SEPTEMnF.R, 1911. 



KNOWLEDGE. 



363 



Figure 1. 



A pair of Stars distorted 

 coining into impact. 



and 



That is. if trains possessed this velocity, their 

 coHision would have an energy hundreds of miUions 

 of times greater than that of colHding express trains. 

 It cannot be imagined that a shght graze of suns 

 passing one an- 

 other N\ith these 

 speeds will stoti 

 them. The porti(_ .1 

 actualh' in one 

 another's paths 

 \\ill be shorn a\\a\-, 

 and the torn suns 

 will proceed on 

 their journey with 

 orbits modified bv the 

 attraction of the newly- 

 formed third star. The 

 phenomena of these 

 torn suns may be 

 of the most varied 

 character. They ex- 

 plain many of the 

 characteristics of the 

 wonder stars and 

 double stars of the heavens. In 

 telling the stor\' of Nova Persei 

 the\' do not greath' concern us, 

 but must be referred to when we 

 study the wonderful spread of light 

 that flashed through the previously 

 existing nebula, at whose centre 

 Nova Persei appeared. 



Figure 2. 

 A pair of Stars in impact. 



Figure 



The Theory of the Third 

 Body. 



It is the properties of the coalesced portion torn 

 from the two passing suns, that correspond with, and 

 explain in the minutest detail, every one of the 

 multifarious observations that astronomers have 

 made of Nova Persei. The deductions that 

 explain these observations were published fully a 

 score of vears before the wondrous star appeared. 



The accompanving Figures (1-5) have been photo- 

 graphed from diagrams made and published more 

 than thirty years ago. and show kinematically the 

 progress of an impact during its first few hours. 

 Eigure 4 is probabh' the most instructive of the 

 whole, because it shows not merely the form and 

 motion of the third body, but also the distribution 

 of the adherent heated matter, clinging to the two 

 retreating suns. 



The most important characteristic of this third 

 body is its stupendous, its absolutely abnormal and 

 explosive energy. Ritter and myself have shown 

 that the energy of the critical velocity of a pair of 

 similar completeh" colliding gaseous suns, is exactly 

 one half of that necessary to produce an infinitely 

 diffused nebula. It must be remembered that similar 

 chemical elements, colliding with similar velocities, 

 produce the same temperature, and hence, however 

 small the portion torn away, if it be of the same 

 composition, whether small or large, it will have the 



1 he Stars passing ont of impact, and 

 G3 the formation of a third bodv. 



same temperature as though tiiere were a complete 

 collision. Thus, contrasting a complete collision 

 with a graze of one-tenth, in the one case we have 

 the whole matter heated to a certain temperature 

 and in the other case, one-tenth is heated to the 

 same temperature. In the third body there is one 

 tcntli the mass, and one tenth the heat ; hence the 

 temperature is the same as with complete collision. 

 The speed of a particle possessing sufficient power 

 to enable it to escape completely from a body, is 

 called the critical velocity. Now the critical velocity 

 depends to a large extent on the mass of the attract- 

 ing body. Thus a body ha\-ing a velocity of one-and- 

 a-half-miles a second could escape the moon, a 

 particle with a speed of seven miles a second 

 could escape the earth : whilst an asteroid 

 requires to ha\e a velocity much over three 

 hundred miles a second to entirely escape the 

 sun. Consequentl}' with two bodies of the 

 same temperature and different mass the 

 molecules may move fast enough to get entirely 

 free from the bodv of small mass, and be 

 retained by the body of large mass. The 

 third body is a small mass at an exceedingly 

 high temperature, as high as if the 

 whole of the two suns had collided, 

 and hence, if it he onl\- one-tenth 

 of the mass of a sun formed by 

 complete collision, this third star 

 possesses man\- times more energy 

 than is necessary to make it 

 explode. 



The new star formed bv a 



zing collision of suns, being ex- 



Flci'Rii 4. 



Showing entanglement of matter in 

 each bodv. 



once begins to 

 expand at some- 

 thing like a 

 million miles an 

 h our. W h e n 

 first formed it 

 is a bod\' of 

 a s t o n i s h i n g 

 brilliancy, and 

 as this vast bon- 

 fire grows it 

 becomes more 

 and more bril- 

 liant. Themaxi- 

 mum of bril- 

 lianc\- is quickly 

 reached, but the 

 velocit\' of the 

 particles has 

 scarcely dimin- 

 ished at all, and 

 so they go diffusing in space, until the mass forms 

 a rare nebula ; the luminosit\' gradualh" dim- 

 inishing from maximum until the star becomes 

 in\isible to the naked e\e. The great energv 

 of the molecules is not equally distributed 

 amongst the elements, for it is a property of 

 molecules that when at the same temperature each 



Figure 5. 

 Two variables and a temporary Star. 



