115 
103] The Annihilation of Matter 
in which such a great concentration of energy can be stored except in the 
actual matter of electrons and protons. 
We are not in a position to deny absolutely that the energy may be stored 
in other ways. Our knowledge of physics is derived from a study of molecules 
which are not liberating any appreciable amount of energy (§ 104), and this 
may be because they have no stored energy to liberate. A search for the 
mechanism of storing energy ought, if possible, to take place in regions 
where large amounts of energy are known to be stored, and we have to 
admit that a study of molecular physics in the Sun might disclose molecular 
mechanisms for storing energy, as so also of course mass, which are unknown 
to terrestrial physics merely because terrestrial molecules have no energy 
to store. 
But so far as we can judge from terrestrial physics, the obvious place for 
storing the energy and mass in the enormous quantities needed is in the 
existence of electrons and protons, so that it seems reasonable to suppose that 
the liberation of energy arises from the annihilation of electrons and protons. 
Thus we suppose that as a star ages, its atoms and electrons must undergo 
annihilation, their imprisoned energy being set free in the form of radiation. 
Coal, which has been picturesquely described as bottled sunshine, might 
more accurately be described as re-bottled sunshine. The bottles in which 
sunshine and all the radiation of the stars were first imprisoned, were the 
atoms and electrons of matter long since annihilated ; the breakage of these 
bottles set free the radiation which warms and lights our earth and makes it 
a possible abode of life. 
Those who feel that this solution of the problem of the source of stellar 
radiation is ultra-modern, and therefore under suspicion, may perhaps find 
comfort in the following transcript from Newton’s OpticJcs* (1704): 
Query 30. Are not gross bodies and light convertible into one another; and may not 
bodies receive much of their activity from the particles of light which enter into their 
composition ? 
The changing of bodies into light, and light into bodies, is very conformable to the 
course of Nature, which seems delighted with transmutations. Water, which is a very fluid, 
tasteless salt, she changes by heat into vapour, which is a sort of air; and by cold into ice, 
which is hard, pellucid, brittle, fusible stone; and this stone returns into water by heat, ' 
and vapour returns into water by cold....Eggs grow from insensible magnitudes, and 
change into animals; tadpoles, into frogs; and worms, into flies. All birds, beasts and 
fishes, insects, trees, and other vegetables, with their several parts, grow out of water and 
watery tinctures and salts; and by putrefaction, return again into watery substances. 
And water, standing a few days in the open air, yields a tincture, which (like that of malt) 
by standing longer yields a sediment and a spirit; but before putrefaction is fit nourish 
ment for animals and vegetables. And among such various and strange transmutations, 
why may not Nature change bodies into light, and light into bodies ? 
I am indebted to Sir J. J. Thomson for bringing this to my notice.