A gigantic instrument to unravel the mysteries of the smallest.
In June of this year, after many delays, the largest and most powerful particle accelerator in the world, the Large Hadron Collider (or LHC), will begin operating. Large Hadron Collider), at a cost that could reach 10 billion dollars. It is the most expensive experimental device in history; With it we hope to find the path that physics must follow to understand the Universe more intimately. This project was conceived in the 70s and was approved in 1994; This is an international adventure in which several research centers in Mexico participate.
An accelerator, as its name suggests, accelerates charged particles using electric and magnetic fields. The particles then collide with each other and from these collisions new particles emerge.
New computer network
Physics seeks to understand the Universe by deducing general laws, the more general the better. For example, many physicists are dedicated to searching for the basic ingredients of everything that exists. In that search they have come across patterns in the behavior of things—phenomena that are repeated and that can be used to describe nature and make predictions. Those patterns are the laws. Physicists have always sought to reduce to a minimum the set of physical laws they need to understand the Universe, in other words, to achieve a unified vision of nature.
The first philosophers of classical Greece already asked themselves what is the primordial matter from which everything else can be formed. Behind the apparent diversity of manifestations, they thought, a fundamental unity must be hidden. Since then, and especially in the last four centuries, physicists have struggled for this unity. Each new synthesis has expanded our understanding of the constitution and functioning of the Universe a little more. Towards the end of the 17th century, Isaac Newton proposed that the fall of objects on Earth, the tides, and the orbits of the planets were different aspects of a single phenomenon: the force of universal gravitation. Almost 200 years later, James Clerk Maxwell synthesized the phenomena of electricity and magnetism into a single theory. In 1967, physicists Sheldon Glashow, Steven Weinberg and Abdus Salam proposed, each on their own, a precise theory that unites Maxwell’s electromagnetism with the so-called weak force, a type of interaction between the components of the atomic nucleus. The work of Glashow, Weinberg and Salam, known as electroweak theory, promoted, in the 1970s, the development of the Standard Model, the most general theory of physics, which describes the fundamental particles of which everything in nature is composed and three of the four “forces” through which they interact those particles. In the Standard Model the forces between objects operate by exchanging some type of particles between them.
The electroweak theory is very well founded. In 1983, the particles mediating the weak force, called W and Z bosons, predicted by the theory, were detected. However, the values of their masses—and the very existence of mass in general—remain an enigma. Why do the masses of fundamental particles have these precise values? And beyond that: where does the dough come from? In the Standard Model, the existence of a special particle is proposed that, when interacting with the others, would give them mass. This particle is known as Higgs’ Boson and has never been observed.
Big hopes
The LHC is being built several tens of meters deep, on the border between France and Switzerland, near Geneva. This particle accelerator consists of a circular tunnel 27 kilometers in circumference, with sections that are at different depths (between 50 and 175 meters). Two tubes run through the tunnel, inside which two beams of particles will circulate in opposite directions. The particles, which increase in speed with each revolution, are kept in circular trajectories by enormous superconducting magnets. When the desired energy is reached, the beams are deflected and collided with each other at specific points in the accelerator, where the detectors are located. When colliding with very high energies, you are part of the LHC’s 27 km circular tunnel (blue) is located on the border between Switzerland and France; The main detectors are located in underground caverns connected to the surface. cells are destroyed and produce secondary particles. Physicists collect collision data using different special detectors and compare them with the predictions of the hypotheses or theories they wish to evaluate.
The superconducting magnets that keep the particles on their course operate at a temperature of four kelvin, that is, about 270ºC below zero. At that temperature, its components can conduct electricity without losing energy in the form of heat (without resistance). However, when the particle beams collide, temperatures of billions of degrees will be produced, such as those that must have existed in the first fractions of a second after the origin of the Universe, about 13.7 billion years ago, when matter possibly existed in a a kind of soup of elemental particles in freedom.
The LHC is the most ambitious project carried out so far by CERN, the French acronym for the European Nuclear Research Organization, formerly the European Council for Nuclear Research. CERN was founded in 1952 and has become the world center for particle physics. Scientists from the organization’s 20 member states work there, as well as many other invited countries. The Standard Model, work under construction It is expected that with the experiments that will be carried out at the LHC, several problems of the so-called Standard Model can be solved: the most general theory of physics, which describes all the matter and forces in the Universe (except the force of gravity), and explains many of our questions about their structure and interrelationship. According to this theory, which was developed during the 70s and 80s, the raw material of everything that exists is made of six types of particles called quarks and six of others known as leptons (the electron is the best known of these)… or maybe not? Better let’s go in parts. A simple way to approach the description of the Standard Model is to divide it into three sections: particles of matter, particles mediating forces and the famous Higgs boson, which bears that name because it was predicted in 1964 by the British physicist Peter Higgs.
Atoms are made up of protons, neutrons and electrons. Protons and neutrons, in turn, are composed of more elementary particles, quarks. Quarks and leptons are “point” particles, that is, dimensionless, like points. Unlike leptons, which can exist individually, quarks are only found forming composite particles, which are known as hadrons (protons and neutrons are two types of hadrons).
Particles have four basic ways of interacting (affecting each other), called interactions or fundamental forces: gravity and the electromagnetic force, which operate at long distances and which we perceive in the macroscopic world in which we live; and two forces that only act on the scale of the atomic nucleus: the weak nuclear force and the strong nuclear force. The Standard Model describes only the last three; gravity has not been able to be incorporated into the unified description of particles and interactions. Forces in the Standard Model are communicated through carrier particles, as if interacting particles were throwing billiard balls at each other to get deflected. The carrier particles are the photon for electromagnetism, the W and Z bosons for the weak interaction, and the gluons for the strong interaction. If gravity is incorporated into the model, it would be mediated by particles called gravitons, which have not yet been detected in nature.
But there are still many loose pieces in the Standard Model puzzle. One of them, central to deepening our knowledge of the nature of things, is the mystery of mass. Calling it a mystery may seem absurd, since in daily life everything has mass. The origin of the problem is that, according to the Standard Model, all truly fundamental particles should be massless. However, with exceptions such as the photon, all particles have it, a fact that the theory should be able to explain.
Today, the most favored hypothesis to explain it is known as Higgs mechanism. This has to do with what scientists call the Higgs field, a field (like the gravitational field, say) that is present throughout space. By interacting with the Higgs field, fundamental particles gain mass. We can imagine it as an immense bowl of cream in which a fruit is bathed. The fruit would be the particle and the cream would be the mass it acquires when interacting with the Higgs field. Or like a celebrity trying to navigate a crowd of admirers; In that case, the fans are like the Higgs field and the artist is like the particle, struggling to move while his admirers ask for autographs. Like every field, the Higgs field must have a mediating particle: the Higgs boson. Finding it would be essential to discover if such a field really exists and thus clarify the enigma of mass. To achieve this, physicists have put their trust in the Large Hadron Collider.
New computer network
In order to manage and examine the millions of data that the Large Hadron Collider will produce, the “Grid” was created, a computing network distributed throughout the world, whose capacity allows data to be sent and analyzed with much greater efficiency.
Unlike previous generation experiments, whose data had to be stored and transported on tapes for later analysis, computing nodes have been developed across the planet and a software that makes communication compatible. In contrast to the Web, also developed at CERN, which contains a large amount of information, the Grid rather represents an enormous computing capacity, since it will use the resources of thousands of computers in many countries, whose data will be available to all researchers.
In fact, the first Latin American node of the Grid is already operating at the Institute of Nuclear Sciences, named Tochtli (rabbit, in Nahuatl). Formed by a cluster of personal computers, it is linked to the network, from where it is integrated into the world through Internet 2.
The concept has important consequences in other fields. In Europe, the Grid was the inspiration for the Mamogrid network, which handles an enormous amount of data and digitizes information about…