Everything is composed of energy. In fact, matter is
simply energy in a condensed form. Matter and energy
can be transformed into one another according to Einstein’s
famous formula, E = mc².
Over
the course of the Universe’s evolution, initially
high concentrations of energy gradually cooled and expanded,
giving rise to the first particles of matter (electrons,
protons, neutrons, etc.). Atoms were next to develop,
beginning with the lightest elements, such as hydrogen
and helium, and gradually extending to heavier and more
complex atomic compositions.
The warmest
clouds of matter in the expanding cosmos condensed to
form galaxies, stars, and planets. On Earth (and possibly
elsewhere) the interactions between energy and matter
combined to form the complex aggregations we call living
organisms. In particular, compounds of carbon atoms have
played a predominant role in the evolution of life on
Earth. For now, we do not know if carbon-based life exists
anywhere else in the Universe, or if non carbon-based
life forms are possible. Every aspect of life is connected
to the transformation of energy. The fundamental source
of life is energy from the Sun. The Sun is a huge thermonuclear
furnace, which gives off light and heat produced during
the transformation of hydrogen into helium. During this
transformation, a certain amount of matter is converted
into energy. This conversion occurs according to the
formula E = mc 2. Since c, the speed of light, is a very
large number (300,000 kilometers per second), a small
mass (m) of matter is sufficient to produce a large amount
of energy (E). Plants use solar energy to transform simple
molecules (water and carbon dioxide) into more complex
molecules (carbohydrates), to provide a source of food
for animals and human beings. Thus, plants represent
the first step of the food chain, which is the basis
of all life.
Thousands of years ago, humans began to
learn to use naturally occurring processes of energy
transformation for their own needs. Fire (which is a
transformation of the chemical energy contained in wood
into light and heat energy) allowed us to stay warm,
cook food, and forge metals. Wind allowed us to sail
great distances, fostering trade of goods and knowledge
between distant countries. Other examples of ancient
energy-related technologies include an early type of
battery invented in Babylon, “Greek fire,” an
incendiary mixture composed of set burning fuel oil, wind-powered
and water-powered mills for grinding grains, and wells
that utilized gravitational energy by using heavy stones
to help extract water. Gradually, humans developed more
sophisticated methods of energy conversion. Thanks to the
invention of mechanical engines, this process has expanded
at an exponential rate since the Renaissance. The “steam
engine” was a major step in this energy-related technology
boom. A steam engine operates by transforming heat energy
(typically produced by burning coal) into work (i.e. the
movement of mechanical parts.) This innovation, created
by a Scotsman named James Watt in 1765, gave rise to the
Industrial Revolution, and all of its incalculable concomitant
social changes. Today, Watt’s name continues to be
used as the base unit of power, the watt (W), which is
used to measure the amount of energy produced in one unit
of time. Another important step in the history of energy
was the invention of the battery, which transforms chemical
energy into electrical power. The Italian Alessandro Volta
invented the first battery in 1799. Volta’s name
is still used today as the unit of measurement of electrical
tension, the volt. Electrical energy and its descendants,
such as hi-tech electronics, are the basis for much of
the technology we use today. In fact, the computing revolution
in which we are currently immersed has the potential to
change human society and culture as much as the Industrial
Revolution.
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