-
460 BCE
Democritus was born
in Abdera, Greece -
400 BCE
Democritus develops the Atomic Theory
Around this time, Democritus and his teacher, Leucippus, developed the first basis of the atomic theory which stated that everything is composed of atoms, which are physically, but not geometrically, indivisible, that between atoms there lies empty space, and that atoms are indestructible. The theory also stated that atoms have always been and will always be in motion and that there are an infinite number of atoms, and kinds of atoms, which differ in shape and size. -
370 BCE
Democritus died
-
Antoine Lavoisier was born
in Paris, France -
John Dalton was born
in Eaglesfield, Cumbria, United Kingdom -
Lavoisier and his Research with Combustion
Lavoisier found out the effects of combustion of phosphorus. He realized that the process required a lot of air and that the consequence was a gain in mass. Later, he conducted the same experiment on sulfur, and arrived at the same inferences. This research proved to be one of the most pioneering chemical theories ever produced, and it remains applicable in the field of science to this day. -
Lavoisier on Mass Conservation in a Chemical Reaction
He deduced that any substance can alter its state (liquid, gaseous, or solid) while showing no change in the total mass. This led to the law of conservation of matter which states that atoms are neither created nor destroyed in a chemical reaction. -
Lavoisier's Disproves Phlogiston
Phlogiston was thought to be the flammable substance in the elements before 1777. It was said to be released into the air when the elements were burned. In 1777, Lavoisier was ready to compose a theory that excluded phlogiston. -
Antoine Lavoisier died
-
John Dalton: Modern Day Atomic Theory
Dalton proposed the present day atomic theory which is two centuries old but still valid in modern chemical thought. It stated that all matter is made up of atoms, that atoms are indivisible and indestructible, that all atoms of a given element are identical in mass and properties, that compounds are formed by a combination of two or more different kinds of atoms, and that a chemical reaction is a rearrangement of atoms. -
John Dalton died
in Manchester, United Kingdom -
J.J. Thomson was born
in Cheetham Hill, Manchester, United Kingdom -
Max Planck was born
A Planck is a unique unit of measurement solely defined by the physical constants. The man for whom they were named was born at this date. -
Marie Curie was born
in Warsaw, Poland -
Robert Millikan was born
in Morrison, Illinois -
Ernest Rutherford was born
in Brightwater, New Zealand -
Albert Einstein's Birth
One of the most famous men in history was born today. He theorised that time moves at a different pace depending on your size, had an IQ of 160, and was a big hit with the ladies. -
Niels Bohr's birth
The man after which Bohrium was named was born on this day. He also updated the electron model with his own version called the Bohr Model. -
James Chadwick's Birth
The man who would later become the head of the British Division of the Manhattan Project was born. -
Louis De Broglie's Birth
One of the few French Physicists to contribute to the war effort, De Broglie not only paved the way for Schrodinger with his Pilot-Wave Theory, but also won the Nobel Prize in Physics for his work. -
Marie Curie: Emission of Rays
Henri Becquerel’s discovery of uranium salts emitting rays led Curie to take the work a little further. She employed an electrometer to find out that the rays remained constant, irrespective of the condition or form of uranium. After conducting her research, she found out that the rays were emitted from the element’s atomic structure and were not the outcome of the interaction of molecules. It was due to this revolutionary finding that the field of atomic physics came into existence. -
J.J. Thomson: Discovery of the Electron
Thomson began seminal research on cathode rays that led him through different alleys. Through this research, he discovered the electron which changed the face of natural sciences. -
Erwin Schrodinger was born
The man behind Schrodinger's Paradox and author of "What is Life?" was born on this day. -
Werner Heisenberg was born
A key member of the Uranprojekt(Germany's version of the Manhattan Project), Heisenberg was an avid Physicist who would later win the Nobel prize for his creation of Quantum Mechanics. -
J.J. Thomson: Positive Ions and Electrons
He spent the latter part of his career conducting research on isotopes that led to the discovery of positive ions and later on he went on to make more important discoveries such as the radioactivity of the element potassium. He was also able to assert that hydrogen did not have more than one electron. -
Ernest Rutherford: Geiger-Marsden Experiment
In collaboration with Hans Geiger and Ernest Marsden, Rutherford conducted the Geiger-Marsden experiment, which established the nuclear atoms by deflecting alpha particles passing through a thin, gold foil. -
Robert Millikan: Oil Drop Experiment
He determined the unit charge of the electron with his oil drop experiment at the University of Chicago. This allowed for the calculation of the mass of the electron and the positively charged atoms. -
Marie Curie died
in Sancellemoz -
Ernest Rutherford died
in Cambridge, United Kingdom -
J.J. Thomson died
in Cambridge, United Kingdom -
Robert Millikan died
in San Marino, California
