WCP2823

[1]¹

Scotsdale,

Grantchester Street,

Cambridge.

1903 April 24^th [sic]

Dear Professor Darwin²

Thank you for sending me Dr Wallace’s interesting queries: I must apologise for having kept them so long, but I have been away from Cambridge & only returned this evening; & when your letter came, I tried to get something like an answer to some of the questions, instead of answering the letter promptly. I think you tell him, in the [2]³ enclosed sheet, all that is at present known about the "Problem of an infinite number of bodies".

Judging from the questions, it would appear that Dr Wallace is aiming at a gravitational explanation of star-clusters, nebulae, the Milky Way, etc. Personally I doubt whether this is likely to lead to anything, for I _{doubt whether} don’t believe that the principal⁴ [3]⁵ phenomena of the stellar universe (e.g. the spirality of nebulae, the occurrence of variables in star-clusters, etc) are consequences of the law of gravitation at all. I have been working myself at spiral nebulae, and have got a first approximation to an explanation — but it is electrodynamical & not gravitational. In fact, it may be ^questioned doubted whether, for bodies of such tremendous extent as the Milky Way or nebulae, the effect of which we call gravitation is given by Newton’s⁶ Law⁷: just as [4]⁸ the ordinary formulae of electrostatic attraction break down when we consider charges moving with very great velocities⁹.

With regard to Dr Wallace’s proofs, I am not quite clear as to what kind of help he wants. If he merely wishes to have a professional mathematician read the pages in a general way (not looking for misprints or minor errors, but only considering the general drift of the argument), then I should be glad to do it myself. But if he wants proof-reading in the stricter sense, I should think L. N. G. Filon¹⁰, now lecturing at University College London, might possibly do it.

Ever yours sincerely | E T Whittaker¹¹ [signature]