A little man from Scotland,
162cm tall, who was born as James Clerck, he had his name changed and added one
more surname, Maxwell. The reason was because his father wanted him to receive
a heritage. This man is as important as Newton and Einstein to the Physics
knowledge. He created a theory that unified two another different ones,
Magnetism and electricity, with a non-creative name Electromagnetism.
Students from engineering and physics have a discipline that involves a part of Maxwell’s theory. Normally this matter doesn’t bring good memories, this issue is very complex besides the physics that involves is not trivial the math that describes phenomena needs different types of integrals.
Nowadays, we live
surrounded for electromagnetic waves. Electronic products as cellular phones,
TV, radio and a lot of them come from the sun.
Some of these waves are
vital for development and maintenance of life on Earth. Ultraviolet B(UV-B)
waves are capable to bring vitamin B to our bodies. In countries that do not
receive sun during winter, where the inclination of planet doesn’t allow enough
insolation, children can have a “beach” in their living room.
In another cases and, for different
reasons, people can take an artificial sun.
Abundant ultraviolet waves
are hazardous for the living beings. In particular, UV-C waves are dangerous
for all kind of lives. UV-B waves are able to burn skin and a long-term
exposition produces genetic damages that can generate skin cancer.
In the 80’s, society knew
that the ozone layer (O3) that protects the Earth from UV waves had holes. In
natural way this layer has empty space, orifices, however they were getting
bigger and bigger. Holes located at the North Hemisphere were increasing in
diameter. The scientists figured out the reason why: was because there was
excess of use of CFC gas, chlorofluorocarbon.
The phenomena that occurred
was CFC acted as a catalyzer and broke the interatomic bond, destroying the
ozone layer, on troposphere. This layer is above the surface.
This type of gas is used in
a lot of equipment for our comfort and welfare. Air-conditioning, refrigerating
machines and in beauty products like cream shave and similar ones. This gas was
banished from any kind of use, China was one of last big countries to use it.
Today others gases, that don’t affect ozone layer, substitute CFC gas.
This is a good example,
because it shows us when there is a problem that really affects society, is
defined and solutions are put into practice.
In a clear way, even you
take a sunbath with or without sunscreen your body can absorb/retain vitamin D,
without sunscreen cause skin burns.
some others texts about
the same issue can be see at
Euclid's Window: the
Story of Geometry from Parallel Lines to Hyperspace
em http://www.researchgate.net/publication/44575224_Photoprotection_and_vitamin_D_status?ev=pub_cit_inc
