Graphics Reference
In-Depth Information
The Strong Nuclear Force
As the structure of the atom became more evident, researchers realized that
there was a force that bonded the protons together, working against the force
caused by their electronic charge. Physicists discovered that gravity was far
too weak a force to be responsible for this phenomenon, so they had to find
another very strong force capable of allowing this binding to occur. The
strong
nuclear force
is the strongest of nature's forces; however, like the weak force,
it has a very short range and is ineffective beyond the region of the proton
or the neutron. Only the heavier atomic particles are influenced by this force;
both protons and neutrons are subject to its influence, whereas electrons,
photons, and neutrinos are not. The strong nuclear force is the source of great
energy. Perhaps the best illustration of this concept can be found in sunlight.
It is the strong nuclear force that controls the nuclear reactions in fusion
reactors, examples of which are our own sun and other stars.
The Electromagnetic Force
By comparison to gravity, a
magnetic force
exerts a stronger force, though
its effect is felt over a much shorter distance. If you hold even a very small
magnet over a nail, you will see how the force from the magnet pulls the nail
upward off the surface it sits on to snap onto the magnet. The force exerted by
a magnet small enough to hold in your hand is greater than the gravitational
force exerted by an object as large as the earth. Move the magnet just a
couple of inches above the nail and the electromagnetic force is not strong
enough to move the object, let alone lift it. It's only when the magnet is
located very close to the nail that its force exerts any perceivable influence.
Electromagnetic force
plays a major role in all the phenomena that we
encounter in our daily lives. Electromagnetism provides the force that holds
all the electrons and protons together in all matter. Without this force, matter
would not bind together to form atoms, atoms could not form molecules,
and the structures that form all the recognizable material could not exist. Still,
as important as this force is to our very existence, its implications may be of
relatively limited value to us as animators attempting to gain more insight
into action and dynamics.
Gravity
Unlike the other forces of nature for which range is limited, the range of
gravity
is universal. Its effects can be felt across the universe. All objects in the universe
exert a gravitational pull on all other objects in the universe. When an apple
falls to the ground from a tree branch, its downward motion is due to the
gravitational forces exerted on it by the earth. However, the apple also exerts
a force (an infinitesimally smaller one) on the earth. Though we can detect the
former (the falling apple), it is not possible to detect the latter. Large buildings
