Life on Earth
The universe is inconceivably large. It may be made up of as many as one hundred billion galaxies.
Each galaxy contains anywhere from a few million to a few trillion stars. Our own galaxy, the Milky Way, has about three hundred billion stars glittering within its core and its spiral arms.
Of all this, our sun is but one star; one star lost in vast crowds.
Surrounding the sun is a family of smaller bodies, billions of them, ranging in size from the largest planet to the smallest asteroid or comet. (Perhaps every star has such a family.)
Our earth is just one of all those objects circling the sun and is not even the most impressive. It is the fifth largest.
It may be that only on our earth, on this one world in an enormous universe, is there to be found the phenomenon of life.
There may be other worlds full of life, to be sure, innumerable examples of them dotting the universe—but we don't know of them. The few nearby worlds we have reached and examined seem lifeless.
Is there any point in studying life? If it is such a small part of the scheme of things, can it have any importance? After all, if all of life on the earth were to vanish suddenly, the planet would continue to spin and circle the sun and would do so unperturbed for billions of years. The sun certainly would continue shining for those billions of years, in no way affected by the disappearance of living things on one of the many objects circling it.
And the rest of the universe? It could not be altered or touched in any way by that disappearance.
Still—we are part of life, so we may be excused if we find selfish cause to be interested in it and to find it a wonderful phenomenon.