364 



KNOWLEDGE. 



Skpti;mi!Er. 1011. 



atom possesses the same energy. An atom of lead 

 weighs two hundred and seven times as much as an 

 atom of hydrogen, and }-et when both the atoms are at 

 the same temperature each has the same energy : one 

 has great mass, the other great velocity. Immediate!}- 

 after the collision all the elements have the same 

 velocity, that is at the moment of the formation of 

 the third body, lead is excessively hot. and h\drogen 

 much cooler. As equality of temperature is gained, 

 the h\-drogen robs the heavier elements of their 

 energy, and may attain an extraordinary velocity. 

 The velocity of hydrogen actually recorded in the 

 case of Nova Persei, was fully a thousand miles 

 a second. In this way the light gases escape 

 away from the heavier 

 ones, and leave them 

 behind, the light elements 

 forming vast ensphering 

 shells constanth' expand- 

 ing outwards. The heavy 

 gases tend to form an 

 intensely brilliant nucleus, 

 that has not sufficient 

 energy for complete dissi- 

 pation. Hence there is a 

 limit to its expansion. But 

 the outward momentum 

 of the particles will carr\- 

 them beyond the limit of 

 equilibrium. When the\' 

 come to rest, gravitation 

 will cause the mass to 

 shrink again: as it 

 shrinks it will increase in 

 brillianc)- ; but again 



7 9 11 



I-IGURE 6. 



tht 



momentum 



.f the 



molecules will carry them past the position of 

 equilibrium, and this oscillation may go on for an 

 indefinite number of times, until an approximate 

 balance is obtained. This balance is not one of 

 rest ; for, as will be show n immediatelv. the third 

 body must be in a rapid state of rotation, due to the 

 conflicting forces of impact. Let us examine the 

 light curve of the third bod\- and we shall see that 

 the curve deduced by dynamical reasoning (see 

 Figure 9) is absolutely similar in every respect to 

 the curve drawn at South Kensington, from actual 

 observation of Nova Persei. 



Calculation shows the imjiact, that is, the initial 

 explosion, takes an hour, and the body is at once 

 of transcendent brilliancy. It then expands with 

 extreme rapidity, hence the light curve to commence 

 with is almost vertical. It increases with great 

 speed for a short time, remains for a while 

 approximately at the same height, and then begins 

 to fall, falling much more slowl}- than it rose. 

 Presently contraction sets in, during which time 

 the curve rises, because, under the influence of 

 pressure, the light becomes more intense. Then 

 again expansion ensues with lessened luminosity. 

 to be again followed with another period of com- 

 pression, with increased light, .^nd so the curve 

 continues to oscillate for a period that is dependent 



on a \-ast number of special circumstances, which 

 must vary with each nova. In the case of Nova 

 Persei the oscillations were very long sustained. 



The Foinr (_)F the Third Body and its 



ROT.\TIOX. 



It will readily be seen that the light gases on the 

 outside of the two impacting suns will be the first 

 to meet, hence, as the material crowds in upon itself, 

 this light material will, when the body is first formed, 

 be at its centre. As we examine the effect of the 

 collision on each of the two suns, we see that it 

 must form a long valley in each ; this valley 

 graduall\- becoming deeper and deeper. As the two 



torn suns leave each other, 

 the material deep down 

 in its mass will be dragged 

 along, and much of it 

 will be left adhering to 

 the end of the vast valley, 

 that has been cut in each 

 sun. As the suns leave 

 one another the new third 

 body stretches out into 

 the spindle form, and the 

 distribution of material 

 will now be that the 

 lightest elements will be at 

 its centre, the somewhat 

 -- . . heavier ones will surround 

 o "20 ^e^^hn these light gases, whilst 



Yb K'n7rrh the heaviest portion of the 

 third bod\- will be at the 

 ends of the spindle. These 

 ends may consist of elements whose atomic weight 

 will seldom be less than fort\' or more than seventy. 

 The reason it will not contain very heavy elements 

 is because, for various reasons, it can be show n that 

 when there is an exceedingly deep graze the three 

 bodiesdo not part company, but form a rapidly rotating 

 mass, that is probabh' what is known as a Wolf- 

 Rayet star. I have named such a deep collision a 

 case of Whirling Coalescence. Owing to this fact 

 of the difference of the quantity of material meeting 

 on opposite sides, the third star is set rotating. The 

 mountainous mass of material left on each of the 

 torn suns also in these scarred globes produces 

 rotation. These complex phenomena explain man\- 

 characteristics of variable stars, not howe\-er of 

 interest in connection with Nova Persei. This 

 peculiar property possessed by the light gases, of 

 sorting themselves into concentric shells according 

 to their speeds, we have called Atom Sorting or 

 Selective Molecular Escape. The principle here 

 introduced was fully studied in 1878, and the late 

 Dr. Johnstone Stoney devoted a considerable amount 

 of time to showing its influence with regard to 

 h\drogen and other 

 atmosphere. 



The principle is of supreme importance in 

 connection with tiie impact theory of cosmic 

 e\i)lutiiiii. and must be clearly understood. To 



I? 14 ,6 

 Atomic Kiiictol 



ight elements, m our 



