by Mike Bennett
Newton’s postulation of an invisible force able to act over vast distances led to him being criticised for introducing occult agencies into science. Later, in the second edition of The Principia published in 1713, Newton firmly rejected such criticisms, concluding that it was enough that the phenomena implied a gravitational attraction, as they did. However they did not indicate its cause, and it was both unnecessary and improper to frame hypotheses of things that were not implied by the phenomena.
With The Principia, Newton became internationally recognised. He acquired a circle of admirers, including the Swiss-born mathematician Nicolas Fatio de Duillier, with whom he formed an intense relationship. This abruptly ended in 1693, and at the same time Newton suffered a nervous breakdown.
It would be another century before any further major steps forward were made in physics following the groundbreaking work of Sir Isaac Newton.
In 1777 another pioneering physicist named Hans Ørsted from Rudkøbing in Denmark appeared on the scene. He was the first physicist to discover that electrical currents create magnetic fields; the fundamental aspect of electromagnetism.
In 1819, he noticed the deflection of a compass needle while performing a demonstration for his students. The discovery of this basic cornerstone of physics, the demonstrable connection between electricity and magnetism, rocked the scientific community. It led to a flurry of activity in electro-dynamic research by such investigators as Ampère and Arago.
After all, the magnetism produced by a current would generate a force. Forces are capable of producing motion, so motion could come about which would lead to a current. While this is not a conservation law, it is a statement about the fundamental inter-convertibility of natural phenomena.
Ørsted’s experiment showed that there were underlying connections between what appeared to be quite different physical phenomena, and encouraged other scientists to seek them out. In more recent times, connections between superconductors and gravity have been demonstrated, but our understanding of this phenomenon is still not complete. While universal convertibility is not the same as conservation, the two are nonetheless closely related. Thus, a connection or conversion between different phenomena, especially two as outwardly dissimilar as electricity and magnetism, was a step towards a unified concept of energy.
Today physicists are investigating what is known as “Zero Point Energy” and its connection to other established laws of physics. This energy form appears to defy some of our currently accepted laws of physics, but this has happened with many new discoveries over the centuries.
The Holy Grail in modern physics is to develop a unified field theory which ties up all of the loose ends and fills in all of the blanks in our current knowledge, but this may not be achieved for a very long time.
Until 1820, the only magnetism known was that of iron magnets and of “lodestones”, natural magnets of iron-rich ore. It was believed that the inside of the Earth was magnetised in the same fashion, and scientists were greatly puzzled when they found that the direction of the compass needle at any place slowly shifted, decade by decade, suggesting a slow variation of the Earth’s magnetic field.
On 21st April 1820, during a lecture, Ørsted noticed that a compass needle deflected from magnetic north when an electric current from a battery was switched on and off, confirming a direct relationship between electricity and magnetism. His initial interpretation was that magnetic effects radiate from all sides of a wire carrying an electric current, as do light and heat. Three months later he began more intensive investigations, and soon thereafter published his findings, showing that an electric current produces a circular magnetic field as it flows through a wire. This discovery was not due to mere chance, since Ørsted had been looking for a relation between electricity and magnetism for several years. The special symmetry of the phenomenon was possibly one of the difficulties that retarded the discovery.
It is sometimes claimed that the Italian scientist Gian Domenico Romagnosi was the first person who found a relationship between electricity and magnetism, about two decades before Ørsted’s 1820 discovery of electromagnetism. Romagnosi’s experiments showed that an electric current from a voltaic pile could deflect a magnetic needle. His researches were published in two Italian newspapers and were largely overlooked by the scientific community.
Ørsted’s findings stirred much research into electrodynamics throughout the scientific community, influencing French physicist André-Marie Ampère’s developments of a single mathematical formula to represent the magnetic forces between current-carrying conductors. Ørsted’s work also represented a major step toward a unified concept of energy, and in 1822, he was elected as a foreign member of the Royal Swedish Academy of Sciences.
Soon after the advances made by Ørsted, his discoveries were further developed by Michael Faraday. He was an English scientist who contributed to the fields of electromagnetism and electrochemistry. His main discoveries include those of electromagnetic induction, diamagnetism and electrolysis. Faraday was born on 22nd September 1791, in Newington Butts in the UK.
Faraday received little formal education, but he was one of the most influential scientists in history. It was due to his research on the magnetic field around a conductor carrying a direct current that Faraday established the basis for the concept of the electromagnetic field in physics. He similarly discovered the principle of electromagnetic induction, diamagnetism and the laws of electrolysis. His inventions of electromagnetic rotary devices formed the foundation of electric motor technology, and it was largely due to his efforts that electricity became practical for use in technology.
As a chemist, Faraday discovered benzene, investigated the clathrate hydrate of chlorine, invented an early form of the Bunsen burner and the system of oxidation numbers, and popularised terminology such as anode, cathode, electrode and ion. Faraday ultimately became the first and foremost Fullerian Professor of Chemistry at the Royal Institution of Great Britain, a lifetime position.
Faraday was an excellent experimentalist, but his mathematical abilities, however, did not extend as far as trigonometry or any but the simplest algebra. James Clerk Maxwell took the work of Faraday and others, and summarised it in a set of equations that is accepted as the basis of all modern theories of electromagnetic phenomena. James Maxwell’s achievements will be discussed in the next section.
On Faraday’s use of the lines of force, Maxwell wrote that they show Faraday to have been in reality a mathematician of a very high order. Today the fundamental unit of capacitance, the Farad, is named in his honour.
Faraday is best known for his work regarding electricity and magnetism. His first recorded experiment was the construction of a voltaic pile (an early battery) with seven penny coins, stacked together with seven disks of sheet zinc, and six pieces of paper moistened with salt water. With this pile he decomposed sulphate of magnesia.
Faraday went on to build two devices to produce what he called “electromagnetic rotation”. One of these, now known as the homopolar motor, caused a continuous circular motion that was engendered by the circular magnetic force around a wire.
This wire extended into a pool of mercury into which he placed a magnet. The wire would then rotate around the magnet if supplied with current from a chemical battery. These experiments and inventions formed the foundation of modern electromagnetic technology.
From his initial discovery in 1821, Faraday continued his laboratory work, exploring the electromagnetic properties of materials. In 1824, Faraday briefly set up a circuit to study whether a magnetic field could regulate the flow of a current in an adjacent wire, but he found no such relationship.
Two years after the death of Faraday’s fellow physicist Humphry Davy in 1831, Faraday began his great series of experiments in which he discovered electromagnetic induction. Faraday’s breakthrough came when he wrapped two insulated coils of wire around an iron ring, and found that upon passing a current through one coil, a momentary current was induced in the other coi
l. This phenomenon is now known as mutual induction.
In subsequent experiments, he found that if he moved a magnet through a loop of wire, an electric current flowed in that wire. The current also flowed if the loop was moved over a stationary magnet. His demonstrations established that a changing magnetic field produces an electric field. This relation was modelled mathematically by James Clerk Maxwell as Faraday’s law, which subsequently became one of the four Maxwell equations. Faraday would later use the principles he had discovered to construct the electric dynamo, the ancestor of modern power generators and the electric motor.
In 1845, Faraday discovered that many materials exhibit a weak repulsion from a magnetic field – a phenomenon he termed diamagnetism. In his work on static electricity, Faraday’s ice pail experiment demonstrated that the charge resided only on the exterior of a charged conductor, and exterior charge had no influence on anything enclosed within a conductor. This is because the exterior charges redistribute such that the interior fields due to them cancel. This shielding effect is used in what is now known as a Faraday cage.
CHAPTER 6
In some previous sections I have been criticising Christianity, and in particular the Catholic church and the Quakers. In order to try to redress the balance of the situation, I will now recall some of my encounters with other religions. I think that the underlying problem today is that what one group considers normal is totally abnormal to another group, and this often causes misunderstandings and conflicts.
I need to stress that I personally am not a religious man, but I have worked on every continent bar Antarctica in the course of my career in the worldwide oil and gas industry. I believe that every country and every religion has a lot of very good and devout people, but also some people who are not so savoury.
My first encounter with people in a non-Christian country was in Jordan. Jordan is a fantastic country and is steeped in history with many outstanding historical sites dating back to the dawn of modern history. The capital Amman, along with Damascus in Syria, are said to be two of the oldest continuously inhabited cities in the world. My agent at the time took me to a restaurant in the old part of the city, where it is said that Jesus Christ ate over 2,000 years ago. Jordan is also a very moderate Muslim state, and westerners along with people from all creeds are well received. However my insight into how the mind-set of some of the local people works occurred at that time.
I was working as a contractor on a land-based drilling rig in the very south of Jordan. I was around twenty-five years old at the time, and the assistant driller there was a Jordanian of about the same age. We got on very well, and when we were off shift we would spend a lot of time in each other’s trailers talking and getting to know each other. On one occasion when he came over to my trailer, I was enjoying a beer as I was off shift for twelve hours.
We got talking about life in general, and he then asked if he could take one of my beers as he had never tried alcohol before. Not wishing to be rude, I offered him a beer. He asked me if I had ever had a girlfriend. I considered that to be a strange question to ask a twenty-five-year-old European, but I just replied “Yes, I have.” He then started complaining that I was so lucky, as in his country it was impossible to get a girlfriend before a man is married.
After drinking two more bottles, he promptly fell asleep in his chair. An hour or so later he woke up, sat bolt upright in the chair, and asked me if any of my girlfriends had been virgins. He had obviously been dreaming about our conversation. I replied that I did not think so, but this is the 20th century so who really cares.
He then started ranting on about how he would never take a wife who had been with another man. I told him that in my culture this is about as important as if a female has worn denims in the past or not. This was an eyeopener for me, because the poor man did not understand the reason why he could not get a girlfriend, and that all of the problems he was complaining about were entirely of his own making.
Having said that, I have a lot of respect for the way in which some people evaluate situations in many Muslim countries. Saudi Arabia is considered to have one of the strictest Muslim regimes in the world. While working in Jordan, I needed to regularly travel from the rig site back to Amman in order to attend meetings and perform other duties.
One morning I needed to leave the rig site, but there had been a flash flood in the desert the previous day. Even though I was driving a 4x4 with lockable diffs, it was not possible for me to drive in the required direction. I therefore needed to make a major detour to avoid the floods. After several hours, I came across a road and headed in a northerly direction. I was running low on diesel at the time, so stopped at the first fuel station that I encountered. After filling the tank and my spare jerry cans I tried to pay the bill. It was then I realised that I was now in Saudi Arabia, but they accepted my US dollars for the fuel.
Being in Saudi Arabia when you have entered unlawfully with no visa, and you are also in a pickup truck with empty crates of beer bottles in the back, is not a comfortable position to be in. I considered my options, and figured that the only thing I could do was to carry on and try to get back into Jordan the best way I could. Before too long, I came upon a border crossing.
At this stage it was too late to turn back, as there were many armed Saudi police and soldiers at the checkpoint. I explained the situation to them, and after detaining me for twenty minutes or so they said that it was an honest mistake and that I could cross back into Jordan. This was very generous of them, as I could have been in a lot of trouble for this.
Back to the science, and we will now look at the developments made by James Clerk Maxwell. Maxwell was an outstanding Scottish mathematical physicist. His most famous achievements were to formulate a set of equations that described electricity and magnetism, and his work on the kinetic theory of gases. He was born on 13th June 1831 in Edinburgh, Scotland, and Maxwell’s achievements concerning electromagnetism have been called the second great unification in physics after the initial work of Sir Isaac Newton.
With the publication of his work on the theory of electromagnetic fields in 1865, Maxwell demonstrated that electric and magnetic fields both travel through space as waves moving at the speed of light. Maxwell proposed that light is in fact undulations in the same medium that is the cause of electric and magnetic phenomena. The unification of light and electrical phenomena led to the prediction of the existence of radio waves.
Maxwell helped develop the Maxwell-Boltzmann distribution, which is a statistical means of describing aspects of the kinetic theory of gases. He is also known for making the first durable colour photograph in 1861. His discoveries helped usher in the era of modern physics, laying the foundation for future work in such fields as relativity and quantum mechanics. Many physicists regard Maxwell as the 19th century scientist who had the greatest influence on 20th century physics.
Maxwell had studied electricity and magnetism as early as 1855 after he read On Faraday’s lines of force. This paper presented a simplified model of Faraday’s work, and detailed how the two phenomena were related. Maxwell then reduced all of the current knowledge into a linked set of differential equations with twenty equations and twenty variables. This work was later published as On physical lines of force in 1861.
Around 1862, Maxwell calculated that the speed of propagation of an electromagnetic field is approximately that of the speed of light. He considered this to be more than just a coincidence.
Working on the problem further, Maxwell showed that his equations predicted the existence of waves that travel through empty space at a speed that could be predicted from simple electrical experiments. Using the data available at the time, Maxwell calculated this velocity to be 310,740,000 metres per second.
In his 1864 paper A dynamical theory of the electromagnetic field, Maxwell wrote, “The agreement of the results seems to show that light and magnetism are affections of the same substance, and that light is an electromagnetic disturbance propagated through the field
according to electromagnetic laws”.
His famous equations first appeared in fully developed form in a textbook in 1873. Maxwell’s theory consists of four differential equations, known now collectively as Maxwell’s Laws. These laws have stood the test of time, and his quantitative connection between light and electromagnetism is considered one of the great accomplishments of 19th century.
Maxwell also introduced the concept of the electromagnetic field in comparison to the force lines that Faraday described. By understanding the propagation of electromagnetism as a field emitted by active particles, Maxwell could advance his work on light. At that time, Maxwell believed that the propagation of light required a medium for the waves, dubbed Aether. Over time, the existence of such a medium, permeating all space and yet apparently undetectable by mechanical means, proved impossible to reconcile with experiments performed. These difficulties inspired Einstein to formulate the theory of special relativity, and in the process Einstein dispensed with the requirement of a stationary Aether.
Twenty-five years after Maxwell’s birth, the great physicist, engineer and inventor Nikola Tesla was born. Although Tesla was born in Smiljan, Croatia, he spent most of his life in the USA. He was a physicist, electrical engineer, mechanical engineer and futurist best known for his contributions to the design of the modern alternating current electricity supply system.
I personally consider Nikola Tesla to be one of the greatest scientists and engineers of the recent era. His understanding of concepts including AC electricity and the transmission of energy through both cables and the atmosphere were leagues ahead of any of his peer group.
A testimony to his genius is that when he died in Manhattan, USA in 1943, his residence and lab were immediately raided by the US secret service. Many of the documents that they removed in 1943 still remain classified today, and cannot be obtained even under the Freedom of Information Act. This information is known to exist following Tesla’s public demonstrations of many of his inventions, but his research notes on how these inventions were developed will not be shared. As is the case with all sensitive officially unpublished information, any enquiry is met with the standard reply that “no records can be found”.
