STRUCTURE OF THE UNIVERSE—HEAPS 169 
We are unable to put a stop at the right-hand end of our line, as we 
have done at the left end. Space may go on into infinity—possibly 
matter may go on bunching up into larger and larger aggregates 
with no limit as to the ultimate size of any final bunch, because there 
may never be any final bunch. Speculations of this kind may be 
interesting but they are not of much significance otherwise, because 
they take us outside the realm of possible human experience. 
M = 1,000,000 
NUMBER OF NEBULAE: 100M 
STARS PER NEBULA= 100,000M 
LOU OGUMLNGA si) o 1 
AVERAGE 
FIaure 2.—Sphere of view of the 100-inch telescope. Distances are in light-years, 
L. Y., and the diagram ig not to scale. Our earth is about 30,000 L. Y. away 
from the center of the central nebula above. 
It seems probable that in detecting the supergalaxy man has reached 
the limits of observation in his probing of the depths of space. The 
new 200-inch telescope will be doing a fine job in helping to chart and 
analyze these enormous groups of matter. 
The line diagram of the universe, limited at one end by the electron, 
at the other by the supergalaxy, has given a rather simple picture in 
terms of two variables, space and matter. The third variable, time, 
must now be considered. We have to consider the relationship be- 
tween the various units of our structure as this relationship may 
