Modern Physics: An Introduction
Welcome to the world of modern physics. To help you make sense of this fast-changing field of science, this program has two parts. Part One will take you on a brief tour of the history of physics. Part Two will introduce you to some working physicists today.
So let’s get started.
Part 1: A Brief History of Physics
Physics has always been the basic science. Physics is the science that asks and tries to answer the basic questions. about matter. About light, about motion, and energy and power. About the universe at its largest and about the universe at its smallest.
Working physicists have always been looked on by other scientists, as well as by citizens, as the very model of what scientists should be. To appreciate why this should be so, it helps to know a little of the history of physics. This is almost the same thing as the history of science itself, the two are so closely identified.
Like the broader field of science itself, physics has two faces-human wonder and human power. Both were born in ancient times.
From the power side the first working physicists were the human beings who first learned how to move a heavy rock by using a long stick. The human beings who learned how to chip a stone, to make an axe head. The human beings who learned how to make a wheel, dig a well, plow a field, and navigate a ship.
From the wonder side, the first physicists were the curious human beings-the dreamers-who first looked up at the sky and out to the sea and asked themselves big questions. What is the sun? How do the stars move? How did the earth come to be the way it is? What makes light and darkness? How did human beings come to be the way they are?
Unfortunately, these two human sides-the inventor and the dreamer-did not have much do to with one another in most ancient societies. The inventors tended to be people who worked with their hands. The dreamers tended to be people who came from a more leisurely class who worked with their heads. For thousands of years these two kinds of early working physicists had little to do with one another. The science of physics had not yet been born.
Beginnings were made in many parts of the world. In ancient China, for instance, theories to answer some of the big physical questions were developed out of a religious tradition called Taoism. These Taoist theories did not turn out to be very useful in practice.
At the same time in China, however, skilled mechanics did invent many useful tools. Like the world's first water clocks, seismographs, and most important of all, the magnetic compass.
In ancient India one of the world's first atomic theories took shape from a Buddhist tradition. Early thinkers in India also had a subtle theory of forces and motion that was closer to our modern theory than any developed in the nearby Greco-Roman world.
So, too, in other early civilizations in South America, Africa, and Asia, people wondered about the big questions of physics and astronomy. Other people invented solutions to practical everyday problems. Occasionally these two traditions would cross. Calendar construction, for instance, was based on accurate observations of heavenly bodies.
Still another place where the traditions of theory and practice crossed was in the science and practice of warfare. A stronger sword, a more powerful catapult, a faster ship, a more impregnable fortress. All these and more were designed and improved in many ancient and medieval societies and this military knowledge found uses in peacetime as well.
One of the most important steps forward was taken here on the eastern shores of the Mediterranean Sea about 2500 years ago. In what was then called Ionian Greece (today a part of modern Turkey). lively new schools of bold thinkers began to speculate in a new way about physical questions. Greek natural philosophers like Thales, Anaximander, Democritus and Aristotle asked some of the same big questions about astronomy, about forces and motion, about light and sound, and about the structure of matter that physicists are still asking today.
What was new in their day, these Greek thinkers answered these questions with physical theories that for the first time did not include supernatural gods. In searching for rational explanations for all physical changes they looked to the day when human beings could control physical changes, and not have to rely solely on magic and myth.
A dramatic poet of that day, Sophocles, wrote lines that caught the spirit of these bold thinkers and that could still today serve as a rough definition of science.
"Wonders are many and none is more wonderful than man. The power that crosses the white sea driven by the stormy south wind, making a path under surges that threaten to engulf him."
This combination of wonder and power, of philosophy and invention, would eventually lead to modern physics and indeed to modern science and society. It took more than a thousand years, however, for the marriage to bear fruit.
Most scholars say that modern physics (and science) was born in the late Middle Ages and the Renaissance, five to six hundred years ago. Here is the man who in his own lifetime and work is often given credit for being the first modern physicist-Galileo Galilei. As a young university professor of physics and mathematics, he would sit here in the great cathedral in Pisa, Italy, and watch the altar lamp swing back and forth. Back and forth. Back and forth. Curious, he timed its swing with the only watch he had available in those days, his own pulse. He found that it took the same amount of time to make one swing, regardless of how wide or narrow the swing!
From simple experiments like this one, Galileo constructed a new theory of forces and motion. This new theory could be tested in experience. This new theory of motion explained not only why the altar lamp should swing the way it did, it also explained why the earth and the moon moved the way they did. And why cannonballs and catapults, slingshots and snowflakes, carriages and cathedral bells obeyed the same laws of force and motion.
Galileo's new way of looking at force and motion was important enough. Even more important were the methods that he and others of his day were inventing and developing. These were the methods of modern physics. There are the methods of modern science.
Two things were crucial to these new scientific methods, theory and experience, wonder and power. From now on, it would not be enough to invent a brilliant new theory. The theory had to be tested. The theory had to prove itself true or false when confronted with stubborn facts.
Galileo and his fellow physicists of the Renaissance set the pattern and laid the first basic building blocks in mechanics, optics, astrophysics, mathematics and thermodynamics. Their pioneering work culminated in the world of the man whom many call the greatest physicist, indeed the greatest scientist who ever lived, Isaac Newton.
Working alone here in his family home in Woolsthorpe, England, as well as in London and Cambridge, Newton pulled together the threads that Galileo and others had spun, and wove them into his famous Laws of Motion and Law of Universal Gravitation. He also invented a whole new branch of mathematics, calculus, to describe motion.
Looking out his bedroom window here at Woolsthorpe, Newton himself tells us, he saw an apple fall and it gave him the idea for his law of universal gravitation. An apple falls, he said, because there is a universal force that exists between all objects in the universe! Just as the apple is attracted to the earth, the earth is attracted to the apple. In exactly the same way the earth is attracted to the sun and the sun to the earth; the earth to the moon, the moon to the earth; the stars to each other, and so on, and so on and so on.
Newton did not just notice this attraction, he described it in a mathematical equation that could predict in numbers exactly how strong that attraction was between two bodies in the universe! The attraction of gravity varies, he discovered, depending on two things-the mass of the objects and the distance between them! The greater the mass the greater the attraction, the greater the distance the less the attraction.
Using these new laws of motion and gravitation that Newton described with mathematical precision one could in principle predict how all bodies in the universe moved! The laws did predict accurately, for instance, how far a rifle bullet or a cannonball would go given its initial velocity. The laws predicted accurately how long the earth would take to go around the sun, how long the moon would take to go around the earth. In our day the same laws predict how long the space shuttle takes to orbit the earth at different altitudes or how long a spaceship would take to go to Mars.
These new discoveries in physics were so powerful and so impressive that for over two hundred years Newton's laws of Motion were taken to be the centerpiece and the very model of what it means to be scientific. Some went so far as to suggest that if you knew the position and velocity of every particle in the universe, you could, using Newton's laws, predict with 100 percent accuracy every event in the universe-past, present, and future. Even though everyone admitted that in practice you could never know all of these positions and velocities, still in every case where you did know, the theory worked. And so Newton's laws reigned supreme for over two hundred years. As a poet of his day wrote: "All nature lay hidden from sight. God said, let Newton be, and there was light."
It turned out to be not quite that simple. To demonstrate the errors in the Newtonian world view major discoveries had to be made in other branches of physics. In the 18th and 19th centuries, discoveries did come fast and furious in all these branches of physics.
Famous theoretical physicists like Michael Faraday, James Clerk Maxwell, Thomas Young, Nicholas Sadi Carnot, Hermann von Helmholtz, Hans Christian Oersted and Joseph Henry forged the outlines and the details of the chapters on optics, wave motions, heat, electricity, magnetism and nuclear physics that you now study in high school and college textbooks.
Building on the new marriage of theory and practical invention, the power side of physics also made giant strides in the 18th and the 19th century.
Around the time of the American Revolution a Scottish mechanic named James Watt invented the first practical steam-engine. In England improved steam engines were soon used to ventilate mines, to propel trains and ships, to power textile mills and machine shops.
In America self-educated physicists and inventors like Thomas Edison, Nikola Tesla, George Westinghouse and Charles Steinmetz led the way in finding practical ways to produce and use electricity. Alexander Graham Bell pioneered a new way of communication, the telephone. Eli Whitney invented the cotton gin, one of the first steps in mechanizing agriculture--and eventually in abolishing slavery.
German engineers Gottlieb Daimler and Karl Benz made the first practical automobile in 1885. The American self-taught inventor and capitalist Henry Ford made the first mass-produced automobile in the early 20th century began. At about that same time Dayton bicycle shop mechanics, Wilbur and Orville Wright, using and revising theories of motion control, mechanics and airflow, built the first powered airplane. All of these giant steps in human ingenuity and power created an Industrial Revolution that is still with us today.
At just about the turn from the 19th to the 20th century, there came another revolution in physics as profound as that of Galileo and Newton in the Renaissance. This revolution in physics we are still today trying to understand and cope with in our science, our technology and our society.
The first scientific revolution in the Renaissance had the physicist Isaac Newton at its center. The second scientific revolution in the twentieth century has many heroes, but the most justly famous and central is the physicist Albert Einstein.
Einstein was a very young man, newly married, a clerk in the Swiss patent office in Berne, the capital of Switzerland, when he made his first great discovery. Looking out this window of his small apartment along the main street of Berne, Einstein dreamed dreams and wondrous as those of Isaac Newton. Time and space puzzled him. Matter and energy puzzled him.
His new theory showed that Newton's hitherto unchallenged laws of force and motion were not quite true!
Newton's laws were, Einstein showed, only special cases of a more general law, his own special theory of relativity. Einstein opened the door. Soon from many other sides, other physicists of the early 20th century were poking more holes in the accepted wisdom of classical physics.
In Paris, Marie Curie and her husband Pierre Curie discovered new elements that were what Marie called "radioactive." Ernest Rutherford, Neils Bohr, Enrico Fermi and their physicist colleagues found case after case where classical physics was inadequate to explain what they were observing in their laboratories. This was especially true when it came to the very small and to the very large. When it came to the inner structure of the atom. When it came to the outer structure of the universe.
In these new observations it was not that classical physics was totally wrong. Classical physics was, however, limited to special cases. When you venture out of these special "normal" cases into the very large, the very small, or the very fast, different laws were shown to apply. And these different laws, combined with the classical ones (which still work in normal cases) give modern working physicists power beyond the wildest dreams of their ancestors.
In basic science, for instance, modern physicists use powerful tools like the giant accelerator at Fermilab to rip apart the smallest structure of matter, the atom, and then to study the quarks that make it up.
At the other extreme, modern physicists use the most advanced telescope in the world, the Hubble Space Telescope, to look out to the stars and learn what happens on the largest scale we know of-the billions of years ago universe. Exploring how it began, how it evolved and how it works today.
Modern physicists also work with lasers and with computer chips to study the basic units of "information." The knowledge gained from their work is at the foundation of the new communications systems and information highways that today are making the world into a global village. It is also physicists' work that makes possible the many new tools used in modern medicine for diagnosis and for treatment.
In fact if you look at just about any tool of our modern age from automobiles to spaceships, from digital cameras to dish washers, from bridges to power plants, from nuclear submarines to heart pacemakers, you will find the work of modern physicists at the foundation level. This is the level of atoms and molecules, of light and sound, of heat and motion, of electricity and energy. The basic levels of our universe. The basic levels of our lives. Where, indeed, as in days of old, "wonders are many, and none is more wonderful than man."
Part 2: Working Physicists Today
Sally Ride, Astronaut
"Physics is a very basic science. And the goal is a very basic understanding of all the aspects of our world. The very small parts and the very large parts. Trying to connect the very small with the very large. Connecting elementary particles with the creation of the universe."
Don Eigler, Nanotechnology
"So, what we're going to do is move this atom from this location here to a location right over here. We'll move it just along this path here. Now you gotta get excited about that. Now you just gotta get excited about that."
Barbara Loch, Physicist at Fermilab
“When Fermilab started 28 years ago we didn’t envision the whole field of superconducting magnet technology. That we are pioneers in now...”
Roger Koch, Superconductor Research
“Who can get the highest transition temperature, who can make the material that has the highest onset of transition, who can get the highest current density material and who can understand why it’s really superconducting. No one really knows at the present time why it’s superconducting.”
Ken Zweibel, Photo-voltaic Research
“We’re attempting to make photo voltaics inexpensive. In fact we think photo-voltaics can drop in cost in the 21st century. There are not many options for making electricity that can make that claim.”
Bernard Cohen, Radiation Physics
“Well there are several differences between the Chernobyl type reactor and the type used in the United States. One is that the Chernobyl reactor used graphite as a moderator and the American reactors use water. Graphite burns. Water doesn’t.”
Amory Lovins, Sustainable Technology
“I’m talking about energy efficiency. I don’t use the term energy conservation, because to about a third of Americans conservation means privation, discomfort, containment, doing without. What I’m talking about is doing more with less.”
Donald Huffman, Physics of Molecules:
"And the way we did this was we took two carbon rods embedded them together and then put a large electric current through them in an environment of helium and this produced a sooty old smoke of carbon and we were interested in this because interstellar grains are known to be rich in carbon."
Drasko Jovanovic, Fermilab Cosmologist
"I practice what is called high-energy physics--experiment. It’s a frontier of science. Physics. That’s what I do."
All of the people you have just met are modern working physicists. Pioneers on the frontiers of energy and of matter. Energy and matter at the most basic level.
Let’s take energy first.
Human civilization everywhere on earth relies on an ever-increasing supply of energy to power its factories, its farms, its homes, its schools and churches and stadiums and automobiles and airplanes and computers and cell phones and television sets. In bygone days that energy came from the muscles of animals and human beings. In the 19th century physicists and engineers found ways of using fossil fuels–coal, oil and gas–to provide the energy that powered the industrial revolution.
Today most of our energy still comes from fossil fuels, nature’s gift from millions of years ago . They won’t last forever. More important, scientists today are realizing that the byproducts from the burning of these fossil fuels are threatening our environment with global warming and with air, water and soil pollution.
The search for safe and plentiful alternatives takes many forms today. Ken Zwiebel, physicist at the Solar Energy Research Institute (SERI) in Golden, Colorado, is working on photo-voltaics as one practical power source for the 21st century. We asked him to explain just what are photo-voltaic cells?
“Most familiar is the name solar cells that transform light directly into electricity. They have been used in space for over 30 years to power most of the satellites the U.S. Has launched. Essentially they are layers of semi-conducting materials that face the sun and when the sunlight is absorbed in these layers that sunlight is directly made into electricity.”
Aren’t they a terribly expensive way to make electricity compared say to conventional coal-burning or nuclear power plants?
“Conventional electricity costs about twice as much in environmental impact as we actually pay, and if that was added to these costs photo-voltaics would be very close to being competitive right now!
“We’re attempting to make photo voltaics inexpensive. In fact we think photo-voltaics can drop in cost in the 21st century. There are not many options for making electricity that can make that claim.”
What about other fields of solar energy?
“SERI has a mandate to look into renewable energy of all sorts. And we do work in other fields of solar, and wind energy and also an interesting one called bio fuels, which is essentially the use of trees or grain to transform into ethanol or methanol that can be used as a portable fuel to replace gasoline.
“One of the important things for the future in the 21st century is going to have an energy mix. There is not going to be any one single energy form be it nuclear, photo-voltaics or biofuels that absolutely dominates in terms of production of electricity of producing of energy without endangering the environment. There is going to be a mix of different forms of energy that combine together too produce a less threatening picture. So what I see as SERI’s role is to help to create the momentum for the other technologies that eventually bring them into commercial use and allow them to be a major option.”
Another possible path is nuclear power which does not generate any carbon dioxide or other gases to contribute to global warming or to air pollution. While nuclear reactors working today supply about 20% of the energy in the United States (over 75% in France!) there have been no new plants built in the United States in the past 25 years because of concern about safety as well as cost. Bernard Cohen, a radiation physicist at the Univ. of Pittsburgh, thinks we are making a big mistake.
“The dangers of any technology are relative. It is possible that on the average nuclear power may eventually cause the deaths of ten people per year in the United States. On the other hand the principal alternative to nuclear power would be burning coal. And if you produce the same amount of electricity by burning coal you will be killing tens of thousands of people per year in the United States.”
Tens of thousand!!??
“I think the best study is one done by Harvard University. They did a re-analysis under contract to the Department of Energy and that was the conclusion. Something like 100,000 people a year in the United States die from air pollution. Perhaps 30% of this is due to coal burning power plants which would be 30,000 deaths a year. But I mean the numbers are not that important. Suppose it was 10,000 or even 5,000. In nuclear power we are talking about numbers like ten, not 10,000 deaths a year.”
But does that estimate of only ten deaths a year include the possibility of catastrophic accidents like Chernobyl?
“The estimate does include accidents. Now the Chernobyl type accident, anything like the Chernobyl accident, would be impossible in the United States. The U.S. Type reactors are very different type reactors.
“You could with some very small probability have an accident that eventually could kill tens of thousands of people with very very small probability. You might expect an accident like that once in 10,000 years. So all the accidents are taken account in the estimate.”
But what about radioactive wastes? Aren’t they a serious problem?
“Radioactive wastes is the least problem from a technical standpoint. What you do is you convert them into a rock and put them underground where the rocks are. We know all about how rocks behave. If you put our knowledge of rocks to radioactive wastes it turns out that the health effects of radioactive wastes are very very minimal
“In fact there are three types of buried wastes from coal-burning power plants that are a thousand times more harmful than the ones from nuclear power. For example, a coal-burning plant releases a lot of cancer causing chemicals like beryllium, cadmium, arsenic. They go into the ground and eventually get into the food supply. People eat them. When you figure out the health effects of these materials, it turns out to be a thousand times worse than the health effects of nuclear radioactive wastes.
“In both cases you do the same analysis. You put materials into the ground and know that they might back into the food chain. You do the calculations the same way.
“Another one if that the wastes from coal burning is actually radioactive waste. Coal contains a fair amount of uranium, thorium, radium and these things get released into the ground. People build houses on the ground and eventually these wastes turn into radon. The effects of radon which will be carried into the house will eventually kill thousand of times as many people as the nuclear power wastes.
“So compared to any of the alternatives, nuclear power is very very safe.”
As you can see experts do not always agree in physics or in any other science. Some experts in energy supply and use like environmentalist Amory Lovins of the Rocky Mountain Institute think greater efficiency is the best answer.
“I think there are roughly two ways energy systems could evolve over the next half century or so. We could continue to try and use more energy not very efficiently and get it from sources that run out, convert it in ever larger and more complicated plants into more expensive forms, especially electricity.
“On the other hand, if we use energy in a way that saves money, if we take economics seriously and try to choose the best buy first, we will end up using less energy rather than more. We will be doing more work with the energy but will be using it more efficiently than we do now. We’ll get it increasingly from what I call soft technologies, renewable sources that don’t run out and that provide energy of the right size, of the right kind to do each task in the cheapest way.
“And we’ll be using fossil fuels as a transition to get us from here to there, because it will take some decades to switch over from living on our energy capital to living on our energy income.”
Could you give us some practical examples of how you can save energy in such large amounts?
“We’re in a building right now which is way up in the Rockies where it goes down to 47 below Fahrenheit and we don’t have a furnace. We capture the heat through windows that insulate 2 to 3 times as well as triple glazing. So that the light and heat come into the building, but the heat can’t get out. We also super insulate the walls and roof. Our electric bill for all our household uses is about five bucks a month, because we use super efficient appliances and lighting.
“In commercial buildings most of the energy used is directly for lighting and there are improvements you can do to the fixtures, the lamps, the devices that control the lamps which can save 80 to 90 percent of the energy used for lighting and yet you see better and it looks nicer.
“In industry most of the electricity is used to drive motors, and there are about 14 classes of things you can do to improve motors, the controls and mechanical drive chains which drive transmit the motor power to the machines. This would save maybe half the drive power at a cost of less than one half cent a kwh.
What all this adds up to is that we can save with technology now on the market about three fourths of all the electricity we use. We’ll do the same jobs and we’ll do them better. And every cent of the saving will be much less than what it costs to operate a coal or nuclear power plant even if building it were free. Now that we’ve built the plants its cheaper to write them off and give away efficiency instead of operating them.
“Similarly with cars, with buildings, with industrial processes, aircraft and other kinds of vehicles that are already mostly on the market and we can save about three quarters of all the oil we use at a cost of below 10 bucks a barrel, much less than the world oil price.”
Scientists do not always agree. Especially when it comes to energy paths to the future. Nuclear expert Bernard Cohen for instance says about Amory Lovins plans.
“Lovins is a very political person and his politics are such that he wants that to be true. Now nobody is in favor of waste. I don’t know anybody who thinks we should waste it we want to be as efficient as we can but efficiency can only be carried so far. There have been very large improvements in efficiency and there can be more improvements in efficiency. But there are no panaceas waiting out there when you push a button and all of a sudden we need only half as much electricity as we are using.
“Everybody knows there are electrical light bulbs you can put in your home that will use half as much electricity. Well, they cost more and up till now people aren’t buying them. So what do you do, force people to do it.. Maybe you can. But lighting is only 15 percent of our electricity. Electric motors certainly cannot made much more efficient. Electric motors now are well over 90 percent efficient and no way can that be improved more than a few percentage points. And that’s a major use of electricity.
“So I haven’t seen the details of his plan but I’m sure it’s not a feasible plan.”
Physicists like Watt, Edison, Maxwell, Steinmetz, Sadi-Carnot and others did the basic research that provided the foundations for the industrial revolution of the 18th and 19th centuries,. Today modern physicists are leading the way into a 21st century world. A world of computers and other modern communication technology is often a world of physics on a small scale.. The smallest scale today is called nanotechnology, technology at the atomic level.
Dr. Don Eigler, a physicist at IBM, for instance, has learned how to manipulate single atoms, one at a time!
"So, what we're going to do is move this atom from this location here to location right over here. We'll move it just along this path here...Now you gotta get excited about that!
"It was a very special experience to be able to tell an atom that you want it to go from here to there and stop at the place where you wanted it to end up. For scientists it changes our perspective. There are new kinds of experiments we can do. We don't have to take the atoms wherever they end up. We can put them in the positions that we want them to be in."
This world of nanotechnology may lead to computers so small they can be injected into human arteries and programmed to seek and destroy cancer cells, Or to robots that can seek and destroy environmental chemicals in the air, water and soil. Or to a million and one other at present unforseen applications.
Dr. Paul Grant. also at IBM, is doing basic research directed toward making new materials that put up little or no resistance to an electric current, what are called superconductors. Such materials could save very large amounts of energy enabling us to do more work with less energy in the 21st century.
"Now instead of having to work at the ultra cold temperature of liquid helium we can use liquid nitrogen which can be stored in a simple vacuum jar much like those you find in a common household kitchen. What we are doing right now is pouring liquid nitrogen into a simple little chemical petri dish and as the liquid nitrogen settles down it surrounds the circular pellet you'll watch the magnet lift off the pellet as the pellet goes through what we call a superconducting transition temperature, that is when it gets cold enough so that it becomes truly superconducting.. The magnet will stand up off the superconductor or levitate. It really is table top physics or if you want physics for the people."
"Who can get the highest transition temperature. Who can make the material that has the highest onset of transition. Who can get the highest current density materials. And who can understand why it's really superconducting. No one really knows at present why it's a superconductor. With this material you know the group of sciences as a whole have the real possibility of discovering something and seeing a change in the way people do things in this world. And that's really what drives a lot of people in this I think."
From a different direction, a physicist at the University of Arizona was also working at near-atomic level when he stumbled on a way to make a new molecule that has chemists around the world very excited. Dr. Donald Huffman explains how he came to discover a way to make Buckminsterfullerene, Buckyballs for short. Buckyballs are carbon atoms hooked together in a radically new way, a three dimensional soccer-ball shape.
"The story goes back a long time. It's really an example of perseverance and serendipity. We began studying carbon small particles in the early 70s in our lab here in Tucson. the way we did this is we took two carbon rods, imbedded them together and ran large current through them in an environment of helium. This produced a soot smoke of carbon. We were interest in this because interstellar grains, particles, we know to be rich in carbon. Studying these properties back in the early 1970s and producing soot most people didn't want to make in the labs.
"Then in 1982 I went to Germany on sabbatical, began working with my colleague Wolfgang Kratcher at the Max Planck Institute for Nuclear Physics in Heidelberg. There we decided we needed to study further carbon smoke cause we were interested in interstellar particles and there were still some unknown things.
"The big breakthrough actually came in 1990 about May when we realized working independently in our labs in Heidelberg and Tucson, that it was possible to dissolve the Buckminsterfullerene selectively in liquid such as benzene or toluene. In that case you mix the soot with benzine and it would produce a reddish liquid. Liquid would be buckminsterfullerene dissolved. Then you filter out the black soot and you're left with pure buckminsterfullerine and then you could dray that would form the little solid particles that no one had ever seen before."
This new molecule was made by two physicists. Why are chemists all over the world so excited about it?
"Well, the reason is because this is a new building block for chemical compounds. One can make an analogy perhaps with the benzene ring. The benzene ring is six carbon atoms in a hexagonal array with hydrogens hanging out. The benzene ring was discovered in the early 1800s and it is now known to be the base for several million compounds, many of them natural, many of them artificial. What we have here now is a sort of three dimensional benzene ring. A very elegant structure made of sixty carbon atoms and the idea is that this may be the basis for many many organic molecules of a three dimensional nature just as benzene is the basis for compounds based on the six carbon ring. And one can point out we now have this new molecule and we are not in the early 1800s. So we have all sort of sophisticated techniques to synthesize compounds with and to study compounds with."
You are a physicist and this seems to be chemistry. What is the connection between physics and chemistry?
"At this level of science chemistry and physics overlap a great deal. Our original goal was to make particles smaller and smaller and to investigate the optical properties cause this is what the astronomers would like to know.. If you made a solid smaller you get the atoms and molecules. It was almost inevitable that if we pursued our program successfully we would overlap with the chemists and indeed we have."
Our interview with Dr. Huffman was in the late 20th century. At this level of physics and chemistry, sometimes called nanotechnoology, there has been as he predicted much overlap and much progress. In both energy and matter research.
Carbon atoms, for instance, have been formed now into tiny nanotubes. Strings of these sub-microscopic nanotubes may be able to be woven into long wires that would be far stronger, lighter and much more efficient than copper wires. Even though they are not alive, physicists and chemists think they may even prove able to clone these carbon nanotubes!
Such carbon-based conductors could make it much cheaper to move electricity long distances. Solar and wind energy could become more practical. Efficiency gains predicted by Amory Lovins could increase in size. Dangers from the greenhouse effect and global warming could be reduced in size. You can see how science overlaps can work for everyone’s benefit.
Energy and matter at the smallest level is one thing. Energy and matter at the largest level is still another frontier for modern physics. Here too, these levels are often connected in surprising ways.
Sally Ride was America's first woman astronaut. She recently left NASA but continues her work as an astro-physicist.
"I am an astrophysicist. Astrophysics basically means applying the principles of physics, or asking the questions of physics about our universe, galaxies, solar systems. It's applying physics to the study of astronomy.
"So now I'm doing primarily engineering work, engineering consulting. I am using the physics in the way that I ask questions and in the way that I approach problems. So I spend a lot of time working with the experimenters or the researchers who have experiments on the space shuttle. I try to understand their experiments and to help them design their experiments to work in the shuttle where you operate in weightlessness, to get their experiments to operate in the environment that we operate in.
"It's almost impossible to guess what will be possible in ten years. If you had asked someone 30 years ago whether 30 years from then we would have had people on the moon, we would have a space station, we'd have something like an airplane that goes up into earth's orbit, spends a week up there, then lands just like an airplane they might be used to seeing, nobody would have believed the person that predicted that. We’re going to be in that same situation 15, 20 years from now. We’re not going to be able to predict what we’ll be doing. One thing that we can say is that space travel will be a very routine part of our normal lives."
NASA is one research center for physics today. Another one is in Batavia, Illinois. Called Fermilab. Physicist and communication director Barbara Loch explains.
"The good of the science we do here at Fermilab is to ask fundamental questions about the origins of the universe or about the fundamental building blocks of matter, the quarks. For example. To ask questions and to offer answers. The research we do at Fermilab is pure research. It’s basic research. It doesn’t have a product, doesn’t have something we can guarantee to sell.”
Are there any practical spin-offs from this basic research here at Fermilab?
“Three things come to mind in terms of possible spin-offs. In the early 1970s it was clear we wanted to go to higher energy accelerators. To do that one way was super conducting magnets. The super conducting magnet research that we have done here has enabled hospitals throughout the country to have magnetic resonance imaging for medical diagnosis. That’s superconducting technology.
“A second major spin-off is the computer industry. High energy physicists need very fast, very high memory computers. So they push the computer industry. The computer industry provides the top line computers. High energy physicists build more exotic, more elaborate experiments--bigger and better computers -- so it’s a kind of symbiotic relationship.
"The third spin-off is since 1976 we have operated at Fermilab a neutron therapy facility. Part of our accelerator is used in a parasitic way to accelerate neutrons which are used to bombard certain cancers in patients. We have a very good rate of helping some cancer patients. So those are three we have right now.”
One of the senior physicists here at Fermilab is Drasko Jovanovic. He explains spin-offs this way.
“Well there are a million and half objects flying up there in space and I don’t know what they will do. You do things out of curiosity. We are maybe messengers or spies for humanity to tell them what it is. On the other hand I came to this country in 1953. There were no transistors. I used vacuum tubes. I had to look up in a table sins and cosines. I did my thesis on a machine that I had to crank. I had to sweat it out with something that you do now with a ten dollar calculator.”
Physicists in the past taught us that the world is powered by radiation and is made of atoms. Atoms, physicists discovered almost a hundred years ago, are made of protons, neutrons, and electrons. But what are protons, neutrons, and electrons made of?
"In the last decade and a half, we have absolutely decided that protons and neutrons are not simple particles. They are actually made up of three tinier particles than they, called quarks. In fact, a proton is made up of two quarks and one down and a neutron is made up of two down quarks and one up and the charges on these quarks are such fractional, one third and two thirds. So when all is assembled the proton has a charge of plus one and the neutron of zero. Electrons on the other hand, is totally elementary. No matter how hard we tried, electrons are point-like and simple. We tried to get to the core of the electron and we haven't succeeded. It is still an electron."
You say you are a high energy physicist. I understand that here at Fermilab you use as much energy in your mile wide circular accelerator as a small city would use. You use this energy to create conditions on an atomic level that may have occurred on a cosmic level at the beginning of the universe some fifteen billion years ago–what physicists call the Big Bang. A biologist, Loren Eiseley, once pointed out that if the Big Bang is true, then we ourselves are actually made of "dust and the light of a star.” As a physicist, Dr. Jovanovic, what do you think of that way of putting it?
"Correct. That is absolutely correct. I mean it is all tied into this compact picture...Sure. It is even conjectured that we are coming from material made from at least several supernovas explosions. It wasn't enough to have one. There is no iron, no oxygen, no nitrogen in it. To make these heavy elements you have to have a supernova. You have to cook the material, have it explode, neutrons bombard it and build heavy elements. To make things all the way up to uranium have to go through this process. You have to cook us in several stars. So we have a history of probably five supernova."
Just how did the earth and all of us living on earth, come out a supernova?
"There was a supernova's explosion somewhere in this galactic arm of ours. There was probably a star which was so heavy and it collapsed and exploded. In the ejected material was lots of dust. Stars are created in these galactic arms, apparently, so this dust floated about the recondensed into another star-and then that star exploded. Then there's dust again and again. Finally out of this dust, after three or four generations of supernovas, a fortunate star was created, which is our sun. Which somehow is not of the same size to be a supernova.
“Now they did it and here we are!"