www.lsmsa.edu teacher Robert Dalling's Physics Lectures (see also www.ushumans.net)
The wonders of nature as revealed by science
What is physics and what is science? Science is our collection of facts and understandings obtained from repeatable experiments. Physics is the study of motion, energy, light, gravity, and electricity and such. Physics forms the basis of everything in the universe, including biology, chemistry, geology, astronomy, and technology. What can be done with science? We build understanding that satisfies and further drives human curiosity and we build machines and medicines meant to make the world a better place for all of us. Here are some of the aspects of nature that we will learn about this semester.
By carefully observing the Earth, physical scientists learn much about our world and its interrelated cycles, as seen in NASA’s music video Pulse of the Planet.
Astronomers have measured the distance to each star and to each dust region within the Orion Nebula, which you may have seen as a fuzzy spot in the nighttime sky, and then created a computerized map of the nebula. The San Diego Supercomputer Center and The American Museum of Natural History Hayden Planetarium have made Volume Visualization of the Orion Nebula that takes one on a flight through this nebula, passing newly forming solar systems along the way.
In this introductory physics course, we will learn about the nature of energy, heat, pressure, and temperature and we will learn about the fundamental role these quantities play in most every system. For example, we will see how energy from the sun heats our planet and causes its weather. The Earth Simulator Center and the Frontier Research System for Global Change have modeled the circulation of air around the globe. We will learn about the nature of force, torque, and levers and see examples of them in galactic collisions, bones ( of special interest to people, doctors, and athletes), buildings (how much do you suppose a skyscraper weighs? The total weight of the Empire state Building is 365,000 tons), implosions, bridges (The Newton site has video clips of the Tacoma Narrows Bridge oscillations: Tacoma-a, Tacoma-Car.mov, camguys), airplanes (in this animation, the wing is pushed upwards because it pushes air downwards), windsurfers, and even robots. Here is a video clip of Sony’s QRIO robot, including glimpses of its internal design.
We will find that there is only one equation for force and that it describes the forces in every system, including all those just mentioned. This equation was written in the year 1687 by Isaac Newton. Newton’s equation is used thousands of times per day by scientists and engineers. It has been used to build all of our machinery. It is used to determine the motion of your car as it moves and turns, the motion of the fluids in the fuel and hydraulic systems of a car, the motion of the air that flows around airplanes and lifts them into the air, the movement of the Moon around the Earth, and the trajectories that take spaceships from the Earth to the other planets. Nobody in the year 1687 could imagine the endless uses of this equation. It is a fundamental truth of nature that will be useful for all of humanity for the rest of time. Newton’s equation was used to take explorers to the moon and even to the parody studio.
In the year 1865, James Clerk Maxwell wrote a set of four equations that describe all electrical and magnetic phenomena, including light such as occurs in lenses and cameras or in radio, infra-red, or x-ray devices. These equations describe the operation of every electrical machine–from toasters to computers–that has been made and all of those that will be made in the future. Nobody in the year 1865 could imagine the endless uses of these equations.
In the year 1926, Erwin Schroedinger adjusted Newton’s equation to describe the observed motions and energies of atom-sized particles. This quantum mechanics results in machines from transistors to lasers. Nobody in the year 1926 could imagine the machines that would result from Schroedinger’s equation.
What future uses unimaginable today will result from current research in quarks, elementary particles, and the behavior of gravity on an atomic scale? Will fusion power bring megawatts to each home, allow us to make food directly from carbon, hydrogen, and oxygen and such, and end factory labor? What will life be like, if nobody works in a factory? The resulting change in our daily way of life may be as great as earlier occurred when we changed from gathering to farming or from farming to factory work.
Nature, science, and math often merge in art. How many geometrical shapes and how many angles can you see in these photos? 1 2 3 4 5. The math department of the Stony Brook State University of New York has a collection of chaos videos, including two video zooms within the Mandelbrot set, which is art in itself. The colors depict iteration counts at each point in the same way that contour maps show elevation levels at each point. The videos fractal1.mpg and fractal2.mpg were made by the University of East Anglia.
Everything is physics. What is light? (We see the stuff as if it is something real, but if we cannot hold it in our hand can it be real?) How fast does it move? (Seven times per second around the circumference of the Earth) Why can you see through glass but not wood? What are the differences between water, glass, wood, iron, electricity, and air? Aren't they all made of atoms and molecules? What happens to wood when it burns? Where does it go? Is it still wood? What is sound, and how fast does it move? What's the difference between music and noise? What is an echo? When a police siren passes you, why does the tone change from high to low? How do you hear, see, smell, taste, and feel? Why do different things smell, taste, sound, appear, and feel different? Why is it so hard to force a ball to stay completely under water? Why do balloons float? When you spin a glass of water, why does the center of the water move downward and its edges upward? How does a lever work? After an upward-tossed rock has left your hand, what keeps it moving upward? When you drive your car and turn a corner, why does all that stuff slide toward the side of the dash? How did that stuff know you had turned the corner? What is the difference between ice, water, and steam? When you stretch a rubber-band and release it, what makes it snap back? Why doesn't a bent wire snap back into place? If you bend a wire back and forth it gets hot and breaks. Why? How does a magnet attract things? What is gravity? Does it pull in one direction or does it pull sideways, too? Is gravity the same thing as magnetism? How are mountains formed? Why does the Moon go around the Earth? Why don't we fall off the Earth? Why doesn't the Earth's atmosphere leak off into space? How big is the Earth? Where do clouds and the Sun go at night? Where do the stars go during the day? Where has the Moon gone when we can't see it? Why does the Moon's shape change from night to night? Why are the Sun and Moon larger while they are rising and sitting? Do the Moon, Sun, clouds, and stars follow you as you walk down the street? Where does the sky end? Is it taller than it is wide? What is electricity? How is it different from magnetism and gravity? How does a gun make a bullet move? How do binoculars make things appear to be larger? Why does a pencil appear to bend when you put it into a glass of water? Is it bent? When you spill water on your shirt why does the shirt then appear darker? If the "darkness" is in the water, then why isn't a glass of water dark? When you slam on the brakes why do you fly forwards? Why doesn't the dust blow off your car when you drive down the highway at the posted speed limit? Why doesn't the dust blow off your home cooling fan blades? (Those things are always full of dust.) How does a drinking straw work? What in the world is a fire flame, and why does it rise? Why is the sky blue, and why does it turn red at sunset? What is lightning? What is thunder? Does one cause the other? What causes tornadoes and hurricanes? Why do the ice skaters spin faster when they pull their arms inward? What is heat and just how is it different from cold? What are the coldest and hottest temperatures that exist? Does hot flow toward cold or does cold flow toward hot? How does heat get into things? How does a coat keep you warm? How does sweating cool you off? When you place clothes in the dryer, where does the water go? When water boils, where do the bubbles come from? What is a cloud? Why are some clouds bright while others are dark? Why does that little patch of winter ice always form in the car window? How does a glass of ice-water get wet on the outside? What keeps a car window from frosting over when you park under a carport? How do geysers like Old Faithful work? When you hold a spoon in the stream of a water faucet, sheets of water shoot out. What does this have to do with Space Shuttle engines? What is the difference between green and blue? The hairs of a paintbrush spread out when placed underwater but cling together when taken out of the water. Why? What is a rainbow? Why do camera lenses appear blue? Why does the doorknob sometimes give you that electric shock? What determines the color of an object? What are the Moon and the Sun? What are those funny little points of light in the nighttime sky? The Omni magazine has asked "If you place a lightbulb in the middle of a mirror-lined room and then turn off the light, why doesn't the room stay bright?" Why does a mirror reverse right and left but not up and down? Jearl Walker gives hundreds of examples of physics in everyday phenomena in his book The Flying circus of Physics. For example, hot water running into the sink doesn't splash as much as cold water, and it sounds different. Why? Water falling out of a slightly-on faucet narrows as it falls? Why? You might like to use the internet to gather information about one of these questions, or find some more.
We find that nature is filled with incredible phenomena, each of which involves a curious mixture of interacting components. For example, the colors of a rainbow (pictures) occur as sunlight interacts with water drops, while the colors of a hot spring occur as water, bacteria, and heat from underground magma combine in one place.
We humans share a beautiful planet (photo-a, photo-b) with plants and animals in an interconnected web. We find that each species has incredible features and behaviors. We humans consist of 10,000 cultures, each an expression of our nature. Most every aspect of physics that we will study also occurs within the bodies of the world’s plants and animals. We see how each field of scientific study also involves the study of ourselves.
Our studies will reveal the physics occurring within the objects, plants, animals, homes, factories, and phenomena of the world, including ourselves. We will then understand the motion of cars, passengers, airplanes, thunderstorms, blood and breath flowing in veins and lungs, runners, spinning skaters, drifting continents, planets, the expanding universe, assembly lines, spaceships, swimming fish, gliding birds, leaping lizards, rising flames, and the dispersing seeds of a Maple tree. We will study the forces in bones and muscles, volcanoes, chairs, floors, and walls. We will understand the pressure in tires, footballs, drinking straws, balloons, and lungs. We will survey the flow of energy in human and other animal bodies, homes, geysers, cars, factories, cities, civilization, planet, trophic levels, and in the universe. Something like 1068 joules comprised the Big Bang. The total energy in the universe today is exactly the same. We will study the energy of motion, position, chemicals, heat, light, and mass (E=mc2). Listen to Einstein say his equation or here. (Incredibly, the energy within a basketball-sized piece of uranium provides 1,500 megawatts of power, which is enough to power 1.5 million homes.) We will learn about the physics behind the color of objects, including the colors of green leaves and blue skies, red tomatoes, flowers and orchids, butterflies, soap bubbles 2, diamonds, rubies, clothing, insects, birds, and blue or red skies. We will understand the flow of light through things like sunglasses, your own eyes, a window, a water glass, or a video projector. We will understand the electrical binding of atoms, crystals, and molecules, including the molecules of life. We will study the flow of electricity in nerves, brains, lightning, electrical discharges, eels, cars, the circuits of machinery, and the static cling of clothing and saran wrap. We will learn about the radiation that enables cancer treatment, pasteurization, smoke detectors, supplies powers for pace makers and spaceships, and warms the interior of the Earth. We will study the magnetic fields of an MRI machine and of the earth. We will learn about the electromagnetism behind phenomena involving light, including aurora, rainbows, St_Elmo’s_fire (which left sailors awe-struck), lenses, mirrors, the distortion of the setting sun, prisms, the hallos seen around the sun and moon, bright cloud tops and dark cloud bottoms, terawatt lasers that momentarily produce as much power as is used by everyone on the planet combined, and the dimming that results when we spill clear water on our shirt. The sounds of echos, pianos, sopranos, babbling brooks and roaring rapids, waterfalls, sonic booms, passing sirens, noise, music, and speech. We will begin to understand something about the nature of space and time.
Science, scientists, and the scientific method
Whenever you hear the word "science" you should think of "facts and understandings learned from repeatable experiments." An experiment is repeatable if everyone performing that experiment obtains the same measurements. A new understanding, machine, or medicine can then be based on that repeatable aspect of nature. If an experiment is not repeatable then it can not be scientifically studied and will not be the basis of a medicine or machine. DrPat says that if scientific theories were approved by vote instead of using repeatable experiments then scientific conferences would include people shouting "Birkowitz Lied, and Bean-Plants Died!" while demanding a recount on the human genome.
What sort of people do science? Let’s listen to Philippa Marrack, John Kappler, Don Ganem, B Brett Finlay, Christine E. Seidman, Michael Rosbash, and Richard Lifton describe scientists and the ingredients for scientific success. They work with the Howard Hughes Medical Institute, see also. You might like to visit the Royal Society, the Association for the Advancement of Science, the Research Channel, and the American Institute of Physics. The Exploratorium has interviews with science team members.
What are the differences between scientists, artists, and engineers? Scientists perform experiments in an attempt first to discover and then to understand new aspects of nature. Scientists always connect new understandings to older understandings and often find equations that describe their measurements. Physicists don't make equations for everyday machines; that's what engineers do. Engineers make machines that are based on existing understandings. They imagine new uses for old understandings. The physicist Richard Feynman explains that scientists use their imagination to guess the true reality of nature while artists use their imagination to invent a reality that does not otherwise exist.
Zack Booth Simpson from the Marcotte Lab at the University of Texas at Austin has videos of interactive art involving RNA folding, optical interference, melting crystals, fractals, molecular bubbles, moles, butterflies, fire, smoke, and motion and making wiggly-leaf figures
that move and come to life as a museum goer wands over a canvas.
In the last five hundred years, but especially in the last one hundred years, tens of thousands of scientists have spent their entire lifetimes measuring literally billions of facts about millions of natural phenomena. As each new fact is found, it is shared with everyone on the planet by being recorded in one of the scientific magazines–for example, the Philosophical Transactions of the Royal Society of London which began publication in 1665. Today’s scientific and technological knowledge consists of all of the facts that have been gathered by all of the people of the world along with the sum of all the procedures that all of the world's people have developed.
Scientists have studied–that is, they have measured–millions of species of plants and animals, millions of stars, millions of physical phenomena, millions of chemicals, millions of fossilized bones, millions of archaeological artifacts from previous cultures, and they have observed millions of facts concerning living cultures. For example, in the Human Genome Project, biologists have recently finished the Herculean task of studying the 3.6 billion letters in human DNA. Scientists completed this task in just twelve years.
You never forget the first time you see with your own eyes the Rings of Saturn in a telescope or the microscopic creatures that live in a drop of water, including amoeba and paramecium and such. These other worlds seem to be stranger than fiction. The Cassini-Huygens mission recently landed on Saturn’s moon Titan. Will signs of life be found on Titan or in the liquid pools of water just below the surface of Enceladus?
Atoms and the electrical force are important to us because we are made of atoms that are held together and interact through this force. The electrical force binds together atoms and molecules, including the molecules of life. A molecule can not take on any random shape. Only those shapes are possible that place slightly positively charged regions near slightly negatively charged regions. (Imagine many persons trying to hold onto each other when variously magnetized like the south and north poles of magnets.) Those molecules having such a shape will form–indeed, they must. Proteins are important biological molecules that are collections of tens to thousands of units or amino acids each comprised of about twenty carbon, hydrogen, and nitrogen atoms. Proteins and other biological molecules can have a very tangled shape. A certain biological molecule began as a few carbon rings and grew in length at an average rate of one atom per year; after one billion years it had grown to a length of one billion atoms to become DNA.
A copy of a specific section of DNA is made within the cell nucleus by temporarily unwinding that section. Such a DNA section is called a gene. One gene contains the chemical-construction map needed to produce one specific protein. This is the so-called Central Dogma of biology. DNA is a self-duplicating, self-operating, and self-building combination of molecules. The electric force among the atoms comprising a billion-atom DNA molecule orchestrates the formation of life’s proteins. It also orchestrates the folding of a newly formed protein.
The single-celled E. coli bacteria live in our stomach and help us digest food. Scientists have found that an E. Coli organism contains 500 kinds of small molecules, 3,000 proteins, and 1,000 nucleic acids. There is a constant and ordered sequence of chemical reactions occurring within this "simple" life-form (see The Chemistry of Life by Martin Olomucki and The Realm of Molecules by Raymond Daudel). Since the lifetime of bacteria is typically twenty minutes, there have already been about one trillion generations of bacteria on the Earth.
A human being consists of a trillion cells forming four types of tissue comprising eleven organ systems, including the heart and a couple hundred bones. The Visible Human Project shows a succession of slices through a person, from head to toe.
The Human Genome Project studied the 3.6 billion letters in human DNA and found that the operation of a human is conducted by thirty or forty thousand genes encoding one or two hundred thousand proteins. In contrast, bacteria typically have one to four thousand genes.
Two human individuals are 99.9% genetically identical. Two unrelated individuals differ by only about 30 out of 30,000 genes, which is a difference of 0.1%. This is true whether or not those two individuals are of the same race, come from the same hometown, or come from opposite sides of the Earth. We now know how thoroughly we share the genes that make us human. Two siblings differ by half of that 0.1%. This also means that a stranger from the other side of the planet is only twice as different from you as is your sibling and gathering five persons from throughout the planet produces no more variety than gathering five siblings.
It is often mentioned that humans and chimpanzees share 98% of their genes. This means that the two species differ by only about nine hundred genes, which is about 900,000 A-T, G-C base pairs. The 0.1% difference between unrelated human individuals is 5% as great as the 2% difference between humans and chimpanzees. Both being mammals, humans and mice share 85% of their genes because most genes make lungs and livers and such. We animals are not all that different from each other, we mammals are even less so, and we primates have the least differences of all. Just as mouse and human insides are much the same, so are their outer behaviors: we both forage, mate, raise children, and grow old. The article Initial sequencing and comparative analysis of the mouse genome in the December 5, 2002 Nature magazine explains that less than 1% of the genes of a mouse occur only in mice, 14% of its genes are common only to other mammals, 6% is shared with other chordates, 27% with other metazoans, 29% shared with eurkaryotes (single-celled creatures having a nucleus), and 23% with prokaryotes that have no nucleus. (Prokaryotes existed for two billion years before eurkaryotes first appeared.) Generalizing freely to ourselves, this means that approximately the same percentages of our genes are unique to us Homo sapien sapiens and similar percentages make us mammals and chordates and such. The percentages of genes serving various functions can be shown in a pie chart. On the average, genes diverge at rate of about 1% every three million years. The 15% difference in genes between mice and humans means that the two species diverged about 45 million years ago. We share 50% of our genes with those of worms.
Scientists have cataloged 4,000 species of mammals, 9,000 bird species, and about one million insect species. Each species is a wonder in its own right, having incredible characteristics. All together, more than 1.5 million animal species have been studied, but this is only a fraction of the existing species. The total number of animal species is estimated to be anywhere between two and ten times the number already studied. (By the way, the total mass of all the Earth’s plants far exceeds the total mass of animals.) And for each species existing today, it is estimated that one hundred have come and gone in the past. A species typically exists for a few million years before becoming extinct but some last one hundred times that long. If you line up a series of two hundred of these typical lifetimes for a species, each lasting about three million years, then the series will extend through 600 million years, which is about the amount of time that has elapsed since multicellular life developed. Hence, very roughly speaking, we can say that a sequence of just a couple hundred species-sized modifications can change bacteria into humans.
Biologist Zen Buraceski explains how a sequence of changes in body shape changes jellyfish into winged insects. DNA controls the size of animals simply by controlling how long they grow, chemically signaling when it is time to stop. DNA controls the shape and symmetry of every plant and animal species, including jellyfish (movie or photo). With a small change in DNA, round jellyfish bodies become rectangular flatworm bodies. The body of a roundworm results when the body of a flatworm is rolled up. Mollusks, such as a clam, develop if instead a shell is secreted from the body. Segmented insect bodies develop by adding legs to segmented roundworms. (Listen to various insect sounds.) If a protrusion emerges from one of those segments then a winged insect results. Still another type of animal–the fish–develops from a roundworm by adding first gills and later a mouth, fins, and cartilage, which becomes bone.
Scientists see that as animal forms have evolved in time, a series of particularly successful types emerged because they had each developed an additional organ system. By adding additional systems, one-by-one, onto those already existing, the resulting sequence of animal types–including amphibians, reptiles, and then both mammals and birds–form the stepping stones from bacteria to today’s species. One after another, the sensory, digestive, circulatory, neural, and skeletal systems were accumulated. Another important development was the improved means of temperature control, which is one of the distinguishing features of mammals and birds. Shellfish are the earliest animals to have digestive and circulatory systems and increased senses, nerves and senses are yet more developed in insects and spiders, and the back-boned animals (vertebrates) developed a central nervous system. You might like to explore the Tree of Life or search PBS and NOVA videos for one-minute clips of various animals and their behaviors. NOAA has photos of various plants and animals. Millions of species have come and gone during this time because of the ever changing environment of climate, predators, and food.
We humans are but one type of primate who are particularly talkative and cultural. There have been some 10,000 human cultures on the earth, each as strange and fascinating as the other. The Balinesian Kecak dance (see also Spirit of Baraka) is one element of one human culture. We create a tool for every need, and every tool changes our way of life a little.
At any time or in any place around the planet, whenever hundreds of us humans get together to form a tribe or chiefdom, we will build structures like earthen mounds, including Poverty Point video in Louisiana, irrigation systems, and stone monuments. One of the first things such a group of people will do is to try to find how big a rock they can carve or move or how large a mound of earth they can create. Whenever tens of thousands of us get together, we build temples, palaces, cities, and city-states. What will billions of us build?
Archaeologists reconstruct the cultures, cities, and civilizations of past times and places.
We humans first began the switch from gathering and hunting to full time farming about 10,000 years ago in Ancient Iraq. Our first cities were built in Mesopotamia some 5,000 years ago. The Taisei Corporation has an incredible reconstruction that transports one back in time to Ancient Mesopotamia and brings the city of Ur to life. They also have reconstructions for India, Egypt, Greece, China, Mexico, Rome, and Venice. Cahokia was a city of 20,000 persons during the years 800 to 1300 ad. Situated across the Mississippi River from present-day St. Louis, Cahokia had its own Woodhenge for conducting astronomically based activities and ceremonies.
Scientists have gathered billions of facts. At first, many of these facts seemed to have no relation to any of the others. Eventually, scientists were able to deduce the handful of basic, underlying principles of nature that explained all those facts and revealed their interrelations. For example, the answer to every question in biology is given in terms of evolution, which is "changes in the most appropriate traits of individuals due to changes in its environment of climate, predators, and food." Much of psychology and anthropology are different manifestations of the biology of the brain. In this physics course we will see how all phenomena involving motion, heat, electricity, magnetism, light, sound, and energy are simply different manifestations of one underlying aspect of nature: if you push on an object with a force–which occurs only in gravitational, electromagnetic, or nuclear forms–then it will speed up. All of nature–humans included–is understandable in terms of the few fundamental rules that we will learn in this course.
Scientists measure everything from motion to society, even love is a topic of scientific study. The topic of our own emotions and behavior is subject to many rumors, partially true stories, and guess work by each of us. This happens because we accumulate our own experiences and form our own descriptions of these things. A scientific study can add to our own somewhat vague notion of love by providing concrete facts determined by measurement and by discussion with many different persons. It's also fun to find out how similar or different we are from others and about the range of characteristics in people. It's fun for us to learn about the amount of variation in these things from one person, or one culture, to the next. The scientist also has fun making measurements to learn more exactly what is occurring. It should at least be fun for us to know that there are people who actually think such a study is fun.
A scientist will ask specific questions like how many times does a person fall in love, how do we fall in love, and what sorts of chemicals are going through our brains while this is happening. For example, it has been found that we have elevated levels of certain chemicals during the first two years we are in love with a person. Do you think you feel differently during the first two years of being in love? Every child asks his or her parents how to know if he or she is in love. Scientific studies make more concrete our vague notions, sometimes verifying what we already suspected about ourselves. Have you noticed that we often fall in love in steps. First, we enjoy this certain person's company. We begin to pay attention to every detail of their movement and behavior, and soon, we can think of nothing else besides this person. We have a tender first-kiss which we might replay in our mind every few seconds through the next week. During each replay in our mind, we see the other’s face and feel the press of lips. We are unable to focus on our work except for ten seconds out of every three minute period, and we can’t sleep. Scientists find that the chemical oxytocin is being produced and released within our brains. It is enabling this extraordinary power of concentration, and it is forging our love. We are now fiercely smitten. The beauty of this person becomes more pronounced and we become unaware of the existence of all other persons. Everything around us that used to be dull and boring suddenly takes on a new brightness; an old familiar song now sounds different. Finally, we never want to be away from this person. We feel that the universe was made for the two of us and that compared to love, what does the universe matter; without our love, their would be no universe. Did you experience any of these steps? In what way is falling in love different for you? Can you put these steps into a poem or song? Notice that as you replay in your mind the sight of this person’s face and the press of your lips that no words are being spoken: the feeling you are experiencing is older than words. For a few million years, our ancestors were falling in love–and being in love–without holding a single conversation.
Scientists make measurements, form conclusions, and then make additional measurements to further test and refine those earlier conclusions. They repeat endless cycles of measuring, concluding, and further testing as they move ever closer to understanding. They continually decide what should be next measured to further test conclusions. Every conclusion is tentative because the next measurement might prove it to have been incomplete or even wrong. As soon as a scientist believes something to be 100% true then that person is no longer a scientist. Each measurement and conclusion is reviewed by other interested scientists and is subject to verification or disagreement. The goal is continually to refine measurements and conclusions to gain a more accurate understanding of a phenomenon. “Truth” and our level of understanding is measured by counting the number of significant figures in repeatable measurements.
A scientist studies one of the following four fields: matter and its motions and interactions, plants and animals, chemicals, or people and our societies. From these studies emerge an understanding and appreciation for nature and for human beings along with some useful machines and medicines. A scientist will learn the general, underlying principles that explain the millions of previously-measured facts within one of these fields, and then become an expert at a more specific aspect of that field. A single scientist knows a tiny, tiny fraction of all of the known facts of a given field, but will know a meaningful percentage of the facts within one specific aspect of a field. For example, a particular biologist learns the general principles of plants and animals, then thoroughly studies hundreds of species and becomes an expert in a small number of them or of a certain aspect of them.
Scientists operate from a fundamental base of well-understood phenomena. These are the things that they all agree on. Luckily, there is also a never ending list of undiscovered phenomena and also newly discovered phenomena that are incompletely understood. When scientists recognize a new phenomenon of nature they will make a list of things that might produce or affect that phenomenon and then do experiments designed to vary just one listed item. In this way they measure each listed variable's affect on that new phenomenon. This tells them if any of the items did cause, or at least affect, that new phenomenon. The measurements from each new experiment reveal clues to the nature of the phenomenon.
Physical phenomena are the easiest to study because they usually involve a small number of variables, while biological, economical, and sociological phenomena involve thousands–or even billions–of variables. For example, when scientists try to determine the cause of cancer they are faced with countless variables, each of which is difficult to isolate for study. Even the tiniest biological phenomenon is incredibly complicated. But it is understandable when its entire process is broken into a series of smaller, individual steps. Each biochemical phenomenon involves a long list of complicated chemical reactions. The operation of your thyroid gland, or its reaction to an increase in the level of any single chemical, involves a series of many interacting chemicals.
Scientists show every human characteristic and emotion as they debate and compete at the frontiers of knowledge. They will always argue and disagree about the not-yet-understood aspects of nature. There is disagreement while measurements are revealing more of the true nature of the phenomenon. For example, look at a picture that is hanging on the wall, except, imagine that most of the picture has been covered by hundreds of little square tiles. Each scientific experiment reveals more about a phenomenon in the same way that more of that picture is revealed by removing a randomly chosen square. Until enough squares have been removed there will be a debate about the contents of the picture. Some might argue that it is a picture of a giraffe eating a railroad car while others think the picture shows a bush listening for a bee. One feature of doing science is that the pieces of the picture are revealed in random order. The full picture is not understood for days or weeks–in fact, it usually takes many years. If you like mysteries, then you might enjoy a career in science. Nature provides the most interesting mysteries.
Scientists do science because they have a passion for nature and want to understand how nature works. They also want to make the world a better place for all of us. Science produces results that change our way of daily life. The inventors of factories, steam engines, automobiles, and computers have changed our daily way of life, while Napoleon managed only to temporarily rearrange political maps, see The Western Intellectual Tradition by J. Bronowski and Bruce Mazlish. If Napoleon wanted to change the world, he should have been a folk singer, or at least a scientist. Bronowski and Mazlish explain that ideas have a life of their own and serve as stepping-stones to new ideas. The old ideas do not go away–they cannot be un-known. Ideas and society continually interact and affect each other. (You might like to visit Public Radio’s The Engines of Our Ingenuity for a discussion of technological creativity.)
Those of us who build roads and construct buildings feel a sense of accomplishment when we see the results of our work. We hope that it will last for decades, even centuries. Scientists build understanding and hope that it will be useful for people for decades or centuries to come. For example, electricity and antibiotics will be useful for all humans for centuries to come. An explorer wants to go where nobody has ever been. A scientist wants to know and understand what has never been known or understood–to think what has never been thought. Scientists feel as explorers do when they are the first to understand a phenomenon. They jump up and down and scream and shout when they have come to understand a piece of the universe.
The current state of our understanding of the universe is the result of the lifetime's efforts of thousands of scientists who have been working for the last five centuries.
After a scientist has pondered questions with importance for all humankind–for example, the question of the origin of the universe–then everyday questions like getting there via Main street or Broadway, or the color of today's shoes and shirts, even material pursuits, become unimportant. In fact, the scientist sees that her own life is but a very small part of the universe. This is a very humbling experience and often results in the scientist's behavior being mistaken for either boredom or arrogance. The scientist prefers to spend time only on the most important questions.
Many scientists will work eighty hours per week for years with a single-minded obsessiveness in pursuit of this knowledge. You know that feeling of confusion you have as you are trying to figure out a complicated problem; it is like a painful knot inside your head. The obsessed scientist has this feeling throughout most of the day and sort of becomes addicted to it. The end of a good day's work means that you are so mentally exhausted that voices dance on their own through your head (this is nirvana). These obsessed workers are aware of each minute that they are not working and become panicked if just a few minutes are spent away from their work for "no good reason."
Such an obsession is not anything new. For example, it was the cause of the death of Archimedes 2. He lost his life while working on a mathematical problem and refusing to pay due attention to a Roman soldier who was anxious to question him, see Watchers of the Sky, by Patrick Moore. “Don’t disturb my circles!,” were his last words, as explained here.
Each scientist takes the results of the previous generation of scientists, adds something to it, and passes the increased knowledge on to the next generation. As we strive to understand a newly discovered aspect of nature, we usually fumble around in the dark for a while as we try to make sense of it. Once it is understood, soon everyone else on the planet also knows about it, and we never un-learn anything. Throughout history, the use of each new tool soon spread around the planet. Today’s science and technology is the sum of all the facts, procedures, and understandings ever obtained by any person on the planet.
Scientists test our assumptions about nature by making numerical measurements of phenomena. For thousands of years, we have sat in our "arm chairs" imagining how nature works. We tried to reason logically and to keep our newly developed deductions logically consistent with our previous deductions, but we have been constantly surprised to find that nature behaves very differently than we had naively expected. Quite often, nature has been found to behave in a way that nobody had imagined. For example, no physicist could have guessed how either atomic-sized objects interact in nature. "Fast" objects are those moving at more than 90% of the speed of light (at such speeds they could travel around the Earth’s equator seven times per second). They are also said to be moving at “relativistic” speeds because they are in the realm of Einstein’s Theory of Relativity. Instead of guessing correctly before measurements are made, we find out the actual ways of nature when we make measurements. The equations of quantum mechanics and relativity numerically describe the way nature was found to behave when scientists measured these things. No matter how many logical reasons we can think of that objects should be able to move faster than the speed of light, we have never observed any object doing so in nature despite the fact that millions of high speed particles are observed in elementary particle accelerators every single day. Fermi Lab has more information about this so-called quantm mechanics.
If a proposed process cannot be repeatedly measured despite sufficient attempts then that process is probably does not happen in reality. For example, one might propose that migrating birds navigate by detecting the gravitational pull of the stars. The complete lack of repeatably-measurable results is the reason that scientists complain about such things as paranormal phenomena, extra sensory perception (ESP), and communication with the dead, see the Skeptical Enquirer magazine. Scientists have never been successful in their attempts to measure these phenomena. If these things cannot be repeatedly measured then they cannot be understood as real events or used to make machines or medicines. Many persons (like my friend John) like to point out that as much as we would like for ESP, telekinesis, mind-reading, astrology, and paranormal phenomena to be real things, none of these have improved the quality of life of the general population. They have not solved a single social problem or even built a single building. In contrast, science and technology have enabled our modern civilization.
We have all heard that each newly answered question in science leads to many additional questions. This means that many questions do not yet have an answer, you might choose to contribute in finding their upcoming answers. Physics and engineering have been fields where a young mind could hope to produce great changes in the lives of many persons. The results of biological studies are having a great and immediate impact on our lives today by maintaining our health and providing "magical" solutions to many problems. These experimental sciences have also allowed us to understand something of our own nature. Our social scientists help us direct the actions of our civilization toward the best life for all of us. If you are a young person just now beginning high school and are trying to choose a field of study, you might like to choose a field of science to attempt to find and understand a new aspect of nature or to attempt to better-understand our own nature. (For information about careers in science, visit www.careercornerstone.org.) You might choose to express and communicate our nature to others through art, see www.nea.gov and http://k-12.ccad.edu/careers.htm. If you want to help find the most-just arrangement for the interacting elements of our civilization then you might choose to become a social scientist or a political scientist.
Nature is full of surprises. The closer one looks, the more surprising it becomes. We will learn something about the physical world around us--making it less mysterious. Why:
1) This is fun because it satisfies our natural curiosity: we want to understand things because they are there
2) We become a fuller person with each thing we learn
3) We need to know something of the science behind our technological world. Every few seconds we use a machine resulting from science, including TV, radio, cds, electronic games, phones, and cars. How many machines can you list that you use every day?
4) Many of you will become scientists or engineers and will use physics everyday
5) To change the world, to advance civilization, to make the world a better place for all of us
6) As voting citizens we need to understand something of those numerous aspects of science having societal consequences, including
i) the scientific attempt to determine if there is man-made global warming
ii) the choice between nuclear-, coal-, hydro-, or natural gas-powered electrical generating plants
iii) funding of scientific research
List other aspects of science having societal concern.
Modeling nature with mathematics
Traditional peoples worshiped the "power in the bush." There was a mysterious power that made a bush just grow out of the ground where none had been before. They see many other powers, including the power in the thunderstorm, in the dance, in the house, in the fire, and in the sun, rain, and wind. A deity is a name that represents a particular power. Consider a hunting bow. There is "something" that enables it to function: There is a "power" in the bow. When you hear a particular group of people say that "Blog is the god of the bow," then you should think to yourself that Blog is the power of the bow and that Blog is the name for the thing that makes the bow function.
Instead of attributing the event to water deities, the Greeks were the first to explain annual river rises in terms of snow melting off nearby mountains. For the next 1,500 years, we sat in our armchairs trying logically to understand and deduce the ways of nature. Greeks debated such things as does ash float, is the ideal horse the only that is real while visible horses are inferior copies, is a number real, and what are the fundamental units of matter. The scientific method of making repeatable measurements was not stumbled upon until the Renaissance that occurred as Europeans were rejecting and questioning everything about their world because they believed it was inferior to that of the Roman Empire that came before them. Once we started making measurements instead of logical arguments, our understanding of nature became much more accurate.
The Ancient Greeks (600 - 200 BC) were the first to figure out something of the geometry of triangles and of spheres. We have all heard of the Pythagorean Theorem: a2 + b2 = c2. This was something different. No "triangle god" was needed to explain triangles. There was no myth concerning triangles. The old deities were somehow lacking. By the way, one poem states that Pythagoras, who lived in the mid 6th century bc, stopped a man from beating a dog, saying "Don't beat him. He's the soul of a friend; I recognize his voice," see page 11 of Early Greek Science: Thales to Aristotle by G.E.R. Lloyd, 1970. Archimedes
The Greeks also found a mathematical ratio of string-lengths producing successive musical notes. They were shocked that nature could be described mathematically. Still today we wonder why this is so. Why can nature be modeled mathematically? Is nature mathematical? In addition, some scientists wonder whether mathematics exists on its own or if it is simply invented. Humans model the universe with mathematics because this allows them to more accurately understand nature and to build more useful machines and medicines. Scientists try to imagine how nature works in a specific situation and then go make measurements to find out if they are right. The measurements often show that nature has much more imagination then we do. As much as we hate to admit it, our imagination is limited. An example of our limited imagination is that we cannot think of a new color–not simply "sand-dab melon chardonnay" but a new color, one that does not contain red, green, orange, violet, or blue. Even more telling about ourselves is the fact that we cannot think of new emotions or behaviors for ourselves that are not already innate to a human.
Athenian Greeks were free to theorize and debate, but this freedom was ended by Alexander the Great. Learning continued in India, China, the Islamic equator, and in Rennaisance Europe. Knowledge accumulates and consists of the contributions of many individuals around the world. For example, algebra was developed in the eighth century a.d. by the Persian al-Khwarizmi, whose book name is mispronounced "algebra."
Standing right here, using this meter stick we can measure the diameters of the Earth and Sun (see Hewitt).
The Earth's diameter is 25,000 miles and it turns in 24 hours. This means the sun moves 25,000 miles/24 hours=1,042 miles per hour or 0.3 miles per second or 6 miles per 20 seconds. (Time zones are about 1,000 miles wide). If you kneel down and watch the Sun's top set just at the horizon and then stand six-feet higher you'll again see the sun. Measure the time elapsed until the Sun again sets to the same point. The horizon is 6 miles away from an eyeball 6 feet above the ground. The Earth has spun 6 miles in that measured elapsed time, which is 20 seconds. Measuring the elapsed time allows us to work backwards to find that the Earth's diameter is 25,000 miles.
Method 2.
Place a coin away by a distance equal to 110 times its diameter and it will eclipse the moon or sun because they each make a 0.5 degree angle at our eye. The angle a=s/r and is .5 degree times 2 pi rad/360 degrees = 1/114.
1/110 = coin diameter/coin distance = moon diameter/moon distance =sun diameter/sun distance because they each make a 0.5 degree angle at our eye. We can measure the coin's numbers and look up one for the moon or sun's distance.
Let's try it: the sun-earth distance = 1.5 x 1011 meters,
and
sun diameter = sun distance/110 = 1.5 x 10 11 / 110 = 1.4 x 10 8 ?
yes, this checks with the accepted value.
moon diameter = moon-earth distance/110
= 63.84 x 10 8 /10=3.5 x 10 6 =twice its radius of 1.7 x 10 6 .
yes, this checks with the accepted value.
Use imaginary sunlight on one billiard ball, as observed from the ball it is orbiting, to show Moon's phases as it circles the Earth. This explains the 90 degree angle at half-moon shown in Hewitt fig 1.5.
Try the pinhole method of measuring the distance to the Sun as shown in fig 1.6.
Hewitt Fig 1.2: The distance on the left between the Moon and the Earth is also the same distance on the right between the Moon and the Earth.
More accurately, pi has the value
3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679821480865132823066470938446095505822317253594081284811174502841027019385211055596446229489549303819644288109756659334461284756482337867831652712019091456485669234603486104543266482133936072602491412737245870066063155881748815209209628292540917153643678925903600113305305488204665213841469
Do you see your phone number within this approximation of pi? The Pi-Searcher will check for you within the first 200 million digits of pi. Since π has an infinite number of digits, any given sequence of digits will occur somewhere within pi. In fact, the phone numbers of every person on the planet occur in alphabetical order somewhere in pi.
Did you know that the fundamental numbers are related through e i Π + 1 = 0
Give one-paragraph answers
1. What is science? Who pays for it? Who benefits from it? How many scientists are there? What portion of science is funded by government or business? Do we need science?
2. How much does your country spend on each of science, art, sports, education, health, and the military?
3. What is the difference between science and technology? What has been the role of science in building roads, boats, cars, planes, buildings, cities, electronic gadgets, business procedures, political campaigns, home appliances, and farming techniques?
4. Should science provide understanding, or just practical tools, or both? Should we stop doing science?
5. Is it important for everyone to understand the science behind the machines that we use every day? Is it important for everyone to understand the natural world? What do we need to understand about science before we vote on scientific issues?
6. List some fields of science.
7. Discuss the personality of some movie characters that were scientists.
8. List some objects in motion.
9. List the electric and magnetic machines you use every day.
10. Describe a phenomenon that involves light.
11. Describe a phenomenon involving heat.
12. Describe a use of nuclear radiation.
13. Secretly write a numeral on a sheet of paper and cover it up with a dozen squares. Then remove squares, one by one, in random order while other persons try to guess which number had been written down. (Watch out for foreign, ancient, or backwards and upside-down numerals.) Similarly try uncovering a photo.
14. Name a scientific study that is useful and one that is useless. Does everyone agree with you? How can we gauge the "usefulness" of a study?
15. Create a piece of art that explains how you feel about science.
16. Measure the period of a pendulum.
17. What are the roles of business and government in scientific progress?
18. Can you prove or disprove that white fence posts, green homes, or trees do or do not cause cancer?
19. Should we patent both machines and scientific principles?
20. How have today's science and technology depended on that of past centuries?
21. What portion of the world's population is involved in research in science and technology? How has this portion changed through the centuries?
22. Why do some machines behave in a way that wasn't expected?
23. What’s the purpose of knowledge? Of machinery? Why do humans pursue these fields?
24. How do science and technology affect our social and cultural ways? Our health has certainly been improved by this research, have our social and cultural ways been "improved?" What portion of our happiness is due to the machines we use or the knowledge we hold? Compare the effects of science and technology on the happiness and the social interactions of people living in Ancient Egypt, an industrialized nation today, the Medieval world, and as gatherer-hunters in today's Brazilian jungle or in ancient America.
25. What is the number of things that might affect your health? How can you measure some of these things?
26. How many facts do you think have been measured about each of the following? Bees, the human heart, the human body, flowers, iron, water, earthquakes, nuclear radiation, stars, fossil skeletons, primate behavior, human emotions, satisfaction in the workplace, the economy, and ancient Mesopotamia.
27. List some evidence for ESP. How many facts have been measured about ESP?
28. Toss a coin 100 times. For each toss, try to predict if the coin will land heads or tails. How many times were you right? Count the number of heads and tails. Was the difference in counts less than the square root of the number of times you tossed the coin?
29. Does a plant hear? When is it happy? How can we measure these things?
30. Is scientific understanding important? Is art important? Are sports important? Are material possessions important? Who is to decide if these things are important to a person, or to a group of persons?
31. Is astrology a science?
32. Think of a statement that you were told as a child, whose truth you have taken for granted your entire life. Since the evidence for this statement is nothing but hearsay, what should you research or measure to determine whether this statement is in fact true. For example, many of us have heard the following claims. Cats eat mice, sugar is bad for you, elephants fear mice, feed a fever but starve a flu, baldness comes from your uncle, muscle turns to fat when you're lazy, red headed people have tempers, blonds are dumb, all persons born under the astrological sign of Aries act smukely, the Earth is round, lightning never strikes the same place twice, radiation from plutonium kills people, all politicians are crooks, you can't teach an old dog new tricks, we use only 10% of our brain, people act differently during the full Moon, criminals have bad genes, animals can't think and don't feel emotions.
33. During each day you hear many statements made by persons who simply claim that the statements are true. List some of them, and describe what you should research or measure in order to determine whether this statement is in fact true. How can you determine if a news story is true? List a sentence from a news report, or from a person you had talked with today, that you knew was true. How did you know it was true?
34 When and where did we first learn to make paper, dishware, pajamas, cigars, bread, and maple syrup?
35. To experience the thrill that scientists feel as they explore the world you might try looking at a drop of water with a microscope–its abundance of living things will surprise you. You might look at the Moon or the rings of Saturn in a telescope. Since we see it most every night, we think we are familiar with the Moon until we see the detail visible in a telescope. It is thrilling to see three-foot lightning bolts emitted by Tesla coil.
36. Are triangles, circles, and spheres just "theoretical" shapes? Does anything in nature have the shape of a perfect triangle, circle, or sphere? Have we built anything that has such a shape? Do molecules form these shapes? Does the Earth or the Sun have the shape of a perfect sphere?
37. If two people measure the same event will they both obtain identical measurements? While driving a car, if one drops a rock out of the window onto the road, does the rock fall straight down? Would a second rock fall straight down if it is dropped onto the floor of the moving car? Would a person standing on the curb watching the moving car and the dropped rock think either rock fell straight down?
38. Interview a scientist to find out about his or her life and research.
39. What have been the most important experiments of one of the fields of science?
40. Do either scientists, teachers, politicians, dictators, or business operators ever change civilization?
41. Is mathematics real in that it exists on its own so that we simply discover new aspects of it or do we instead invent mathematics as the need arises? Do natural phenomena exist on their own? Does either art or understanding exist on its own?
42. How many factors might affect the weather, the economy, our behavior on Tuesday, a nation's decision to convert their political system, global warming, the causes of famine, the causes of poverty, or the brain's operation. Which of these things is well understood? Is radiation, nuclear energy, or genetic engineering well understood?
43. Compare a scientist's and a poet's description of love, roses, gnats, and a sunset. What is the difference in motivation of these two persons? Why do we ponder love, roses, gnats, and the sunset?
44. Place the following items into some categories: hat, horn, blue, rat, running, tag, bat, volcano, cow, dog, Jupiter, algae, Saturn, ape, knee, algae, whale, liver, heart, Asia, Africa, Tuva, Brian, Greg, knife, arrow, Kari, clamp, home, tribe, chiefdom, farmer, teacher, DNA, happiness, smelter, anger, justice, play, eat, hydrogen, carbon, sleep, neon, gazelle, toaster, radio, Islam, x-ray, Hinduism, thunderstorm, computer, Napoleon, shoe, steam engine, chocolate, tire, music, governor, debt, and nothing. A physicist might categorize these items by electrical resistance and mass-density. What sort of categories might a biologist, psychiatrist, political scientist, politician, business person, gatherer-hunter, farmer, or sociologists use?
45. What is a person?
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