Sir C. V. Raman is best known for his work in the field of light scattering. Raman was intrigued by the blue colour of glaciers and the Mediterranean Sea and wanted to unravel the mystery as to why water, a colourless liquid, appeared blue to the eyes.

    Thus, he began a series of experiments on the scattering of light which ultimately led to what came to be known as the ‘Raman Effect’. Raman also discovered that when light interacts with a molecule, the light can donate a small amount of energy to te molecule. As a result of this, the light changes its colour and the molecule vibrates.

   The change of colour can act as a ‘fingerprint’ for the molecule. Today, Raman spectroscopy, which relies on these ‘fingerprints,’ is used in laboratories all over the world to identify molecules and to detect disease such as cancer.

     Sir C. V. Raman received the Nobel Prize for Physics in 1930. He was the first Indian to win the Nobel Prize for Physics, and is considered to be a scientist par excellence.

Srinivasa Ramanujan was, without doubt, a mathematical genius. Without any formal training in the subject, he made significant contributions to the theory of numbers, investigation of elliptical functions, infinite series, continued fractions, and Mock theta functions.

    Ramanujan showed a natural inclination towards mathematics when he was ten years old. By age 11 he had more mathematical knowledge than two college students who were lodgers at his home. He completely mastered advanced trigonometry by the age of 13, and discovered sophisticated theorems on his own.

   His memory for mathematical formulae and constants seems to have been boundless- he amazed classmates with his ability to recite the values of irrational numbers to as many decimal places as they asked for.

   Ramanujan went to Cambridge in April 1914, thanks to the help of Prof. G. H. Hardy. Two years later, he was awarded the equivalent of a PhD. for his work. The notebooks he had brought from India were filled with thousands of identities, equations and theorems which he had discovered for himself.

   In 1918 Ramanujan became the first Indian Mathematician to be elected a Fellow of the British Royal Society.

Sir Jagadish Chandra Bose is one of the most famous among Indian scientists. He was a physicist, biologist, biophysicist, botanist and archaeologist, as well as a writer of science fiction.

  Bose proved by experimentation that both animals and plants share much in common. He demonstrated that plants are also sensitive to heat, cold, light, noise and various other external stimuli.

   Bose built a very sophisticated instrument called Crescograph which could record and observe the minute responses of plants to external stimulants. He authored two illustrious books and extensively researched the behavior of radio waves.

       Bose devised another instrument called ‘Coherer’. In 1917, he founded the Bose Institute, and dedicated it to the promotion of scientific studies in India.

Aryabhata was a great mathematician and astronomer in Ancient India. He wrote many mathematical and astronomical treatises. His chief work was the ‘Ayrabhatiya’ which was a compilation of mathematics and astronomy.

   Ayrabhatiya covers several branches of mathematics such as algebra, arithmetic, plane and spherical trigonometry. Included in it are theories on continued fractions, sum of power series, sine tables, and quadratic equations.

  Aryabhata also did a considerable amount of work in astronomy. He knew that the Earth is rotating on an axis around it. He discovered the position of nine planets and stated that these also revolved around the sun.

    Aryabhata stated that the correct number of days in a year is 365. He was the first person to mention that the Earth was not flat but, in fact spherical shape. This great man has been honored in many ways. The first Indian satellite was named ‘Aryabhata’. A lunar crater and Indian research centre also bear his name.

Sushruta, who lived in the 7th century BC, was an ancient Indian surgeon who was famous for his pioneering operations and techniques. His book the’ Sushruta Samhita’, is an advanced collection of the surgical, as well as information on other specialties, geriatrics, diseases of the ear, nose, throat and eye, toxicology, aphrodisiacs and psychiatry.

   Examples of some of Sushruta’s groundbreaking operations include rhinoplasty which involves repairing or restructuring the nose, removal of a dead foetus, and surgical removal of stones in organs like the urinary bladder.

      Sushruta used wine to dull the pain during operations. He encouraged his students to practice surgical techniques by operating on objects like watermelons and reeds.

    Sushruta took surgery in ancient India to admirable heights and because of his numerous contributions to the science and art surgery in India; he is regarded as the ‘father of surgery’ and ‘father of plastic surgery’.

Stephen Hawking, theoretical physicist and cosmologist, is remarkable in many ways. Despite challenging physical impairments, he has contributed hugely to he world of science.

   Hawking suffers from a type of motor neuron disease that has left him almost completely Paralyzed. This did not stop him from working on the subject of black holes and providing theories for their behavior, including the idea that they emit radiation.

    Hawking believed black holes to be celestial death traps that swallowed up all energy. However, he determined there was room for this phenomenon, through the merging of quantum theory, general relativity and thermodynamics, distilling it all into one path breaking formula in 1974.

      Hawking wanted to write a book about the mysteries of the universe that would connect with the public. This task seemed impossible after he lost the abilities to write and speak. But Hawking did not give up, and his vision was finally realized when finally realized when his ‘A Brief History of Time’ became a best-seller. 

James Watson, an American molecular biologist, geneticist, and zoologist shared the 1962 Nobel Prize in Physiology or Medicine for discovering the structure of DNA in 1953. He gained worldwide fame and prominence as the joint author of the scientific papers between 1953 and 1954 which he co-wrote with fellow scientist Francis Crick. Their work laid down the double helical structure of deoxyribonucleic acid, or DNA.

    The DNA molecule is a mega molecule that is the process of genetic  replication. One of the most celebrated science writers, Watson published his textbook ‘Molecular Biology of the Gene’ in 1965 and his best-selling autobiographical book ‘The Double Helix,’ in 1968.

    Watson helped to establish and direct the Human Genome Project at the National Institute of Health, where he oversaw the mapping of the genes in human chromosomes. His own genome was sequenced in 2007, making him the second person to have this done.

Richard Feynman was an American Scientist who is considered to be one of the greatest and most influential theoretical physicists in history.

  Feynman revolutionized the field of quantum mechanics and formulated te theory of quantum electrodynamics.

  Feynman is responsible for the introduction of fundamental computational techniques and notations into physics. The Feynman diagrams have dramatically changed the way in which basic physical processes are conceptualized and calculated. He also studied the physics of super cooled liquids. In order to increase the understanding of physics among the general public,

   Feynman wrote two important books- ‘The Character of Physical Law’ and “Q.E.D: The Strange Theory of Light and Matter’. He was awarded the 1965 Nobel Prize in Physics for successfully resolving problems related to the theory of quantum electrodynamics.

Christiaan Huygens, a Dutch philosopher and mathematician, was one of the leading scientists in the 17th century. He started by trying to disprove theories that had been established by Ancient Greeks in geometry.

      He was interested in telescopes and astronomy, and spent a lot of time designing methods to improve the mechanical and optic performance of telescopes.

In his book entitled ‘Systema Saturnium’ published in 1659, he noted the discovery of the rings around the planet Saturn, and made observations about the planets, the Moon, and Orion Nebula. His keen interest in the field of astronomy led him to measure time and other matters that relate to mechanical physics.

      One of his most important contributions was that he explained the vital principles of classical physics like centripetal force and gravity in a vacuum in another book of his.

      Huygens also put forward a theory explaining the wave behavior of light. His reputation as a scientist and a scholar became known worldwide, and remains so to this day.

Robert Boyle was a famous Anglo Irish scientist who transformed chemistry in the 17th century. Till then, chemistry was confined to alchemy and mysticism.

       Alchemy was the study of how to change basic substances such as metals into other more valuable substances. Boyle made chemistry a science based on measurement.

       He defined elements, compounds and mixture and he coined the new term ‘chemical analysis,’ a field in which he made several contributions. Robert Boyle is most famous for Boyle’s law. It was the first of the gas laws linking the pressure of a gas to its volume. He established that electrical forces are transmitted through a vacuum, but sound is not.

       Boyle also stated that the movement of particles is responsible for heat. He was the first person to write specific experimental guidance for other scientists, telling them the importance of achieving reliable results. He was indeed a ‘mighty chemist.’

      Robert Boyle is regarded as the first modern chemist, and is referred to as one of the founders of modern chemistry.

Alexander Graham Bell was an influential scientist engineer, and inventor who is considered to be the inventor of the first practical telephone. Bell’s mother and wife were both deaf, and this motivated his research on hearing and speech.

         Bell experimented with sound, working with devices such as ‘harmonic telegraph,’ that is used to send multiple messages over a single wire. While trying to discover the secret to transmitting multiple messages on a single wire, Bell heard the sound of a plucked string along some of the electrical wire. This was caused because one of Bell’s assistants, Thomas A. Watson, was trying to reactivate a transmitter. It made Bell believe he could send the sound of a human voice over the wire.

        After receiving a patent on March 7th, 1876, for transmitting sound along a single wire, he successfully transmitted human speech on March 10.

        Bell’s first words with the working telephone were spoken to his assistant Watson. They were “Mr. Watson, come here. I want to see you.”

        Bell also had a strong interest in other scientific fields, conducting medical research, searching for alternative fuel sources, developing hydrofoil watercraft and much more.

J.J. Thomson, an English physicist, took science to new heights with his 1897 discovery of the electron the subatomic particle.

     When Thomson began his research career, it was thought that atoms were the smallest particles. Nobody had a clear picture of how atoms might look. It was already known that atoms were associated in some way with electric charges.

   In 1897, aged40, Thomson carried out a now famous experiment with a cathode ray tube. His experiment proved the existence of a new fundamental particle that was much smaller than the atom. It was named the electron.

     In discovering the electron, Thomson also moved toward the invention of an immensely important new tool for chemical analysis the mass spectrometer.

      Then, in 1912, Thomson discovered that stable elements could exist as isotopes. Isotopes are different forms of the same element that exist with different atomic masses.

    J.J. Thomson was awarded the Nobel Prize for physics in 1906

Sigmund Freud was an Austrian neurologist. He is best known for developing the theories and techniques of psychoanalysis.

       Psychoanalysis is a method of treatment through which an analyst uncovers unconscious conflicts based on the free associations, dreams, and fantasies of the patient.

     All of Freud’s work revolved around the mind how it worked, and how to diagnosis and treat certain maladies of the mind. He analyzed himself as well. He began to pick apart his dreams, and tried to decipher their meaning.

    In doing so, he provided an incredible account of how dreams originate and why. He explored what would become known as Freudian slips, where one has a slip of the tongue and either misreads something, or forgets a name.

    Freud established a theory as to why this happens often to some people. Sigmund Freud’s greatest achievement was in the area of the unconscious mind.

    Although many before him were aware of its existence, he was the one who was finally able to achieve scientific recognition in the area of psychoanalysis.

Max Planck was a German theoretical physicist, who made significant contributions. He changed our understanding of physics when he discovered that hot objects do not radiate a smooth, continues range of energies as was earlier believed.

      Instead, he found that the energies radiated by hot objects have distinct values. His discovery was the beginning of the Quantum theory an entirely new type of physics that revolutionized our understanding of atomic and subatomic processes. In fact, we can say that the quantum theory grew from the ideas of Max Planck.

    A quantum is the smallest possible amount of energy. Planck’s constant a fixed number is used to calculate the energy of quanta. The theory has been developed to explain the behavior of particles and the energy they emit. Planck was awarded the Nobel Prize for physics in 1918.

Henri Becquerel was a French physicist who discovered radioactivity through his investigations of uranium and other substances.

       Becquerel had become a highly respected physicist by 1896. After the discovery of the x-ray in 1895, Becquerel began to investigate whether there was a fundamental connection between this form of invisible radiation and visible light.

      His expertise with phosphorescent materials, his familiarity with uranium compounds, and his general skill in laboratory techniques, including photography, all played a key role in his discovery of radioactivity. Becquerel experimented by placing phosphorescent crystals on a sealed photographic plate that had been wrapped in opaque paper, and never exposed to direct light.

    After the plate was developed, images were visible on it. He passed the results on to Madame Curie, who named this phenomenon radioactivity. In 11903, Becquerel shared the Nobel Prize for physics with the chemists Pierre and Marie Curie.

Ivan Pavlov, a Russian physiologist, is an iconic figure who was the first to offer a scientific approach to psychology.

     Pavlov studied medicine under a famed physiologist of the time, S.P. Botkin, who taught him a great deal about the nervous system. Pavlov is known primarily for his work in conditioned response.

     He conducted a legendary experiment in which he trained hungry dogs to drool at the sound of a bell, or buzzer. Moments before feeding, a bell was rung to measure the dogs’ saliva production when they heard the bell.

     Pavlov found out that once the dogs had been trained to associate the sound of the bell with food, they would produce saliva, whether or not food followed. Pavlov became fully convinced that human behavior could be understood and explained best in physiological terms, rather than in mentalist terms. He won the 1904 Nobel Prize for physiology or medicine.

Thomas Edison’s story is truly an inspiring one. He struggled at school, but loved reading and conducting experiments.

      This American inventor began sending and receiving messages via Morse code an electronically conveyed alphabet using different clicks for each letter at the age of 15. Later, he invented a version of the telegraph that could send four messages at once. In 1877, Edison invented the phonograph. The phonograph was a machine that recorded and played back sounds. He perfected the phonograph by recording ‘Mary had a little Lamb’ on a piece of tin foil!

     In 1878, Edison invented the light bulb, as well as the power grid system, which could generate electricity, and deliver it to homes through a network of wires.

    Edison registered 1,093 patents in the US, as he continued to invent products. He made significant contributions to storage batteries and motion pictures. His inventions changed the world forever, and Edison remains a colossus in the field of science to this day.

Wilhelm Rontgen, a German scientist, was the recipient of the first Nobel Prize in physics. Rontgen carried out research in several fields, but his main claim to fame is the discovery of X-rays.

        In 1895, Rontgen was conducting an experiment by passing an electric current through a gas at extremely low pressure. He noticed that even though the room was dark, and the tube was covered with black carbon, a screen covered with fluorescent material was being lit up.

      By placing a photographic plate at the other end, Rontgen was able to capture the image that was being lit up by these unknown rays. Since he did not know the nature of these rays, he called them X-rays. The first X-ray ever taken was an image of Rontgen’s wife’s hand. His discovery of X-rays ushered in a great revolution in the fields of physics and medicine.

Robert Koch was a famous German physician who gained renown as one of the founders of bacteriology and microbiology. Koch was very much interested in how the disease known as anthrax spread from cattle to humans.

           He laid down four criteria in 1890 for establishing the cause of an infectious disease. These rules are known as ‘Koch’s postulates’. Many of the basic principle and techniques of modern bacteriology were adapted, or devised by Robert Koch, who therefore is often regarded as the chief founder of that science.

        Robert Koch’s brilliant contributions were acknowledged in 1905, and he won the Nobel Prize for medicine for his groundbreaking work on tuberculosis. Directly or indirectly, Koch has influenced authorities in many countries to introduce public health legislation based on knowledge of the origin of various infections.

     He is also responsible for a more enlightened attitude towards the measure for controlling such disease, and the hygiene that must be observed for preventing, as well as treating them.

August Weismann was a German biologist and one of the founders of the science of genetics. He is best known for his ‘germ plasm’ theory. Weismann’s early studies were on the hydrozoa, which are small predatory animals which live mostly in the sea.

      Weismann’s research on hydrozoa convinced him that the germ cells of animals contain ‘something essential for the species, something which must be carefully preserved and passed on from one generation to another’.

      Thus was born the theory of the germ plasm, which he embodied in a book first published in German and then in English. Its essence was the notion that all living things contain a special hereditary substance, the germ plasm.

     The general idea is still accepted as valid today, though in place of germ plasm one speaks of chromosomes, genes, and DNA. Weismann’s ideas made him one of the leading biologists of the world.

James Maxwell, a Scottish physicist and mathematician, was a remarkable scientist. He brought together a large number of equations, experiments, and observations related to electricity and magnetism, and showed them to be different manifestations of the same phenomenon.

       Maxwell produced a set of equations that explain the properties of magnetic and electric fields, and help show that light is an electromagnetic wave. He also described the nature of Saturn’s rings as numerous small particles, rather than a solid or fluid ring.

      Maxwell’s contributions in the fields of kinetic theory and thermodynamics are many. He is even believed to have created the first true colour photograph. His contributions played an important role in the advances made in 20th century physics.

Wilhelm Wundt, a German doctor and philosopher, is acknowledged as one of the greatest and most influential psychologists of all time.

       As one of the early pioneers of scientific psychology, Wundt introduced the usage of experimental methods in psychology. He developed psychology as an independent field of science, and set up a laboratory to explore the nature of religious beliefs, identify mental disorders and abnormal behavior, and find damaged part of the brain.

      He also published the first journal of psychology, ‘philosophische studies’ or ‘philosophical studies’ in 1881. Wilhelm Wundt was in fact, the first person to ever call himself a ‘psychologist’.

Joseph Lister, a British surgeon, made surgery safer for generations of patients by introducing sterilization techniques in the operation theatre. His greatest contribution to medicine was to promote the use of carbolic acid as an antiseptic.

     He lived in an era when surgeons wore dirty aprons, surgical instruments were unclean, and surgeons didn’t even wash their hands before carrying out operations. Lister soon realized that urgent changes were needed to prevent so many people dying after surgery, due to infection. He tested what would happen if the surgical instruments and bandages were treated with carbolic acid, and he was pleased to see that infection was significantly reduced.

     Other surgeons soon followed his example. Carbolic acid was used on bandages, and was even sprayed into the air during operations to kill bacteria, and reduce the risk of the wound becoming infected.

    Lister is often called the ‘father of modern surgery’ because of the life saving precautions he introduced in the field of surgery.

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.

Pierre-Simon Laplace was a French physicist and astronomer of the 19th century. He had a phenomenal natural mathematical faculty, and predicted many things, using only maths.

           These predictions were later confirmed with powerful telescopes. He wrote a book explaining his theory of the origin of the solar system.

           Laplace presented a steady stream of remarkable mathematical papers that spread his fame. Pierre-Simon Laplace is highly regarded for his influential, five-volume treatise which developed a strong mathematical understanding of the motion of the heavenly bodies. This work interpreted the geometric study of classical mechanics, starting up a wider range of problems.

          Laplace’s work, and the results he produced, made him one of the most important and influential scientists that the world has seen. The Laplacian differential operator that is named after him is widely used in mathematics.

           Laplace won many awards for his studies, and he was made a marquis, but he remained modest, saying, “What we know is little. What we know not is immense.”

         His work regarding the theory of probability and statistics is considered pioneering.

Jean Babtiste Lamarck was one of the pioneers in the field of biology.

   In fact, the very name ‘biology’ was coined by this French naturalist. He is best remembered for his theory, the characteristics an organism develops during its lifetime in response to its environment are inherited by, or passed on to, its offspring.

       Lamarck was the first to use the term invertebrate to describe animals without backbones. He began collecting fossils and studying all sorts of simple species.

        As a result of these studies, he was able to revise the classification of lower animals that had been unfinished by the Swedish biologist Linnaeus.

        Lamarck’s study of invertebrates also led to the publication of his major work ‘The Natural History of Invertebrate Animals’ in 1815-22.

William Herschel was a German-born British scientist who became one of the most important astronomers of the 18th century. He built his own telescopes.

           From the garden of his house, William Herschel noted ‘every star in the heavens’ through a telescope that he had constructed himself.

         He also manufactured over 400 telescopes that were in great demand worldwide. His study of the heavens led him to the discovery of a planet that would eventually be called Uranus. William Herschel would also discover Titania and Oberon, which were the moons of Uranus as well as Enceladus and Mimas, the moons of Saturn.

          Herschel maintained that the solar system is moving through space, and found out the direction of that movement. He also suggested that the Milky Way was in the shape of a disc. Herschel is considered to be the founder of modern stellar astronomy.

       William Herschel, a great scientist was a gifted musician too. He played the oboe, violin, harpsichord and organ.

Antoine Lavoisier revolutionized chemistry. It was he who coined the name oxygen for the element released by mercury oxide.

            He found that oxygen made up 20 per cent of air, and was vital for combustion and respiration. He also concluded that when phosphorus or sulfur is burned in air, the products are formed by the reaction of these elements with oxygen.

                  The elements carbon and hydrogen were also named by him. Another milestone was when Lavoisier correctly identified sulfur as an element. A year later, he found that when mercury oxide is heated, its weight decreases. The oxygen it releases has exactly the same weight as the weight lost by the mercury oxide. After carrying out further experiments, Lavoisier announced a new fundamental law of nature- the law of conversation of mass. This law states that the total mass of a chemical reaction’s products is identical to the total mass of the starting materials.

William Harvey was an English physician who lived in the 17th century. He was the first person to correctly describe blood’s circulation in body.

       He showed that arteries and veins form a complete circuit starts at the heart, and leads back to the heart. He also established that the heart’s regular contractions drive the flow of blood around the whole body.

        Before his discoveries, blood was thought to ebb and flow through the body by the contraction of arteries. Harvey’s knowledge came from observations he made of blood flowing through the veins and arteries of living animals that he cut open. This may seem cruel, as there were no anaesthetics in Harvey’s time.

        Nevertheless, it is how we arrived at an understanding of blood and its circulation in the body.

       William Harvey’s work also laid down the foundations of physiology, which is the study of body functions. 

Joseph Black, a British chemist and physicist, is famous for his discovery of carbon dioxide. Black was always a meticulous chemist, keeping careful note of all his results and measurements. It was this which led to his discovery of carbon dioxide.

      Black also took an interest in the science of heat. In the 18th century, there were several competing theories about the nature of heat, and how it related to temperature.

      Black’s investigations not only clarified the distinction between temperature and heat, but also resulted in the theory of latent heat. Black was gifted and effective teacher. His course in chemistry proved so popular that many students, even those with no particular interest in the subject, were eager to attend.

     Alongside his teaching, black carried on an active and demanding medical practice. Joseph Black, widely respected both as a scientist and a physician, is truly one of the titans in the world of science.

Joseph Priestly, an Englishman is noted for his groundbreaking contributions to experimental chemistry, electricity, and the chemistry of gases.

       Before him, scientists thought that the air on earth consisted of carbon dioxide and hydrogen. Priestley brought 10 more gases to this light, such as nitrogen, hydrogen chloride, carbon monoxide, nitrous oxide and oxygen.

       He isolated oxygen in its gaseous state, and conducted a series of experiments to distinguish each gas based on its properties. Priestley also made another discovery that has been highly appreciated by surgeons worldwide. He discovered nitrous oxide, which was also known as laughing gas. It was the first surgical an aesthetic to be used.

      Priestley’s best known achievement in the field of biology in 1772 was his work with photosynthesis. Priestley’s other interesting discoveries include the fact that graphite is a good electric conductor, and that gummy tree sap is a good eraser for pencil marks.

      Did you know that you can enjoy your favorite fizzy drink thanks to Joseph Priestley, for he was the one who invented soda water?

The English scientist Henry Cavendish was an experimental chemist and physicist par excellence. Cavendish was the first to recognize hydrogen gas as a distinct substance. He called it inflammable air.

         Cavendish showed that hydrogen is much less dense than air. In 1785, he published a paper showing the earth’s atmosphere consists of four parts nitrogen to one part oxygen.

         In addition, to his achievements in chemistry, Cavendish is also known for the Cavendish experiment. He was the first to measure the force of gravity between masses in a laboratory, and to produce an accurate value for earth’s density.

       Henry Cavendish also experimented with electricity, but much of his work on the subject was only published after his death. He was renowned for the great accuracy and precision of his scientific research.

In the 18th century, the Swedish naturalist and physician Carl Linnaeus introduced the scientific system of classifying plants and animals that is used all over the world to this day.

      Under this system, each living thing is assigned a name consisting of two Latin word is the name of the genus, and the second, the species. The classification of living things is called taxonomy.

     In 1737, Linnaeus published the first edition of his book titled systema naturae or system of nature. Over the years, Linnaeus continued to develop his ideas and add new species so that the book grew in period of about 30years from 12 outsize pages in its first edition, to 2400 pages in its 12th edition.

     This was the first serious attempt ever made to document all of our planet’s species. It was a huge effort, and it won Linnaeus acclaim as the ‘Father of Taxonomy’.

Edmond Halley was an English scientist who became very interested in a comet that he saw in 1682. After being told that a similar comet had appeared in 1531 and 1607, he suspected that it was the same comet that he had seen.

        By using the laws of gravity discovered by his friend Sir Isaac Newton, Halley realized that he could predict when it would return. Halley worked out that he comet would appear in our skies every 75 to 76 years.

        He was correct in his prediction, but sadly when the comet did reappear, he was no more, and he could not witness the confirmation he had waited for so eagerly. In his honour, the comet was named after him.

     Though he is remembered foremost as an astronomer, Halley also made significant discoveries in the fields of geography, mathematics, meteorology, and physics. Halley was very close to Newton.

Sir Isaac Newton, an Englishman who lived in the 17th century, is scientific legend. He came up with numerous theories and contributed ideas to many different fields including physics, mathematics, and philosophy.

      In 1687, Newton published his book philosophiae Natural is principia mathematica. In it, he describes universal gravitation, and the three laws of motion. It is widely regarded to be one of the most important books in the history of science. It is well known that his work on formulating a theory of gravitation was inspired by watching an apple fall from a tree!

        During his lifetime, Newton developed a new type of mathematics called calculus, and made breakthroughs in the area of optics such as the reflecting telescope. He also discovered that white light is made up of a wide range of different colors.

       Newton was a deep thinker with an insatiable curiosity to know everything about everything he saw. His contributions are so numerous, that e changed forever the way in which we look at the world.

Tycho Brahe was a famous Danish astronomer who played a vital role in the development of various astronomical instruments.

    He devised his own instrument even before the invention of the telescope, to observe the heavens. These instruments allowed Brahe to determine the movements of heavenly objects more precisely.

     Brahe made significant contributions in the study of the moon and the planet Mars, which would later prove extremely useful to other astronomers. Instruments built by Brahe proved to be very helpful in accurate determinations of latitude and longitude.

       Brahe built his first observatory at Herrevead Abbey in 1572, and another one named ‘Uraniborg’ in 1576. He also built a third one called ‘Stjerneborg’ IN 1581

Andreas Vesalius was the founder of modern anatomy. This 16th century physician and surgeon completely revolutionized the science of biology and medicine.

     By careful and painstaking dissections of cadavers, he learned a great deal about the structure of the human body and laid the foundation for modern physiology.

    In 1543, he published a remarkable book ‘De humani corporis fabrics’. It was a fully illustrated anatomy of the human body, based on the observations Vesalius had made during his dissections. The book destroyed the misconceptions in anatomy that had persisted for over a thousand years.

    Vesalius’ anatomical studies corrected many religious beliefs and the finding of a previous physician Galen, who had dissected apes because religion forbade him to dissect real human cadavers.

     Vesalius was the first surgeon to actually cut open a cadaver or dead body of a human being, and his exceptionally detailed muscle drawings changed medical history for all time.

Paracelsus was a renowned German physicist, and botanist of Swiss origin. His path breaking findings in botany and medicine made him a pioneer in his field.

     Paracelsus became a notable physician in the early 16th century. He rejected most of the prevalent and widely accepted world views, and magic theories of medicine. While working on medicines, Paracelsus brought together the use of chemicals in medicines. In1526, he coined the term ‘ZINCUM’ for the chemical element zinc. He is also known for discovering ‘Laudanum’ which is an alcoholic herbal preparation.

      Paracelsus was a strict follower, and a firm believer of the classical Greek concept of elements. However, he added his own findings to this concept. Paracelsus’ real name was Philipp us von Hohenheim.

       The name ‘Paracelsus’ was actually a nickname. It means ‘equal to or greater than celsus’ and refers to his medical skill.

Nicolaus Copernicus was a 15th century astronomer, mathematician, translator, artist, and physicist, among other things.

      He is best known as the first astronomer to put forward the idea of a system in which the planets and planetary objects orbit the sun.

         By 1508, Copernicus had begun to create his model of the planetary system, suggesting that the sun, and not our Earth, was the centre of the universe. His model of the universe was accepted, whereas earlier models had not been, because his was more detailed and accurate. He also had a better formula for the calculation of the positions of the planets at different times of the year.

     The Roman Catholic Church criticized Copernicus’ theories. It went so far as to ban his book ‘De Revolution bus Erbium Coelestium,’ after he died, and it remained a forbidden book for almost three hundred years.

          The ideas of Copernicus were instrumental in the evolution of the field of astronomy. In fact, almost every notable astronomer who came after him was influenced by his theories.

Roger Bacon was an English philosopher and Franciscan monk who promoted experimental science and was deeply interested in the study of nature.

      He studied mathematics, astronomy, optics, alchemy and languages. His studies on the nature of light, and on rainbows, are especially noteworthy, and he seems to have planned and interpreted these experiments carefully.

     He seriously studied the problem of flying in a machine with flapping wings. He was also the first person in the West to give exact directions for making gun-powder.

     Roger Bacon’s work was talked about everywhere, and eventually won him a place in popular literature as a kind of wonder worker. He was also called Doctor Mirabilis- ‘mirabilis’ in Latin means ‘wonderful teacher.’

Galen was a Greek who became the Ancient Roman Empire’s greatest physician. He had great expertise in anatomy, surgery, pharmacology and therapeutic methods.

    Galen had an absolute belief in the power of experiment and observation. He did not believe in merely following what books told him was true. He needed to verify the truth for himself.

     His anatomical reports, based mainly on dissection of monokeys, remained uncontested until 1543, when printed descriptions and illustrations of human dissections were published.

   Galen, the great scientist, consolidated the work of previous Greek medical researchers, adding the results of his own research, to create an incredibly long-lasting medical doctrine. This medical doctrine dominated the Western world for 1500 years.

Ptolemy was a Greek astronomer, astrologer, mathematician and geographer who lived and worked in Alexandria in Ancient Egypt, in the second century AD.

      His work ‘Almagest,’ is one of the most important works in ancient astronomy. It covers the motion of sun, moon, and the planets around the Earth. It also contains a catalogue of stars with their brightness on a logarithmic scale.

      Ptolemy’s description of the universe was accepted by the astronomical community for more than a thousand years. Ptolemy’s second important work is called ‘Geography.’ It is a thorough discussion of the geographic knowledge of the Greco-Roman world.

       Ptolemy’s treatise on astrology was influential because of its practical treatment of astrology. Ptolemy discarded practices that did not have a logical basis, and also believed that astrology was not a completely reliable science.

Eratosthenes was an Ancient Greek scientist born in the town of Cyrene, which is no in Libya, in about 276 BC. He was famous as a mathematician and geographer.

         Eratosthenes produced a reliable, logical method to discover prime numbers. It’s known as the sieve of Eratosthenes, and is still important in modern number theory in an updated form.

    Assuming that the earth was a sphere, Eratosthenes calculated its size with good accuracy. He also calculated the tilt of earth’s axis fairly accurately. Eratosthenes produced the first map of the world which used meridian lines and parallel lines. These were similar to our modern lines of latitude and longitude. This great scientist can be said to have invented geography

     In fact, today we still use the word he invented for this new discipline. ‘Geo’ was Greek for ‘Earth’ and ‘graphy’ meant ‘field of study.’

      Eratosthenes also wrote books on philosophy, mathematics, astronomy, history, comedy, and poetry. His all-round knowledge made him the ideal choice for the most prestigious job an academic could enjoy in Ancient Greece. He was the director of the library of Alexandria, the greatest intellectual institution of the ancient world.

Johannes Kepler was a leading astronomer of the scientific revolution. The scientific revolution is the term used to describe the emergence of modern science that took place throughout the 16th and 17th centuries.

        Before the scientific revolution, astronomy was closely tied to astrology, which is the belief that the movement of the stars and planets can be interpreted to predict the future.

      As the scientific revolution progressed, astrology increasingly came to be replaced by astronomy as a modern, legitimate science. Johannes Kepler is best known for his discovery that the orbits in which the earth and the other planets of the solar system travel around the sun are elliptical, or oval, in shape.

     He was also the first to explain correctly hoe human beings see, and demonstrated what happens to light when it enters a telescope.

      In addition, he designed an instrument that serves as the basis of the modern refractive telescope.

      Since he was such a prominent figure in the field of astronomy, a lot of spots on distant planets have been named after him such as ‘Kepler’s Crater on Mars’ and ‘The Kepler Crater,’ on the Moon.

Born in the tenth century AD, Alhazen was an Arab who was known as the first true scientist.

           He developed the scientific method of experimentation, and was the first person to formulate hypothesis and conduct verifiable experiments. A scientist, philosopher, astronomer, and mathematician, Alhazen wrote over a hundred books, more than half of which have been preserved.

        One of his most influential writings was in the field of optics. In this book, Alhazen gave experimental proof of the nature of light, the structure of the eye and the basic principles of reflection via mirror. He stated that contrary to popular belief, the eye does not send out rays to the object it sees. Rather it is the light reflected via the object that the eye beholds.

     This was a completely new and revolutionary concept. The book comprises seven volumes, and was translated into Latin.

Galileo Galilei was a groundbreaking Italian astronomer, physicist, mathematician, philosopher and inventor. He opened the eyes of the world to a new way of thinking about how the solar system works.

       For many years, scientist had believed that the solar system revolved around the earth, and that the earth was the centre of the universe.

         Galileo was the first scientist to prove that this wasn’t correct. He stated that in fact, the solar system revolved around the sun.  he also invented an improved telescope so that he could gaze far into space. He was the first to see Jupiter’s moons, and the first to realize that our moon was covered with craters. Besides inventing the improved telescopes, he also invented the compass and a thermometer. Galileo has played a major role in the scientific revolution of the 17th century.

Euclid, who was born in Alexandria in Egypt, lived more than 300 years before Christ. He is renowned to this day for his book ‘Elements’.

      For centuries, this book was one of the main texts for teaching geometry. ‘Elements’ is divided into thirteen books, which cover plain geometry, arithmetic and number theory, irrational numbers, and solid geometry.

     His books begin with basic definitions, and then go on to prove different mathematical theories. So, it is only natural that Euclid is called the father of geometry. He stressed the importance of logic and reason in teaching and understanding maths. Though some of his books are lost, at least five of them are still in existence, and are proof of his remarkable gift for mathematics.

Aristotle was one of the most respected Greek thinkers. He was the star pupil of Plato, a famous Greek philosopher. He was also the teacher of Alexander the great!

     Aristotle wrote on many subjects including physics, biology, zoology, meta-physics, logic, ethics, aesthetics, poetry, theatre, music, rhetoric, linguistics, politics, and government.

        He believed that the universe was eternal, that there was neither a beginning nor an end. Aristotle accepted that things can change, but fundamentally believed that the overall conditions would always remain the same. He studied zoology very closely, and through careful observation, he was able to arrive at his conclusions. His careful study of animals enabled him to classify them into different groups and species.

     Aristotle’s influence on western culture and science has been enormous. His writings show him to be a man of tremendous intellect, who thought deeply about the world.

Hippocrates, a Greek physician, lived in the 5th century BC, and founded the Hippocratic School of medicine. He revolutionized Greek medicine, for he believed in, and developed the practice of the clinical method of observation. This was the careful nothing of all the symptoms of a disease, and of the changes in a patient’s condition during the illness.

       Hippocrates believed that the body must be treated as a whole. He made medicine a discipline distinct from other fields, and his biggest contribution was that he rejected superstition and the belief that supernatural, or divine forces, were the cause of illness.

       In short, it was Hippocrates who transformed medicine into a science. He wrote on a variety of medical topics including diagnosis, epidemics, obstetrics, paediatrics, nutrition and surgery.

       To this day, newly qualified doctors take an oath called the Hippocratic Oath that lays down the basic rules of conduct that doctors must follow.

Pythagoras was an ancient Greek mathematician and philosopher who lived more than 500 years before Christ.

        He spent most of his life in the Greek colonies in Sicily and southern Italy. He was also a philosopher, and founder of the religious movement called Pythagoreans.

        Pythagoras had a group of disciples who followed him around, and taught other people what he had taught them. He made crucial contributions to modern philosophy, as well as mathematics, science, and religious mysticism. It is also believed that he had a significant influence on medicine, music, astronomy, and divination.

        Pythagoras is best known for the mathematical theory named after him. He is without doubt, one of the greatest scientists not only of the ancient world, but of all time.