Newcomb and Young who have estimated that the visible stars are fifty to one hundred millions in number. Assuming the average mass of these stars to be equal to the mass of our sun, the amount of mass in the visible universe is about 2 1036 metric tons.
Now, if these thousand million suns had been uniformly distributed within the sphere in question, and had started from rest twenty-five million years ago, they would have acquired under the law of gravitation about such velocities as the stars are now observed to possess; or, if thousands of millions of years ago they started from rest at mutual distances asunder, very great in comparison with the radius of the supposed sphere, and so distributed that they would now be temporarily equally spaced in that sphere, their mean velocities would be of the same order as that actually observed. A non-uniform initial distribution of the suns would give higher velocities for the stars than the observed values; and any great increase in the assumed number of suns would require far greater velocities than the observed values. Hence Kelvin infers that the amount of mass in our universe is greater than one hundred million times and less than two thousand million times our sun's mass.
That there would be plenty of room for a thousand million suns in the assumed sphere is shown by a striking calculation made by Kelvin. Thus, if the suns were placed severally at the centers of the thousand million cubes into which their enclosing sphere may be supposed to be divided, then each sun would be nearly fifty million million kilometres from each of its six nearest neighbors. This distance is a little greater than the distance of the nearest fixed stars from our solar system.
SCIENTIFIC ITEMS.
The great Nobel prizes, each of the value of about $40,000, have now been awarded for the first time as follows: In Medicine to Professor Behring, in physics to Professor Röntgen, in chemistry to Professor van't Hoff. The prize for the promotion of peace has been divided between Dr. Dumant and M. Passy, and the prize in literature has been awarded to M. Prudhomme.
The Copley Medal of the Royal Society has been awarded to Professor J. Willard Gibbs, of Yale University.—Director W. W. Campbell, of the Lick Observatory, has been elected an associate member of the Royal Astronomical Society.—Professor F. Lamson-Scribner, of the United States Department of Agriculture, has been given charge of the Bureau of Agriculture established in the Philippines.
The most important scientific news of the month is Mr. Carnegie's offer of $10,000,000 to endow a national university or institution for scientific research at Washington. The national government hesitates to accept the bonds of the United States Steel Corporation offered by Mr. Carnegie, but this is a detail which will doubtless be arranged.—On the same day that Mr. Carnegie's gift became known, it was announced that Mrs. Stanford had signed the final papers transferring property, estimated at $30,000,000, to Leland Stanford Junior University. It appears that the endowment of Stanford is now about equal to the combined endowment of our three richest universities—Harvard, Columbia and Chicago.
