Horton.Holmes.historytimeline


 * __ANCIENT TIMES__

Aristotle (384-322 BCE)**

Aristotle was a Greek philosopher who was born in Stagira in northern Greece in 384 BCE. He was a student of Pluto and was also the teacher of Alexander the Great. He wrote about numerous different topics including; poetry, government and politics, logic, ethics, and physics. He was an extremely intelligent and gifted individual. Aristotle is even thought to be a key figure in the development in western philosophy. It truly was remarkable what Aristotle was able to do in his life with the lack of sources he had available. Aristotle lived in a time where there was little known about our world. However, Aristotle managed to discover that our world consisted of four majors parts; Fire, Water, Earth, and Air.

Aristotle discovered natures four major components; Fire, Water, Earth, and Air. By doing so, he put up the first stepping stone to the discovery of the atom in the extremely distant future. Aristotle was literaly the first known person in the world to organize organisms in way that made sense. However, Aristotle did techniquly have another element called Aether. Aether was said by Aristotle who was an extremely religous individual to be the stars and planets, which are also the Greek Gods. However, when it comes down to it, if it wasn't for Aristotle's discovery, many of the well known sicentists concerning the atom (that you will soon find out!) and its overall understanding couldn't have been able to do so, nor discover the amazing facts and parts about the atom.

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 * Democritus (About 460-370 BCE)**

"Nothing exists except atoms and empty space; everything else is opinion" (Introduction to Chemistry; Third Edition).



Democritus was a Greek scholar and born in 458 BCE. He was born in Abdera, Greece. Democritus was an exremely intelligent individual and basically, discovered what the atom was without any scientific technology to use at all. With the help of his teacher and mentor, Leucippus, Democritus came up with the well known atomic theory. The fact that Democritus came up with this idea of "atomos" (invisible parts) is truly remarkable. There are many scientists today that claim Democritus to be the "father of modern science" with his incredible discovery.

...This is a picture of what Democritus beleived the atom looked like.

Democritus's atomic theory discovery was very important to what today's scientists view as the atom. This theory was really the first of it's kind in Democritus's day and age. Democritus theory claimed that everything was made up of atoms and also, that atoms are physically "atomos", or invisible. Furthermore, Democritus claimed that there was space between atoms and atoms are constantly moving. Democritus's theory also claimed that there are many different types of atoms that vary from different shapes and temperatures. Although Democritus had all of these great observations and ideas on atoms, he lacked hard evidence to back up his theory. Therefore, it wasn't for a couple thousand years later until the progress on the atom really took place again with a lot of evidence to back it up.


 * Small, spherical, solid, indivisible model of the atom

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The small, spherical, solid, indivisible model of the atom created by Democritus is shown above. Basically, this model is the basis of the origional thought view of the atoms. This model is what Democritus beleive the universe what made up of. He thought the world was made up of empty space and an infinate amount of atom. Through this model, you can notice how basic this atom is viewed as due to the lack of any legitament knowledge of the atom during this time period. However, this is what Democritus believed that all matter was composed of and this model is the basis of what we know to be the atom today.

([]) ([|http://www.gap-system.org/~history/Mathematicians/Democritus.)]. ([]) ([]) ([]).


 * __Leucippus__ (460-370 BCE)**

Leucippus was a Greek philosopher who was born in Abdera, Greece in 440 BCE. Leucippus was a mentor type figure for Democritus and a lot of Democritus published works on the atom and the atomic theory were due to reasearch with Leucippus. When it comes down to it, Leucippus and Democritus made there atomic theory by simply ignoring was known as pure fact in their lifetimes. Everyone in ancient times believed that "everything is one" and that change and motion is an illusion ([]). However, it was up to Leucippus (along with the help of Democritus) to make sense out of the every day world around them. Therefore, these two in fact did so through their atomic theory.

Leucippus's discovery was a major contributor to Democritus's well known Atomic Theory. The two of them together discovered that the atom was in fact "invisible" and was in constant motion as well. Leucippus and Democritus also discovered that these atoms were indestructable and also that they vary in shape. Although Leucippus was a huge contributor to Democritus's discovery of the atomic theory, he lacks the recordings of books and such that Democritus sucessfully did after the discovery. However, if it wasn't for the help of Leucippus, then Democritus wouldn't have been able to come up with his atomic theory. Therefore, Leucippus better helped the world with his discoveries about the atom and what is known as today.

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**__1700-1800__**

( []) Isaac Newton was born On January 4th 1643 in Lincolnshire, England. He was believed to be the greatest scientist that came out of England of all time. Isaac was basically treated as an orphan even though he was relative rich at the time. His childhood was not a happy time; his step-father treated him poorly. His real father did when Isaac was three months old. He went to a school in Cambridge and there he wanted to study law but his school was known for philosophy of Aristotle. In Newton's greatest achievement was his work in physics and celestial mechanics, which is his theory of universal gravitation. And his three laws of motion also is what makes him stand out as a great scientists. He had also discovered the law giving the centrifugal force on a body moving in a circular path. He was the president of the Royal Society from 1703-1727. He was knighted in 1705 by Queen Anne he was the first scientist to be known for his work. He died March 31 1727 in London. ( [] )
 * Isaac Newton**


 * Joseph Priestley**

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Joseph Priestley was born in Fieldhead, which was an English county of Yorkshire, on March 13, 1733. He had three brothers and two sisters and he was the oldest of them all. Priestley went to school as a child but had to withdraw himself because he came done with tuberculosis. Priestley soon recovered and he started teaching himself the basics of geometry, algebra and mathematics. He also taught himself French, Italian, and German and learned Chaldean, Syrian and Arabic. This is pretty amazing knowing all those languages never mind teaching yourself. Joseph Priestley is best known as the discoverer of oxygen. Though he was not known for chemistry and vivid research, he is known for his theory. Also around 1767 he wrote his first scientific publication on the combination of water and air. He was rewarded with the Copley Medal of the Royal society. All the carbonated beverages of today can be related to Priestley. Why was the discovery of oxygen a big deal back around 1767? Because Priestly had no modern tools, and equipment to notice all of the different types of gasses like we do today. That is why it was a big achievement. Joseph Priestley died on February 6, 1804. (http://www.woodrow.org/teachers/ci/1992/Priestley.html)


 * Antoine Lavoisier **



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Antoine Lavoisier was born on August 26, 1743 to a wealthy Paris family. His child hood was normal except the fact that he grew up as a wealthy child. He working conditions was that during the time of the French Revolution. This was a big factor in his life because in the end it is that what killed him. He was elected into the Royal Academy of Science in 1768. He and his wife the daughter of Jaques Paulze in which they became a great team, where she deciphered English documents, especially those of Joseph Priestley. What Lavoisier is most known for is his law of the Conservation of Mass. Which states matter is neither created nor destroyed. He also developed the system of chemical nomenclature still largely in use today, including names such as sulfuric acid, sulfates, and sulfites. This is why he is known for being the father of Modern Chemistry. Lavoisier began working on the problem of combustion in 1777; Lavoisier conducted an experiment that presented a problem for the phlogiston theory. Proof of the validity of Lavoisier's Oxygen Theory came when Lavoisier he decomposed water into two gases, which he named hydrogen and oxygen, and then reformed them into water as had been previously done by Priestley (1781). That supports his law of Conservation of Mass. He was later guillotined in November 1793. ([]),([])


 * __1800-1875__

John Dalton (1766-1844)**

[] ...**The Atom Song!!**

[] ...**Dalton Video**

John Dalton was a scientist who was born in Cumberland, England in 1766. Dalton grew up in a time period where there wasn't a lot of discoveries or imformation about the atom. The world had just gotten over the Dark Ages where Plague and Relgion lead to the deaths of many scienists and such. However, Dalton was an extremely gifted scientist, and through hard work and determination he better helped the world understand the atom. Dalton helped do so through Dalton's Atomic Theory, which was built off of Democritus's initial atomic theory thousands of years before. Through his experiments, Dalton was able to create a rough draft per say, of the periodic table as shown in the picture above. With the lack of technology, Dalton was still able to discover many elements like hydrogen, oxygen, iron, gold, copper, zinc, and mercury. Some of the data he collected for his able was incorrect, but he helped start up the Periodic Table known worldwide today. By organizing this table and through his atomic theory, Dalton was one of the most significant scientists relating to the discovery of the atom to ever live (if not the most important).

John Dalton's Theory was composed of five main points listed here: With these main points, the understanding of the atom increased significantly for scientists and people worlwide. These points helped Dalton come up some of the elements we know today in the first periodic table. He was able to organize many elements including the first element Hydrogen in the periodic table. Dalton's discovery bettter helped the world understand the atom and also what atoms put together make, elements. Before Dalton, the atom was simply known as an indistructable and invisible. However, after Dalton, the world now knew that atoms make up elements, and that those elements can therefore make up compound. John Dalton is a pioneer of the basic understanding of atoms and how they are viewed today.
 * Elements are made of tiny particles called atoms.
 * All atoms of a given element are identical.
 * The atoms of a given element are different from those of any other element; the atoms of different elements can be distinguished from one another by their respective relative weights.
 * Atoms of one element can combine with atoms of other elements to form chemical compound; a given compound always has the same relative numbers of types of atoms.
 * Atoms cannot be created, divided into smaller particles, nor destroyed in the chemical process; a chemical reaction simply changes the way atoms are grouped together.

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Demitri Mendeleev (1834-1907)

Dmitri Mendeleev was both a chemist and inventor who was born in Tobolsk, Russia during the year 1834. Growing up, Dmitri was from an extremely poor family, yet he still managed to become a successful scientist and create one of the most important inventions used for chemistry today, the Periodic Table. Dmitri created the Periodic Table in the year 1871, and built a lot of his works off of John Dalton's Atomic Theory and his "rough draft", of the table and also the work of John Newlands and Lothar Meyer and their discovery of different elements. During Mendeleev's lifetime, Russia was in poor condition and not exactly the best place to work, even for a scientist. However, through pure intellgience, hard work, and hints from previous scientists before him, Mendeleev made history through the discovery of the Period Table, which is used in classrooms and work places all over the world.

As you already know, Mendeleev's discovery was the creation the Period Table. Now, Mendeleev was an intelligant man and noticed that the atomic weight of atoms could be used to rank different elements from lightest to heaviest. Furthermore, he would constantly stress the fact that there was an order to elements, and that putting the elements in order would help predict undiscovered elements (and he was correct!). Although Mendeleev's Period Table had a few errors, his organization of elements through atomic weight helped further overall understanding of the atom and its organization and also helped scientists throughout the world the ability to discover new elements and add them to the table. Below is a picture of Mendeleev's 1869 Period Table;

//Mendeleev's elements (1869) compared to periodic "Groups."

And Today's Table!!!!!!

//

As you can notice, compared to todays Period Table (shown below Mendeleev's Table), Mendeleev was extremely accurate with his discoveries of elements as well as the order of the elements.

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G.J. Stoney (1826-1911)

-Electron in motion around nucleus

G.J. Stoney was an Irish Physist born in the year 1826 in the Irish Midlands. Stoney grew up during the Great Famine, where many Irish folks left the country due to starvation because of poor farming conditions. At a young age his family lost their land due to the Great Famine, yet Stoney was still abel to attend a prestigious college in Ireland and become a famous physisist throughout the world. G.J. Stoney is known for many different reasons, but he is best known for his orgional discovery of the electron in the year 1874. Stoney's most important scientific work was the conception and calculation of the magnitude of the atom or particle of electricity, for which he coined the term "electron" ([]). The fact that Stoney was able to discover the electron at such an early point in time is truly amazing.

Stoney's discovery of the electron helped understand the atom in many different ways. Before this discovery, the atom was thought of as just an atom, the smallest indistinguishible unit of an element. However, after this discovery, the world discovered that the atom is not the smallest unit in the world, and that there are subsystems that make up the atom. Therefore, the discovery of the electron (which is a part of the atom that orbits outside of the nuclues) better helped the world understand the atom and helped scienists discover that the atom alone, isn't the smallest unit the the world.

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 * __1875-1900__**

Wilhelm C. Roentgen

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Wilhelm C. Roentgen was born on March 27, 1845 in a burrow called Lennep which is now Remscheid in Rhenish Prussia. Roentgen was a only child of a merchant cloth manufacturer. In 1848 the family moved Alpeeldon and Wilhelm moved to the Netherlands. He received his education at a private school called the institute of Maritinus Van Doorn. He was then expelled from his school called Utricht Technical School because he would not tell who drew an unappealing picture of his teacher. He then went to Federal Polytechnic Institute. He received his PhD there in 1869. He Started his career at Strasbourg University where lectured and eventually became a professor of physics. Roentgen had family in Iowa in the United States and he eventually wanted to emigrate to the U.S. But Roentgen bought tickets to the U.S but WWI had just begun so he remained in Munich for the rest of his Career. During 1895 Roentgen was doing an experiment using Crooks Tube and he noticed when he added cardboard to block off the light he noticed that the invisible cathode rays caused fluorescence on a small piece of cardboard painted with barium platinocyanide. He founded the new rays and decided to call them x-rays. He soon then started putting images in the way of the X-rays to see what the image would look like. Once he asked his wife to put her hand there and in the photo you could see her bone and the ring on her finger. Thus creating the first X-Ray image. ([])

In 1901 Roentgen was awarded the Nobel Prize in Physics. He later died in 1923.

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Eugen Goldstein ([]) Eugen Goldstein was born in 1850 in Gleiwitz, Poland now known as Gliwice. Goldstein was studied at Breslau and later Berlin. Goldstein later received a job at the Berlin Observatory but he spent most of his career at the Potsdam Observatory where he was the head of the astrophysical section in 1927. Like Roentgen, Goldstein studied the discharging tubes where he named the light emitting rays as cathode rays. Goldstein also concluded that electrons moved from the negatively charged cathode towards the positively charged anode. Goldstein's work with anode rays was the first observation of the proton so it was Goldstein who is credited with the discovery of the Proton. He later died in 1930.

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Josiah Willard Gibbs ([])

Josiah Willard Gibbs was born on February 11, 1839. Gibbs attended Hopkins school Gibbs eventually went to Yale where he spent the rest of his career there. He graduated at the top of his class. In 1869, Gibbs was appointed Professor of Mathematical Physics in 1871, the first such professorship in the United States and a position he held for the rest of his life. Between 1876 and 1878 Gibbs worked on what is now know as the greatest and biggest achievement for the 19th century. His work was called On the Equilibrium of Heterogeneous Substances. In his papers he described thermodynamics and what is now known as physical chemistry. Gibbs achievements went most unknown in his home country U.S but after many years his theories were recognized and here is a quote supporting Gibbs accomplishments. Gibbs died in 1903. <span style="font-family: Calibri; font-size: 11pt; line-height: 115%; mso-ansi-language: EN; mso-ascii-theme-font: minor-latin; mso-bidi-font-family: 'Times New Roman'; mso-bidi-language: AR-SA; mso-bidi-theme-font: minor-bidi; mso-fareast-font-family: Calibri; mso-fareast-language: EN-US; mso-fareast-theme-font: minor-latin; mso-hansi-theme-font: minor-latin; msoansilanguage: EN; msoasciithemefont: minor-latin; msobidifontfamily: 'Times New Roman'; msobidilanguage: AR-SA; msobidithemefont: minor-bidi; msofareastfontfamily: Calibri; msofareastlanguage: EN-US; msofareastthemefont: minor-latin; msohansithemefont: minor-latin;">([]).

“Just as Newton first conclusively showed that this is a world of masses, so Willard Gibbs first revealed it as a world of systems” (—Lawrence Joseph Henderson, American biochemist in //The Order of Nature// (1917: 126).


 * __1900-1915__**

**Henri Becquerel**(1852-1908)

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Henri Becquerel was born on December 15, 1852 in Paris, France. He was educated at Lycee Louis-le-Grand, Ecolésar Polytechnique. He received his engineering training at Polytechnique. On leaving the school, he married Lucie-Zoe-Marie Jamin who was the daughter of J.C. Jamin, who was a professor of Physics. His early research was on optics and light polarization but soon turned toward the infrared spectrum. This and the work of Roentgen ’s “X-rays” persuaded Becquerel to seek the meaning behind the unusual  phosphoresce. His questioning is what leads him to discover radiation. Along with Pierre and Marie Curie they discovered radioactivity through his investigations of uranium and other substances. In 1903 he shared the Nobel Prize for Physics with them. He died August 25, 1908.

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 * Earnest Rutherford

** ([]) Earnest Rutherford was born on August 30, 1871 in New Zealand. He went to Nelson College and then Canterbury College, University of New Zealand. He then later on went to University of Cambridge in England to study after he graduated from Canterbury. During his time in England he coined the terms alpha and beta and later gamma as regards to radioactivity. What Rutherford is most known for is the Rutherford model or the planetary model of the atom. A very small positively charged nucleus was orbited by electrons.

  (http://msc.phys.rug.nl/QuantumMechanics/images/ATOM1.jpg)

He also later theorized that something else existed in the atom, the existence of neutrons. This is what offset the repelling of the protons. He was awarded the Nobel peace prize in 1932 for this theory. His work during the times of World War I help was instrumental in the development of the first nuclear weapons for the Manhattan Project. He died on October 19, 1937. (http://www.rutherford.org.nz/biography.htm) 

 (http://www.chemheritage.org/classroom/chemach/images/lgfotos/05atomic/thomson1.jpg) J.J Thompson was born on December 18, 1856 in Manchester England. He went to Owens College in Manchester and then Trinity in 1880. He then later became a professor at Cambridge. What J.J Thompson is most known for is his discovery of the electron while observing the cathode rays. For this discover he was awarded the Nobel Peace prize in 1906. He was also Knighted in 1908. He died on august 30, 1940.
 * J.J Thompson **

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Marie Curie (1867-1934)
 * [[image:http://upload.wikimedia.org/wikipedia/commons/d/d9/Mariecurie.jpg width="319" height="368" caption="File:Mariecurie.jpg" link="http://upload.wikimedia.org/wikipedia/commons/d/d9/Mariecurie.jpg"]] ||
 * File:Mariecurie.jpg ||

Marie curie was a scientist born in Warsaw,Russia in 1867. Marie was the first person to recieve a Nobel Prizes. Marie recieved the Noble Prize in Physics in the year 1903 and also reecieved a Nobel Prize in Chemsitry in 1911. In Marie's time, women were not yet thought of as equals to men, and her achievements were a blatent example of how women can contribute to society along with men. She was an extremely determined scientist as shown through her Nobel Prize's and she her acomplishments were made with the help of her Husband Pierre Curie.

Marie Curie had an enormous inpact on the chemsitry world. "In 1903, the Royal Swedish Academy of Sciences awarded Pierre Curie, Marie Curie, and Henri Becquerel Nobel Prize in Physics "in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel" ([]). This was the first award Marie recieved for her work with radiatio. Then in 1911, Marie was awarded yet again with the Nobel Prize "in recognition of her services to the advancement of chemistry by the discovery of the elements radium and polonium, by the isolation of radium and the study of the nature and compounds of this remarkable element ([]). After the discoveries of rays by Roentgen, Marie was determined to whether there were any other elements that could give off radiation and through extremely difficult and tedious experiments. She discovered that both radium and polonium were highly radioactive. Through her discoveries of Radium and Polonium, Marie better helped the world understand chemsitry and the atom. Before, it was difficult for people to believe that there were atoms with such radiation, but shortly after her discoveries these new elements Marie discovered were added on the periodic table and the understanding of radiation increased significantly. Also, Marie somwhat led to the idea of treatment of diseases used today thorugh radiation. Overall, Marie Curie is considered to be pioneer per say of the chemistry world for her remarkable discoveries.

([]). ([|http://en.wikipedia.org/wiki/Marie_Curie).(http://nobelprize.org/nobel_prizes/physics/laureates/1903/marie-curie-bio.html]). ([]).

[] ....**Educational rap on Neils Bohr and his life!!**
 * Neils Bohr (1885-1962)**

Neils Bohr was a physicst who was born in Copenhagen, Denmark in the year 1885. Borh grew up around physics along with his brother due to the fact that his father was a physiologist. Borh worked in Manchester, England at Earnest Rutherford's lab and was influenced by him tremendously during his younger years as a physicist. Bohr also had a close reltionship with fellow phsicist Heinsburg and I beleive that many of his ideas and such could have been because he was highly influenced by some of histories other great chemsits and physicists. In Bohr's lifetime, he is most recognized for the Bohr Model of the atom, which was built off of the Plum Pudding and Rutherford model's. In 1932 Borh was awarded the Nobel Prize for, " his services in the investigation of the structure of atoms and of the radiation emanating from them"([]). Many people today call it the Rutherford-Borh model due to the fact that if it wasn't for Rutherford, there wouldn't have been a Borh model. Aside from the Borh model, Neils is also well known for his work in the Manhatten Project during World War II.

Of all of the great contributions to science Borh has done, the Borh Model is by far the greatest. Borh took the previous Plum Pudding and Rutherford Model's and expanded it into futher undrstanding for the world. Bohr published his theory about the atoms structure in 1913, and he based it off of his mentor's model. Rutherford claimed in his model that the atom"consisted of a positively charged nucleus, with negatively charged electrons around it." ([]). However, Bohr took this and exapnded, saying that electrons "travel only in certain successively larger orbits." ([]). Borh also claimed that the outer orbits could hold more electrons than the inner orbits and that the outer orbits, "determine the atom's chemical properties" ([]). So basically, Bohr's model highly impacted the way people viewed the atom at that point in time.


 * Rutherford Bohr Model**

Shown above are pictures of Neil Bohr's infamous Rutherford-Bohr Model and what exactly in involved in the model. Before this model scientists knew that electrons were orbiting around the positively charged nucleus. However, as shown in these models above, Bohr added orbits to that. Furthermore, with the orbits, Bohr claimed that electrons only orbit in "sucessively" larger orbits. Bohr also discovered that the outer orbits could hold more electrons that the electrons located in the inner orbits.

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 * __1915-1950__**

**Robert Millikan**



([]) Robert Millikan was born on March 22, 1868 in Morrison Illinois. He attended Oberlin College in Ohio were his favorite subjects were Greek and Latin. He achieved his mastership in Physics in 1893. He later went on to spend a year in Germany at The Universities of Berlin and Gottingen. In 1910 he discovered what he is most known for, the discovery of the Charge of the Electron. This was in 1910. He used the Falling Drop Method and he proved that the charge was constant for all electrons. He too was a Scientist during World War 1 and this made all his findings even more substantial considering the time of hardships. He died on December 19, 1953. (http://nobelprize.org/nobel_prizes/physics/laureates/1923/millikan-bio.html)


 * Erwin Schrodinger

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Erwin Schrodinger was born on August 12, 1887 in Vienna. He went the University of Vienna. He studied Physics. He later held positions at the University of Zurich. In 1927 he moved to Berlin which at the time was having a big scientific movement in Germany. This was right around the time Hitler was coming to power and Schrodinger moved again to escape Hitler’s growing fame. What Schrodinger was famous for was “Schrodinger equation” which described not only atomic and subatomic systems but also atoms and electrons. He also was awarded the Nobel Peace Prize for his work on Wave mechanics in 1933. Also his Cat experiment is what started quantum mechanics and represents how bizarre it is. Erwin Schrodinger died on January 4, 1961 in Vienna of Tuberculosis. (http://nobelprize.org/nobel_prizes/physics/laureates/1933/schrodinger-bio.html)