The Celestial Lightshow

By Earl Hunsinger

Some of us look up at the night sky and marvel at the vastness of the universe. Yet many, perhaps most, people today never consciously look at the stars. They’re like a person living in a glass house that refuses to look outside. Some, like a shut-in agoraphobic, may fear the unknown and seemingly limitless expanse around us. Most of us though are just apathetic, seeing nothing of interest when we look at the stars. We see uniform pinpricks of white light and dismiss the universe as cold and unexciting.

Have you ever been enthralled by the dancing flames of a wood fire, thrilled by a fireworks display, or dazzled by a laser light show? All of these pale into insignificance when compared to the celestial light show going on around us. We see pinpricks of white light, yet this is only because the stars are so far away and we see so little light from them. In actuality, the stars vary in both size and color. As the website Enchanted Learning (www.enchantedlearning.com) explains, white dwarf stars can be the size of the earth. Other stars are much bigger. For example, by conservative estimates, the star Betelgeuse is 250 million miles in diameter. If it sat where our sun sits, it would engulf the solar system out to mars and the earth would be inside the sun. As the Sloan Digital Sky Survey discusses, the stars also range in color, from white, bluish-white, and yellow to orange, orange-red, and deep red.

Even our own sun is impressive. Although we’re 93 million miles away, you know that if you stare at the sun for a few minutes your eyes will water and if you stand in the sun for a few hours your skin will burn. Yet it may surprise you to learn that the energy we receive from our sun is only about 5 parts in a trillion. This is still 100,000 times the energy used by the world’s industries. The total energy the sun generates in a single second is more than man has used throughout his entire history. To put it another way, the total energy generated by the sun in a single second would be enough to power a 1,000 watt electric heater for 10,000 trillion years. To generate this energy, it burns 655 million tons of hydrogen every second. Yet, scientists say that in ten billion years it will have only decreased in size by about one percent.

If the stars still seem unexciting, remember that our sun is only an average size star, out of perhaps 100 billion in our galaxy alone, with billions of other galaxies, each with billions of stars.

If that is still not enough, remember that our eyes see only a small fraction of the energy given off by these stars. If we could see a broader spectrum of light than we do, colors deeper than the deep violet of a pansy, into the ultraviolet and beyond, and redder than the red of a ruby, into the infrared and beyond, we would see an even greater light show.

Imagine seeing black holes, stars whose gravity is so great that even light can’t escape, and whose neighbor stars are slurped up, sending jets of plasma streaming across the sky with the energy of a hundred million stars.

We could see stars so small they could fit comfortably in Lake Tahoe, yet able to spin at 643 times per second with the accuracy of a stopwatch. We might see neutron stars, which are so dense that a teaspoonful of their tiny bodies weighs a billion tons, or see a solar cloud bigger than our solar system collapse in on itself.

Of course, you may not see these things in a brief glimpse at the night sky. Even a good telescope may not capture all there is to see. The gallery on Hubblesite (hubblesite.org) contains a gallery of impressive images that you might enjoy. In any case, even if you have no special interest in astronomy, don’t turn your back on the windows to the rest of the vast universe around us, dismissing it as unexciting. Instead, look at the stars. As you do, remember the celestial light show that we know is taking place there, and wonder about the light show that we have yet to discover.