chase the dream not the competition

Over 1000+ articles, updated everyday...for Free SMS Alerts click here , Engineering Q&A forum here

Invite Friends
Search:     Advanced Search
Browse by category:

Possible Existence of Anti-Matter in Bulk

Vist the new KnowledgeBin forum to ask all your questions! SMS Registration

Click Here to Register Online

Creative Commons License is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 2.5 India License.

For every particle (matter) there is a corresponding antiparticle (antimatter). Antiparticles are the same as the corresponding matter particle in every respect except for their opposite charges. A proton is electrically positive: an anti-proton is electrically negative. They both have the exact same mass, so they are affected in the same way by gravity.
When a particle and its antiparticle meet, they annihilate into pure energy. This energy may then give rise to neutral force-carrier particles, such as photons, Z bosons, or gluons.
The symbol for an antimatter particle is a bar over the corresponding matter particle symbol. For example, a proton () has an antiparticle denoted by , pronounced p-bar. The antiparticle of a proton is called an antiproton. An electron's (e-) antiparticle is a positron (e+).
The existence of antimatter was first proved in 1932 by Carl Anderson. Anderson utilized the property of magnetic fields that moving positive and negative particles bend in opposite different directions. He showed that there was a particle with the mass of an electron that moved in the opposite direction from the electrons in an magnetic field, meaning that the particle was of positive charge, the antimatter equivalent of electrons, the positron. The discovery of the antiproton took longer than the discovery of the positron because mass of a proton is two thousand times greater than that of an electron. Therefore, much more energy is necessary to make an antiproton bend like a positron. The existence of antimatter can be proven using electromagnets in the above described manner, or by using accelerators to produce antimatter and letting the antimatter and matter collided together, annihilate, and release their rest mass energy energy. It is now believed that every fundamental particle has a corresponding antiparticle.
Understanding antimatter requires understanding three main ideas. The first idea is the theory of relativity, with E = mc2. Relativity tells us that no particle can travel faster than light, and that everything is time relative - event viewed from one frame of reference and from another frame moving with respect to it do not observe to physically separated events to occur in the same relative time. The second important idea lies in quantum mechanics. Both the uncertainty principles and wave properties must be understood to completely grasp antimatter. And the last idea is causality, meaning the cause comes before and effect. While these three ideas may not seem integral to antimatter, knowing them is essential to understanding antimatter and how it works. Antimatter is a complete symmetric mirror of regular matter. They both have the same chemical and physical properties. For example, antimatter ice would have the exact same melting temperature as regular ice. One difference, though, is that antiparticles are equivalent to ordinary matter particles moving backwards through time. This is where the three ideas come in. While a particle should not be able to affect things that light which started at the same place and time cannot affect, there is always a chance that it could, because of the uncertainty principle. However, when and if this ever happens, some interactions with an antiparticle will push it back into the correct space.
Science fiction often makes use of antimatter, such as a method of energy storage. The truth is, matter and antimatter collisions are perfectly efficient, meaning all the mass would be converted into pure energy. In this case, antimatter would be the ideal way of transporting energy. When an particle and an antiparticle meet (for example, an electron and a positron), they annihilate, leaving two photons. The matter and antimatter would be annihilated in equal amounts in this case, and to give some idea of how powerful this is, 60 kilograms of mass converted into pure energy would be the equivalent of thousands of thermonuclear warheads.
As temperature increases for matter, the matter can be seen as becoming less complicated, but more symmetric. For example, ice has complicated crystal structures, but not much symmetry as compared to water, which is at a higher temperature. In turn, water vapor is simpler and more symmetric than water in liquid phase. This idea continues as the temperature goes up, eventually with the matter breaking from individual molecules into individual atoms, then nuclei break into free electrons and nuclei, protons and electrons, mesons, and finally quarks and antiquarks. At this extremely high temperature (which is representative of the temperature of the big bang), everything would be simple and have perfect symmetry. Every quark in this matter would have a symmetric antiquark to balance it. It is believed that at the beginning of the universe, all matter was at this highest state, made up of equal numbers of quarks and antiquarks. The next question is, how did the matter and antimatter separate or get out of perfect balance and collect into regions dominated by matter as the universe expanded and cooled down?
Upon simple observation of the universe it becomes apparent that the majority of the observable universe (if not all of it) is made of regular matter. Although there have been many searches, there appears to be no substantial amount of antimatter in the universe. So what would happen to the symmetric amounts of matter and antimatter created during the big bang? It becomes apparent now that there must have been a slight asymmetry in the amounts of matter and antimatter. This asymmetry may have been as small as one part in a billion. So, in the early universe, there may have been what some physicists call "a matter-antimatter war", a billion particles would annihilate with a billion anti-particles leaving one particle.
So, the search for anti-matter continues. Experiments have been launched in both high-altitude balloons and the Space Shuttle to try to determine whether cosmic rays bombarding the Earth originate from matter or antimatter. So far the results have been negative. One interesting source of anti-matter occurs in vacuum energy. While classical physics tends to believe that interstellar space is a true vacuum, with no matter present. Yet, quantum mechanics allows for the possibility that "virtual" particle-antipartice pairs can be created out of the vacuum. This particle-antiparticle pair can exist for a period of time limited by the Heisenberg uncertainty principle. Shortly after creation of this pair, they rejoin and annihilate each other. This still does not provide an explanation for existence for large amounts of antimatter.

Here's an interesting question about antimatter that puzzles physicists:

If matter and antimatter are exactly equal but opposite, then why is there so much more matter in the universe than antimatter? Why did matter "win" instead of antimatter?
Any answers to that question???

SMS Alerts

SocialTwist Tell-a-Friend

Admission Updates

KnowledgeBin Forum Invite Friends

KnowledgeBin Forum Discuss In Forum

Views: 1560
Votes: 0

Others In This Category
document What is HOTS introduced by CBSE?
document Frequently Asked Questions About IIT-JEE Preperation
document A Dummies Guide To Crack IITJEE - 1
document A Dummies Guide To Crack IITJEE - 2
document A Dummies Guide To Crack IITJEE - 3
document A Dummies Guide To Crack IITJEE - 4
document Changes in IITJEE - Reasons & Impact
document New IITs and IIMs Locations announced
document Why the the change in pattern of IIT-JEE?
document President Kalam speak to IIT
document Which books to study
document Physics of Time Travel by Michio kaku
document List Of Some Major Engineering Institutions To Aim For.
document AIPMT 2008 - Answer Key, Solved Papers & Analysis:courtesy Akash Institute
document IITJEE 2008 SOLUTIONS For Paper 1 & 2 for Various Codes
document NCERT Online Text Books Download Links
document CBSE Class 10th Result Announced on 29th May2008
document AIEEE: Recommended Books
document Why Students Are Not Preferring IT Courses?
document IIT Director questions the IIT- JEE pattern
document Every Thing You Wanted To Know: Delhi College of Engineering (DCE) and NSIT
document Solutions: CBSE - 2008, IIT-JEE-2008, AIEEE-2008, CBSE Mains-2008, DPMT 2008, DCE 2006
document FAQs On IIT-JEE - Questions You Generally ASK!!
document Karnataka CET - Admission, Time Table, Breakup, Fee Structure
document Every IITian has created 100 jobs : A survey
document How to prepare for IIT JEE 2009 when you have only 4 months in your hand!
document IIT JEE 2009 Solutions by Brilliant-Tutorials, FIITJEE, Narayana, Resonance, Prerna, Vidyamandir, Bansal, Career Launcher, Time and Career Point
document The Concepts of Chemical Equilibrium for IIT-JEE
document JEE Book recommended by Bansal Classes
document Increased Seats in IIT-JEE and AIEEE 2009
document CBSE Class 10th and 12th 2010 Exams from March 3, 2010
About Us | Contact Us | Feedback | Copyright © 2008™ All rights reserved