Monday, Dec. 15, 1924

Relatives

Recently, Dr. James H. Jeans delivered a paper before the Royal As- tronomical Society (London). It so aroused Prof. Henry H. Turner of Oxford that he reverted to the venerable English pastime of "writing to the Times" about the "remarkable occur-rence." Unlike so many letters written to the Times, Professor Turner's letter Avas taken up by the press on both sides of the Atlantic, reprinted and headlined and garbled until a small but respectable portion of the earth's inhabitants had been instructed that the Einstein theory had led scientists to believe that other suns than ours (i. e., some stars) had planetary systems of their own, which might well harbor life.

The point of what Dr. Jeans had to say and which Professor Turner ad- mired was this: that by virtue of the theory of relativity it was estimated that the sun and other stars were not millions of years old, but millions of millions of years. Dr. Jeans hypothecated that our planetary system was produced by the collision or close approach of another star to the sun. Knowing the distance of the stars from each other, their speed of travel, and having an estimate of the length of life belonging-to stars and to our sun in particular, Dr. Jeans calculated the mathematical chance of the happening of such an accident as he believed produced our planetary system. The chance was so small as to make the event seem impossibly improbable.

Then, suddenly, Dr. Jeans revised his estimates of the lifetimes of the stars by many millions of years. This greatly improved the possibility of such an event's happening.

So, Dr. Jeans' mathematics no longer allows him to say that the chance of there being other planetary systems is inconceivably small. So far as his calculations go, there may be planets belonging to other stars, and if planets, why not life?

Of course, Dr. Jeans did not confine his consideration of relativity to the hypothetical existence or nonexistence of other planetary systems. His other conclusions include: 1) that the universe is slowly expanding; 2) that stars, in giving off heat and light, diminish in mass (weight), that the sun, for example, loses about four million tons of weight a second; 3). that, as a star becomes smaller, its speed increases.