# data[].attributes.attachment_link.readable_text
Sir James Chadwick (1891-1974) was an English physicist and winner of the 1935 Nobel Prize in Physics.

James Chadwick began his academic studies at the University of Manchester under the tutelage of Ernest Rutherford. Here, he earned his B.S. in 1911 and his MSc in 1913. Chadwick then decided to take up research under Hans Geiger in Berlin. His intention was to study beta radiation, but shortly into this endeavor, World War I broke out and the German government imprisoned Chadwick in the Ruhleben internment camp for four years.

Aided by sympathetic German soldiers, Chadwick was able construct experiments even while imprisoned during the war. When the war came to a close, Chadwick returned to England and continued research under his previous advisor Ernest Rutherford at the Cavendish Laboratory at Cambridge University. There, he received his doctorate in 1921 and remained with the laboratory until he moved to the University of Liverpool in 1935.

SCIENTIFIC CONTRIBUTIONS

Chadwick is best known for his discovery of the neutron in 1932. A neutron is a particle with no electric charge that, along with positively charged protons, makes up an atom's nucleus. Bombarding elements with neutrons can succeed in penetrating and splitting nuclei, generating an enormous amount of energy. In this way, Chadwick's findings were pivotal to the discovery of nuclear fission, and ultimately the development of the atomic bomb. For more on Chadwick's scientific contributions, please visit the Nobel Prize website.

WORLD WAR II

Chadwick was a member of the British MAUD Committee, which concluded that the creation of nuclear weapons was possible and even inevitable. This supposition contributed towards President Roosevelt's decision to build the atomic bomb. Additionally, Chadwick was an integral figure in the Tube Alloy Project-the codename for the British program to devise and develop nuclear weapons. His overtures to government officials in the UK and US were central to UK-US cooperation.

From 1943 to 1946, Chadwick headed the British Mission to the Manhattan Project. He also served as the technical advisor to the US-Canadian-UK Combined Policy Committee, which coordinated control of the project between the three nations involved. In 1944, Chadwick moved his family to the Project's main research facility in Los Alamos. Finding the housing conditions distasteful, his twin daughters objected to the move, and so the family relocated to Washington D.C. where he continued to contribute to the Project's efforts.

Chadwick formed a particularly congenial relationship with General Leslie Groves during the war. The two's friendship aided British efforts to maintain strong support with the United States throughout the Manhattan Project. Chadwick was the only civilian-and non-American-allowed to access the entirety of the Manhattan Project's research, data, and production plants.

Throughout the war, Chadwick drafted agreements to supply uranium for the Manhattan Project. Additionally, he observed the first atomic explosion, known as the Trinity test. Because of Chadwick's insistence, British observers were allowed to be present at the bombing of Nagasaki.

POSTWAR

Shortly after the war ended, Chadwick became an outspoken advocate for the United Kingdom to acquire a nuclear stockpile of its own. He was appointed to the British Advisory Committee on Atomic Energy (ACEA) and served as the UK delegate to the United Nations Atomic Energy Commission. Patrick Blackett, another Nobel laureate and eminent British scientist, vehemently opposed Chadwick's argument for British atomic capability. Ultimately, though, Chadwick won out and the United Kingdom pursued its own nuclear arsenal.

Chadwick became the Master of Gonville and Caius College at Cambridge University in 1948. He resided in this administrative position for the remainder of his career. He took up retirement in North Wales beginning in 1958. He eventually moved back to Cambridge, where he passed away in 1974.

In addition to receiving the Nobel Prize in Physics, James Chadwick was knighted in 1945. He was awarded the US Medal of Merit in 1946 and the Copley Prize by the British Royal Society in 1950.

Additional Resources:
Excerpt from Great Lives from History Scientists and Science by Joseph Spradley Chadwick's Famous "Possible Existence of a Neutron"

# data[].attributes.attachment_link.description
Sir James Chadwick (1891-1974) was an English physicist and winner of the 1935 Nobel Prize in Physics.James Chadwick began his academic studies at the University of Manchester under the tutelage of Ernest Rutherford. Here, he earned his B.S. in 1911 and his MSc in 1913.

# data[].attributes.attachment_link.readable_text
On August 12, 1887, Austrian physicist and Nobel Laureate Erwin Schrödinger was born. Schrödinger developed a number of fundamental results in the field of quantum theory, which formed the basis of wave mechanics: he formulated the wave equation and revealed the identity of his development of the formalism and matrix mechanics. Schrödinger proposed an original interpretation of the physical meaning of the wave function. Although many of you are not physicists, you probably have heard of Schrödinger's famous cat thought experiment, which has already become something linke an internet meme. But, before we come to the experiment, let's have a look on this extraordinary scientist.

"The task is, not so much to see what no one has yet seen; but to think what nobody has yet thought, about that which everybody sees." Erwin Schrödinger, as quoted in Problems of Life (1952), by Ludwig von Bertalanffy

Youth and Education

Schrödinger was born in Erdberg, Vienna, Austria, as an only child to Rudolf Schrödinger, who ran a small linoleum factory which he had inherited from his own father, and Georgine Emilia Brenda Schrödinger, who was of English-Austrian descent. At early age, he received lessons at home from a private tutor up to the age of ten, when he entered the Akademisches Gymnasium in 1898 until he graduated in 1906.[1] From 1906 to 1910 Schrödinger studied theoretical physics in Vienna under Franz S. Exner (1849-1926) and Friedrich Hasenöhrl (1874-1915), who was Boltzmann's successor. He also conducted experimental work with Karl Wilhelm Friedrich "Fritz" Kohlrausch. It was in these years that Schrödinger acquired a mastery of eigenvalue problems in the physics of continuous media, thus laying the foundation for his future great work.[2] In 1910, Schrödinger was awarded his doctorate for the dissertation On the conduction of electricity on the surface of insulators in moist air.

Academic Career

In 1911, Schrödinger became an assistant to Exner, not in theoretical physics but in experimental physics. In 1914 he achieved Habilitation (venia legendi), but with the outbreak of World War I Schrödinger received orders to work as a commissioned officer in the Austrian fortress artillery. In the spring of 1917 Schrödinger was sent back to Vienna and assigned to teach a course in meteorology. He was able to continue research and it was at this time that he published his first results on quantum theory. In 1920 he became the assistant to Max Wien, in Jena, and in September 1920 he attained the position of ao. Prof. (ausserordentlicher Professor), roughly equivalent to associate professor in Stuttgart. In 1921, he became o. Prof. (ordentlicher Professor, i.e. full professor), in Breslau (now Wrocław, Poland). Soon however he was to move yet again, accepting the chair of theoretical physics in Zürich in late 1921, where his closest colleague in the first years was Hermann Weyl,[4] who was to provide the deep mathematical knowledge which would prove so helpful to Schrödinger in his work. His papers at that time dealt with specific heats of solids, with problems of thermodynamics (he was greatly interested in Boltzmann's probability theory) and of atomic spectra.[2]

The Study of Quantium Statistics

In 1924 he began to study quantum statistics. When he read de Broglie's thesis [5] ( Researches on the quantum theory) in which he put forward his theory of electron waves, based on the work of Einstein and Planck, this should a turning point in the direction of Schrödinger's research. Upon the suggestion of a student Schrödinger began his work on his wave equation, which is known as Schrödinger equation. Schrödinger published his revolutionary work relating to wave mechanics and the general theory of relativity in a series of six papers in 1926. Wave mechanics, as proposed by Schrödinger in these papers, was the second formulation of quantum theory, the first being matrix mechanics due to Heisenberg.[6] In those papers he described his partial differential equation that is the basic equation of quantum mechanics and bears the same relation to the mechanics of the atom as Newton's equations of motion bear to planetary astronomy. The solutions to Schrödinger's equation, unlike the solutions to Newton's equations, are wave functions that can only be related to the probable occurrence of physical events. The definite and readily visualized sequence of events of the planetary orbits of Newton is, in quantum mechanics, replaced by the more abstract notion of probability.[3]

Leaving Germany

In 1927, he succeeded Max Planck at the Friedrich Wilhelm University in Berlin. In 1934, however, Schrödinger decided to leave Germany; he disliked the Nazis' anti-semitism and became a Fellow of Magdalen College at the University of Oxford. Soon after he arrived, he received the Nobel Prize together with Paul Dirac.[7] In 1934, Schrödinger lectured at Princeton University; he was offered a permanent position there, but did not accept it. In the end he took up a position at the University of Graz in Austria in 1936. He had also accepted the offer of chair position at Department of Physics, Allahabad University in India. However the advancing Nazi threat caught up with Schrödinger again in Austria.

Schrödinger's Cat

In the midst of these tenure issues in 1935, after extensive correspondence with Albert Einstein, he proposed what is now called the Schrödinger's cat thought experiment. A cat is locked in a steel box with a small amount of a radioactive substance such that after one hour there is an equal probability of one atom either decaying or not decaying. If the atom decays, a device smashes a vial of poisonous gas, killing the cat. However, until the box is opened and the atom's wave function collapses, the atom's wave function is in a superposition of two states: decay and non-decay. Thus, the cat is in a superposition of two states: alive and dead. Schrödinger thought this outcome "quite ridiculous," and when and how the fate of the cat is determined has been a subject of much debate among physicists.[3]

Emigration

In 1938 he was dismissed from his university post in Graz for 'political unreliability'. He suffered harassment and received instructions not to leave the country, but he and his wife fled to Italy. From there, he went to visiting positions in Oxford and Ghent University. In the same year he received a personal invitation from Ireland's Taoiseach, Éamon de Valera, to reside in Ireland and agree to help establish an Institute for Advanced Studies in Dublin. He moved to Clontarf, Dublin, became the Director of the School for Theoretical Physics in 1940 and remained there for 17 years.

What is Life?

In 1944, he wrote What Is Life?, which contains a discussion of negentropy and the concept of a complex molecule with the genetic code for living organisms. According to James D. Watson's memoir, DNA, the Secret of Life, Schrödinger's book gave Watson the inspiration to research the gene, which led to the discovery of the DNA double helix structure in 1953. Schrödinger had a lifelong interest in the Vedanta philosophy of Hinduism, which influenced his speculations at the close of What Is Life? about the possibility that individual consciousness is only a manifestation of a unitary consciousness pervading the universe. In 1956, he returned to Vienna as professor emeritus at the university. At an important lecture during the World Energy Conference he refused to speak on nuclear energy because of his skepticism about it and gave a philosophical lecture instead. During this period Schrödinger turned from mainstream quantum mechanics' definition of wave-particle duality and promoted the wave idea alone, causing much controversy with other leading physicists.

"Although I think that life may be the result of an accident, I do not think that of consciousness. Consciousness cannot be accounted for in physical terms. For consciousness is absolutely fundamental. It cannot be accounted for in terms of anything else."
- Erwin Schrödinger, As quoted in The Observer (11 January 1931); also in Psychic Research (1931), Vol. 25, p. 91

Later Years

During his last few years Schrödinger remained interested in mathematical physics and continued to work on general relativity, unified field theory and meson physics.[1] On 4 January 1961, Schrödinger died of tuberculosis, aged 73, in Vienna. Because of his exceptional gifts, Schrödinger was able in the course of his life to make significant contributions to nearly all branches of science and philosophy, an almost unique accomplishment at a time when the trend was toward increasing technical specialization in these disciplines.[3]

At yovisto academic video search, you can learn more about the Schrödinger equation in the lecture of Prof. Catherine Drennan from MIT on Wave-particle duality of matter and Schrödinger equation.
References and Further Reading:

[1] O'Connor, John J.; Robertson, Edmund F., "Erwin Schrödinger", MacTutor History of Mathematics archive, University of St Andrews.

[2] Erwin Schrödinger - Biographical, at Nobelprize.org

[3] Erwin Schrodinger, Austrian physicist, in Britannica Online

[4] Hermann Weyl - between Pure Mathematics and Theoretical Physics, SciHi Blog

[5] Louis de Broglie and wave nature of matter, SciHi Blog

[6] Werner Heisenberg and the Uncertainty Principle, SciHi Blog

[7] Paul Dirac and the Quantum Mechanics, SciHi Blog

[8] Schrödinger's Cat at Wikidata

[9] Erwin Schrödinger at Wikidata

[10] Timeline for Erwin Schrödinger, via Wikidata

# data[].attributes.attachment_link.title
Erwin Schrödinger and his Famous Thought Experiment - SciHi Blog

# data[].attributes.attachment_link.description
On August 12, 1887, Austrian physicist and Nobel Laureate Erwin Schrödinger was born. Schrödinger developed a number of fundamental results in the field of quantum theory, which formed the basis of wave mechanics: he formulated the wave equation and revealed the identity of his development of the formalism and matrix mechanics.

# data[].attributes.attachment_link.readable_text
Ernest Rutherford

Ernest Rutherford, 1st Baron Rutherford of Nelson was a New Zealand chemist who has become known as the "father of nuclear physics". In 1911, he was the first to discover that atoms have a small charged nucleus surrounded by largely empty space, and are circled by tiny electrons, which became known as the Rutherford model (or planetary model) of the atom. He is also credited with the discovery of the proton in 1919, and hypothesized the existence of the neutron. He was awarded the Nobel Prize in Chemistry in 1908 "for his investigations into the disintegration of the elements, and the chemistry of radioactive substances".

Ernest Rutherford was born on 30 August 1871 in Spring Grove (now called Brightwater) near Nelson, New Zealand, the fourth of twelve children of a Scottish farmer and an English schoolteacher. He was educated at Havelock School and then, at age 16, Nelson Collegiate School, before winning a scholarship to study at Canterbury College at the University of New Zealand in Wellington in 1889. He graduated with an MA in 1893, with a double first in Mathematics and Physical Science.

He continued with research work at Canterbury College for a short time, receiving a BSc degree in 1894, before traveling to England in 1895 for postgraduate study at the Cavendish Laboratory at the University of Cambridge, where he studied under J. J. Thompson (soon to become the discoverer of the electron). During Rutherford's investigation of radioactivity at Cambridge, he invented an ingenious detector for electromagnetic waves, and coined the terms " alpha" and " beta " to describe the two distinct types of radiation emitted by thorium and uranium. In 1897, he was awarded a BA Research Degree and the Coutts-Trotter Studentship of Trinity College, Cambridge.

In 1898, Rutherford was appointed to the vacant chair of physics at McGill University in Montreal, Canada. In 1900, he married Mary Georgina Newton, and they had a daughter, Eileen Mary, the next year.

During his nine years in Montreal, Rutherford collaborated with the young Frederick Soddy (winner of the Nobel Prize in Chemistry in 1921) on ground-breaking research into the transmutation of elements. His "disintegration theory" of radioactivity identified radioactive phenomena as atomic, not molecular, processes, due to the spontaneous disintegration of atoms. He also noticed that a sample of radioactive material invariably took the same amount of time for half the sample to decay (known as its " half-life") and suggested a practical application using this constant rate of radioactive decay as a clock, which could then be used to help determine the age of the Earth (which turned out to be much older than most of the scientists at the time believed). It was for this work that he was the Nobel Prize in Chemistry in 1908. Otto Hahn (who later discovered nuclear fission) worked under Rutherford at the Montreal Laboratory in 1905 - 1906.

In 1907, Rutherford was appointed professor of physics at the University of Manchester, England. He directed Hans Geiger and Ernest Marsden in the famous Geiger-Marsden experiment (or "gold-foil experiment") in 1909, which demonstrated the nuclear nature of atoms. It was his interpretation of these experiments in 1911 that led him to the Rutherford model of the atom, involving a very small positively-charged nucleus orbited by even tinier negatively-charged electrons, a great advance on J. J. Thomson's so-called "plum pudding" model.

In 1912, Niels Bohr joined him at Manchester, and Bohr adapted Rutherford's nuclear structure to Max Planck's quantum theory, and so obtained a theory of atomic structure which essentially remains valid to this day. In 1913, together with H. G. Moseley, Rutherford used cathode rays to bombard atoms of various elements and showed that the inner structures correspond with a group of lines which characterize the elements. Each element could then be assigned an atomic number which would define the properties of the specific element.

In 1919, Rutherford returned to Cambridge when he was offered the Directorship of the Cavendish Laboratory in Cambridge, a position he retained for many years, effectively until the end of his life. He was considered an inspiring leader of the Cavendish Laboratory, and steered numerous future Nobel Prize winners towards their great achievements (including James Chadwick, Patrick Blackett, John Cockcroft and Ernest Walton) as well as working with many others for shorter or longer periods (including George Thomson, Edward Appleton, Cecil Powell and Francis Aston).

In 1919, he became the first person to transmute one element into another when he converted nitrogen into oxygen through a nuclear reaction involving the shooting of alpha particles into nitrogen gas. He is also credited with the discovery of the proton, when he noticed the signatures of hydrogen nuclei being emitted during this process. While working with Niels Bohr in 1921, he theorized about the existence of neutrons, which could somehow compensate for the repelling effect of the positive charge of protons by causing an attractive nuclear force and thus keeping the nuclei from breaking apart. Rutherford's theory of neutrons was eventually proved in 1932 by his associate James Chadwick.

Rutherford had been knighted in 1914, and was subsequently awarded the Order of Merit in 1925. In 1931, he was created the 1st Baron Rutherford of Nelson and Cambridge. In addition to directing the Cavendish Laboratory, he also went on to take up several additional positions including Chairman of the Advisory Council of the Department of Scientific and Industrial Research, Professor of Natural Philosophy at the Royal Institution in London and Director of the Royal Society Mond Laboratory in Cambridge. He had been elected a Fellow of the Royal Society back in 1903, and he acted as its President from 1925 to 1930. He was awarded many prizes and honours, including the Rumford Medal, the Copley Medal, the Bressa Prize, the Albert Medal and the Faraday Medal, as well as countless honorary degrees and doctorates.

Rutherford died unexpectedly in Cambridge on 19 October 1937, aged 66, following an operation for an umbilical hernia. As a British peer, protocol at that time required that he be operated on by a titled doctor, and the delay may well have cost him his life. He is buried in Westminster Abbey, alongside Lord Kelvin and near Sir Isaac Newton.

Ernest Rutherford Books

See the additional sources and recommended reading list below, or check the physics books page for a full list. Whenever possible, I linked to books with my amazon affiliate code, and as an Amazon Associate I earn from qualifying purchases. Purchasing from these links helps to keep the website running, and I am grateful for your support!

# data[].attributes.attachment_link.title
Ernest Rutherford - Important Scientists - The Physics of the Universe

# data[].attributes.attachment_link.description
Ernest Rutherford Ernest Rutherford, 1st Baron Rutherford of Nelson was a New Zealand chemist who has become known as the "father of nuclear physics". In 1911, he was the first to discover that atoms have a small charged nucleus surrounded by largely empty space, and are circled by tiny electrons, which became known as the Rutherford model (or planetary model) of the atom.

# data[].attributes.attachment_link.readable_text
Modern Atomic Theory: Models

In 1897, J.J. Thomson discovered the electron by experimenting with a Crookes, or cathode ray, tube. He demonstrated that cathode rays were negatively charged. In addition, he also studied positively charged particles in neon gas. Thomson realized that the accepted model of an atom did not account for negatively or positively charged particles. Therefore, he proposed a model of the atom which he likened to plum pudding. The negative electrons represented the raisins in the pudding and the dough contained the positive charge. Thomson's model of the atom did explain some of the electrical properties of the atom due to the electrons, but failed to recognize the positive charges in the atom as particles.

In 1911, Ernest Rutherford, a former student of J.J. Thomson, proved Thomson's plum pudding structure incorrect. Rutherford with the assistance of Ernest Marsden and Hans Geiger performed a series of experiments using alpha particles. Rutherford aimed alpha particles at solid substances such as gold foil and recorded the location of the alpha particle "strikes" on a fluorescent screen as they passed through the foil. To the experimenters' amazement, although most of the alpha particles passed unaffected through the gold foil as expected, a small number of particles were deflected at an angle, and a few ricocheted straight back. Rutherford concluded that the atom consisted of a small, dense, positively charged nucleus in the center of the atom with negatively charged electrons surrounding it. The discovery of the nucleus is considered to be Rutherford's greatest scientific work.

# data[].attributes.attachment_link.description
Modern Atomic Theory: Models In 1897, J.J. Thomson discovered the electron by experimenting with a Crookes, or cathode ray, tube. He demonstrated that cathode rays were negatively charged. In addition, he also studied positively charged particles in neon gas. Thomson realized that the accepted model of an atom did not account for negatively or positively charged particles.

# data[].attributes.attachment_link.readable_text
John Dalton Modern Atomic Theory (John Dalton)
Experiments with gases that first became possible at the turn of the nineteenth century led John Dalton in 1803 to propose a modern theory of the atom based on the following assumptions.

1. Matter is made up of atoms that are indivisible and indestructible.

2. All atoms of an element are identical.

3. Atoms of different elements have different weights and different chemical properties.

4. Atoms of different elements combine in simple whole numbers to form compounds.

5. Atoms cannot be created or destroyed. When a compound decomposes, the atoms are recovered unchanged.
Dalton's Law of Partial Pressures (John Dalton)
John Dalton was the first to recognize that the total pressure of a mixture of gases is the sum of the contributions of the individual components of the mixture. By convention, the part of the total pressure of a mixture that results from one component is called the partial pressure of that component. Dalton's law of partial pressures states that the total pressure of a mixture of gases is the sum of the partial pressures of the various components.

P T = P ₁ + P ₂ + P ₃ + ...

Dalton derived the law of partial pressures from his work on the amount of water vapor that could be absorbed by air at different temperatures. It is therefore fitting that this law is used most often to correct for the amount of water vapor picked up when a gas is collected by displacing water.
Origins of Stoichiometry (John Dalton)
John Dalton was not familiar with Richter's work when he developed his atomic theory in 1803. By 1807, however, references to this work appeared in Dalton's notebooks, and Dalton's contemporaries viewed his atomic theory as a way of explaining why compounds combine in definite proportions.

Consider water, for example. In his famous textbook, Trait lmentaire de Chimie, which was published in 1789, Lavoisier reported that water was roughly 85% oxygen and 15% hydrogen by weight. Water therefore seemed to contain 5.6 times more oxygen by weight than hydrogen. Dalton assumed that water contains one atom of hydrogen and one atom of oxygen, as shown below, and concluded that an oxygen atom must weigh 5.6 times more than a hydrogen atom. On the basis of such reasoning, Dalton constructed a table of the relative atomic weights of a handful of elements.

Dalton assumed that water contains one atom of hydrogen and one atom of oxygen and concluded that the relative weight of the oxygen atom must be 5.6 times as large as the hydrogen atom.

# data[].attributes.attachment_link.description
John Dalton Modern Atomic Theory (John Dalton) Experiments with gases that first became possible at the turn of the nineteenth century led John Dalton in 1803 to propose a modern theory of the atom based on the following assumptions. 1. Matter is made up of atoms that are indivisible and indestructible.

# data[].attributes.body
James Chadwick was a Physicist that lived in the United Kingdom. He was awarded the Noble Peace prize in 1935 for the discovery of the neutron. He discovered the neutron after he took beryllium and polonium and put them in a vacuum chamber. The polonium then emitted alpha rays, which struck the beryllium. This proved that neutrons existed. A fun facts about Chadwick is that he was awarded many awards for his discovery of the neutron. Some of them include the Hughes Medal of the Royal Society in 1932, the Nobel Prize in Physics in 1935, the Copley Medal in 1950 and the Franklin Medal in 1951. He was also Knighted in England in 1945.

# data[].attributes.body
Erwin Schrödinger was a Physicist that lived in Vienna, Austria and in Dublin, Ireland. Schrödinger took Bohr's model a little further and added math equations to it  to describe the likelihood of finding an electron in a certain position. He figured this out after experimenting more with Bohr's theory because he was not satisfied with it and came up with Schrödinger's cat experiment where you put a cat in a box with a bit of radioactive substance in it. Some fun facts about Schrödinger is he was against the Prosecution of Jews and he won the Noble Peace prize in 1933. He also had a Irish passport.

# data[].attributes.body
Ernest Rutherford was a Physicist that lived and studied his research and experiments in Canada. He was known for  discovering the nucleus and how surrounding it were electrons. Rutherford's gold foil experiment uses radioactive elements and lets them emit alpha partials using them as probes to the unseen world of atomic structure. A fun fact is Rutherford was the first person to win the Noble Piece prize in Oceania. He was also the 4th of 12 children in his family.

# data[].attributes.body
Niels Bohr was a Physicist that lived in Copenhagen, Denmark and found out that electrons travel in separate orbits around the nucleus and that the number of electrons in the outer orbit determines the properties of an element. he proved this by making a model that showed how electrons traveled in orbits of fixed size and energy. A fun fact about Bohr is that he set off explosions in his university's chemistry lab. Another is his dad was nominated three times in two years for a noble peace prize.

# data[].attributes.body
JJ Thomson lived in England where he became a Physicist. Thomson is known for discovering the electron. He did this by experimenting with a  Crookes tube and also with neon gas. A fun fact is Thomson was awarded the Nobel Prize in Physics in 1906 for his work with the electron. He also went to Trinity College at Cambridge when he got older.

# data[].attributes.body
John Dalton lived in Britain during his time working with the atomic theory. Dalton's theory was that all matter was made up of indivisible and indestructible building blocks called atoms and all compounds were made up of atoms in a fixed ratio. He proved his theory by experimenting with gases during the 19th century. Dalton studied the atomic theory, meteorology, and color blindness. A fun fact about John Dalton was that he was a teacher and started teaching at the age of 12.

# data[].attributes.attachment_link.readable_text
Democritus, (born c. 460 bce-died c. 370), ancient Greek philosopher, a central figure in the development of philosophical atomism and of the atomic theory of the universe.

Knowledge of Democritus's life is largely limited to untrustworthy tradition. It seems that he was a wealthy citizen of Abdera, in Thrace; that he traveled widely in the East; and that he lived to an advanced age. According to Diogenes Laërtius (flourished 3rd century ce), his works numbered 73; only a few hundred fragments have survived, mostly from his treatises on ethics.

Democritus's physical and cosmological doctrines were an elaborated and systematized version of those of his teacher, Leucippus. To account for the world's changing physical phenomena, Democritus asserted that space, or the Void, had an equal right with reality, or Being, to be considered existent. He conceived of the Void as a vacuum, an infinite space in which moved an infinite number of atoms that made up Being (i.e., the physical world). These atoms are eternal and indivisible; absolutely small, so small that their size cannot be diminished (hence the name atomon, or "indivisible"); absolutely full and incompressible, as they are without pores and entirely fill the space they occupy; and homogeneous, differing only in shape, arrangement, position, and magnitude. But, while atoms thus differ in quantity, differences of quality are only apparent, owing to the impressions caused on the senses by different configurations and combinations of atoms. A thing is hot or cold, sweet or bitter, or hard or soft only by convention; the only things that exist in reality are atoms and the Void. Thus, the atoms of water and iron are the same, but those of water, being smooth and round and therefore unable to hook onto one another, roll over and over like small globes, whereas those of iron, being rough, jagged, and uneven, cling together and form a solid body. Because all phenomena are composed of the same eternal atoms, it may be said that nothing comes into being or perishes in the absolute sense of the words, although the compounds made out of the atoms are liable to increase and decrease, explaining a thing's appearance and disappearance, or "birth" and "death."

Just as the atoms are uncaused and eternal, so too, according to Democritus, is motion. Democritus posited the fixed and "necessary" laws of a purely mechanical system, in which there was no room for an intelligent cause working toward an end. He explained the origin of the universe as follows. The original motion of the atoms was in all directions-it was a sort of "vibration"; hence there resulted collisions and, in particular, a whirling movement, whereby similar atoms were brought together and united to form larger bodies and worlds. This happened not as the result of any purpose or design but rather merely as the result of "necessity"; i.e., it is the normal manifestation of the nature of the atoms themselves. Atoms and void being infinite in number and extent, and motion having always existed, there must always have been an infinite number of worlds, all consisting of similar atoms in various stages of growth and decay.

Democritus devoted considerable attention to perception and knowledge. He asserted, for example, that sensations are changes produced in the soul by atoms emitted from other objects that impinge on it; the atoms of the soul can be affected only by the contact of other atoms. But sensations such as sweet and bitter are not as such inherent in the emitted atoms, for they result from effects caused merely by the size and shape of the atoms; e.g., sweet taste is due to round and not excessively small atoms. Democritus also was the first to attempt to explain colour, which he thought was due to the "position" (which he differentiated from shape) of the constituent atoms of compounds. The sensation of white, for instance, is caused by atoms that are smooth and flat so as to cast no shadow; the sensation of black is caused by rough, uneven atoms.

Democritus attributed popular belief in the gods to a desire to explain extraordinary phenomena ( thunder, lightning, earthquakes) by reference to superhuman agency. His ethical system, founded on a practical basis, posited an ultimate good ("cheerfulness") that was "a state in which the soul lives peacefully and tranquilly, undisturbed by fear or superstition or any other feeling."

# data[].attributes.attachment_link.description
Democritus, ancient Greek philosopher, a central figure in the development of philosophical atomism and of the atomic theory of the universe. His works reportedly numbered 73, though only a few hundred fragments have survived, mostly from his treatises on ethics. Learn more about Democritus's life and theories.

# data[].attributes.body
Democritus lived in Abdera and studied ethics universe,  atomic theory, and void. In his studies of the atomic theory he made a theory that all material bodies are made up of indivisibly small atoms. He came to this conclusion after braking a rock and eventually the pieces of the rock became too small to see. A fun fact is that Aristotle rejected Democritus' theory in his paper "On Generation and Corruption".