Four interactions or
forces govern all known phenomena in the universe
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Electromagnetism
acts on electric or magnetic charges. This force holds together atoms
and molecules and is responsible for all chemistry. The force carrier is
the photon.
Molecular forces are
residual electromagnetic forces. Also responsible for all
macroscopic electric and magnetic phenomena, TV, radio, light,
communication, lasers, etc.. The quantum theory of electromagnetism is
called quantum electrodynamics or QED for short.
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Strong force, acts
on
color charges. This
force
confines quarks
inside particles. The force carriers are 8 gluons.
The nuclear force that
hold the nucleus together is residual strong force. The nuclear
energy radiated by stars mainly through the nuclear fission processes is
energy stored by the strong force. The quantum theory of the strong
force is called quantum chromodynamics or QCD for short.
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Weak force acts on
"weak" charges. This force is responsible for decay of particles and
change of "flavor". The decay process also contributes to the energy
radiated by stars, including the Earth. The force carriers are W+,W-,Z0.
The Weak and Electromagnetic forces are unified at 10-18
meters (one thousandth the size of a proton). This is explained by the
Standard Model and is called the unified
electroweak force,
and its quantum theory is called quantum flavordynamics of QFD
for short. QFD contains QED.
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Gravitational force
acts on mass or energy. This force holds people on Earth, planets around
the Sun, stars in galaxies, governs the expansion of the universe as a
whole, is responsible for quasars, supernovae, black holes, bending of
light around stars, .… The quantum of gravity, the graviton, has
not been seen in experiment yet.
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