COSMOGONY—JEANS 157 
minute would amount to exactly the 250,000,000 tons in question. 
The crux of the situation lies in the circumstance that at most a 
millionth part of the total mass of the sun is of this easily shed 
kind, and that if this were the only part of its mass of which the 
sun could dispossess itself, its radiation could not possibly last for 
more than a few millions of years. Suppose, however, that proc- 
esses are at work in the sun’s interior by which the molecules can 
be not merely slowed down, but actually annihilated. In such a 
case the whole mass of the annihilated molecule is turned into en- 
ergy, and the whole mass of the sun—two thousand million million 
million million tons—becomes available for transformation into 
radiation. At the present rate of radiation, represented by 250,- 
000,000 tons a minute, the total mass of the sun would provide 
radiation for fifteen million million years. 
The most likely way in which mass could be compietely trans- 
formed into radiation would be by the positive and negative electric 
charges of which all matter is constructed rushing into one another 
and mutually annihilating one another. When the two terminals 
of a charged Leyden jar are brought into contact, we see a spark 
and hear a snap—a thunderstorm in miniature—which show that 
energy has been set free somewhere. In actual fact we know that 
the energy came from the rushing together of electric charges of 
opposite sign which have neutralized one another. Recent research 
has shown quite conclusively that a hydrogen atom consists of two 
electrically charged particles, one, the electron, being negatively 
charged, and the other, the proton, being positively charged; there 
is nothing else. If these two charged particles could be brought 
into actual contact it is fairly certain that the charges would neu- 
tralize one another, and, as we have no experience of uncharged 
electrons or protons, it may reasonably be supposed that the electron 
and proton would annihilate one another also. It is even more prob- 
able that there would be nothing left to annihilate, for it is already 
known that the whole mass of the electron comes from its electric 
charge, so that to speak of an uncharged electron is a contradiction 
in terms, and the same is almost certainly true of the proton. Thus, 
in the falling together of the electron and proton of the hydrogen 
atom, the whole mass of the atom ought to be transformed into 
radiation. It hardly seems likely that more complex atoms would 
annihilate themselves in a single process of the kind; more prob- 
ably there would be a successive falling in of electrons one at a 
time, so that the atom would gradually diminish its mass, and, of 
course, also its complexity. But the details of the process are un- 
important; in whatever way the annihilation of mass is achieved, 
the final result is the same, as also, of course, is the total amount of 
radiation which is set free. 
20837—27——-12 
