LARGE HADRON COLLIDER

Today has begun the experiment called Large Hadron Collider (LHC). This experiment is located in CERN (European Organization for Nuclear Research) and is considered the scientific experiment of this century. It has costed 3000 millions euros and, in order to build it, more than 10000 scientists have taken part. This experiment has been built in a circular tunnel 27km long in the border between France and Switzerland depths, at between 50 and 120 meters under the floor.

LHC architecture and its experiments

The LHC is really an enormous particle accelerator which constitutes the most powerful machine ever built by physicians. This accelerator will make possible collisions of high energy protons at almost the speed of light. The main goal of this high energy collisions is to discover the hypothetical Higgs boson, which is predicted by the Standard Model of elemental particles.

These are the four main experiments in the LHC:

- CMS (the Compact Muon Solenoid) - and Atlas are the LHC's general purpose detectors to investigate a wide range of physics, including the search for the elusive Higgs boson, extra dimensions, and particles that could make up dark matter, which gives other particles their mass. Atlas will be responsible for the search of dark matter.

CMS detector for LHC

- The LHC Beauty (LHCb) detector is designed to answer a specific question: where did all the anti-matter go? Equal amounts of matter and its opposite counterpart anti-matter were created in the Big Bang. But today we find no evidence of, for example, anti-matter galaxies or stars. The LHCb experiment will help us to understand why we live in a Universe that appears to be composed almost entirely of matter, but no antimatter.

- ALICE While the other LHC detectors will use proton beams to do their science, Alice relies on smashing together electrically charged lead atoms. Scientists hope to re-create a state of matter called quark-gluon plasma which existed just after the Big Bang.Matter was in this "liquid" state because the early Universe was still extremely hot.The Alice detector will be used to study this quark-gluon plasma as it expands and cools. In doing so, they will observe how it progressively gives rise to the particles that make up the matter in our Universe today.

Concerning the LHC there are some scientists who are afraid the LHC could cause the end of the world. Experts deny that dangerous black holes could be generated in the LHC. The LHC, like other particle accelerators, recreates the natural phenomena of cosmic rays under controlled laboratory conditions. As this natural phenomena has been happening for millions of years and the Earth still exists, there is no reason, as I see it, to be worried about it.

To know more:

http://news.bbc.co.uk/2/hi/science/nature/7534847.stm

http://public.web.cern.ch/public/en/LHC/LHC-en.html

http://public.web.cern.ch/public/en/LHC/Safety-en.html

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Sustainable development

Nowadays we live better thanks to technology. Technology is used in our lifes in several ways. For instance, communications technology, such as mobile telephones, Internet or computer networks, has made it possible that we are able to communicate with each other easily. Internet lets us get a lot of information without difficulty instead of having to go to libraries for instance. Internet provides us also with an e-mail service that let us send messages all around the world without the postacard's delay.

Computers and Computer's Networks, such as Internet, have improved our lifes

Besides, we have several household appliances at home. Nowadays nobody can imagine our life without a fridge or without a washing machine. The fridge frees us from going shopping everyday and washing machines let us save a lot of time. Of course, transport technology has to be considered as well. Since cars were invented, they have improved a lot, and now they are faster and more secure than before. Thus we can move from one place to another easily. Besides, we can't forget trains and planes, more and more fast and secure. Trains and planes let us travel long distances in a comfortable way.

Airbus A-380, the biggest aircraft ever built. This kind of plane let us travel long distances fast and in a comfortable way
(This file is licensed under Creative Commons Attribution 2.0 License)

Therefore, technology has made our life easier and more comfortable. However, there is an important drawback: the power consumption. Cars, computers consume power, which they transform into heat. This heat makes the Earth's temperature increase. This increase of temperature can be a serious threat for the environment. Moreover, energy have to be obtained in such a way that cars, trains and electronic devices can use it. Therefore, nuclear power stations and power stations have had to be built. Nevertheless, nuclear power stations and power stations pollute the environment.

Nuclear power stations pollute the environment because of radiactive waste

In summary, we can state that technology has made our lives easier. Nonetheless technology has an important drawback: the environment's pollution. Therefore, so as to preserve our planet, mankind has to find a balance between comfort and environment's preservation. A more responsible consume of energy and the development of renewable energies, specially nuclear fusion, could help us to get this balance.

The sun is a natural fusion reactor. If we could reproduce this fusion process of the sun, we would have available an incredibly big amount of energy
(image obteined from www.nasa.gov)

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Philosophy of Science

Philosophy of science is a philosophy's branch developed mainly by Karl Popper. Nowadays Popper is considered one of the most important philosophers of the last century, specially in science. The theory he developed is called Falsacionism. Before speaking about this theory, however, it's necessary to define what science is.

A theory is considered a scientific one if it provides conclusions that can be checked and refuted by experiments. Otherwise this theory doesn't belong to science, but to philosophy.

A scientific law is established according to experience. Researchers obtain a lot of information from many experiments and then they extract a law. Later, they have to check this law with the experience. Therefore a scientific law is continuously to experiments. If a scientific theory explains an experiment correctly, we will be more confident about its truth, but we will never be absolutely confident about it. We will never know whether the next experiment will contradict our theory.

Newton's gravity theory, which explained the motion of planets, has been considered absolutely true for centuries, but Theory of Relativity showed that Newton's Theory was not absolutely true. It's only an aproximation, valid only when gravity is weak and velocity much slower than velocity of light

Even though the quantity of data from which a law is extracted is huge, we will never be able to infer a general statement in a logical way. For instance, if we observe that after A, B always occurs, it can't be infered that this fact has to occur always in this way. We think A is followed by B due to a belief instead of a logical connection between A and B. If a physical law explains the experiments rigorously, it doesn't mean that this physical law will also explain the experiments in the future. Therefore, we can only assure that a theory can be false, but we can never state that a theory is right. The theory that proposes this conclusion is called Falsacionism.

Aerial photo of the Tevatron at Fermilab. The main accelerator is the ring above; the one below is for preliminary acceleration, beam cooling and storage. Experiments in particle accelerators are always exactly explained by the Standard Model of particle physics. However nobody knows whether the next experiment will keep confirming the standard model

Consequently science can be proved neither by experience nor by logic. Hence, science isn't true, but more or less probable. The likelihood of a law depends on the number of experiments that support this law. Science is a process of search for better theories without end and the knowledge it provides is always provisional. We can't state that we know something with certainty, since its falseness is always possible. Hence, we have to understand the notion of truth as an approximation to the truth because we will never be able to know if we have reached the truth.

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True Knowledge

Nowadays, we are pretty sure that all the facts of our daily life will happen as they occurred in the past, but this certainty is actually groundless. Statements such as objects always fall are not absolutely true.

Water of Montjuic magical fountain in Barcelona falls because of gravity

Firstly, it's stated that objects fall because of gravity, so gravity is the cause and the object's fall is the effect. This mechanism is called the cause-effect relation and constitutes almost the only source of knowledge we have. However the effect and the cause are not linked in a logical way, but in a psychological way. That is to say, we think that the effect will always happen after the cause since we are used to this has been occurring for our whole life. As a result, our knowledge is a consequence of the strong belief we feel that events will occur in the future as they did in the past, because we are used to seeing them in this way. Thus, we only have a belief instead of certain knowledge.

Nevertheless there is a kind of knowledge that is not obtained from the cause-effect relationship. This knowledge is the mathematical one, whose certainty comes from the idea that its negation involves contradiction. But this certainty disappears when mathematics is applied to the physical world. Hence, scientific knowledge can't be considered true knowledge. For instance, it can't be stated that a physical law is correct because nobody can assure us that the next event could be explained by this law.

Similary to scientific knowledge, nobody can assure that what our eyes see is what really exists. The coincidence between we think exists and what actually exists is pure chance. Even the existence of oneself can't be really assured. That is to say, the consciousness of what we have been is a consequence of our memory and the existence of a psychological time that allows us to put our memories in order. As I see it, this psychological time leads us to believe in our existence through time since a real time doesn't exist at all.

As it's explained in the movie Matrix, nobody can assure that what our eyes see is what really exists (Image obtained from wikipedia)

In conclusion, all the knowledge we have can't be considered true, but only likely, except for mathematical knowledge. So the limit of knowledge is mathematics. Out of mathematics, nothing is absolutely sure, nothing is true knowledge. Consequently, there is absolute scepticism about we can know with certainty but, certainly, this scepticism is luckily only philosophical, since it's very unlikely that daily events occur in a different way as we think. Therefore our belief is enough to live.

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