Human worth in the big picture

Wildcat File Photo Arizona Daily Wildcat Jon Ward

It's one hell of a big place, we humans have through scrupulous investigation realized. We know the universe holds countless galaxies and suns much like our own, and we're now discovering that those galaxies and suns are home to myriad planets similar to the one we live on.

We also know that our sun will burn itself out in about another 5 billion years, its nuclear fuel exhausted, and Earth will be engulfed in the fires of that swollen, dying star. There will be nothing left of humanity, no record of us ever having existed.

In 5 billion years, Earth will be a charred little ball of ash orbiting an extinguished white dwarf star. True, that's a long time yet, and it would take more than a miracle for humanity to make it that far; but 5 billion is young compared to the universe's age, around 20 billion years, give or take a few billion. Astronomers are not precisely sure just yet. They are however, quite sure that one human lifetime is an infinitesimally small blink in the big picture.

Incidentally, the big picture is getting bigger all the time as the universe expands; but our knowledge of it is increasing too. Humans seem to become smaller and less significant as our knowledge of the universe grows.

For example, this little galaxy is so big that the nearest star, Proxima Centauri, is not really near at all at a distance of 4.3 light-years, or about 409 trillion kilometers away. A rocket traveling at 10 kilometers per second (36,000 km/hour) would take 100,000 years to reach this "nearby" star.

Earth's solar system exists in one of the spiral arms of the Milky Way galaxy. Every star visible in the night sky is part of the Milky Way, which is one galaxy in a galaxy cluster known as the Local Group, which has a diameter of about 5 million light-years.

The Milky Way's nearest neighbor in the Local Group is 160,000 light-years away.

The Local Group belongs to the Local Supercluster, which has a diameter of more than 100 million light-years. Earth is hardly a speck on that scale, which is bigger than us little organisms can dream; but the whole Supercluster itself is just a drop in the ocean, even at 100 million light-years. The observable universe is beyond our grasp at 1026 meters.

So if this whole world is no more than a tiny mote of dust floating in an unfathomable void, then what can a human life be worth? Nothing? Almost nothing?

Actually, worth is just a concept invented by humans, so a human life can be worth whatever it thinks it's worth. But what is a human life's meaning? What about its purpose? Well, humans invented those concepts too. Since they invented the questions those ideas pose, they'll just have to make up the answers too.

But lest we get full of ourselves, basking in the glow of our creative powers, let's get a sharper appreciation of how small and insignificant we are in the big picture...

Consider the stars, galaxies and nebulas which seem to fill the heavens with their brilliance. They are actually pretty sparse. The Milky Way galaxy is so big that if the universe were scaled such that stars were the size of peas, only four of the Milky Way's 100 billion stars would fit in a space the size of the state of Arizona.

In other words, space is mostly bereft of the warm shiny things that allow life to arise, and that's inside the galaxies. Outside of them there are no stars, just more black lifeless space than a tiny human mind can possibly imagine.

It seems like one hell of a waste of space. But that's only if you're under the mistaken impression that its purpose is to contain life.

On the contrary, life is just a natural by-product of a functioning universe, a natural accident, so to speak. The conditions happened to be right for life in this particular universe, so life was able to emerge and eventually creatures like humans emerged who could invent concepts like meaning, worth and purpose, and then be puzzled by their own ideas. It didn't have to happen that way. The charge of an electron, for example, could have been a couple factors higher or lower, and life (at least life as we know it) wouldn't be here to wonder why things worked out so neatly for its existence.

This universe itself may eventually cease to exist; its expansion may halt and it could recollapse in a cataclysmic Big Crunch. Or it could expand forever to where all stars have burned themselves out and everything in the universe eventually becomes the same temperature.

If this happens, chemical reactions will cease. Stars, planets and galaxies will not exist, and the universe will consist of a uniform "sea" of elementary particles. The collapsing universe could also reach this condition before the Big Crunch. Either way, the universe will be here long after we biological organisms have vanished without a trace, leaving behind a huge, dead place which can no longer look at itself and wonder, but which will still exist nonetheless.

I don't know about you, but that doesn't make me feel worthless at all.

Jon Ward is a creative writing and astronomy junior. His column, Who's the Bull Goose Looney?, appears every Thursday. Jon Ward can be reached via e-mail at Jon.Ward@wildcat.arizona.edu.