hello,
anti-matter
anti-matter was postulated by paul Dirac in 1928, he stated that Every Fundamental Particle (i.e. neutrons, protons, electrons) has an antiparticle- a mirror twin with the same mass but opposite charge. He also provided the mathematical basis for the theory. He predicted that an electron, which is negatively charged, should have a positively charged counter part i.e. the positron. Diracs mathematical calculations also apply to other fundamental particles.
The discovery of positrons ( also known as anti-electrons) in the cosmic radiation in 1932 by Carl Anderson vindicated Dirac's bold prediction. 23 years later scientists at the University of California at Berkeley created the antiproton in a particle accelerator. When matter and anti-matter meet, they annihilate and disapear in a violent explosion in which mass is converted in to energy ( predicted by Einstein's formula E=mc2).
If you think that is perplexing, then what about the idea of an anti-universe- a universe parallel to ours? Enter it and you will find your antimatter counterpart: anti-you. But dont shake hands!
Dark Matter
Aside from Normal matter i.e. Solids, Liquids, Gases, Plasmas and Bose-Einstein Condensates is Dark Matter and Exotic Matter both of which is hypothetical. Dark Matter does not emmit or reflect enough electromagnetic radiation to be observed directly, but whose presence can be infered from gravitational effects on visible matter. It accounts for the vast majority of mass in the observable universe. The first to provide evidence and infer the existence of a phenomenon that has come to be called "dark matter" was swiss astrophysicist Fritz Zwicky in 1933. He applied the virtual theorem to the Coma cluster of galaxies and obtained evidence of unseen mass. Zwicky estimated the cluster's total mass based on the motions of galaxies near its edge. When he compared this mass estimate to one based on the number of galaxies and total brightness of the cluster, he found that there was about 400 times more mass than expected. The gravity of the visible galaxies in the cluster would be far too small for such fast orbits, so something extra was required. This is known as the "missing mass problem". Based on these conclusions, Zwicky inferred that there must be some non-visible form of matter which would provide enough of the mass and gravity to hold the cluster together.
So in the universe we have Radiation, fundamental particles floating around i.e. quarks which in turn are combined with gluons to create subatomic particles like protons and neutrons. In this world we have also anti-particles which are composed of anti-quarks and anti-gluons which roam distant places in the universe. Also there is dark matter particles, say, axions roaming around neutrons and protons taking up lots of mass in the universe. There is also exotic matter which, instead of bending the fabric of the universe lift it due to the fact it has negative mass.
So basically anti-matter is considered to be a mirror of normal matter i.e subatomic particles and dark matter is a seperate form of matter which exists in large quantites whose hyperthetical particles are WIMPS or axions.
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By Kurt.physics
Yr. 8 student
fav. topic Physics, Mathematics