Man's physical universe

xanabras

92 THE UNIVERSE A VAST SYSTEM OF PARTS

Sirius wa.s found to shift back and forth every 25 years. In 1844

Bessely on the basis of his computations of the orbit of Sirius, predicted

that Sirius was a double star. Later both Sirius and its companion

were observed through a telescope.

The companion of Sirius is a very interesting star, for although its

mass is 4/5 as great as that of the sun, it radiates only 1/360 as much

light. It must, therefore, either be cooler or have a much smaller surface

than the sun. When it was proved in 1914 that the companion of

Sirius is a white-hot star, the conclusion was drawn that it must have a

smaller surface. The volume of the companion of Sirius is estimated to

be 0.00004 of the volume of the sun.

Its diameter is about 1/19 of the

sun's diameter, which would make it about the size of the planet

Uranus, or three times the size of the earth. Inasmuch as the companion

of Sirius is therefore at least 40,000 times as dense as water, a pint

of its mass would weigh 20 tons, and a tablespoonful could not be

lifted by a strong man.

It seems unbelievable that matter in the gaseous state could exhibit

such a high density, but such is our confidence in Newton's laws upon

which our calculations are based that we must abandon "everyday

common sense" for the higher common sense of Science. Accurate

checks of Sirius' mass, size, and temperature leave no other conclusion.

A number of other white dwarfs (stars resembling the companion of

Sirius) are known. One of these white dwarfs has twice the mass of

the sun, and yet it is no larger than the planet Mars. The gravitational

attraction of this star would be so great that it would cause a man to

spread out on the surface like a puddle of water. A cubic inch of

matter from the white dwarf star. Wolf 457, would weigh 9000 tons,

i.e., just under the weight of a navy cruiser; and if it were placed in a

modern skyscraper, it would probably crush its way right through the

building and proceed toward the center of the earth as a cannon ball

sinks in water.

Dwarf stars are now considered to be made up of the nuclei of atoms,

which represent most of the mass of atoms but occupy a very small

portion of the space taken up by an entire atom. Another theory is

that these dwarf stars are made up of very heavy elements not known

on the earth.

Betelgeuse Exhibits Conditions at the Other Extreme.

Betelgeuse is a bright star in the shoulder of Orion, 192 light-years

from the sun. This giant red star has a diameter 345 times that of the

sun, or about 300,000,000 miles, and its volume is 40,000,000 times

that of the sun's volume. Inasmuch as its mass is only twelve times

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