-
460 BCE
Democritus
Democritus was an Ancient Greek pre-Socratic philosopher from Abdera, primarily remembered today for his formulation of an atomic theory of the universe. None of his work has survived. -
428 BCE
Plato
Plato was a Greek philosopher born in Athens during the Classical period in Ancient Greece. -
384 BCE
Aristotle
Aristotle was a Greek philosopher and polymath during the Classical period in Ancient Greece. -
Lavoisier
Antoine-Laurent de Lavoisier, also Antoine Lavoisier after the French Revolution, was a French nobleman and chemist who was central to the 18th-century chemical revolution and who had a large influence on both the history of chemistry and the history of biology. -
John Dalton
John Dalton FRS was an English chemist, physicist and meteorologist. He is best known for introducing the atomic theory into chemistry, and for his research into colour blindness, which he had. Colour blindness is known as Daltonism in several languages, being named after him. -
New Lands Law of Octaves
If the chemical elements are arranged according to increasing atomic weight, those with similar physical and chemical properties occur after each interval of seven elements. -
Robert Millikan
Robert Andrews Millikan was an American experimental physicist honored with the Nobel Prize for Physics in 1923 for the measurement of the elementary electric charge and for his work on the photoelectric effect. Millikan graduated from Oberlin College in 1891 and obtained his doctorate at Columbia University in 1895. -
Mendeleev's Pd. Table
Mendeleev realized that the physical and chemical properties of elements were related to their atomic mass in a 'periodic' way. -
Photoelectric Effect
Phenomenon in which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation. -
Discovery of Radioactivity
In one of the most well-known accidental discoveries in the history of physics, on an overcast day in March 1896, French physicist Henri Becquerel opened a drawer and discovered spontaneous radioactivity. -
Discovery of the Electron
During the 1880s and '90s scientists searched cathode rays for the carrier of the electrical properties in matter. -
Planck's Quantum Theory of Light
Specifically, Planck's quantum theory of fussy light tells us that light bulb filaments should be heated to a temperature of about 3,200 Kelvin to ensure that most of the energy is emitted as visible waves. Much hotter, and we'd start tanning from the ultraviolet light. -
Plum Pudding Model
The plum pudding model (also known as Thomson's plum pudding model) is a historical scientific model of the atom. -
Rutherford's Gold Foil Experiment
A piece of gold foil was hit with alpha particles, which have a positive charge. Most alpha particles went right through. This showed that the gold atoms were mostly empty space. -
Bohr's Planetary Model
The electrons encircle the nucleus of the atom in specific allowable paths called orbits. -
Mosley's Atomic Numbers
In 1914 Moseley published a paper in which he concluded that the atomic number is the number of positive charges in the atomic nucleus. He also stated that there were three unknown elements, with atomic numbers 43, 61, and 75, between aluminum and gold. There are, in fact, four. -
Discovery of the Proton
During this period, his research resulted in a nuclear reaction which led to the first 'splitting' of the atom, where he discovered protons. He named his discovery “protons” based on the Greek word “protos” which means first. -
Charge of the Electron
Electrons have an electric charge of −1 and their mass is approximately about 1/2000 the mass of a neutron or proton. Electron charge is usually denoted by the symbol e. It is a fundamental physical constant that is used to express the naturally occurring unit of electric charge which is = 1.602 × 10-19 coulomb. -
Schrodinger Equation
The Schrödinger equation is a linear partial differential equation that governs the wave function of a quantum-mechanical system. It is a key result in quantum mechanics, and its discovery was a significant landmark in the development of the subject. -
Heisenberg Uncertainty Principle
We cannot know both the position and speed of a particle, such as a photon or electron, with perfect accuracy. -
Discovery of the Neutron
Sir James Chadwick discovered neutrons in the year 1932 -
The Alchemists
The Alchemist is a novel by Brazilian author Paulo Coelho which was first published in 1988. Originally written in Portuguese, it became a widely translated international bestseller.
