The Rhythm of the Cosmos Consists of Many Movements Occurring at the Same Time
+ Von Del Chamberlain +
Whenever I feel that I am going nowhere fast, I try to think about all of the ways I am moving without even being aware of it. One of the most fundamental descriptions of nature is that it is filled with motion. We have discovered it everywhere, at all levels. We study the flight of birds, the movement of masses of air. We watch the graceful and swift-swimming dolphins, whales and schools of tiny luminous fish, and we calculate how dinosaurs moved their massive bodies upon the land. Even the inanimate realm of molecules and atoms, making up things that seem to be solid and stationary, are really flowing with movement all the time. From the smallest particles composing grains of sand to the largest objects of the universe, there is motion everywhere.
Consider, for example, the many ways we move in space. Walking down a street, a few feet every second, we feel confident that the ground beneath our feet is firm, unmoving. Nothing could be further from the truth, for we walk upon a huge ball rotating in space. We discern this motion by watching Sun, Moon, and stars rise, glide across the sky and set. Interesting, isn't it, the way we describe things. We say the Sun rises in the east and sets in the west, but in reality it is the eastern horizon that is constantly setting, making things in that direction in space come into view, appearing to rise. The western horizon is continually rising to cover objects in that direction from our view, making them "set." When we look to the north we find the direction of the axis or rotation of our planet: stars move in circles around the North Star. Each day we move thousands of miles (depending upon our latitude), several hundred miles each hour as the Earth turns. We can, if we choose, forget about this rotation of Earth as we walk along, for the force of gravity between our bodies and the massive planet pulls us toward Earth's core. We cling to the world whose rotation flashes light and dark, one of the basic rhythms of our lives.
At the same time, we shift with Earth as it orbits the Sun, once around its 580 million-mile orbit each year, moving 18 miles every second. Because Earth's axis of rotation is tilted to the axis of its orbital revolution, we have seasons. The amount of energy received by a particular place on Earth is constantly modifying and we observe this as the changing daily pathways of the Sun across the sky that translate into changes in weather through the year. Cold winter snows change to mild spring rains, followed by warmer, dryer summers that modulate into cooler autumn until snow flies again. Equal day and night in spring changes to long summer days with short nights, then equinox conditions again and back to short dim days and long nights of winter. Year after year it continues, pulsing waves of changing seasonal energy, providing another rhythm for life.
But this is not the end of the motions we constantly experience. Sun and its entire fleet of planets move within the Milky Way Galaxy, our galactic city of a few hundred billion stars. It has been estimated that the Sun moves around the galaxy about every 225 million years, a period of time referred to by astronomers as the galactic year. Since we believe the Sun to be about 4.5 billion years old, it has made about 20 trips around the galaxy since its birth. This motion carries us about 140 miles every second of our lives. Although this moves us fast and far, its rhythm in the great Galaxy is slow.
Studying the large-scale structure of the universe, we have discovered that galaxies occur in clusters. Indeed, the Milky Way is part of such a cluster of at least 30 galaxies referred to as the "Local Group of Galaxies." Each member of the group has its independent motion, but the entire group moves along together at the same time. Measuring the movements of galaxies and clusters of galaxies informs us of the evolution of the entire universe. One of the great discoveries that we continue to attempt to understand is that everything we have been able to observe in the universe takes part in an expansion, all parts of the whole moving away from all other parts as though time began in a great explosion. The evidence for this "Big Bang" expanding model of the universe is strong. Apparently everything that exists came out of the energy of that explosion, transformed into galaxies and stars, producing all the rhythms we perceive around us.
So, when next you feel like you are going nowhere, think again. Look around at the movement within and all about you. Consider the motions on Earth and in the sky: atoms swimming everywhere; planets rotating and cruising about stars that fly around the Galaxy; clusters of galaxies exploding apart to define the universe. Dance to the rhythms of all these movements, beating out the days, years, and even our portion of the galactic year that marks the time of our lives.