112                        The Bible According to Einstein

History of Electromagnetism⁸⁶

Now man has known about magnetism and electric forces since antiquity, but before the last four centuries of the second millennium, man regarded them as a kind of natural mysticism.

Chapter II: The Seventeenth Century

Now in the middle of the seventeenth century did scientists play with light in many ways. To determine "how light acted," scientists performed experiments. And through such experiments, interference and diffraction were observed. Thus in the year 1665 did Robert Hooke propose that light was made of waves, for waves can interfere and can diffract.
     And it came to pass that, in the year 1676, the eye of an astronomer peered at Io through a telescope. And he saw Io orbiting around the planet Jupiter as it had always done. And with a watch in his left palm and a pen in his right hand, the astronomer wrote down the times at which Io disappeared behind the planet Jupiter. And for many months did he do this. Now when Jupiter moved away from Earth, the orbital times were longer by a tiny bit. And when Jupiter moved toward the Earth, the orbital times were shorter by a tiny bit. And the astronomer went into deep contemplation. And from deep thought emerged a revelation – the answer to the puzzle was an "optical illusion" – not a mystical but a physical optical illusion. And the astronomer concluded that the speed of light was finite, for if its speed were finite and if Jupiter were moving away from Earth, then extra time would be needed for light to reach the Earth from successive disappearances of Io. And if the speed of light were finite and if Jupiter were moving toward the Earth, then less time would be needed for the light to reach the Earth from successive disappearances of Io. And from solar system information, the speed of light was crudely measured. And for the first time was it realized that light did not go instantly from here to there. And so by observing Io and Jupiter at night, man became enlightened about the speed of light.

____________________

⁸⁶ For an understanding of electromagnetism, see the New Testament Book of Classical Physics, Chapters XI-XIII.

The New Testament                                       113

Chapter III: The Eighteenth Century

Now at the beginning of the eighteenth century did Newton, the mighty scientific prophet, propose that light might be made of particles. But others disagreed. And a battle between those who thought that light be particles and those who thought that light be waves. This battle over light would last two hundred years.
     Now in the year 1729, electricity was shown to flow. And so, electricity was thought to be a fluid. And in 1745, electric sparks were captured in a Leyden jar: Apparently, the "fluid" could be stored. At that time, electricity seemed like a mystery.
     Then in the year 1752 did Benjamin Franklin go out into a thunderstorm with kite and key beneath his arm. And he set the kite aloft, and to the string he tied the key. And when lightning struck the kite, the key lit up. From this, Franklin concluded that lightning was electricity in air. So lightning in part enlightened man.
     Then some years later, Franklin hypothesized two kinds of charge – positive and negative. And furthermore, he guessed that electricity was the flow of negative-type charge. Next he proposed a fundamental law – the conservation of electric charge. Someday his hypotheses and proposals would become accepted truths. And for his insights and his thoughts, he became the father of electricity.
     And it came to pass that, in the year 1767, the electric force was quantified – experiments showed that the electric force weakened with distance as the distance squared.⁸⁷ And by 1785, another law of Nature was uncovered – it was Coulomb’s law, the law that governed force between electric static charge.

Chapter IV: The Early Nineteenth Century

And in the year 1800, scientists placed certain chemicals in jars, which reacted and produced electric flow. Thus chemical energy was converted into electricity – the battery came into being. The moment marked the beginning of electrochemistry. And scientists began "to play" with electricity and chemicals in many ways. And some ways seemed mysterious. And for example, when electric currents ran through water, water was divided into hydrogen and oxygen in the form of gas. Thus man began to split the molecule by using sparks.
     And in the year 1801, infrared and ultraviolet radiations⁸⁸ were discovered in the Sun. And in 1813, Siméon-Denis Poisson summarized the laws of electrostatics using two equations. Then in the early nineteenth century, the laws describing static magnetic forces were established, and Michael Faraday experimentally confirmed the conservation of electric charge.

____________________

⁸⁷ This is called the inverse square law. See the Book of Classical Physics, Chapter XI.
⁸⁸ These radiations are discussed in the Book of Electromagnetic Waves, Chapter V.

114                        The Bible According to Einstein

Chapter V: The Unification of Electricity and Magnetism

And in the year of 1820, Hans Christian Ørsted announced that electric current flows produced a magnetism – the mechanism of magnets seemed like mysticism. Then André-Marie Ampère turned wires carrying currents into magnets: Parallel wires with currents flowing in the same direction were attracted to each other, while parallel wires with currents flowing in the opposite direction repelled. And it was hypothesized that magnets were created by microscopic currents – the hypothesis would someday be accepted as a truth. And the difference between electricity and magnetism thus began to blur.
     And it came to pass in the year of 1827 that Georg Simon Ohm quantified electric flow; he showed that current flowing in a wire increased with increasing voltage: When doubled he the voltage, the rate of flow of charge so doubled. And he showed that current-flow decreased with an increase of resistance of a wire: when he doubled the resistance, the rate of flow of charge so dropped in half. And this new law of physics was entered in the scientific testament. And Ohm’s law was its name.
     And in the year of 1831 did Faraday in England and Joseph Henry in America separately announce that changing magnetic forces made electric currents flow. And the difference between electricity and magnetism once again diminished. But even scientists considered the connection between electricity and magnetism as mysterious as ever. But from 1831 and on, man would be well aware that magnets could create electric force.
     And years went by. And it came to pass that Faraday proposed the concept of magnetic and electric fields and lines of force. Now the electric field was defined to be the electric force per unit of electric charge. And the magnetic field was similarly defined. And it was hard for common man to understand how lines of force, like wind-blown hair, could flow through empty space.⁸⁹
     And in the year of 1865, a great synthesis occurred – James Clerk Maxwell unified the laws of electricity and magnetism. And the new laws were given a new name – Maxwell’s equations were they so named. Finally, electromagnetism was established. And as a consequence of these equations, Maxwell predicted the opposite of Faraday induction, that changing electric fields would create magnetic fields. Furthermore, thought he, if changing magnetic fields produce changing electric fields and if changing electric fields produce changing magnetic fields, then "perpetual motion" of these fields should so persist! Now such fields should travel at a certain calculable speed. And Maxwell calculated the speed from his equations. And behold, it was the speed of light! And so Maxwell concluded that light was the "perpetual motion" of a wave, an electromagnetic wave. For him all seemed to fit, but his theory was formulated in a complicated way, and few physicists accepted it.

The New Testament                                       115

     And in the year of 1884, it came to pass that Heinrich Hertz reformulated Maxwell’s four equations in their modern form. And the fundamental symmetry between magnetic and electric forces was made manifest at last.
     And four years later, Hertz observed that certain non-light waves also travelled at the speed of light – these waves were radio waves. This discovery was the confirmation of a prediction Maxwell previously had made. And the non-believers of electromagnetism suddenly became believers. And so scientists accepted Maxwell’s theory.⁹⁰

Chapter VI: QED

Now in the year of 1887, Hertz by accident discovered the photoelectric effect, in which electricity is generated from the surface of a solid by striking it with ultraviolet radiation.⁹¹ And further observations produced a pair of puzzles. And the first was this: If the frequency of ultraviolet light was low, no current from the surface flowed. And this was true even if the ultraviolet-light intensity was substantially increased. Now the second puzzle appeared much later, after the discovery of the electron. And it was this: The energy of charged electrons emitted from the solid depended only on the frequency of ultraviolet light and not on its intensity – intensity controlled instead the number of emitted charges.⁹²
     And in the year of 1895, electric currents were forced to flow between two metal wires in a bottle void of air. And behold, the electricity flowed in the bottle, though it be void of air – the cathode tube⁹³ had come about. Now since the rays were so mysterious, they were named X-rays; these were the first such man-made rays. And it happened that X-rays, escaping from a bottle, were recorded on a photographic plate. And by chance, the rays passed through an outstretched hand. And bones were seen upon the photographic screen. Then scientists "turned into doctors" and photographed the skeletons of people.
     And in the year of 1897, with a cathode tube in hand, Sir J. J. Thompson demonstrated that electric currents were the flow of microscopic particles of tiny charge and mass. Although smaller than an atom, these particles, named electrons, had been "indirectly seen" and thus discovered. And so one principal source of electromagnetism was uncovered.

116                        The Bible According to Einstein

     Then in the year 1905, Albert Einstein proposed that electromagnetic radiation was composed of packets of fixed energy – each packet was a photon. Now this idea resolved the two photoelectric puzzles: When the frequency of ultraviolet light was low, then the energy of its photons, too, was low; and such photons had too little energy to knock electrons out of atoms in a solid. But when the frequency of ultraviolet light was high, then the energy of its photons, too, was high; and such photons had sufficient energy to knock electrons out of atoms. And as for the second puzzle, it was resolved as follows. When ultraviolet light was of higher intensity, it contained more photons available to strike electrons. Hence higher-intense ultraviolet radiation produced a higher current.
     And in the year of 1922, it happened that Arthur Holly Compton scattered X-rays off electrons. And the X-rays deflected just like microscopic particles. And so the question, which was posed two centuries before, arose again: How could light be both a particle and wave? In quantum theory, the answer lay.
     And in the decade of the 1920’s, there was a scientific revolution – it was the quantum-mechanic revolution. Now quantum mechanics explained the nature of the atom and the small. And Niels Bohr, Louis-Victor de Broglie, Erwin Schrödinger, Werner Heisenberg, Max Born and others etched in texts the theoretical foundation. And subsequently, Paul A. M. Dirac, Wolfgang Pauli, Heisenberg and others made quantum theory compatible with special relativity – the result was relativistic quantum theory.⁹⁴
     And in the decade of the 1940’s, Freeman Dyson, Richard P. Feynman, Julian S. Schwinger, S. Tomonaga and others constructed a consistent quantum version of electromagnetism. And it was provided with a name: quantum electrodynamics, or QED. And it explained the interaction⁹⁵ between photons, protons and electrons. And the basic notion was that electric and magnetic forces arose from the exchange of photons.⁹⁶

____________________

⁹⁴ For an explanation of quantum theory, see the Book of Quantum Mechanics.
⁹⁵ The word "interaction" is synonymous to "force."
⁹⁶ In QED, the answer to the question "Is light a particle or a wave?" is simple: The microscopic world is vastly different from the macroscopic world of man. Man thinks in terms of things he sees. Man attends a sports event – he sees a ball. Man observes the sea – he thinks of waves. But why should balls and waves exist in the microscopic world? Words like "ball" and "wave" can, at best, be metaphors for the dominion of the small. Energetic electromagnetic radiation is like a bullet or a ball. Low-energy electromagnetic radiation is like a wave. Thus light behaves like a bullet and like a wave. But light is neither particle nor wave. Light is what it is. Light is light.

The New Testament                                       117

Chapter VII: Electroweak Unification

It was the decade of the 1960’s. It was a time of revolution. And it came to pass that Steven Weinberg, Abdus Salam and Sheldon Glashow unified QED with the weak force.⁹⁷ And the electroweak theory thus was born at last. Now the theory predicted the existence of three heavy particles, the W-plus, W-minus and the Z. Now for some physicists, it was a prophecy, which although incredible, just had to be. And fourteen years later in the year of 1983, an accelerator near Geneva, Switzerland, produced the predicted heavy W-plus, W-minus and the Z.
     Now in the decade of the 1980’s was the internal magnetism of the electron measured. And it agreed with theoretical predictions from QED to one part in ten-billion. Then in the last two decades of the twentieth century, accelerators near Geneva measured quantum electroweak effects. And measurements agreed perfectly with theory. And so it seemed the theory had no defects.

Chapter VIII: Electromagnetic Technology⁹⁸

Now what were the twentieth-century technological wonders generated from electric and magnetic science? Water flowing through dams could be converted into currents flowing in a wire. Energy could be obtained by inserting a pronged object in a pair of holes in household walls. Filaments encased in glass could give off light sufficiently bright to light rooms and roads at night. Humans thousands of kilometers apart could talk with one another by speaking into hand-held devices. A crate could keep a chamber cold enough to maintain food. Another kitchen apparatus could cook food on a surface coil or in a cubic cavity. An even smaller box could heat food by striking it with microwaves. Humans could listen to beautiful sounds on disks by placing them in a seemingly mysterious device. Or they could go to auditoriums with rows of seats to watch screens with images and voices. Humans could be transported in apparatuses with wheels simply by pouring liquid in a hole and turning keys to make them start. Bird-like structures with several hundred passengers inside could be made to fly through clouds. Messages, on the backs of unseen waves and emitted from tall towers far away, could pass through buildings, air and walls and be detected with a box inside a home to yield images and sound. And artificial arms could maneuver to assemble cars in factories.⁹⁹ To ancient man, these inventions would have seemed like mysteries.

118                        The Bible According to Einstein

     And the twentieth century held more marvels.¹⁰⁰ Children played with toys that floated, flew, walked or talked. Boxes containing microscopic chips and tiny wires were used to calculate and think. Probes were propelled to outer space to spy on the Moon and distant planets. Images of inner bones were made by passing unseen rays through human bodies. Likewise, with magnets, pictures of organs or the flow of blood in the body or the brain were made. Artificial human parts were implanted and made to function like their real counterparts. A person with a faulty heart had a device inserted in the chest to help him keep the beat. Another module in the ear made the hard-of-hearing hear. Electric shocks sometimes restarted hearts which had, for several minutes, stopped.

To ancient man, these would have seemed absurd.

     The hard-of-hearing were made to hear. The dying were given longer lives. Among the stars of night were man-made spots of moving light. The invisible was made, in certain cases, visible. That which produced no sound was heard. The non-living were made to move and think.

Were these not miracles?

____________________

¹⁰⁰ To us, these things may seem commonplace; we have become use to them. One should try to imagine how a person of the eighteenth century or earlier would have viewed them.