Telescopes Harvest Fossil Light to Reveal the Universe Being Born
+ Von Del Chamberlain +
Science is an observational activity, beginning with the human senses. We observe the world around us, analyzing what we see, and constantly strive to find better ways to measure what can be observed more precisely, adding refinement to the data that facts and theories are based upon. All our knowledge goes back to our abilities to perceive through touching, tasting, smelling, hearing and seeing. Only one of these senses allows us to know about things that are far away, and long ago.
Eyes are wonderful tools! Lenses focus light that energize optic nerves sending, messages to our brains. We see things across a room, across a street, or from a mountain top across a wide valley. "How far can we see?" a child asked, and a wise teacher answered, "as far as light can reach to us." It is our eyes, after all, that reveal to us the stars and they are so far away that it difficult to conceive of their distances. Our first knowledge about stars came through just our eyes, but to continue our quest to comprehend we invented instruments to focus, resolve, disassemble and analyze that light, and we discovered that objects in space radiate a broad spectrum of energy of which visible light is only a tiny part.
Telescopes are light buckets. Using large lenses or mirrors, they gather lots of light coming in from stars, then focus that light so that the images are clear and can be analyzed. Think of it this way. Astronomers are the miners of precious information about the universe. They use their light buckets to gather in and collect the information contained in light coming in from all directions around us. Included in the "ore" are light-messages from things near by and very far away.
The light astronomers collect is fossil light! Even though light is the fastest thing in the universe, the stars are so far away that it takes years to reach us. The one exception is the Sun, only 8 light minutes away. Our nearest neighbor star is just over 4 light years away and the distances go out from there. Light moves at 186,000 miles each second, about 6 trillion miles each year. Thus, one light year is about 6,000,000,000,000 miles. Most stars we see with just our eyes are dozens, hundreds or thousands of light years away. Without a telescope we can see some things that are hundreds of thousands to a few million light years away. Beyond that, we must use telescopes.
Beginning with Galileo telescopes became better and larger, so that now we have gigantic light buckets that collect primitive light from very dim objects located billions of light years out there--fossil light indeed! Fossils not only tell us about how things were, they also inform us of how things came to be as they are, and this is the knowledge cosmologists seek from archaic light.
Most of our telescopes have a very serious problem to contend with: Earth's atmosphere absorbs a lot of the knowledge-ridden energy coming from stars and causes the images to blur in and out even under the best atmospheric conditions. This is the fundamental reason that it is so important to use modern technology to boost our light buckets beyond the interfering atmosphere. For this reason, the Hubble Space Telescope is the gem in our treasure trove of astronomical instruments. It has a nearly undistorted view and can collect the old light of objects that are very dim and remote. With it astronomers are looking for light from the edge of the universe, light that started its journey many billions of years ago when the universe was born.
Recently, examples of these Hubble fossil images have appeared in newspapers, magazines and on video monitors for our enjoyment. In living color we can see crisp pictures of interstellar clouds, remnants of exploding stars, galaxies and great clusters of galaxies. We can even see intricate details showing stars in formation and possibly planets evolving with them. What a gift! What a privileged to be able to see these wonders! How blessed we are with the light that comes to us through the workings of brilliant people whose minds and toils have resulted in telescopes, radios, rockets, computers and all the other associated technologies that allow everyone to behold such wondrous realities that are so far away in both space and time. Through these images we can appreciate the far away, and we can travel back in time to know something about the long ago.
With just our eyes we can harvest ancient light. With both earth-bound and orbiting instruments we can enhance our vision to examine the real fossils of the luminous universe, the sparks of light that were emitted when things were getting started. This is a supreme example of science, the human quest for understanding through looking around.