 My scientific work is motivated by an irresistible longing to understand the secrets of nature and by no other feelings. Albert Einstein spoke of the irresistible longing that people have felt since they became capable of wondering why and how. A longing to look into the heavens and know the secrets of the universe and our part in it. To hear the rhythmic signals of space and understand the messages they send. To penetrate the ocean depths as if they were our natural place. To know the mysteries of our home, the earth. A longing to see the unseeable atom and then beyond to its still hidden parts, perhaps to the very essence of matter. To understand the complexity of ourselves, our bodies, our minds, our feelings, our genes, our chromosomes and cells with an intimacy both thrilling and terrifying. Irresistible, that longing to understand, to find the hidden clues to nature and then to place that new knowledge into the marvelous puzzle of the universe. To know what no one knew before you, that is the irresistible longing of the scientist. You may choose to search for it in the frozen desolation of Antarctica. Provided you don't mind a little cold, scientists from all over the world come to this storehouse of secrets to look for clues to the earth's past and perhaps to its future. In the process your eyelids may freeze closed, but don't worry, they do come apart. Eventually, not every scientist chooses such a physically demanding kind of research. For some the equally exhausting, equally exhilarating search may take place solely in the mind. And in that private place, you ask a question. Perhaps it is, what are the fundamental building blocks of matter? What are the smallest things in the world? Let's not start modestly. They joke that the simpler or more basic the question, the more complex the tools you need to check it out. Recently, for example, scientists believed that they had finally found the tracks that revealed the existence of the single most fundamental particle of matter, the quark. No, this is not the search for an extinct duck. But it is the relentless search for the thing of which all other things are made. And now, there are questions even about the quark. What is it made of? So you have to ask, is there an ultimate particle? Perhaps this material world is an infinite onion that we will peel forever without finding the core. But learning about our universe as we go. And so the search continues. And so do the questions. But the same question can mean different things to different people. When a child asks, Mommy, where did I come from? He or she may mean, did we move here from the Bronx or from Brooklyn? When a scientist asks, where did I come from? He or she may look for the answer in the dark reaches of space, probing deep into our galaxy with radio telescopes like these. We have found organic molecules, unexpected signs that could be associated with life. Until recently, we thought these molecules only existed here on our own planet. Is it possible that drifting down from the deathly cold of interstellar space came the first fragments that allowed life to begin here on our planet Earth? But for most of us, when we ask, where do we come from, we mean the miracle of conception and birth and the continuity of the generations. What are the exact biochemical processes that trigger a new individual into being? This sea urchin egg is surrounded by thousands of sperm, yet only one is permitted to enter. What keeps the others out? We want to know how this happens and its implications. Each new living thing, whether sea urchin or grandchild, arrives carrying its inheritance with it. Its accumulated evolutionary legacy packed tightly in the DNA molecule that exists in every cell of every species of living thing. And how perfectly it performs its historical task to order up a fin, a petal, a leg, to order growth and function and reproduction. For in this DNA molecule is the essence of life. Someday we would like to know all it knows. Perhaps lasers, capable of following the chemical reactions within a living cell, will help us reveal the source of its secrets in the future. Microelectronics is another tool that may help us do it. This ability to shrink electronics has had profound effects in many fields. In astronomy for example, computers can turn a galaxy upside down or let you glimpse it from behind or show you the inside of a star or a comet. But it is you who must pose the problem. For as complex and sophisticated as any computer may be, it is a child's toy compared to the human brain. Billions of nerve cells and a thousand times as many interconnections. What an explosion of activity must take place there when we are in the process of learning something. What exactly goes on? Scientists attack the problem from many different directions. Perhaps the chimp, the being genetically closest to man, can help shed light on the links or differences between animal and human intelligence. For example, can it learn to communicate through sign language? Me, time eat? Notice the questioning look. Time, time eat? Okay. Time eat, time eat, the declarative. In still simpler systems as in the locusts, scientists are on the verge of localizing cells where learning actually takes place. While in the ever-faithful fruit fly, geneticists by altering one of the fly's genes have been able to breed flies that cannot learn. These flies are also deficient in an enzyme. Is it possible that this enzyme is related to learning? Part of the learning process is the inexhaustible desire to know. And scientists long to know the nuts and bolts of everything. For instance, when did we first become human? This hand, so similar to our own, is three million years old. It is part of a recently found skeleton. Although the creature's brain was small, it walked upright. Perhaps during the course of evolution, some parts of us became human before other parts did. Ever think of that? Another aspect of the study of humans focuses on our social behavior. For example, social scientists have been analyzing our national voting patterns for the past 25 years. They are trying to understand the reasons for different patterns of stability and change of American voters. Almost as unpredictable as the American public is the weather. Weather gone wild. 147 tornadoes in 24 hours. A killer wind. To study the storms, the rains and winds of the world. To wrestle the weather and learn its secrets. To understand how climate changes. That too can be an irresistible longing of the scientific mind. And the mysteries of our world continue to intrigue us. Take this salt bush for instance, which thrives on the parched desert floor of Death Valley. Environmental biologists want to find out how it has managed to adapt to these brutal conditions and how other plants can be helped to adapt. And speaking of mysteries, take a look at these fossils. Proof that warm weather plants once grew here. In what are now the frozen wastes of Antarctica. What happened? Could this vast continent have moved from somewhere else? And if so, how? According to the theory of plate tectonics, huge slabs of the Earth's crust slide and crunch past each other. Sometimes leaving disaster in their wake. Clues to this phenomenon lie at the bottom of the sea. Where scientists have found evidence of massive forces capable of driving the continents apart. To this day they leave the Earth no rest. If one day we understand the source of this raw power under the sea, can we then prevent earthquakes? And will we then possess a source of limitless energy? Speaking of limitless energy, science is exploding with questions. Some of these children are the ones who will try to answer them and ask still more questions. In school and out, we must encourage them so that those who have that irresistible longing to understand will follow it wherever it leads. To the frontiers and unknown places where only the trained mind can take you. And who knows, here comes another Einstein.