[citation needed] In 1916 he joined a group of mathematicians led by A. V. Hill for the Ministry of munitions working on the ballistics of anti-aircraft gunnery, they became known as ′Hill's Brigands′.

[10][11] William Whetten was the nephew of American architect James Renwick Jr., and designed Saints Peter and Paul, a Roman Catholic cathedral in Indianapolis, Indiana, United States.

[13] Milne died of a heart attack in Dublin, Ireland, while preparing to give a set of lectures.

In the 1920s much of Milne's research was concerned with stars, particularly the outer layers known as stellar atmospheres that produce the radiation observed from the Earth.

He considered a grey atmosphere, a simplifying approximation in which the strength of the absorption of light by the hot ionized gas is the same at all wavelengths.

This produced predictions of how temperature varies through the atmosphere, including the mathematical expression now known as the Milne Equation.

With McCrea (1934) he also showed that the 3 models which form the foundations of modern cosmology first proposed by Friedmann (1922) using the general theory of relativity, can also be derived using only Newtonian mechanics.

In Minkowskian coordinates, this constant proper time forms a hyperbolic surface which extends infinitely to the light-cone of the event of creation.

Milne's model is, therefore, that of a sphere, with an approximately homogeneous matter distribution within several billion light years of the center which then increases to an infinite density.

The spherical distribution is unique in that it is essentially the same after a Lorentz transformation, except that a different stationary particle is at the center.

In fact, many passages in Relativity, Gravitation and World Structure are devoted to attacking Eddington's preconceptions.

[20] Milne was a theistic evolutionist who held the view that God intervenes with "deft touches" to steer mutations in the right direction.