupp shell ; that is, an 

 energy of unit mass or kinetol a quarter of a million times 

 that of our swiftest projectiles. The surface to be sheared is 



proportional to the square of the diameter of a sphere, whilst 

 shearing force is as the mass ; that is, as the cube of the 

 diameter ; and as the mass of the suns is quadrillions of times 

 that of any military projectile there remains no question but 

 that grazing suns shear one another. According to Dr. 

 Crommelin, Nova Persei was estimated to have a maximum 

 intensity ten thousand times that of the Sun. That is, were 

 this tremendous blaze kept up by fuel, it would require to be 

 stoked with six million times the entire coalfields of the earth 

 • each minute of its maximum. The impact of suns is the only 

 known source of such a suddenly developed store of energy. 



Professor Bickerton next pointed out that the third star 

 would be formed in an hour, would expand, and would 

 dissipate, giving a light-curve with a sudden uprise as novae 

 always exhibit, whereas the commonly received explanation of 

 Seleger and Halm, that of a sun entering a nebula, must 

 give a light-curve almost horizontal. The explanation given 

 in the lecture followed that in " Knowledge " (September, 

 1911), as did also the explanation of the series of spectrograms, 

 Professor Bickerton stated that although such physical 

 agencies as pressure might account for some of the peculiarities 

 of the spectra of novae there was no need to bring in 

 anything but the Doppler principle. This, taken in conjunction 

 with the deduced properties of the third star, was sufficient to 

 account for any physical fact even of so complex spectra as 

 those of Nova Geminorum as obtained at Cambridge. 



The Chairman, Professor Schuster, F.R.S., stated that the 

 whole theory was extremely suggestive, and that Professor 

 Bickerton had devoted a third of a century to its study. 

 There was one point he should like discussed, and that was the 

 high velocity of hydrogen referred to. Experimentally it had 

 been shown that, no matter how enormous the pressure to 

 which the gas was subject, the velocity of escape never rose 

 above that of sound. 



Professor Bickerton replied that the velocities observed in 

 novae was a question of temperature, not pressure. The 

 velocity of sound was a question of thermodynamics. If the 

 compressed hydrogen had the enormous temperature attained 

 during and subsequent to the collision the velocity of sound 

 would be proportionally increased. 



A hearty vote of thanks was accorded to the lecturer. 



