It's time to look back and ponder upon the past fifteen weeks. We shall make no effort to summarize the many facts and concepts this course presented. Instead, we shall explore some connections among science, society, and the individual; connections which seem to have emerged from our cursory excursion into astronomy and physics.

Science often presents us with surprising results. Earth gives every sign of being stationary, but astronomers tell us that it moves. Common sense suggests that the sun and moon are equal in size, but mathematical calculations tell us that the sun is as large as 64 million moons. We believe that the chair we sit on is solid, yet physicists tell us that it is, for the most part, empty space. If you could eliminate emptiness from the entire Earth, for instance, Earth would weigh as much as it weighs now, but it would only be as big as an orange. We feel no pressure upon us, yet we believe that every square inch of our bodies is usually under 15 lb. of pressure.

This tells us that common sense and intuition are not infallible guides to reality. Sometimes, thinking logically about things can get us far closer to the truth than feeling our way through. Needless to say, feelings, emotions, and intuitions are important, but they should not serve as the only guide of our thoughts and actions.

Convergence between Scientific and Spiritual Truths

But there is another side to this, a side which concerns some of our most fundamental spiritual convictions. In some ways, science merely rediscovered a few age-old aspects of our spiritual heritage. Biology tells us that our grandfathers of one million or so generations ago were ape-like creatures; of some 30 million generations ago, snakes. It tells us that in our basic logic of construction, in the materials that make us, we are the kin of everything that lives. Ecology reminds us of the biosphere's fragility and our responsibility towards nature.

Astronomy reminds us of our loneliness in the universe; as things stand now, we can't get out of the solar system and we are unlikely to survive on any other planet besides our own. The destiny of our astonishingly small planet is our destiny.

Science reminds us of the limits to our knowledge; we know little about ourselves, others, and the world. It reminds us that we are here

one day, and some unknown place another day, and that, in the universe's scheme of things, the last day of our existence is just around the corner. Science tells us that greed, international anarchy, and the will to power might bring about a cataclysm, perhaps even the extinction of our species. It suggests that kindness, thoughtfulness, and compassion towards our fellow humans and creatures are more conducive to the survival of our species. Science tells us that each individual that has ever existed is unique.

All this is far from being identical to the fundamental teachings of most religions and spiritual movements. However, it is interesting to note the striking parallelism that does exist between science and spirituality. Although science contradicts many of our commonsense intuitions about he world, it often concurs with some pre-scientific spiritual beliefs.

We are familiar with compromises in our daily lives. Your spouse would like to spend $3,000 on a computer. You want to spend $1,000. You end up spending $2,000. A similar situation is often encountered in the physical world. The mercury in the barometer stays where it is because it is in equilibrium between two forces--the weight of the mercury and the weight of the atmosphere. A planet stays in its elliptical orbit as a compromise between its own inertial motion and the gravitational pull of the sun. We owe the sun's steady light to the equilibrium between the gravitational force pulling everything towards its center and the ongoing nuclear explosions pulling everything away from its center.

Nation states often disintegrate because they are subject to many opposing forces. Likewise, the multiplicity of forces operating in the

universe partially explains its instability. We prefer a chair to a seesaw because we depend on no one to counterbalance the chair. Nature, however, is full of seesaws and, hence, of change.

Modern scientific conceptions are in perfect agreement with the belief of the ancient Greek philosopher who claimed that you can't bathe twice in the same river. Everything in the universe is in flux; everything comes and goes. Biologists have excellent reasons to believe that living things constantly evolve, and that commonsense notions about the fixity of species are incorrect. Astronomers have reasons to believe that stars, galaxies, nebulae, and everything else in the universe evolve too, and that the ancients' belief in the permanence of heavenly bodies was mistaken. Things look permanent to us because they are far longer-lived than we are. To a moth whose life span is a mere few days, we may look eternal. To us who live but a few decades, continents, mountains, and stars look eternal. But their immutability is a chimera; they merely enjoy longer life spans.

Aging then is in the nature of things. Some things decay faster than others; eventually, everything vanishes. Our radiant sun will one day turn into a red giant; then into an invisible, small, unimaginably heavy dead star. The universe itself may one day assume its primordial

position, beginning again a 40 billion cycle of creation of galaxies, stars, planets, and perhaps even life.

It is important to remember that many astronomical events take place thousands of light years away from Earth. Astronomers talk about a supernova explosion, for instance, as if it is a contemporary event, but that of course it is not the case. Many of the events they get so excited about took place thousands, or even millions, of years ago. Cosmologists are not scientists in the conventional contemporaneous sense; they are archaeologists of the universe.

And this is not the only limitation placed on the would-be students of the sky. They are limited to observations of what they can detect with their instruments, which is very little. Unlike other natural scientists, they can't manipulate their objects of study. They can only describe them and, by relying on special situations and opportunities, test their theories and predictions. Cosmology talks about supernovas, black holes, quasars, and an expanding universe as if they had the same status of probable knowledge as atoms, genes, dinosaurs, and the molecular composition of water. The truth is that they don't. The evidence for just about any astronomical conception about anything outside the solar system is indirect and tenuous. Sure, that is the best we can do, given our instruments and earthly location, but we should always keep this limitation in mind when we hear speculations about such things as the origin of the universe or the birth and death of stars. Science as a whole is plagued by uncertainty. Despite the fancy instruments, the advanced level of mathematical reasoning, the occasionally brilliant and persuasive cosmologist, the chances that the basic picture is flawed are probably greater in cosmology than in any other hard science. Cosmology presents us with the most reasonable picture of the universe we can have at the moment; as such, it seems reasonable to embrace it. But we should keep our critical faculties on guard and remember that, someday in the future, this picture may radically change.

Our Place in the Universe

We often take ourselves more seriously than we should. Compared to the size of Earth, each of us is but a grain of sand. Our Earth itself, in comparison to the sun, is vanishingly small. In our galaxy, the sun again is one of billions. And we can't yet tell how many galaxies make up the universe. So, in the universe's scheme of things, we are but a speck of a speck of a speck of a speck.

The same can be said about human beings and time. Time before and after us stretches into eternity. For every three years or so of our lives a star lives a billion--and even a billion years is a speck of eternity.

Someplace in the back of our minds, we are aware of our smallness and mortality. Still, we often behave as if the time given to us is practically endless. We often live unprotestingly in decaying cities, with few if any intimate friends, spending most of our waking hours doing things we don't like to do, telling ourselves that we shall start living on some future day, not here and now. If we could just internalize and really believe our smallness and death, the incredible small morsel of space and time that is given to us, we might tear apart our self-imposed straitjacket. We might begin to feel that we have an inalienable right to be fully alive. We might treat our fellow passengers to the grave with greater compassion. Thus, by reminding us of our "speckiness" in both space and time, the study of astronomy and physics does not merely add to our store of knowledge; it may also alter some of our views about the world, others, and ourselves.

Source:  Moti Nissani.  Permission for the free use and publication of this material is hereby granted.

Back to Atoms & Stars, Main Page