My Science School

Gustav Kirchhoff, a German physicist, is remembered for his pioneering work in spectroscopy, which permitted investigation of the chemical composition of stars.

       His circuit laws are the foundation of electrical engineering. In 1845, while still only a student at the university, Kirchhoff wrote a paper detailing his circuit laws.

      Kirchhoff discovered that radiation is given off by all objects that have a temperature greater than absolute zero, and gave a proof for his law of thermal radiation in 1861. He experimented with electrical circuits and spectroscopy, and coined the term ‘black-body’ radiation in 1862.

       Along with Robert Bunsen, Kirchhoff founded the science of spectrum analysis by proving that every element gives off a characteristic wave length of light when heated to incandescence.

     He also discovered that when light is passed through a gas, the gas absorbs those wavelengths it would have emitted if heated. This discovery was of great importance to the field of astronomy.

Louis Pasteur, a French chemist and microbiologist made many important discoveries related to the immune system, vaccinations, chemistry, and the nature of diseases.

     Pasteur’s work helped show that microorganisms are the true cause of many diseases. Pasteur used his knowledge of germs to investigate how beverages such as wine and milk were spoiled by microbes such as bacteria.

      He found that heating up the liquids would kill most of the microbes, and allow the beverages to last longer, and be safer to drink. This process became known as pasteurization, and is still done on many foods such as milk, vinegar, wines, cheese, and juices. He studied the immune system and vaccination through his research, and helped produce the first vaccine for rabies, saving the life of a young boy in 1885.

     Pasteur is also responsible for many breakthroughs in the field of chemistry. He discovered the molecular basis for the asymmetry of certain crystals, and made important discoveries related to the nature of tartaric acid.

     Today, Louis Pasteur is known as one of the most important scientist in history.

Gregor Mendel, a 19th century monk, is the founder of modern genetics. He is famous for his pea plant experiments which helped to establish some of the now accepted laws of heredity. Heredity is when certain traits like eye colour, height, and athletic ability are passed from the parents to the children. In biology the study of heredity is called genetics.

     In 1856, Mendel began studying hereditary features in pea plants, and concluded that all living things, including humans, passed on their characteristics to their children in predictable ways.

    Mendel grew, and tested almost 28,000 pea plants during 8 years of research. He came up with the terms recessive and dominant, to describe type of genes that are passed down through generations.

     Mendel’s findings, which he presented on meetings of the natural history society of Brno, in 1865, were rejected by his fellow scientists while he was alive. It wasn’t until later that his work was rediscovered and confirmed through further experimentation.

The English physicist James Joule studied the nature of heat, and established its relationship to mechanical work.

         He showed that the various forms of energy mechanical, electrical, and heat are basically the same, and can be changed, one into another. This is known as the conservation of energy, and the idea was proved by Joule in a series of experiments.

        In his early years, joule proved that heat produced in a small electromagnet built by him was from electrical energy, which was in turn, generated by mechanical energy which powered the dynamo. The principle of conservation of energy became the first law of thermodynamics, a field of physics that Joule is referred to as the chief founder of.

       Joule was the first person to calculate the speed of a molecule of gas, about 457 meters a second for oxygen at average temperatures. This would lay the foundations for the kinetic theory of gases in the future. Joule recognized the need for standard units of electricity. In fact, the unit of energy is named the ‘joule’ in recognition of his contributions.

Hermann Ludwig Helmholtz, a German physician and physicist, is best known for the law of the conservation of energy. He also made significant contributions to physiology, optics electrodynamics, mathematics, and meteorology.

         In 1847, he published his paper ‘On the Conservation of Force’. This was the first explanation of the fundamental concept of conservation of energy. His inventions of the ophthalmoscope allowed physicians to see inside the eye, and revolutionized the field of ophthalmology.

       Helmholtz was a keen mathematician, and in 1858 published the paper which provided a key to the fundamental structure of matter. He also investigated the physics of tone and colour perception. But above all, it is his theory of the conservation of energy that is his greatest contribution, for it is one of the broadest and most important generalizations ever known in the history of science.

Claude Bernard, a French physiologist, has been called one of the greatest of all men of science. Bernard was fascinated with the mechanics of digestion.

        He made a number of experiments in which he made opening into the stomachs of live animals in order to study their workings. His experiments resulted in a number of important discoveries, including the finding that the small intestine played a key role in the digestive process.

      His experimentation also helped show the significance of the pancreas. In 1857, Bernard discovered glycogen, the large molecule found in animals’ livers which acts as a reserve store of carbohydrates, and helps to regulate blood sugar. Bernard also studied the nervous system. While engaged in this research, Bernard made the important discovery that oxygen was carried around the body by red corpuscles in an animal’s blood.

     Bernard was one of the founders of experimental medicine, and played a vital role in laying down the basic rules of experimentation in the life sciences.

Charles Darwin was an English naturalist who is best known for his ideas on evolution. In 1831, Darwin set sail on the HMS Beagle, a naval survey ship. Darwin’s job was to collect plant and animal specimens from the countries the ship visited. The voyage took five years.

      For Charles Darwin, the most important part of the journey was the time spent in the Galapagos Islands which are the home to plants and animals that can’t be found anywhere else in the world.

      On his return to England, Darwin stated to piece together his theory of natural selection which explains how populations evolve. In 1859, Charles Darwin published his book ‘On the Origin of Species’.

     According to this theory, all species of life have evolved over time from common ancestors. Charles Darwin changed the way humans viewed themselves.

Jean Louis Agassiz, a Swiss-American naturalist, was an outstanding comparative anatomist. When he was only 21 years old, he published the work that launched him on his long and distinguished scientific career. It was titled ‘The Fishes of Brazil’ and it was the most important account of a local fish fauna published till that time.

       Later, Agassiz worked under Georges Cuvier, another brilliant comparative anatomist. Agassiz made extensive contributions to ichthyological classification, including of extinct species.

      Ichthyology is the branch of biology devoted to the study of fish. Agassiz also played an important role in the study of geological history including the founding of glaciology. He was a person with many interests- a biologist, physician, geologist, teacher, and most importantly, a prominent innovator in the field of the study of natural sciences.

John Dalton, a British scientist, is probably best known for his groundbreaking research and contributions to two completely different fields- atomic theory and colorblindness.

It was discovered in 1995 that Dalton actually had a very rare form of color blindness- he was only able to see one colour, yellow.

So, he studied the problem in great detail and concluded that colorblindness was a genetic feature, as his brother was also colour blind.

Dalton was also very influential in the study of meteorology, specifically barometric pressure. This led to his publication of a series of papers called experimental essays in which he discussed the makeup of mixed gases.

The most important of all Dalton’s investigations are those concerned with the atomic theory in chemistry. The research had a great impact on atomic theory. He created a listing of atomic weights for six different elements – hydrogen, oxygen, nitrogen, carbon, sulfur, and phosphorous.

Dalton’s interpretation of atomic theory maintained that atoms are combined in chemical reactions, but also that they can be separated and rearranged. Without doubt, it was John Dalton’s atomic theory that laid the foundations of modern chemistry.

Friedrich Wohler was a German chemist who chose to be a teacher of chemistry. He was one of the finest scientists of the 19th century.

        Wohler gained international renown from two path breaking discoveries. In 1827, Wohler prepared the first pure sample of aluminum. This metal is the third most prevalent element in the earth’s crust, but it is exceedingly difficult to isolate it from its compounds.

        He also discovered how to make urea in the laboratory without the use of a living kidney. This was an important discovery, because it heralded the end of an existing theory that organic compounds could only be made by living things. Wohler was the co-discoverer of beryllium, silicon, and silicon nitride.

       In 1832, Wohler, along with another scientist Justus Liebig published a study on the oil of bitter almonds which proved that a group of atoms can act like a single element, and be exchanged for elements in chemical compounds. This too, took the scientific world by storm.

Michael Faraday was 19th century British chemist and physicist. He is often called the father of electricity with good reason.

       His work on electrochemistry and electromagnetism laid the foundation for many areas of science. It was in 1831 that Faraday discovered electromagnetic induction, the principle behind the electric transformer and generator. This discovery was crucial in allowing electricity to be transformed from a curiosity, into a powerful new technology. He was partly responsible for coining many familiar words including ‘electrode’, ‘cathode’ and ‘ion’ Faraday laid the basis of the electromagnetic field concept in physics, discovered the laws of electrolysis, and invented electromagnetic rotary devices that were vital in the creation of electric motors. Faraday has thus played a key role in the development of electricity for use in, modern technology.

Sir Humphrey Davy was an English chemist who made many notable contributions to science, especially in electrochemistry. He is renowned for the invention, in 1815, of the Davy safety lamp that helped to prevent explosions in coal mines. Davy was the first to isolate several chemical elements, including sodium and potassium.

        He discovered boron, and found that nitrous oxide, or laughing gas, had anaesthetic properties that could be useful in surgery. Davy did many experiments on the effect of breathing in certain gases- and once, almost killed himself by inhaling a mixture of toxic gases.

      His research included work on early forms of electric batteries, and the use of electricity to isolate chemical elements. He also analyzed mineral, and completed many studies in tanning and agriculture chemistry.

    Did you know that in 1809, Humphrey Davy invented the very first electric light? He did this by connecting two wires to a single battery, and then attaching a charcoal strip between the other two ends of the wires. The charged carbon then glowed, making the very first arc lamp. Humphrey Davy was one of the greatest scientists, ever in the history of mankind.

Amedo Avogadro was an outstanding Italian physicist who lived in the 18th century.

    Although he had followed the family tradition by studying law, he gradually lost interest in legal matters. He found science was much more intellectually stimulating.

    Mathematics, and physics, in particular attracted his logical mind. Avogadro is chiefly remembered for his molecular hypothesis, first presented in 1811. He stated that equal volumes of different gases contain an equal number of molecules, provided they are at the same temperature and pressure.

     Amedeo Avogadro was a great scientist who made important contributions to physics. However, he never received any awards for his discoveries.

      Avogadro’s hypothesis gained acceptance only after his death as people did not recognize their significance. In honour of his contribution to molecular theory, the number of molecules in one mole was named Avogadro’s number.

Andre-Marie Ampere was a French physicist and mathematician, who made the revolutionary discovery that a wire carrying electric current, can attract or repel another wire next to it, that’s also carrying electric current. The attraction is magnetic, but no magnets are necessary for the effect to be seen.

      Ampere went on to formulate Ampere’s law of electromagnetism and produced the best definition of electric current of his time. He also proposed the existence of a particle we now recognize as the electron, discovered the chemical element fluorine, and grouped elements by their properties.

     In recognition of Ampere’s contribution to modern electrical science, the ‘ampere’ was established as a standard unit of electrical measurement, in 1881, forty-five years after his death

Samuel Hahnemann, a German physician, founded homeopathy.

        Hahnemann believed that the medicine he had been taught to practice some-times did the patient more harm than good.

       He carried out experiments on the curative power of bark, which was the source of quinine. He was the first person to observe that a remedy that produces symptoms in a healthy person will cure those same symptoms when manifested by a person in a disease state.

     This principle that ‘likes are cured by likes’ is the very foundation of homeopathy. Hahnemann is called the ‘father of experimental pharmacology’ because he was the first physician to prepare medicines in a specialized way, by first trying them on healthy human beings, to determine how the medicines acted to cure diseases.