Waves And Particles: Two Essays On Fundamental Physics

Two Essays on Fundamental Physics

Roger G Newton

• Publisher: WSPC
• Year: 2014
• eBook ISBN: 9789814449694
• Topic: Biological Sciences
• Subtopic: Science General
• Index: Biological Sciences

The book consists of two separate parts, the first part is on waves and the second part on particles. In part 1, after describing the awesome power of tsunami and the history of their occurrences, the book turns to the history of explaining phenomena by means of mathematical equations. Then it describes other wave phenomena and the laws governing them: the vibration of strings and drums in musical instruments, the sound waves making them audible, ultrasound and its uses, sonar, and shock waves; electromagnetic waves: light waves, refraction, diffraction, why the sky is blue, the rainbow, and the glory; microwaves and radio waves: radar, radio astronomy, the discovery of the cosmic microwave background radiation, microwave ovens and how a radio works, lasers and masers; waves in modern physics: the Schrödinger wave function and gravitational waves in general relativity; water waves in the ocean, tides and tidal waves, and the quite different solitary waves, solitons discovered in canals. Finally we return to tsunami and the question of what laws govern them. We conclude that the answer to that question is not quite known yet, but there is ongoing research to solve the riddle.

In part 2, the history of the idea of atoms is reviewed, and then the scientific evidence for their existence, with Rutherford's discovery of the atomic nucleus. The investigation of what the nucleus is like follows, including the discovery of the neutron, followed by that of the neutrino — of which there are several different kinds — and the muon as well as the pion. The important work of Paul Dirac is described, as well as the discovery of the positron and other antiparticles. The ways by which particles are discovered, by cloud chambers, bubble chambers, etc. are all explained, followed by the invention of the various machines to accelerate particles to high speeds: the cyclotron, the synchrotron, and the bigger and bigger machines, in the US as well as in Switzerland, including their storage rings. The new terminology of fermions and bosons are explained, followed by the remarkable use of group theory and group representations by matrices, whose unfamiliar algebra is carefully explained.

Contents:

• Tsunami and other Waves:
  • Introduction to Part I
  • The Story of a Tsunami
  • Science and Mathematics
  • The Sound of Music
  • Electromagnetic Waves
  • Wave Mechanics and Gravitational Waves
  • Water Waves
  • And Back to Tsunami
• Particles:
  • Introduction to Part II
  • Atoms
  • Nuclear Physics
  • Another New Particle
  • Particle Accelerators
  • An Abundance of New Particles

Readership: Academics and students of physics as well as the general public.

Part I

Tsunami and other Waves

Introduction to Part I

We all remember the severe damage to a nuclear power plant in Tohoku, Japan, in 2011, as well as the great loss of life and the enduring radioactivity caused by an enormous tidal wave due to an earthquake. It engraved the word tsunami forever on our memory. Of course, it wasn’t the first event of this nature; there have been many others before, equally or even more destructive.

In this little essay we shall describe tsunami¹ and then compare this wave to other kinds of waves and their properties and underlying laws. Rather than describing the detailed history of tsunami and their well-known causes, earthquakes and volcanic eruptions, our aim is eventually to be able to explain tsunami by means of mathematical equations just as other waves are explained. To set the stage, after a vivid description of a tsunami event in Japan in the nineteenth century, we briefly trace the long history of explaining phenomena by means of equations, from the ancient Greeks to the nineteenth century. Then, to begin our comparison of tsunami with more common kinds of waves, we describe those of sound. The production of musical harmonies by the vibrations of string instruments, which confirm some of the conjectures of the ancient philosopher Pythagoras, is translated into sound waves, governed by laws common to other kinds of waves to be described. We shall discuss not only facts about the acoustics of concert halls, but also ultrasound and its variety of uses, as well as shock waves.

We then turn to electromagnetic waves, beginning with light waves and such phenomena as refraction and the fascinating heavenly ones of the blue sky, the rainbow and the glory. Very rarely observed, a picture of the glory will show that it is well worth seeing if you have the chance. Other electromagnetic waves employed for important purposes are microwaves and radio waves; these are used for radar, microwave ovens, and radio astronomy. We shall describe all of them, including the fundamental discovery about the universe made by two radio astronomers. This essay will also describe the basics of how a radio works.

The next waves described arise in the new kinds of physics introduced in the twentieth century: quantum mechanics and Einstein’s general theory of relativity. Schrödinger’s wave mechanics is fundamental to the quantum theory, and Einstein predicted the existence of gravitational waves, which are very difficult to detect.

Finally, there are, of course, water waves. Some of these we are familiar with, on lakes and oceans, including the tides, but there are also more unusual ones, first seen in the nineteenth century on shallow Dutch canals: solitary waves, later called solitons, that behave quite differently from all the other kinds of waves described. That brings us back to our starting point, the tsunami. Are tsunami waves and their enormous destructive power explicable in the same terms as other ocean waves, or are they more akin to solitary waves and their strange behavior seen on Dutch canals? The final answer to this question is still unknown and subject to ongoing research. No doubt the right set of equations to explain tsunami will eventually be found.

¹The word being of Japanese origin, its plural is tsunami, just as the plural of fish is fish.

1

The Story of a Tsunami

Lafcadio Hearn was born in Greece in 1850. At the age of two he was brought to Ireland, and at nineteen he immigrated to the United States, where he settled in Cincinnati, Ohio, to become a journalist. At the age of forty he travelled to Japan, where he gained a teaching post at a Middle School and then became a professor at Waseda University. The reports he wrote familiarized the world with life in pre-industrial Meiji era Japan, including the island country’s experiences with the sea and its sometimes very destructive storms.

Here is an extended quote from his story, A Living God:

From immemorial time the shores of Japan have been swept, at irregular intervals of centuries, by enormous tidal waves, — tidal waves caused by earthquakes or by submarine volcanic action. These awful sudden risings of the sea are called by the Japanese tsunami. The last one occurred on the evening of June 17, 1896, when a wave nearly two hundred miles long struck the northeastern provinces of Miyagi, Iwate, and Aomori, wrecking scores of towns and villages, ruining whole districts, and destroying nearly thirty thousand human lives. The story of Hamaguchi Gohei is the story of a like calamity which happened long before the era of Meiji, on another part of the Japanese coast.

He was an old man at the time of the occurrence that made him famous. He was the most influential resident of the village to which he belonged: he had been for many years its muraosa, or headman; and he was not less liked than respected. The people usually called him Ojiisan, which means Grandfather; but, being the richest member of the community, he was sometimes officially referred to as the Choja. He used to advise the smaller farmers about their interests, to arbitrate their disputes, to advance them money at need, and to dispose of their rice for them on the best terms possible.

Hamaguchi’s big thatched farmhouse stood at the verge of a small plateau overlooking a bay. The plateau, mostly devoted to rice culture, was hemmed in on three sides by thickly wooded summits. From its outer verge the land sloped down in a huge green concavity, as if scooped out, to the edge of the water; and the whole of this slope, some three quarters of a mile long, was so terraced as to look, when viewed from the open sea, like an enormous flight of green steps, divided in the centre by a narrow white zigzag, a streak of mountain road. Ninety thatched dwellings and a Shinto temple, composing the village proper, stood along the curve of the bay; and other houses climbed straggling up the slope for some distance on either side of the narrow road leading to the Choja’s home.

One autumn evening Hamaguchi Gohei was looking down from the balcony of his house at some preparations for a merry-making in the village below. There had been a very fine rice-crop, and the peasants were going to celebrate their harvest by a dance in the court of the ujigami. The old man could see the festival banners (nobori) fluttering above the roofs of the solitary street, the strings of paper lanterns festooned between bamboo poles, the decorations of the shrine, and the brightly colored gathering of the young people. He had nobody with him that evening but his little grandson, a lad of ten; the rest of the household having gone early to the village. He would have accompanied them had he not been feeling less strong than usual.

The day had been oppressive; and in spite of a rising breeze, there was still in the air that sort of heavy heat which, according to the experience of the Japanese peasant, at certain seasons precedes an earthquake. And presently an earthquake came. It was not strong enough to frighten anybody; but Hamaguchi, who had felt hundreds of shocks in his time, thought it was queer, — a long, slow, spongy motion. Probably it was but the after-tremor of some immense seismic action very far away. The house crackled and rocked gently several times; then all became still again.

As the quaking ceased Hamaguchi’s keen old eyes were anxiously turned toward the village. It often happens that the attention of a person gazing fixedly at a particular spot or object is suddenly diverted by the sense of something not knowingly seen at all, — by a mere vague feeling of the unfamiliar in that dim outer circle of unconscious perception which lies beyond the field of clear vision. Thus it chanced that Hamaguchi became aware of something unusual in the offing. He rose to his feet, and looked at the sea. It had darkened quite suddenly, and it was acting strangely. It seemed to be moving against the wind. It was running away from the land. Within a very little time the whole village had noticed the phenomenon. Apparently no one had felt the previous motion of the ground, but all were evidently astounded by the movement of the water. They were running to the beach, and even beyond the beach, to watch it. No such ebb had been witnessed on that coast within the memory of living man. Things never seen before were unfamiliar spaces of ribbed sand and reaches of weed-hung rock were left bare even as Hamaguchi gazed. And one of the people below appeared to guess what that monstrous ebb signified.

Hamaguchi Gohei himself had never seen such a thing before; but he remembered things told him in his childhood by his father’s father, and he knew all the traditions of the coast. He understood what the sea was going to do. Perhaps he thought of the time needed to send a message to the village, or to get the priests of the Buddhist temple on the hill to sound their big bell . . . . But it would take very much longer to tell what he might have thought than it took him to think. He simply called to his grandson — “Tada ! — quick, — very quick! . . . Light me a torch..” Taimatsu, or pine-torches, are kept in many coast dwellings for use on stormy nights, and also for use at certain Shinto festivals. The child kindled a torch at once; and the old man hurried with it to the fields, where hundreds of rice-stacks, representing most of his invested capital, stood awaiting transportation. Approaching those nearest the verge of the slope, he began to apply the torch to them, — hurrying from one to another as quickly as his aged limbs could carry him. The sun-dried stalks caught like tinder; the strengthening sea-breeze blew the blaze landward and presently, rank behind rank, the stacks burst into flame, sending skyward columns of smoke that met and mingled into one enormous cloudy whirl. Tada, astonished and terrified, ran after his grandfather, crying, “Ojiisan! why? Ojiisan! — why?”

But Hamaguchi did not answer: he had no time to explain; he was thinking only of the four hundred lives in peril. For a while the child stared wildly at the blazing rice, then burst into tears and ran back to the house, feeling sure that his grandfather had gone mad. Hamaguchi went on firing stack after stack, till he had reached the limit of his field; then he threw down his torch and waited. The acolyte of the hill-temple, observing the blaze, set the big bell booming; and the people responded to the double appeal. Hamaguchi watched them hurrying in from the sands and over the beach and up from the village, like a swarming of ants and, to his anxious eyes, scarcely faster; for the moments seemed terribly long to him. The sun was going down; the wrinkled bed of the bay, and a vast sallow speckled expanse beyond it, lay naked to the last orange glow; and still the sea was fleeing toward the horizon.

Really, however, Hamaguchi did not have very long to wait before the first party of succor arrived, — a score of agile young peasants, who wanted to attack the fire at once. But the Choja, holding out both arms, stopped them. “Let it burn, lads!” he commanded, “let it be! I want the whole mura here. There is a great danger, — taihen da!”

The whole village was coming; and Hamaguchi counted. All the young men and boys were soon on the spot, and not a few of the more active women and girls; then came most of the older folk, and mothers with babies at their backs, and even children, — for children could help to pass water; and the elders too feeble to keep up with the first rush could be seen well on their way up the steep ascent. The growing multitude, still knowing nothing, looked alternately, in sorrowful wonder, at the flaming fields and at the impassive face of their Choja. And the sun went down.

“Grandfather is mad, — I am afraid of him!” sobbed Tada, in answer to a number of questions. “He is mad. He set fire to the rice on purpose: I saw him do it!”“As for the rice,” cried Hamaguchi, “the child tells the truth. I set fire to the rice . . . Are all the people here?”

The Kumi-cho and the heads of families looked about them, and down the hill, and made reply: “All are here, or very soon will be . . . We cannot understand this thing.” “Kita!”shouted the old man at the top of his voice, pointing to the open. “Say now if I be mad!”

Through the twilight eastward all looked, and saw at the edge of the dusky horizon a long, lean, dim line like the shadowing of a coast where no coast ever was, — a line that thickened as they gazed, that broadened as a coast-line broadens to the eyes of one approaching it, yet incomparably more quickly. For that long darkness was the returning sea, towering like a cliff, and coursing more swiftly than the kite flies.

“Tsunami!”shrieked the people; and then all shrieks and all sounds and all power to hear sounds were annihila...

Table of contents

• Cover
• Halftitle
• Titlepage
• Copyright
• Contents
• Prologue
• Part I Tsunami and other Waves
• Part II. Particles
• Index