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2000 BCE
Egyptian alchemists
The first people to experiment with science were the Egyptians and Babylonians. Although they made many innovations, such as the refinement of metal ores and in the applications of dyes, little real science had been done. In spite of this, the word alchemy is derived from the Greek for "The Egyptian Art". -
465 BCE
Democritus makes an hypothesis
Democritus hypothesized that atoms cannot be destroyed, differ in size, shape and temperature, are always moving, and are invisible. He believed that there are an infinite number of atoms. This hypothesis was created in 465BC. -
300
Origins of alchemy
Alchemy originated in ancient times, evolving independently in China, India, and Greece. In all these areas the practice ultimately degenerated into superstition, but it migrated to Egypt and survived as a scholarly discipline. In medieval Europe it was revived when 12th-century scholars translated Arabic works into Latin. The rediscovered writings of Aristotle also played a role. By the end of the 13th century it was discussed seriously by leading philosophers, scientists, and theologians. -
312
Aristoltle and his ideas
Aristotle was a pioneering figure in the history of philosophy and science, and his thinking had a significant effect in shaping Western culture. He studied under Plato, who was a student of Socrates. He believed that everything was made of four elements: earth, air, fire and water. -
Jun 13, 1489
Alchemy in the middle ages
Medieval alchemists produced hydrochloric acid, nitric acid, potash and sodium carbonate.They were able to identify the elements arsenic, antimony, and bismuth.Through their experiments, medieval alchemists invented and developed laboratory devices and procedures that are, in modified form, still used today.The practice of alchemy laid the foundation for the development of chemistry as a scientific discipline. -
Daltons Law
In 1803, he theorized what has now become known as Dalton's Law: essentially it states that the total pressure of combined gases is equal to the partial pressures of each of those gases separately. -
Dalton and atomic weights
Dalton's research had a tremendous impact on atomic theory, as his work on the physical properties of different gases required there to be a physical structure to atoms.
From his understanding of atoms, Dalton also published a listing of atomic weights for six different elements: hydrogen, oxygen, nitrogen, carbon, sulfur, and phosphorous. -
Dalton and meteorology
Dalton was also very influential in the study of meteorology, and many of his ideas were not altered until the invention of the airplane and weather balloons.
His work in meteorology, specifically barometric pressure, then led to his publication of a series of papers called Experimental Essays in which he discussed the make up of mixed gases.
He also researched and wrote on the constitution of steam at different temperatures, specifically its atmospheric pressure. -
Henri becquerel discovers radioactivity
By accident, he discovered that uranium salts spontaneously emit a penetrating radiation that can be registered on a photographic plate. Further studies made it clear that this radiation was something new and not X-ray radiation: he had discovered a new phenomenon, radioactivity. -
JJ Thomson estimates magnitude of charged particles
The idea that electricity is transmitted by a tiny particle related to the atom was first forwarded in the 1830s. In the 1890s, J.J. Thomson managed to estimate its magnitude by performing experiments with charged particles in gases. -
Henri switches stream of work
Becquerel's earliest work was concerned with the plane polarization of light, with the phenomenon of phosphorescence and with the absorption of light by crystals. Becquerel decided to investigate whether there was any connection between X-rays and naturally occurring phosphorescence. But instead he discovered radioactivity. And after that he focused on radioactivity. -
J J Thomson discovers electron
The idea that electricity is transmitted by a tiny particle related to the atom was first forwarded in the 1830s. In the 1890s, J.J. Thomson managed to estimate its magnitude by performing experiments with charged particles in gases.Thomson also concluded that electrons are part of atoms. -
Mary and Pierre Curie discover 2 elements
In 1898, they announced the discovery of two new elements, radium and polonium. -
Henri shares nobel prize
For his discovery of spontaneous radioactivity Becquerel was awarded half of the Nobel Prize for Physics in 1903, the other half being given to Pierre and Marie Curie for their study of the Becquerel radiation. -
Curie gets 2 Nobel awards
Curie was a pioneer in researching radioactivity, winning the Nobel Prize in Physics in 1903 and Chemistry in 1911. -
J J Thomson finds way to separate atoms
He discovered a method for separating different kinds of atoms and molecules by the use of positive rays, an idea developed by Aston, Dempster and others towards the discovery of many isotopes. -
Ernest Rutherford discovers radioactive decay
Rutherford worked on radioactivity, coining the terms ‘alpha’ and ‘beta’ to describe the two different types of radiation emitted by uranium and thorium. He also observed that radioactive material took the same amount of time for half of it to decay, known as its “half life”. -
Rutherford's Geiger-Marsden experiment
Rutherford, Hans Geiger and Ernest Marsden carried out the Geiger-Marsden experiment, an attempt to examine the structure of the atom. The surprising results of this experiment demonstrated the existence of the atomic nucleus and became an integral part of the Rutherford model of the atom. -
Rutherford gets the Nobel prize
In 1908, Rutherford was awarded the Nobel Prize in Chemistry for his work on the transmutation of elements and the chemistry of radioactive material. -
Rutherford facts
The element 'rutherfordium' was named in Rutherford’s honor. Famous Ernest Rutherford quotes include: “If you can't explain your physics to a barmaid it is probably not very good physics.” “All science is either physics or stamp collecting.” -
Mary succeeds in isolating pure radium
It took four years of back-breaking effort to extract 1 decigram of radium chloride from several tons of raw ore. -
Bohr completes his atomic theory
In 1913, Neils Bohr completed his theory of the atom called the bohr model. The work said that electrons travel in a certain or a guided path around an atoms nucleus. -
Neils Bohr makes hydrogen theory
In 1913, Niels Bohr proposed a theory for the hydrogen atom based on quantum theory that energy is transferred only in certain well defined quantities. -
Marys contribution in world war
During World War I, Curie served as the director of the Red Cross Radiology Service, treating over an estimated one million soldiers with her X-ray units. -
Chadwick starts working with Rutherford
In Cambridge, Chadwick joined Rutherford in accomplishing the transmutation of other light elements by bombardment with alpha particles, and in making studies of the properties and structure of atomic nuclei. -
Niels Bohr wins nobel proze
He made immense contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922. -
J Chadwick discovers neutron
When Herbert Becker and Walter Bothe directed alpha particles (helium nuclei) at beryllium in 1930, a strong, penetrating radiation was emitted. One hypothesis was that this could be high-energy electromagnetic radiation. In 1932, however, James Chadwick proved that it consisted of a neutral particle with about the same mass as a proton. This was said to be a neutron. -
J Chadwick gets Nobel prize
He was awarded the Hughes Medal of the Royal Society in 1932, and subsequently the Nobel Prize for Physics in 1935. -
JJ Thomson awards
He was elected Fellow of the Royal Society in 1884 and was President during 1916-1920; he received the Royal and Hughes Medals in 1894 and 1902, and the Copley Medal in 1914. He was awarded the Hodgkins Medal (Smithsonian Institute, Washington) in 1902; the Franklin Medal and Scott Medal (Philadelphia), 1923; the Mascart Medal (Paris), 1927; the Dalton Medal (Manchester), 1931; and the Faraday Medal (Institute of Civil Engineers) in 1938. -
Period: to
J Chadwick helps in the making of the atomic bomb
From 1943 to 1946 he worked in the United States as Head of the British Mission attached to the Manhattan Project for the development of the atomic bomb. Chadwick in this way prepared the way towards the fission of uranium 235 and towards the creation of the atomic bomb -
Daltons colurblindness
It was discovered in 1995 that Dalton actually had a very rare form of colorblindness, a fact that Dalton himself studied in great detail and published on many times. He was one of the first to theorize that colorblindness was a genetic feature, as his brother was also colorblind. Due to Dalton's rare form of colorblindness, he was only able to see one color, yellow.
