-
400 BCE
Democritus's Atomos
Democritus believed that there were substances called atoms and that these atoms made up all material things. The atoms were uniform, solid, hard, incompressible, indestructible, and always existed. But this idea was opposed by the another philosopher at that time, Aristotle by saying thighs are made up with 4 elements called earth, wind, fire and water. -
John Dolton's atomic theory
At the beginning of the 19th century, John Dalton's theory contained five main propositions:
1. All matter is comprised of tiny, definite particles called atoms.
2. Atoms are indivisible and indestructible.
3. All atoms of a particular element share identical properties, including weight.
4. Atoms of different elements contain different mass.
5. Atoms of different elements combine in fixed whole-number ratios when forming compounds -
Thomson's Discovery of electron
J.J. Thomson's experiments with cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons. Thomson proposed the plum pudding model of the atom, which had negatively-charged electrons embedded within a positively-charged "soup. -
Quantum Theory Begin
The first phase, known as the old quantum theory, began around 1900 with radically new approaches to explanations physical phenomena not understood by classical mechanics of the 1800s. -
Niles Bohr's Planetary Model
The Bohr Model is a planetary model in which the negatively-charged electrons orbit a small, positively-charged nucleus similar to the planets orbiting the Sun (except that the orbits are not planar) -
Rutherford's discovery of Nucleus and Proton
The discovery of the proton is credited to Ernest Rutherford, who proved that the nucleus of the hydrogen atom (i.e. a proton) is present in the nuclei of all other atoms in the year 1917. Based on the conclusions drawn from the gold-foil experiment, Rutherford is also credited with the discovery of the atomic nucleus. -
Louise de Broglie wave particle duality
Based on the idea that light and all other electromagnetic radiation may be considered a particle or a wave nature, in 1923 physicists Louis De Broglie suggested that the same kind of duality must apply to the matter. He proposed that any particle of matter having momentum (p) Has an associated wavelength (λ) -
Schrödinger's equation
Essentially a wave equation, the Schrödinger equation describes the form of the probability waves that govern the motion of small particles, and it specifies how these waves are altered by external influences. -
Dirac's theory
The theory poses that the continuum of negative energy states, that are solutions to the Dirac equation, are filled with electrons, and the vacancies in this continuum (holes) are manifested as positrons with energy and momentum that are the negative of those of the state -
Discovery of 1st particle of antimatter by Carl Anderson
By studying the tracks of cosmic ray particles in a cloud chamber, in 1932 Carl Anderson discovered a positively-charged particle with a mass seemingly equal to that of an electron. Anderson's particle was the first antiparticle proven by experiment and was named a “positron”. -
James Chadwick discovery of Neutron
By the year 1920 physicists knew there should be a neutral particle in an atom due to the extra mass in the nuclear. But they were unable to detect it at the time. During the experiment he hit a Be sheet by alpha particles and found strange radiation of high energy that appears to be neutrons. He won the Nobel prize in 1935 pro this discovery -
Antiproton
Antiproton were first produced and identified by Emilio Segre , Owen Chamberlain in a proton accelerator called the Bevatron at the radiation laboratory in the University of California at Berkeley. They found that a sub atomic particle which is similar to the proton except the charge. They won the Nobel price for this discovery in 1959. -
The Bevatron discovers the antineutron
On October 19, 1955, the discovery of the antineutron was announced. The culmination of a decades-long hunt for the particle, the discovery won its discoverers Emilio Segre and Owen Chamberlain the 1959 Nobel Prize for Physics. -
Concept of Quarks
A quark is a type of elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. -
Discovery of Antideuteron
Scientists at the Berkeley Radiation Laboratory discovered the antideuteron, consisting of an antiproton and an antineutron -
First proton-antiproton collisions
The Intersecting Storage Rings produced the world's first proton-antiproton collisions on 4 April 1981, paving the way for proton-antiproton collisions in the Super Proton Synchrotron (SPS), and the Nobel prize for Simon van der Meer and Carlo Rubbia -
First Antihydrogen Produced
Bruce Cork and his team's production of the first antihydrogen atoms marked a significant milestone in antimatter research. Antihydrogen consists of an antiproton and a positron, and its creation allowed for further experimental studies. -
First Bose-Einstein Condensate of Antimatter
Wolfgang Ketterle, Eric Cornell, and Carl Wieman's creation of the first Bose-Einstein condensate (BEC) of antihydrogen atoms opened up new avenues for precision studies of antimatter at extremely low temperatures. -
First Anti-Atoms of Antihydrogen Produced
The ATHENA experiment at CERN produced the first stable anti-atoms of antihydrogen, providing scientists with the ability to study antimatter properties and behavior in more detail. -
Discovery of Antihelium-4 Nuclei
The STAR Collaboration at RHIC observed the first artificially produced antihelium-4 nucleus, consisting of two antiprotons and two antineutrons. This discovery provided insights into the behavior of antimatter nuclei. -
First Observation of Antihydrogen Spectrum
The ALPHA experiment at CERN observed the spectrum of antihydrogen for the first time, offering valuable insights into the behavior of antimatter atoms and their interactions with light. -
First Antimatter Gravity Experiment
The AEgIS experiment at CERN conducted the first direct measurement of the gravitational acceleration of antihydrogen. This experiment aimed to test whether antimatter falls under gravity in the same way as matter -
Capture of the first image of a black hole
Scientists have obtained the first image of a black hole, using Event Horizon Telescope observations of the center of the galaxy M87. The image shows a bright ring formed as light bends in the intense gravity around a black hole that is 6.5 billion times more -
Breakthrough in Antimatter Cooling Techniques
Scientists achieve a breakthrough in antimatter cooling techniques, enabling even colder temperatures to be reached for trapped antimatter particles. This advancement allows for more precise measurements and experiments involving antimatter. -
Antimatter-Based Technologies Advancements
Research into potential applications of antimatter, such as propulsion systems for space exploration and medical imaging techniques, sees further advancements, driving innovation in technology and engineering fields. -
Yet Remain
Indeed, the discoveries made in the realm of matter and antimatter have significantly enhanced our understanding of the universe, but many unanswered questions remain. These unresolved mysteries present exciting opportunities for further exploration and research