Primaterra

The Beginnings.

Generically, energy is defined as the capacity to do work, or, in other words, the capacity to alter the characteritics of objects.

We could say that the wind, the water of rivers and humans have energy, as they are capable of moving heavy objects; that in combustion energy is released, so that the heat obtained can be used to produce dilatation or state changes, etc.

It is obvious that the first energy that the human race had knowledge of was that from their own body and this, combined with our intelligence, allowed us to manufacture the first tools such as "mazas", rocks shaped differently for different tasks, bows, arrows, etc...,which is to say, instruments that multiply the physical force. Very interesting in a hunting society, and in a world where natural forces were hostile, because unknown.

The wheel allowed our anscestors to acomplish tasks they would never have thought possible.

Quickly mankind, who until that moment had only used his own muscular strength, realised that a series of animals were stronger and could be used for his purposes. This is how appeared the domestication of some animals such as the bull, the horse, camels, donkeys, etc. for which rudimentary harnesses were developped, allowing a better use of their strength. This is how mankind used the energy named animal traction, and later utilises it to the full with a revolutionnary invention: the wheel. It multiplied the power available and allowed our anscestors to acomplish tasks they would never have thought possible.

When Man, after discovering agriculture, becomes sedentary, the first groups of population settle near water courses. These guarantee the irrigation of crops, but at the same time, block his expansion. Quicly, the energy of moving water will be discovered and will allow, firstly navigation, with which the waterways, far from being obstacles, will become ways of communication, and secondly moving wheels and heavy mill stones, allowing a better use of the crops. This is how humanity starts to discover the potential of hydraulic energy.

There is ample evidence that, more than four thousand years ago, the Chinese and Egyptians were able to use the energy of the wind to sail. In the same way, two thousand years ago the first windmills appeared in Persia, although their introduction to Europe would only occur in the 10th or 11th century, as this technology was brought back by the Europeans that went to fight in the Crusades. This primitive knowledge of wind energy allowed us to move away from waterways and establish populations in places remote from them.

Even if in the stone age mankind already knew fire and was able to control it, using it to cook some foods, harden utensils and for defense against animals, the use of this thermic energy, taken from the combustion of forests, was limited to these applications. The ability for work of humans is very high, which is why it is the most sought after source of energy and why there has been an abundance of esclavagist societies. History teaches us that the reduction of the number of slaves in the Roman Empire, after the decline in its militar power, caused a grave energy crises that had for consequence the difusion of techniques very scarce until then.

Further Development of energy uses and sources.

During the middle ages, the energetic techniques do not change, and what is done is ameliorate the existing ones. In this way, the harness is bettered, increasing the capacity of animals, and the hydraulic wheel become more and more common, giving rise to the establishment of mills, forges and sawmills.

During this time, and also in the Renaissance, the most progress in the use of energetic techniques came from metallurgy, which needed to perfect the systems of energy gathering and movement transmission. We have to signal here that the combustible of choice during these times was wood, which, united with the powerful ship building industry, contributed to massive deforestation of ample zones.

The combustible of choice was wood, which contributed to massive deforestation.

However, this thermal energy could only be used as such, until around 1700, when Thomas Savery developed a machine that could turn it into mechanical energy. This first steam engine was dangerous to handle, because of it’s high working pressure. It was ameliorated by Thomas Newcomen, who worked to reduce the pressures and make it safer to use. These machines were first used to put the water out of coal mines, increasing the extraction of this product, and, little by little, getting it to replace wood as a combustible.

However, the decisive step in the use of this technology did not happen until James Watt, at the end of the 18th century, further modified it to make it really efficient. Watts’s invention was a real revolution in the history of humanity, as for the first time, humans were capable of producing work without using muscular force, just with coal as a combustible and demonstrating at the same time that it is possible to convert one form of energy, thermal, in this case into another, mechanical.

The Industrial Revolution: a consequence of the development of the steam engine.

As is well know, the steam engine gave rise to the Industrial Revolution in which, as we have said, coal is a very important protagonist. The demand for this product increased considerably, because of it’s importance as a combustible, but also of its low price, to which the new machines contribute.

The Industrial Revolution, as a consequence of this energetic revolution, produced radical economic and social changes. It gave rise to a profound transformation of transports, with the apparition of steam ships and the train, able to reach 60 km/h, then a vertiginous speed. All this brings distant places closer and will allow trade to expand, as goods are more easily transportable. We cannot forget the political repercussions that this new ease to travel will bring, like the exchange of ideas.

The wide diffusion of the steam engine will, at first, allow unsuspected levels of productivity to be reached, but its inconvenients appear sharply defined, as apart from its huge size, it needed large sheds to store the wood or coal to be used, and also the smoke that it produced not only dirtied ample zones of cities but also had a marked influence on the increase of respiratory diseases. These drawbacks changed the focus of investigation, using as a base the fact that one form of energy can be transformed into another. These investigation would give rise to an extraordinary result: the use of electrical energy.

Electricity

The word electricity comes from the greek word elektron, meaning amber in Greek, as it had been observed that, when rubbing this substance with a piece of canvas, it went into a special state and attracted small and light objects. However, this discovery wasn’t developed until the 16th century when a series of works were carried out, mostly theoretical, due to the difficulty of producing electricity.

The first important step was taken by the Italian Alejandro Volta, who built in 1794 an electric source that he named pila (a pile, in Italian) as it was constituted of a pile of copper, zinc and carbon disks, which, when immersed in a saline solution, produced quimical reactions from which electricity was produced. This is how electricity was obtained from chemical energy.

The batteries in use today are still based on the same principles as Volta’s primitive one, but neither that one nor the ones available now were a solution to the problem of obtention of electricity, as the small quantities of energy produced make them useful only for very small machines.

The massive electric energy production wasn’t going to be possible until, in 1821, the English physicist Michael Faraday, taking as a strarting point the work of the Dane Oersted, invented the electromagnetic generator.

Effectively, years before, Oersted discovered that all electric field gave rise to a magnetic field, for which, taking the problem in reverse, Faraday moved a magnet close to a metallic lead, verifying that an lectric current was produced, its magnitude depending, amongst other things, on the power of the magnet and the speed at which it moves.

From this, he deduced that if it was possible to rapidly rotate a magnet around metal threads, a current of usable intensity would be produced. Modern generators are based on the same principles as Farday’s primitive one, converting mechanical energy to electricity.

The development of electricity was spectacular from 1850, as this energy carrier substituted coal, being clean and not necessitating any storage. At the same time, Faraday developed the first electric motor, with which it was possible to convert electric energy to mechanical energy.

Joule discovered the possibility of transforming electric energy in thermal energy, and Edison and Swan found at almost the same time a practical application of this with the incandescent light bulb.

Edison himself developed the phonograph, converting electricity in acoustic energy, and this would be used by Alexander Graham Bell to invent the telephone. To close the cycle, Faraday discovered the phenomenon called electrolysis, thus obtaining the process opposed to that of Volta, which is to say, the conversion of electricity to chemical energy.