In surveying our Solar System we cannot leave out our beloved parent, who has stood by us so steadfastly and patiently all these millions of centuries. He is our all. We depend upon him absolutely for everything. A very slight change in him would wipe us and our puny affairs out of existence. So insignificant a thing as a little eruption on his face upsets us seriously, causing violent electrical storms and sometimes complete paralysis of our electrical communication systems. We call these small periodic eruptions "sun-spots."
The Sun is one of the average stars of a galaxy which has come to be called the Milky Way. There are stars much larger and hotter, and there are others smaller and cooler. On the whole, our parent in celestial social circles would just barely make the middle class. It seems disloyal to say so, considering all he has done for us, but as we children grow up and become acquainted with other stars, we are forced to acknowledge that our Sun ranks only as a modest commoner. The aristocracy of the heavens make him look insignificant and shabby.
He is inclined to-be small, as stars go, although to us parasites on one of the smaller and more insignificant of his ten children, he seems incomprehensibly big. He is only 864,ooo miles in diameter. Sirirr, the'Do! Star, is r,365,ooo, almost half as big again; Alpha Ceniauri Ii is r,o5_o,ooo; Procyon B is about ih. ,r-i Altair is 9oo,- ooo; Capella A is 8,6oo,ooo; Betelgeuse is zr(ooopoo; anrl Antares is 3gorooo,ooo miles in -diameter.
Our Sun is not very hot as many stars go, notwithstanding the fact that on his surface the temperature is I'rorrr 6,ooo to B,ooo degrees, while his center is around ,1o rnillion degrees Fahrenheit. A boy,s marble at this lirll('r temperature, if set down at Wichita, Kansas, the ;r.;rlrloximate center of our country, would set fire to everything in the United States and kill every form of lant lift'. 'fhis seems quite hot, until we r.g"id Sirius, which ir rrt'rrrly twice as hot, having a surface-temperature that rnulil [)c around rr,ooo degrees; or S Doradus which has llx)ut -Joo,ooo times the biightness or luminosity of our Srrrr,
At t'vcrr tlie modest temperature of the surface of our Srrrr tlrtrc are no such things as solids or liquids. Every- tlrirrg is :r 1{as, including iron, gold, silver, .opp.r, pl"ii- trlrlr, ('lc. Many molecules are unable to stand the agita- lrurr rrrrtl :rrc stripped of some of their electrons. Storms of unthinkable ferocity must be perpetual, due to the struggles of the electrons to get out of the incompre- hensibly hot and agitated center. Eruptions occur every little while which hurl great masses of incandescent mat- ter a quarter of.a million miles off the surface, whence it falls back in the form of clouds of all the chemical elements in vapor form.
The weight of the Sun is about that of 33z,ooo Earths. The bulk ls such that some r,3oo,ooo Earths could be packed away in its volume. Earth's age, as we have seen, is about zrooo million years. The Sun's age is estimated as something of the order of 8 million million years. He, like all other stars, is radiating huge amounts of energy. He maintains the high temperature and consequent radiation by the destruction of his own matter.
This destruction amounts to z5o million tons per minute. He weighs z,5oo million tons less as you read these lines than he did ten minutes ago. This seems to us little creatures a terrible drain on his system. But he is so large that he has been able to expend his principal, so to speak, at this prodigal rate ever since the planets were born, 2,ooo million years ago, and to-day he is only one hundredth of one per cent lighter than he was then. But our planet's birth was only a moment ago, as stars regard time. Calculations show that we must go back about 6 million million years to find the Sun weighing twice what he now weighs. When he was young and big and lusty, he was hotter and radiated faster. He is now old and relatively feeble, and he radiates slowly. He ought to be able to keep up a strong enough radiation to keep life going on Earth for another million millions of years.
As he dissipates his weight, the Sun reduces his gravitational pull. His grip on Earth becomes correspondingly less. In consequence Earth is allowed to slip farther and farther out into space, as is also the case with its brothers and sisters. This is disconcerting because it hastens the coming of the cold of which our descendants eventually must perish. However, trouble is not imminent as we Earthians regard time, since Earth recedes from the Sun a matter of only something like 39 inches Per century. Our Sun rotates on its axis, turning one revolution in z6 days. He is journeying along in company with his 3o,ooo million brothers of the Milky Way galaxy, bound- we have not a ghost of an idea where. Such is a general survey of the heavenly body to which you and yours and I and mine owe our existence.
* * *
This closes the inventory of our Solar System as of A.D. 1932. We begin to suspect how the planets, at least, came into being, and about how long ago. We shall understand it better as we proceed with this discussion. We shall see how, in the case of our Earth, a mass of glowing gas had to cool to a liquid, then to a solid, and then to a surface temperature of around r5o degrees Fahrenheit before life could start and maintain its existence. We shall see whether it is more likely that life was created here spontaneously as molecules were created from atoms, or whether it had to cross interstellar space on a bit of cosmic matter.
We shall see how life probably appeared on Earth some 300 million years ago in the form of a primitive cell; how It seems to have been able to reproduce its kind, accommodate itself to its environment, and gradually evolve into more and more complex forms until after some 2gg,7oor- ooo years a creature developed which we are justified in calling a man; how all of the time between then and z,ooo years ago was required to lift the creature from a dawn man to a Pythagoras, the Greek mathematician who was among the first to conclude that the Earth was not fixed in space, was not the center of creation, but instead rotated on its axis every 24 hours and thus caused day and night.
We shall see how it was only 2,000 years ago that man began to understand at what he was looking when he gazed into the sky at night. And he had been a man for 300,000 years ! Superstitions in infinite variety and acceptance of the supernatural were responsible for holding him back, but as the truth never can be kept hidden permanently, it finally came out, and men awoke to the importance of basing their reasoning upon ascertained ,' fact only. Our intellectual awakening has, therefore, only I just occurred. While the Cro-Magnons, as we shall see, were the physical dawn men, we of the last two or three centuries will be looked upon by our descendants as the intellectual dawn men. intellectual dawn men. - It was only 300 years ago that evolution on Earth produced a Galileo who could invent and construct the first r,i telescope. It was less than 450 years ago that Columbus discovered that there was a North America. It was only r in 1930 that we discovered that there was another member of our own Solar System
And so it becomes evident that we proud rulers of Earth, with all our big buildings, big cities, big railroads, and beg reputations, have only just emerged from animaiity. Since the first of us came down out of the trees, only six one-hundredths of one per cent of the time have we had telescopes, knives and forks, ald any real knowledge of what we were looking at when we gazed into the sky at night.
We are at the threshold cf unctrerstanding. We shall be regarded by our descendants as men who groped about in the darkness before ihe dawn, in the misty gloom of the morning of understanding, when ignorance, supcrstition, and animal instinct combined attempts to asceltain Nature's truths. We realize that this cosmos is hostile to life ratheer than friendly. We can see how rare are the opportunities offered life to gain a fothold and maintain it for a sufficient period of time to develop an inrelligent being. We are impressed by the profundity of our own loneliness. We find, as we uncover fact after fact, that we are adrift in an incomprehensibly stupendous ocean of space, time, and energy. As we arise and rub our eyes, we find ourselves located upon a very insignificant speck of cosmic dust which happens to be just far enough, and not too far away, from a hot star to maintain a certain narrow range of temperature. Of the nine planetss of our Solar System, we appear to be next to the oldest that might still maintain life. Mars, our next-door neighbor, is the sole place in all the Sun's family where we can look for a fellow intelligence. Venus seems to hot. She is approaching the coolness that we had some 300 million years ago, when life began its career on Earth. Mercury, at a temperature of molten lead, has countless millions of years yet to go before it will cool enough to support life. The other members of the family died of cold eons ago.
However, our Solar System corresponds to only one grain of all the sand on all the sea beaches of the Earth. In the succeeding chapters let us continue our search for a fellow intelligence in some of the other "grains of sand."
©2013
W0IS.com
Copyright and Privacy Notice