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3000 BCE
Invention Of The Precision Balance
The precision scale is an instrument used to measure the weight or calculate the exact mass of something. Invented when the commercial activity boom began. With the passage of time, they were modified to improve its functionality, such as adding a base to the instrument to confirm that it is level and does not cause a change in weight. Romans found a way in which is still currently very useful for the large amounts of weight that the balance can withstand. -
1500 BCE
Invention Of Printing Press During Renaissance
Invented by Gutenberg, the printing press spread rapidly. The immediate effect of the printing press was to multiply the output and cut the costs of books. Printing spread new ideas quickly and with greater impact. Printing stimulated the literacy of people and eventually came to have a deep and lasting impact on their private lives. By giving all scholars the same text to work from, it made progress in critical scholarship and science faster and more reliable. -
Period: 1200 BCE to Nov 15, 1280
St Albertus Magnus
Coming from Germany, Magnus established the study of nature as a legitimate science within the Christian tradition. Albertus distinguished the way to knowledge by revelation and faith from the way of philosophy and of science. Albertus’ lectures and publications gained him great renown. Albertus’ works represent the entire body of European knowledge of his time not only in theology but also in philosophy and the natural sciences. -
Period: 722 BCE to 815 BCE
Abu Musa Jabir Ibn Hayyan
Referred to as the "Father Of Arab Chemistry, " Abu was an Islamic alchemist,pharmacist, philosopher,astronomer, and physicist. His father was a pharmacist who was executed by the Umayyads. Jabir elaborated on systematic experimentation. He is credited with the many types of now-basic chemical laboratory equipment as well as chemical substances and processes. -
Period: 460 BCE to 370 BCE
Democritus
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 beings. 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. Democritus atoms of the soul can be affected only by the contact of other atoms. -
Period: 384 BCE to 322 BCE
Aristotle
Aristotle, the Greek philosopher, learned from Plato, and taught Alexander The Great. He was one of the most influential ancient Greek philosophers of his time, writing about a wide variety of topics. His philosophy made a dramatic impact on Western and Islamic philosophy. Given all that Aristotle has done, it is impossible to summarize everything he did in less than a book. He would speak as though substances were to be identified with the matter of particular objects. -
Period: to
Robert Boyle
Robert Boyle was born on January 27th, 1627. Born in County Waterford , in the Southeastern part of Ireland. Robert Boyle's law is what makes him most famous. It states that if the volume of a gas is decreased, the pressure increases proportionally. Boyle tried to construct a universal 'corpuscular theory' for chemistry. He defined the idea of an 'element' we use today, as well as introducing the litmus test to tell acids from bases, and introduced many other chemical tests. -
Vacuum Tube and Electric Generator
In 1663, Otto Von Guericke invented the first electric generator, which produced static electricity by applying friction against a revolving ball of sulfur. In 1672 he discovered that the electricity thus produced could cause the surface of the sulfur ball to glow. He had also invented the first air pump and used it to study the phenomenon of vacuum and the role of air in combustion and respiration. -
Period: to
Henry Cavendish
Cavendish was distinguished for great accuracy and precision in researches into the composition of atmospheric air, the properties of different gases, the synthesis of water, the law governing electrical attraction and repulsion, and a mechanical theory of heat.The result that he got for the density of the Earth is within 1% of the currently accepted figure. The combo of painstaking care, precise experimenting, carefully modded apparatus, and theory carries Cavendish’s unmistakable signature -
Period: to
Antoine-Laurent Lavoisier
Lavoisier believed that matter was neither created nor destroyed in chemical reactions, and in his experiments he sought to demonstrate that this belief was not violated. Lavoisier is celebrated for the chemical revolution and consequently one of the founders of modern chemistry. Lavoisier's experiments emphasized quantification and demonstration rather than yielding critical discoveries. Such an emphasis suited his determination to elevate chemistry to the level of a rigorous science. -
Period: to
John Dalton
Dalton claimed that atoms of different elements vary in size and mass, and indeed this claim is the cardinal feature of his atomic theory. His argument that each element had its own kind of atom was counter-intuitive to those who believed otherwise. Since then, chemists have shown Dalton's Theory to be a key factor underlying further advances in their field. Organic chemistry in particular progressed rapidly once Dalton’s theory gained acceptance. -
Period: to
Amedeo Avogadro
Amedeo Avogadro was born in Turin. He was an Italian mathematical physicist who showed in what became known as Avogadro’s law that, under controlled conditions of temperature and pressure, equal volumes of gases contain an equal number of molecules. Many of Avogadro’s pioneering ideas and methods anticipated later developments in physical chemistry. His hypothesis is now regarded as a law, and the value known as Avogadro’s number (6.022140857 × 1023), the number of molecules in a gram molecule -
Period: to
Dmitri Mendeleev
From Russia, Dmirtri was a chemist who developed the periodic classification of the elements. The subsequent proof of many of his predictions within his lifetime brought fame to Mendeleev as the founder of the periodic law. He had such faith in the validity of the periodic law that he proposed changes to the generally accepted values for the atomic weight of a few elements. Gradually the periodic law and table became the framework for a great part of chemical theory. -
Period: to
Sir William Ramsey
Sir William Ramsey was a British physical chemist who discovered four gases (neon, argon, krypton, xenon) and showed that they (with helium and radon) formed an entire family of new elements, the noble gases, and won a Nobel Prize for this. Ramsay demonstrated that helium is continually produced during the radioactive decay of radium, a discovery of crucial importance to the modern understanding of nuclear reactions. This also marked his last notable scientific contribution. -
Period: to
Sir J.J. Thomson
English physicist who helped revolutionize the knowledge of atomic structure by his discovery of the electron in 1897. His discovery was the result of an attempt to solve a long-standing controversy regarding the nature of cathode rays, which occur when an electric current is driven through a vessel from which most of the air or other gas has been pumped out. Thomson's importance in physics depended almost as much on the work he inspired in others as on that which he did himself. -
Period: to
Ernest Rutherford
New Zealand-born British physicist considered the greatest experimentalist. Rutherford was the central figure in the study of radioactivity, and with his concept of the nuclear atom he led the exploration of nuclear physics. He won the Nobel Prize for Chemistry in 1908. Rutherford determined that a magnetized needle lost some of its magnetization in a magnetic field produced by an alternating current. This made the needle a detector of electromagnetic waves -
Period: to
Lise Meitner
Lise Meitner was an Austrian-born physicist who shared the Enrico Fermi Award (1966) with the chemists Otto Hahn and Fritz Strassmann for their joint research that led to the discovery of uranium fission. She and Hahn were among the first to isolate the isotope protactinium-231 , studied nuclear isomerism and beta decay, and investigated the products of neutron bombardment of uranium. -
Period: to
Niels Bohr
He was the first to apply the quantum concept.Bohr claimed that electrons could only occupy particular orbits determined by the quantum of action and that electromagnetic radiation from an atom occurred only when an electron jumped to a lower-energy orbit. Although radical and unacceptable to most physicists at the time, the Bohr atomic model was able to account for an ever-increasing number of experimental data, famously starting with the spectral line series emitted by hydrogen. -
Period: to
Erwin Schrödinger
Austrian theoretical physicist who contributed to the wave theory of matter and to other fundamentals of quantum mechanics. He produced the papers that gave the foundations of quantum wave mechanics. 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. His most famous objection was Schrödinger’s cat. -
Period: to
James Chadwick
James Chadwick was born in Cheshire, England. he graduated from the Honors School of Physics in 1911 and spent the next two years in the Physical Laboratory in Manchester, where he worked on various radioactivity problems. Chadwick made a fundamental discovery in the domain of nuclear science: he proved the existence of neutrons - elementary particles devoid of any electrical charge. Chadwick set the way for the fission of uranium 235 creation of the atomic bomb. -
Period: to
Louis De Broglie
The dual nature of light, however, was just beginning to gain scientific acceptance when de Broglie extended the idea of such a duality to matter. De Broglie’s idea of an electron with the properties of a wave offered an explanation of the restricted motion.The first publications of de Broglie’s idea of “matter waves” had drawn little attention from other physicists, but a copy of his doctoral thesis was sent to Einstein, whose response was enthusiastic. -
Period: to
Marie and Pierre Curie
Their marriage marked the start of a partnership that was soon to achieve results of world significance, in particular the discovery of polonium and that of radium a few months later. Pierre and Marie worked together which led to the discovery of the new elements, polonium and radium. One of her most outstanding achievements was to have understood the need to accumulate intense radioactive sources, not only to treat illness but also to maintain an abundant supply for research in nuclear physics. -
Period: to
Frederic and Irene Joliot Curie
In the course of their researches they bombarded boron, aluminum, and magnesium with alpha particles; and they obtained radioactive isotopes of elements. These discoveries revealed the possibility of using artificially produced radioactive isotopes to follow chemical changes and physio processes.They observed the production of neutrons and positive electrons and their discovery of artificial radioactive isotopes was an important step toward the solution of releasing the energy of the atom. -
Period: to
Linus Pauling
Linus was an American theoretical physical chemist who became the only person to have won two unshared Nobel Prizes. In 1954 he was awarded for research into the nature of the chemical bond and its use in elucidating molecular structure. In 1962, the award was for his efforts to ban the testing of nuclear weapons. By using the technique of X-ray diffraction, he determined the 3D arrangement of atoms in several important silicate and sulfide minerals. -
Period: to
Werner Heisenberg
Wener was a German physicist and philosopher who discovered a way to formulate quantum mechanics in terms of matrices. In 1927 he published his uncertainty principle, upon which he built his philosophy and for which he is best known. He also made important contributions to the theories of the hydrodynamics of turbulent flows, the atomic nucleus, ferromagnetism, cosmic rays, and subatomic particles. Heisenberg also worked on the theory of the atomic nucleus following the discovery of the neutron -
Period: to
Rosalind Franklin
Best known for her contributions to the discovery of the molecular structure of DNA. Franklin also contributed new insight on the structure of viruses, helping to lay the foundation for the field of structural virology. Her work of X-ray diffraction technology led to her research on the structural changes caused by the formation of graphite in heated carbons. She discovered the density of DNA and established that the molecule existed in a helical conformation.
