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[22] First observed by Eddington and others in 1919. (Cf.

Appendix III).

[23] Established by Adams in 1924. (Cf. p. 132)

PART III: CONSIDERATIONS ON THE UNIVERSE AS A WHOLE

XXX.

COSMOLOGICAL DIFFICULTIES OF NEWTON'S THEORY

Part from the difficulty discussed in Section XXI, there is a

second fundamental difficulty attending classical celestial

mechanics, which, to the best of my knowledge, was first

discussed in detail by the astronomer Seeliger. If we ponder over

the question as to how the universe, considered as a whole, is to

be regarded, the first answer that suggests itself to us is

surely this: As regards space (and time) the universe is

infinite. There are stars everywhere, so that the density of

matter, although very variable in detail, is nevertheless on the

average everywhere the same. In other words: However far we might

travel through space, we should find everywhere an attenuated

swarm of fixed stars of approrimately the same kind and density.