Antimatter:  Fiction to Reality?

Lugo Nieves, Yolianie

Antimatter is a term that I had listened occasionally. First time that I put attention to it, as many other people, was in the book Angels & Demons (science-fiction) of the author Dan Brown.  In a part of the book it explains the antimatter like something which is created from nothing. Knowing that the book is science fiction, how is even possible that a book with so many scientific terms makes an affirmation like that?   Then many questions without answer came to my mind.  Every person that who has had some contact with the physics knows a very important law, the law of conservation of energy.  It states that the total amount of energy remains constant. A consequence of this law is that energy cannot be created nor destroyed, it can only be transformed.  Then what really is the antimatter?  Is real the antimatter?  How it is created? 

It is not possible to talk about the antimatter, without honoring a name, Paul Dirac.  Paul Adrien Maurice Dirac was an english physicist who made fundamental contributions to many areas of physics (quantum mechanics and quantum electrodynamics).  Paul Dirac received the Nobel Prize in Physics in 1933 because of the discovery of new forms and perspectives of atomic theory.  He also formulated the Dirac equation, and in this equation is the prediction of the real existence of antimatter.  It is important to know that all the matter is formed by atoms. As well, in the atoms the nucleus is formed by protons and neutrons, and electrons that were located around it. Antimatter is composed of antiparticles in the same way that matter is composed of particles. A positron is the antiparticle of the electron.  Electron has a negative charge (e-) and the positron because is the antiparticle has a positive charge (e+). An antiproton is known a “negative proton”.  Differences exist between the proton and antiproton and one of them is the electrical charge.  Also the difference consist that the protons and neutrons are in the atomic nucleus, but the antiprotons are not in the atomic nucleus.   Antiproton can form an antihydrogen atom in the same way that an electron and a proton form a hydrogen atom.  Theory tells us that when antimatter and matter are in direct contact can lead to the annihilation of both.

The antimatter can answer the questions of the Big Bang Theory. It is the most scientific theory of our universe's origin that has been made since the early 1920’s.  It's a central mystery in physics.  In recent studies (published in November 18, 2010) for the first time, scientists have trapped antimatter atoms.   The unprecedented trapping of antimatter atoms for study is a big step for science.  To trap antimatter atoms, scientists had to create antiprotons, antielectrons, and positrons.  Then atoms of antihydrogen are formed.  To make the antiprotons, the scientists took protons normally used, smashed them into metal targets, and captured the products. The positrons were captured from a radioactive sodium source.  To get the antiprotons and positrons to bond, the scientists used an oscillating electric field, balancing the antiprotons into the same energy level as the positrons.  Later the scientist will have to get that the antimatter particles still together.  The problem is at this point because the antimatter particles created are too hot and very energetic to be trapped.  The scientists used electric and magnetic fields to cold and slow down the antimatter.  Because of it, the millions of antihydrogen atoms that the scientifics created, only about 38 were cold and slow down enough to be held in a kind of "magnetic bowl”.  It is necessary the “magnetic bowl” to isolate the antimatter particles to prevent the direct contact with normal matter particles.  This realized experiment proved that antimatter atoms could be trapped, but with no emphasis of how long time were trapped.  But is really an advance to prove that antimatter is turning to real.  In future experiments the time will be a real factor of importance.  If more antihydrogen atoms can be produced and trapped for longer periods, scientists might finally be able to study them in enough detail to explain many things about the universe.  The antimatter is in real studies constantly, and more things to discover are going to come.

A detail of the trap used to combine positrons and antiprotons to create antimatter atoms.  Photograph courtesy Niels Madsen, ALPHA/Swansea/CERN