Keeping things in perspective is hard to do. The theologian Hans Kung pointed out that if the last fifty thousand years of humanity’s existence was divided into lifetimes of 62 years each, then there have been about 800 such lifetimes between then and now.
The first 650 lifetimes were spent living in a cave. Only during the last 70 has writing existed, making it possible to pass down the learning of one lifetime to the next. It wasn’t until the last six lifetimes that printing existed, making books inexpensive and available for everyone.
Kung reminds us that only in this current lifespan has penicillin and other antibiotics been available. The airplane has existed only in the last lifetime and a half. The same can be said of anesthesia, automobiles, and most everything that surrounds us in our homes, from the television to the microwave to the telephone. Only in the last quarter of the present lifetime has the computer become a common household tool.
Another way of putting things in perspective is to think about size. The Earth is 7927 miles (11,743 kilometers) in diameter. The Moon is 2163 miles (3481 kilometers) in diameter, and averages 238,857 miles (384403 kilometers) away from the Earth. This is the equivalent of 1.3 light seconds away. Light travels 186,300 miles (299821 kilometers) per second.
The Sun is 864,000 miles (1,361.505 kilometers) in diameter, more than large enough for the Earth-Moon system to slip inside with room to spare. The Earth is an average of 93 million miles (150 million kilometers) away. This is the equivalent of 8.3 light minutes away—the distance light can travel in 8.3 minutes.
The dwarf planet Pluto averages 3.67 billion miles (5.9 billion kilometers) from the Sun. This is the equivalent of 5.5 light hours away.
More than 99 percent of the mass of the solar system is in the Sun, whose mass is 4.385 times 10 to the 30th pounds (4,385,000,000,000,000,000,000,000,000,000,000) or 1.989 times 10 to the 30th kilograms. This is 333,000 times the mass of the Earth.
The Sun is made of mostly hydrogen gas which is heated by continuous nuclear fusion at the core, where the temperatures are near 27 million degrees Fahrenheit (15 million degrees Celsius). The visible surface of the Sun has an average temperature of 9950 degrees Fahrenheit and continuously radiates power of 3.85 times 10 to the 26th watts (38,500,000,000,000,000,000,000,000,000) into space. The Earth intercepts less than half of one-billionth of that power.
The Sun is a fairly typical star; most stars range from one tenth to ten times the size of our Sun. Antares, the reddish star in the constellation of Scorpius is five hundred times the size of our Sun. Our Sun and all the planets out to the orbit of Mars could easily fit inside it. Antares is 400 light years from Earth.
A light year is the distance that light can travel in one year—about 5.88 trillion miles (9.46 trillion kilometers).
Alpha Centauri is the nearest star to Earth. It is 4.3 light years away—that’s about 25 trillion miles (or 40.7 trillion kilometers). The fastest humans have ever traveled in space was about 25,000 miles per hour (or about 40 thousand kilometers per hour) when they were escaping Earth’s gravity on their way to the moon—which took them three days to reach. It would take 115,340 years to travel to Alpha Centauri at that speed.
Let’s look at these distances another way. Suppose you could drive your car to the Sun, 93 million miles away (150 million kilometers). At sixty miles an hour (96.6 kilometers per hour) it would take you almost one hundred seventy-seven years to get there. Now imagine how long it would take you to get to Alpha Centauri in your car!
Our Sun is a star in the Milky Way Galaxy, a pinwheel-shaped glob of stars 100,000 light years across and 10,000 light years thick. The Sun is 30,000 light years from the center of this galaxy. It takes 230 million years for the Milky Way to revolve once on its axis. Our Milky Way Galaxy contains 100 billion stars.
The nearest other galaxy (excluding the Magellanic Clouds about 150,000 light years away) is the Andromeda Nebula which is about two million light years away from Earth (the average distance between all the galaxies in the universe) and it is 200,000 light years in diameter—twice as big as the Milky Way.
The observable universe is 30 billion light years in diameter and contains approximately 100 billion galaxies (each of which then has at least 100 billion stars, often more). Yet, the observable universe (all 30 billion light years of it) is perhaps only a fraction of one percent of the size of the universe as a whole.
One of the Apollo astronauts on the way to the moon put his hand out at arm’s length and covered the whole Earth with it. He marveled that behind his hand was hidden the place where everyone who had ever lived, everyone he loved, and everything he cared about. Never before had he realized just how small that was.
Blaise Pascal wrote, “When I consider the short duration of my life, swallowed up in the eternity before and after, the little space which I fill and even can see, engulfed in the infinite immensity of spaces of which I am ignorant and which know me not, I am frightened and am astonished at being here rather than there; for there is no reason why here rather than there, why now rather than then.”
So, in the grander scheme of things, what my kids do with their toys might not be so important.