James Prescott Joule

James Prescott Joule
James Prescott Joule

James Prescott Joule (1818 – 1889) was a British physicist whose most important scientific contribution was to establish an understanding of the relationship of heat to mechanical work.  His work set the foundation for the idea of the conservation of energy, later leading to the development of the first law of thermodynamics.

James Joule was born on Christmas eve in England to the father of a successful and wealthy brewer.  As a child he was fortunate enough to be tutored by the famous scientist John Dalton and that most likely had a lasting, positive impression him.  By adulthood Joule was still managing the brewery business, and his business acumen combined with his scientific curiosity led to some important discoveries.  During his free time he experimented with replacing the steam engines in his brewery with electric ones.  This led to the discovery of what is now known as Joule’s Law, which establishes the relationship of the flow of a current through a resistance and the heat it generates.  His experiments contained precise measurements which he reported in a series of scientific papers.

His work was noticed by Lord Kelvin and the two collaborated on several more experiments leading to the discovery of the Joule-Thomson effect – the change in temperature of a liquid or gas as it experiences a rapid change in pressure.  This concept would later be used in refrigeration.  The two also collaborated on an absolute temperature scaled now termed the Kelvin scale.

In 1850 Joule was elected as a member to the Royal Society and two years later he received the Royal Medal for his paper On the Mechanical Equivalent of Heat.  His work helped make the caloric theory of heat obsolete and laid the groundwork for the modern theories of thermodynamics.  The SI unit of energy, the joule, is named in his honor.

Michael Faraday

Michael Faraday portrait
Michael Faraday

Michael Faraday (1791 – 1867) was a key figure in 19th century science whose work was critical in advancing our understanding of electricity and magnetism.  His groundbreaking work and insights helped pave the path for future breakthroughs in the field of electromagnetism.

Faraday was born in London to a struggling family, but also one of strong spirituality.  He began his education inside a church and developed a love for reading.  A big break in Faraday’s life came when in 1812 he attended a series of chemical lectures by Sir Humphry Davy.  Being a detailed oriented person, Faraday took meticulous notes at that fortuitous lecture and then mailed them to Davy in the form of a 300 page binder.  Impressed with work and thanks to an accident to one of his assistants in his laboratory, Davy brought Faraday on as an assistant and opening of the doors of opportunity to science for him.  He was able to study chemistry under Davy and quickly mastered the science of the day. He eventually obtained a position at the Royal Institution of Great Britain, became an expert in his own right in chemical analyses, discovering benzene in 1825, but Faraday’s most important contribution to science came in the field of electromagnetism.

In 1831 Faraday discovered electromagnetic induction – that a moving magnetic field produces electric current.  This is significant because previously the only known way to produce an electric current was with a battery.  But now electric current could also be produced by the movement of a magnet.  This relationship was eventually modeled mathematically by James Clerk Maxwell.

Faraday continued to make important discoveries such as diamagnetism and established two laws of electrolysis, as well as give lectures at the Royal Institution until late in life.  He died at the age of 75 in 1867 as one of the most respected scientists of his day, an achievement extremely remarkable considering his humble origins.

1834: The Electric Motor

An early electric motor
An early electric motor

The invention of electric motor marked a pivotal moment in engineering history.  An electric motor is a devise that uses electricity to create a mechanical force.  There were earlier prototypes to electric motors but they were very weak and more of a spectacle than a working motor capable of producing useful work.

The invention of the electric motor can be said to have first occurred in May 1834 by Moritz Jacobi, although later that year Thomas Davenport independently created an electric motor also.  The Jacobi motor was capable of lifting weights of around eleven pounds at a speed of one foot per second – roughly fifteen watts of mechanical power. 

Early Contributors and Origins of the Electric Motor

Several inventions and discoveries were essential prior to building an electric motor.  As with most modern technological inventions, a synthesis between many ideas developed by different people over a period of time is required.  The roots can be traced back to the 19th century when scientists were beginning to understand and unlock the power of electricity.  

The history of the invention of the electric motor began with the discovery of electricity itself, thanks to experiments such as Benjamin Franklin’s famous kite experiment.  Once this phenomenon was discovered the next steps required a knowledge of storing electricity and then harnessing it to create motion. 

The battery, invented by Alessandro Volta in 1799, allowed for the storage of electrical energy and provided a continuous electric current.  Then in 1820 Hans Christian Orsted observed for the first time a mechanical movement caused by an electric current.  During a lecture he noticed a compass needle was deflected from north when an electric current was nearby.  This was an important step in confirming the relationship between electricity and magnetism.  Later that year in France Andre Marie Ampere showed that effect could be made stronger by coiling a wire.  In 1825 William Sturgeon invented the first electromagnet by wrapping a coil of wires around an iron core.

These experiments and discoveries taken together showed that electricity could be used to produce magnetism. Then, in 1831 Michael Faraday showed the reverse was also true – that magnetism could be used to produce electricity.  Faraday’s work on electromagnetic induction in the early 1830s truly laid the foundation for the creation of electric motors. Building on Faraday’s work in the 1830s was the American blacksmith and inventor, Thomas Davenport. He created a small electric motor by using a battery, a magnet, and a wire coil. His creation was one of the earliest practical electric motors and demonstrated the potential for using electricity as a sources of mechanical power.

An original Alternating Current (AC) Tesla Induction Motors, on display at the British Museum
An original Alternating Current (AC) Tesla Induction Motors, on display at the British Museum in London

Thanks to these important discoveries, electric motors began being invented all over the world.  Soon other scientists and inventors mad further advancements in electric motor technology. Each motor is designed and works differently but they all use the principles of electromagnetism and the power of the electromagnetic field. By the 1870s and 1880s, practical and efficient electric motors began to be widely developed and used. One of the most notable inventors in this period was Nikola Tesla, who made significant contributions to the development of alternating current (AC) motors. In 1888, he patented a design for a polyphase AC induction motor, which utilized two or more alternating currents out of phase with each other. This design allowed for efficient and reliable conversion of electrical energy into mechanical energy. Tesla’s work revolutionized the field of electrical engineering and played a crucial role in the widespread adoption of electric motors. His inventions and innovations greatly advanced the field of electric motor technology.

Impact on Society

The invention of the electric motor and its subsequent advancements have generated an enormous impact on modern society. Transportation and industrialization have been two been two of the most impacted areas. The electric motor played a crucial role in the industrial revolution, powering machinery and enabling mass production of goods. It eventually replaced steam engines as the dominant from of mechanical power in transportation, paving the way for vehicles such as cars, buses and trains.

More recently, electric motors have found their way into an assortment of household appliances that have becomes essential to modern life. They power refrigerators, washing machines, dishwashers, air conditioners, and many other devices. They are indispensable in renewable energy systems such as wind turbines and hydroelectric generators. Electric motors are at the core of automation and robotics as essential components in conveyor belts, assembly line systems, and other industrial automation applications. The electric motor has had a transformative effect on society, and to this day continues to drive technological advancements.

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James Clerk Maxwell

James Clerk Maxwell
James Clerk Maxwell

James Clerk Maxwell (1831 – 1879) was a British scientist famous for his mathematical synthesis of the forces of electricity and magnetism into what is now known as the electromagnetic force. He is one of the most important figures in the history of physics.

Maxwell was born in Dumfrieshire, Scotland where he received an early education from his mother until she passed away when Maxwell was eight. A short time later he was enrolled at Edinburgh Academy where he excelled in mathematics. In April of 1847 Maxwell’s uncle took him on a trip to the private laboratory of physicist William Nicol where he was captivated by the experiments and demonstrations he witnessed and was determined thereafter to become a physicist. He entered Cambridge University three years later, earned top honors in mathematics, and after graduating became a professor in King’s College, London.

It was during his time as a professor at King’s College that he began formulating his theory of electromagnetism. Electric fields changing in magnitude create a magnetic field. Additionally magnetic fields changing in magnitude creates an electric field. Thus these fields moving together as a wave can create a continuous chain of creating. Maxwell realized that he could combine both the magnetic and electric fields into a single electromagnetic field through a series of equations, which we now refer to as the Maxwell equations. When Maxwell calculated the speed of these waves he obtained 186,000 miles per second, and so in 1864 he was able to conclude that light consists of electromagnetic waves. Eventually it was realized that light consists of only a small portion of the electromagnetic wave field with longer and shorter wave lengths being possible, eventually leading to discoveries such as radio waves and x-rays.

Maxwell's Equations

Maxwell also did other important work in optics. He presented the first color image in photography during a lecture in 1861, the same year he was elected the the Royal Society of London. In 1874 he was appointed director of the Cavendish Laboratory. However he did not hold this position long as he died five years later at the age of 48 due to stomach cancer. Even though his life was cut short his accomplishments and contributions to science were immense.

1799: The Battery

The battery has revolutionized the way we live, producing a reliable and portable power source for a wide range of products.  The concept of batteries has a rich history that spans centuries, possibly even millennia.  As far back as the 1st century AD, civilizations may have been experimenting with battery concepts, with artifacts discovered around Baghdad that resemble battery-like devices.  However, the true purpose of these devices remains controversial.

Alessandro Volta and the Birth of the Battery

Voltaic pile
A Voltaic Pile

At the turn of the 19th century electricity was becoming an increasing topic of study.  People were finding various ways to produce or store electric current but there was as of yet no way to produce a continuous flow of electricity.

In 1799 the Italian physicist Alessandro Volta solved this problem and first reported his findings in a letter to the Royal Society in 1800. Called a Voltaic pile, Volta stacked zinc, copper, and brine-soaked paper in layer after later, sometimes referred to as a voltaic cell.  Adding a wire to both ends produced an electric current, with additional layers creating a stronger current.  These additional layers stacked on top of each other created the voltaic pile.  Volta realized that somehow the piles of metal disks were producing the current, an effect called an electromotive force.  

In 1810 Humphry Davy showed that it was the chemical reaction between the two metals (electrode) and the liquid solution (electrolyte).  Various difference metals and solutions can be used all to create an electromotive force.

The voltaic pile marked a significant milestone in the history of electricity.  It was the first true electric battery, setting the stage for the development of modern batteries.

Unleashing the Power of Chemical Energy

A battery is then a chemical means of generating electricity.  It works through a “redox” reaction, which is the process of reduction (one substance gaining electrons) and the process of oxidation (one substance losing electrons) occurring simultaneously. To perform the redox reaction most batteries consist of two electrodes – an anode (negative electrode) and a cathode (positive electrode) – separated by an electrolyte, which is a conductive material. The electrodes are typically made of two different materials, and the electrolyte allows ions to flow between them while preventing contact. When the battery is connected to an external circuit, the redox chemical reaction occurs within the battery, producing the flow of electrons from the anode to the cathode, creating an electrical current that can be used to power devices.

Volta’s battery is called a wet battery.  While it did produce a controlled, continuous flow of electric current it was not very practical.  There were significant limitations with its capacity, size, and portability. The battery was a large and cumbersome device and had a low energy density compared to modern batteries. What it was however, was a groundbreaking invention that paved the way for further development of battery technology. It was not until a dry battery was invented, which replaced the liquid electrolyte with a paste, that batteries portable and practical.

The Rise of Practical Batteries

The battery has undergone significant changes in the past two centuries since the invention of the voltaic cell.  Here are a few notable improvements:

  • Daniell Cell: In 1836, the British scientist John Frederic Deniell invented a new cell using copper sulfate and zinc sulfate, separated by a porous pot, to create a longer-lasting source of power.
  • Lead-Acid Batteries: In 1859 the French physicist Gaston Plante invented the first rechargeable battery.
  • Leclanche Cell: In 1866, the French engineer Georges Leclanche patented a new kind of battery – a predecessor to the modern dry cell battery.  It used a zinc anode and a manganese dioxide cathode wrapped in a porous material, dipped in a jar of ammonium chloride.
  • Nickel-Cadmium Batteries: In 1899 the Swedish inventory Waldemar Jungner invented the first alkaline battery.
  • Lithium-ion Batteries: Lithium is the metal with the greatest electrochemical potential.  These batteries did not come to market until the 1970s and offer the highest densities and can hold its charge for the longest period of any battery. 
Electric Vehicle Battery System
A Modern Electric Vehicle Battery System
(Credit: aec.org)

Peering into the future batteries will increasingly play a role in society. Emerging technologies such as artificial intelligence (AI), renewable energy storage, advanced portable devices, and electric vehicles (EVs) will need powerful batteries to conveniently function. As a result many of these industries are investing heavily in battery technology. Improved battery technology will enable the widespread adoption of many of these technologies, removing their limitations and making the more appealing to consumers.

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Benjamin Franklin

Benjamin Franklin
Benjamin Franklin

Benjamin Franklin (1706 – 1790) achieved much in his life as a scientist, while still having time for success in business as a profitable entrepreneur in printing and writing, an innovative investor, a statesman critical in forming legislation for a new nation, a diplomat allowing a new nation to form, a philanthropist with an eye to be benefit of future generations, and above all – a visionary.  Due to his wide range of extraordinary abilities he is one of the most accomplished and remarkable men in American history.

Ben Franklin was born in Boston and at an early age fell in love with reading.  At age 12 he began an apprenticeship to his brother James, a printer, where he learned the printing trade.  After five years he fled to Philadelphia looking for a new beginning to life and shortly after arrival in the city he quickly relocated to London on a promise from the Pennsylvania Governor that he could get some equipment to start a newspaper.  When the promise fell through he returned to Philadelphia and founded The Pennsylvania Gazette.  He continued to have success as an author when he published Poor Richard’s Almanack, a publication covering various topics which he continued for 26 years.

By the age of 42 Franklin was wealthy enough to retire from the printing business, where he became a gentlemen and began to engage in the curiosities of the day.  This was the beginning of his short, but important time in life as a scientist and inventor.  Some of his more famous inventions were the Franklin stove and the bifocal glasses, but his most famous scientific work is in electricity.  The kite experiment that Franklin is supposed to have carried out was used to prove the lightning and electricity are the same phenomenon.  This led to the invention of the lightning rod placed on buildings used to prevent fires.

As events in the American colonies continued to advance towards revolution Franklin eventually gave up his scientific inquiries and devoted the remainder of his life to being a politician, statesmen, and eventually a peacemaker.  He was one of the founding fathers of the United States and played critical roles in shaping its destiny.

Charles Coulomb

Charles Coulomb portrait
Charles Coulomb

Charles -Agustin de Coulomb (1736 – 1806) was born in France and lived at a time of radical social upheaval and governmental change.  His most famous discovery was an inverse-square law published in 1785, known today as Coulomb’s Law, that quantifies the force with which stationary electrically charged particles repel or attract each other.

The Life of Charles Coulomb

Carles Coulomb was born on June 14, 1736, in Angoulême, France. Both of his parents came from local aristocratic families, and family moved to Paris early in his childhood. In Paris, Coulomb received a comprehensive education in mathematics, physics and engineering at the Collège des Quatre-Nations (College of the Four Nations). His exceptional aptitude for mathematics provided him the opportunity to join the French army in 1761 as an engineer where he was responsible for a variety of engineering projects ranging from structural fortifications to soil mechanics over a period of two decades.  Throughout his military career he began to become interested in research experimentation, presenting his first work in applied mechanics to the Academie des Sciences in Paris in 1773.  In 1777 he submitted his most famous work on torsion balances winning him a share of the Grand Prix of the Academie des Sciences, an award he also won two years later based on the construction of a fort made entirely out of wood.

By the late 18th century, the study of electricity and magnetism was rapidly advancing. In 1785 he published what later became known as Coulomb’s Law.  It described the relationship between electrically charged particles as in inverse-square law.  He noted a similar relationship between magnetic poles.  These discoveries eventually led to the development of the theory of electromagnetism.  For this valuable work the SI unit of electric charge was name in his honor in 1908.

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1796: The First Vaccination

Humanity has achieved countless medical breakthroughs over the centuries, yet few have had as profound and lasting impact as the invention of the first vaccine.  A vaccination is the process of administering biological preparation called a vaccine to stimulate the immune system and protect individuals from infectious diseases.  The primary purpose of the vaccine is to mimic the infection without causing the disease, although sometimes mild symptoms will occur for a brief period of time.  This will prime the immune system to recognize and respond effectively later if the person is exposed to the actual infection.

This remarkable achievement was first performed by the English physician Edward Jenner in 1796.  Despite recent controversies over vaccinations, this medical breakthrough had led to the prevention of many diseases and has undoubtedly saved countless lives.  

Edward Jenner and the Smallpox Threat

This first vaccination was developed against smallpox, a disease that had plagued humanity for thousands of years.  This highly contagious and often fatal disease caused high fever, severe skin rashes, and the formation of fluid-like blisters on the skin.  Smallpox had a mortality rate of up to 30%.  Outbreaks were common, leading to the loss of millions of lives.  Edward Jenner, an English physician and scientists, made his revolutionary discovery late in the 18th century when he developed a vaccine for smallpox.

Edward Jenner Vaccination
Edward Jenner Administering the First Vaccination

Earlier in the 18th century it was observed that people who suffered from a more benign form of cowpox became immune to smallpox.  Jenner had also observed that milkmaids who had contracted and subsequently recovered from cowpox did not appear to contract smallpox.  These observations led Jenner to hypothesize that the cowpox infections somehow helped to protect these people against smallpox.  In 1796 Jenner tested his hypothesis.  He took cowpox material from Sarah Nelmes, a milkmaid, and injected it into the arm of an eight year old boy, James Phipps.  The boy became sick for a few days but soon recovered.  Two months later he was exposed to smallpox and showed immunity to the disease, which lasted for the rest of his life.  It was the proof Jenner was needed.  He had successfully developed worlds the first vaccination, the word derived from the Latin word vacca, which means cow.

Two years later Jenner published An Inquiry into the Causes and Effects of the Variolae Vacciniae, which outlined Phipps vaccination as well as twenty two related cases.  Jenner’s publication soon generated much interest on the topic after subsequent vaccinations were reproduced by others.  His work laid the foundation for the science of immunology, leading the development of vaccines for many other diseases.  Over the coming decades advancements in microbiology and immunology led to the development of vaccines for several diseases, including polio, influenza, measles, mumps, rubella, HPV, and many others.  

Most recently the COVID-19 pandemic, caused by the SARS-Cov-2 virus, highlighted the need for vaccines.  In a remarkably short time multiple vaccines were developed and authorized for emergency use to combat the pandemic.  Governments launched vaccination campaigns globally to control the spread of the disease and reduce its impact on the public health.  

A Long-Lasting Global Impact

Jenner’s discovery of the vaccination was nothing short of revolutionary. Within a few years vaccinations spread around the world and were being endorsed by governments. As early as 1801 Russia supported the use of vaccinations and in 1802 Massachusetts became the first state to actively support their use as well. Today vaccinations provide a variety of public health benefits.  These benefits include:

  1. Disease Prevention:  The primary purpose of vaccines is disease prevention.  They work by stimulating the immune system to recognize and fight specific pathogens, reducing the likelihood of infection.
  2. Reduced Morbidity and Mortality:  Vaccines reduce the incidence of diseases, hospitalizations, and deaths.  Additionally, after a large enough portion of the population is vaccinated, herd immunity is achieved, protecting even those who have not been vaccinated.
  3. Elimination of Diseases: Vaccinations have played a paramount role in the elimination or near elimination of many diseases, beginning with smallpox.  In 1980, the world was officially declared free from this deadly disease.  Polio is another disease on the verge of elimination.  
  4. Various Economic Benefits:  By preventing illnesses, vaccines reduce healthcare costs associated with treating infectious diseases.  They also minimize lost productivity due to illness in the workplace.
  5. Prevention of Outbreaks:  Vaccines are critical in preventing outbreaks of infectious diseases.  

It is because of these and numerous other benefits that vaccines are considered one of the most successful and cost-effective public health measures.

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Joseph Black

Joseph Black portrait
Joseph Black

Joseph Black (1728 – 1729) is considered the father of quantitative chemistry and his research on boiling and freezing liquids revolutionized our understanding of heat.  He is best known for his discoveries of carbon dioxide and latent heat.

Born in Bordeaux into a large family of Scottish wine traders, Black was educated at the University of Glasgow where he studied medicine quickly took a liking to chemistry after attending the chemistry lectures of William Cullen.  In 1752 Black transferred to the University of Edinburgh to finish his medical studies.  His medical thesis turned out to be one of the most important scientific papers in the history of chemistry.  It centered what happened when a from of magnesium carbonate was heated.  He ended up isolating the gas given off, carbon dioxide, but the real importance in his paper was that it was the first instance where anyone was taking careful, precise measurements in chemistry.  This paper and his follow up lectures on it laid the basis laid the foundation for quantitative chemistry.

After obtaining a professorship at Glasgow, Black took up research on the nature of heat.  By exploring phenomenon that there is no temperature change in a phase change, such as solid to liquid or a liquid to a gas, he came up with the notion of latent heat.  Latent heat is then the thermal energy released or absorbed by a substance during its phase change. Heat water at 100 degrees Fahrenheit and its temperature will continually increase until the boiling point of 212 degrees Fahrenheit.  Continue adding heat the the water and its temperature will stay at 212 degrees, while some it evaporates as gas.  This is because all the energy added to the boiling water is being absorbed as latent heat of vaporization.  When James Watt began working at Glasgow University the two became friends and Black shared his ideas on latent heat, which Watt surely used to improve his steam engines powered the industrial revolution.

Black eventually succeeded William Cullen as Professor of Medicine and Chemistry at the University of Edinburgh where he was a superb lecturer.  For thirty years held this position until his failing health forced him to retire.

Joseph Priestley

Joseph Priestley portrait
Joseph Priestley

Joseph Priestley (1733 – 1804) is usually credited with the discovery of oxygen, which helped to overthrow the phlogiston theory that attempted to explain oxidation processes.

Priestly was born in Bristal Fieldhead, England into a family with a strong religious influence.  Throughout his life he had no formal scientific training but his interest in science was aroused when he met Benjamin Franklin in London in 1766 and had discussions with him about electricity.  He took to the subject quickly and the next year published a 700 page work, The History and Present State of Electricity, which went through five successful editions.

The work for which Priestley is most famous for was done in 1774.  He would use a lens to focus sun rays to heat various chemicals and observe what gases they would emit.  When he focused the sun rays on mercuric oxide he was able to capture the gas emitted.  He tested this new gas on mice and noticed they would live much longer entrapped with this gas than with an equal amount of air.  The gas was not soluble in water and candles burned much longer in it too.  He had discovered oxygen.  This work combined with that of Antoine Lavoisier’s further experiments helped to overthrow the theory of phlogiston.

Although Priestly was raised as a devoted Calvinist he came to reject those beliefs and increasing came to hold unpopular religious beliefs.  In the last decade of his life he fled England to the United States where he lived his final days in a more tolerant religious environment.