The Dancing Wu Li Masters Page 4
This is Bohr’s famous solution to the grand-piano mystery. If the electron in a hydrogen atom travels from an outer shell all the way to the innermost shell in one jump, it gives off a certain amount of energy. That makes one line in the hydrogen spectrum. If the electron in a hydrogen atom makes a tiny jump from an outer shell to the next shell inward, it gives off a much smaller amount of energy. That makes another spectral line. If the electron in a hydrogen atom jumps from shell five to shell three, for example, that makes yet another line. A jump from shell six to shell four and then from shell four to shell one makes two more spectral lines, and so on. In this way we can account for the entire hydrogen spectrum.
If we excite a hydrogen atom with white light instead of heat, we can produce the absorption phenomenon that we mentioned earlier. Each electron jump from an inner shell to a shell farther out requires a certain amount of energy, no more and no less. An electron jump from shell one to shell two requires a certain amount of energy, and only that amount. The same is true for a jump from shell five to shell seven, etc. Each jump that the electron makes from an inner shell to an outer shell takes a specific amount of energy, no more and no less.
When we shine white light on a hydrogen atom, we are offering it a whole supermarket of different energy amounts. However, it cannot use all that we have to offer; only certain specific amounts. If its electron jumps from shell one to shell four, for example, it takes that particular energy package out of the array of energy packets that we are giving it. The package that it takes out becomes a black line in the otherwise complete spectrum of white light. A jump from shell three to shell four becomes another black line. A jump from shell one to shell two, and then from shell two to shell six (there are all sorts of combinations) makes two more black lines.
In sum, if we shine white light through hydrogen gas and then through a prism, the result is the familiar white-light spectrum, but with over one hundred black lines in it. Each of these black lines corresponds to a specific energy amount that was required to make a hydrogen electron jump from one shell to another shell farther out.
These black lines in the white-light spectrum form exactly the same pattern that we get when we shine the light emitted from excited hydrogen gas directly through a prism—except, in that case, the lines are colored and the rest of the white-light spectrum is missing. Of course, the colored lines are caused by the electrons returning to lower-level shells and, in the process, emitting energy amounts equal to what they absorbed when we first made them jump. Bohr’s theory permitted physicists to calculate the frequencies of the light given off by simple hydrogen atoms. These calculations agreed with observations. The grand-piano mystery was solved!
Shortly after Bohr published his theory in 1913, an army of physicists began the work of applying it to the other elements. This process was quite complicated for atoms with large numbers of electrons, and not all of the questions that physicists had about the nature of atomic phenomena were answered. Nonetheless, a tremendous amount of knowledge was gained from this work. Most of the physicists who went to work on Bohr’s theory, applying it and further developing it, were technicians. Bohr himself, one of the founders of the new physics, was a scientist.
This is not to say that technicians are not important. The technician and the scientist form a partnership. Bohr could not have formulated his theory without the wealth of spectroscopic data at his disposal. That data was the result of countless laboratory hours. It was beyond Bohr’s capacity, as one person, to substantiate his theory. Technicians did this for him by applying it to the other elements. Technicians are important members of the scientific community. However, since this is a book about Wu Li Masters and not about technicians, we will use the word “physicist” from now on to mean those physicists who are also scientists, that is, those physicists (people) who are not confined by the “known.” From the little that we know about Wu Li Masters, it is evident that they come from this group.
There are certain limitations which no book on physics can overcome. First, there is so much to present that not even twenty volumes could contain it all. There is that much new material published each year. Even physicists find it impossible to keep abreast of the whole field. It requires a steady diet of reading just to keep current in one area. For everything that is included in these pages, there is much more that is not. No matter how much you learn about physics, there always will be something that is new to you. Physicists have this problem, too.
Second, no complete appreciation of physics is possible without mathematics. Nonetheless, there is no mathematics in The Dancing Wu Li Masters. Mathematics is a highly structured way of thinking. Physicists view the world in this way. One point of view is that they impose this structure on what they see. Another point of view is that the world presents itself most completely through such structures. In any case, mathematics is the most concise expression of physics. The reason for writing The Dancing Wu Li Masters, however, is that most physicists are not able to explain physics very well without it. This makes them very concise but, unfortunately, unintelligible. The fact is that most of us use words to do our explaining.
However, it is important to remember that mathematics and English are both languages. Languages are useful tools for conveying information, but if we try to communicate experiences with them, they simply do not work. All a language can do is talk about an experience. Wu Li Masters know that a description of an experience is not the experience. It is only talk about it.
This is a book about physics. Therefore, all it contains is a description. It cannot contain the experience itself. This does not mean that you will not have the experience of physics by reading it; it only means that if you do, the experience is coming from you, and not from the book. Quantum mechanics, for example, shows us that we are not as separate from the rest of the world as we once thought. Particle physics shows us that the “rest of the world” does not sit idly “out there.” It is a sparkling realm of continual creation, transformation, and annihilation. The ideas of the new physics, when wholly grasped, can produce extraordinary experiences. The study of relativity theory, for example, can produce the remarkable experience that space and time are only mental constructions! Each of these different experiences is capable of changing us in such ways that we never again are able to view the world as we did before.
There is no single “experience” of physics. The experience always is changing. Relativity and quantum mechanics, although generally unknown to nonphysicists, are more than a half century old. Today, the entire field of physics is quivering with anticipation. The air is charged with excitement. A feeling is shared among physicists that radical change is at hand. A consensus grows that the near future will see new theories exploding onto the scene, incorporating the older theories and giving us a much larger view of our universe and, consequently, of ourselves.
The Wu Li Masters move in the midst of all this, now dancing this way, now that, sometimes with a heavy beat, sometimes with a lightness and grace, ever flowing freely. Now they become the dance, now the dance becomes them. This is the message of the Wu Li Masters: not to confuse the type of dance that they are doing with the fact that they are dancing.
1
Einstein Doesn’t Like It
Quantum mechanics are not the fellows who repair automobiles in Mr. Quantum’s garage. Quantum mechanics is a branch of physics. There are several branches of physics. Most physicists believe that sooner or later they will construct an overview large enough to incorporate them all.
According to this point of view, we eventually will develop, in principle, a theory which is capable of explaining everything so well that there will be nothing left to explain. This does not mean, of course, that our explanation necessarily will reflect the way that things actually are. We still will not be able to open the watch, as Einstein put it, but every occurrence in the real world (inside the watch) will be accounted for by a corresponding element of our final supertheory. We will have, at last, a
theory that is consistent within itself and which explains all observable phenomena. Einstein called this state the “ideal limit of knowledge.”1
This way of thinking runs into quantum mechanics the same way that the car runs into the proverbial brick wall. Einstein spent a large portion of his career arguing against quantum mechanics, even though he himself made major contributions to its development. Why did he do this? To ask this question is to stand at the edge of an abyss, still on the solid ground of Newtonian physics, but looking into the void. To answer it is to leap boldly into the new physics.
Quantum mechanics forced itself upon the scene at the beginning of this century. No convention of physicists voted to start a new branch of physics called “quantum mechanics.” No one had any choice in the matter, except, perhaps, what to call it.
A “quantum” is a quantity of something, a specific amount. “Mechanics” is the study of motion. Therefore, “quantum mechanics” is the study of the motion of quantities. Quantum theory says that nature comes in bits and pieces (quanta), and quantum mechanics is the study of this phenomenon.
Quantum mechanics does not replace Newtonian physics, it includes it. The physics of Newton remains valid within its limits. To say that we have made a major new discovery about nature is one side of a coin. The other side of the coin is to say that we have found the limits of our previous theories. What we actually discover is that the way that we have been looking at nature is no longer comprehensive enough to explain all that we can observe, and we are forced to develop a more inclusive view. In Einstein’s words:
…creating a new theory is not like destroying an old barn and erecting a skyscraper in its place. It is rather like climbing a mountain, gaining new and wider views, discovering unexpected connections between our starting point and its rich environment. But the point from which we started out still exists and can be seen, although it appears smaller and forms a tiny part of our broad view gained by the mastery of the obstacles on our adventurous way up.2
Newtonian physics still is applicable to the large-scale world, but it does not work in the subatomic realm. Quantum mechanics resulted from the study of the subatomic realm, that invisible universe underlying, embedded in, and forming the fabric of everything around us.
In Newton’s age (late 1600s), this realm was entirely speculation. The idea that the atom is the indivisible building block of nature was proposed about four hundred years before Christ, but until the late 1800s it remained just an idea. Then physicists developed the technology to observe the effects of atomic phenomena, thereby “proving” that atoms exist. Of course, what they really proved was that the theoretical existence of atoms was the best explanation of the experimental data that anyone could invent at the time. They also proved that atoms are not indivisible, but themselves are made of particles smaller yet, such as electrons, protons, and neutrons. These new particles were labeled “elementary particles” because physicists believed that, at last, they really had discovered the ultimate building blocks of the universe.
The elementary particle theory is a recent version of an old Greek idea. To understand the theory of elementary particles, imagine a large city made entirely of bricks. This city is filled with buildings of all shapes and sizes. Every one of them, and the streets as well, have been constructed with only a few different types of brick. If we substitute “universe” for “city” and “particle” for “brick,” we have the theory of elementary particles.
It was the study of elementary particles that brought physicists nose to nose with the most devastating (to a physicist) discovery: Newtonian physics does not work in the realm of the very small! The impact of that earthshaking discovery still is reshaping our world view. Quantum mechanical experiments repeatedly produced results which the physics of Newton could neither predict nor explain. Yet, although Newton’s physics could not account for phenomena in the microscopic realm, it continued to explain macroscopic phenomena very well (even though the macroscopic is made of the microscopic)! This was perhaps the most profound discovery of science.
Newton’s laws are based upon observations of the everyday world. They predict events. These events pertain to real things like baseballs and bicycles. Quantum mechanics is based upon experiments conducted in the subatomic realm. It predicts probabilities. These probabilities pertain to subatomic phenomena. Subatomic phenomena cannot be observed directly. None of our senses can detect them.* Not only has no one ever seen an atom (much less an electron), no one has ever tasted, touched, heard, or smelled one either.
Newton’s laws depict events which are simple to understand and easy to picture. Quantum mechanics depicts the probabilities of phenomena which defy conceptualization and are impossible to visualize. Therefore, these phenomena must be understood in a way that is not more difficult than our usual way of understanding, but different from it. Do not try to make a complete mental picture of quantum mechanical events. (Physicists make partial pictures of quantum phenomena, but even these pictures have a questionable value.) Instead, allow yourself to be open without making an effort to visualize anything. Werner Heisenberg, one of the founders of quantum physics, wrote:
The mathematically formulated laws of quantum theory show clearly that our ordinary intuitive concepts cannot be unambiguously applied to the smallest particles. All the words or concepts we use to describe ordinary physical objects, such as position, velocity, color, size, and so on, become indefinite and problematic if we try to use them of elementary particles.3
The idea that we do not understand something until we have a picture of it in our heads is a by-product of the Newtonian way of looking at the world. If we want to get past Newton, we have to get past that.
Newton’s first great contribution to science was the laws of motion. If an object, said Newton, is moving in a straight line, it will continue moving in a straight line forever unless it is acted upon by something else (a “force”). At that time its direction and speed will be altered, depending upon the magnitude and direction of the force which it encounters. Furthermore, every action is accompanied by an equal and opposite reaction.
Today, these concepts are familiar to anyone who has studied physics or hung out in a pool hall. However, if we mentally project ourselves three hundred years into the past, we can see how remarkable they really are.
First, Newton’s first law of motion defied the accepted authority of the day, which was Aristotle. According to Aristotle, the natural inclination for a moving object is to return to a state of rest.
Second, Newton’s laws of motion describe events which were unobservable in the 1600s. In the everyday world, which was all that Newton had to observe, moving objects always do return to a state of rest because of friction. If we put a wagon in motion, it encounters friction from the air through which it passes, from the ground its tires move on, from the axles that its wheels turn around, and, unless it is rolling downhill, sooner or later it comes to rest. We can streamline the wagon, grease the wheels, and use a smooth road, but this only reduces the effect of friction. Eventually the wagon stops moving, apparently on its own.
Newton never had the chance to see a film of astronauts in space, but he predicted what they would encounter. When an astronaut releases a pencil in front of him, nothing happens. It just stays there. If he gives it a push, off it goes in the direction of the push until it bumps into a wall. If the wall were not there, the pencil would continue to move uniformly, in principle, forever. (The astronaut also moves off in the opposite direction, but much more slowly because of his greater mass.)
Third, Newton’s premise was “I make no hypotheses” (“Hypotheses non fingo”), which means that he based his laws upon sound experimental evidence, and nothing else. His criteria for the validity of everything that he wrote was that anyone should be able to reproduce his experiments and come up with the same results. If it could be verified experimentally, it was true. If it could not be verified experimentally, it was suspect.
The church to
ok a dim view, to say the least, of this position. Since it had been saying things for fifteen hundred years which hardly were subject to experimental verification, Newtonian physics, in effect, was a direct challenge to the power of the church. The power of the church was considerable.* Shortly before Newton’s birth, Galileo was seized by the Inquisition for declaring that the earth revolves around the sun and for drawing unacceptable theological implications from his beliefs. He was forced to recant on penalty of imprisonment or worse. This made a considerable impression on many people, among them another founder of modern science, the Frenchman René Descartes.
In the 1630s Descartes visited the royal gardens at Versailles, which were known for their intricate automata. When water was made to flow, music sounded, sea nymphs began to play, and a giant Neptune, complete with trident, advanced menacingly. Whether the idea was in his mind before this visit or not, Descartes’s philosophy, which he supported with his mathematics, became that the universe and all of the things in it also were automata. From Descartes’s time to the beginning of this century, and perhaps because of him, our ancestors began to see the universe as a Great Machine. Over the next three hundred years they developed science specifically to discover how the Great Machine worked.