Annihilation Theory

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The Mystery of Matter and Antimatter

Written by Mandy Barbour

Year 11 Physics

The current unbalanced state of the universe contradicts what our laws of physics have suggested. At the dawn of the universe an imbalance between the originally equal amounts of matter and antimatter occurred, and in 1967 Russian physicist Andrei Sakharov created three conditions that would allow this imbalance to happen. These conditions have been a topic of much debate between physicists and have not been proven to be totally factual to this day. Despite this, they have acted as important guidelines for others involved in this field, proving their relevance. Progress towards understanding the initial state of the universe is increasing and technology is evolving to aid our education. The root to all scientific cosmology is the Big Bang Theory.

It is believed that the "big bang" left equal amounts of matter and antimatter. Matter and antimatter is a collective term given to two identical particles that are of opposite charge. Therefore they are the same with the exception of charge. There opposite charges adhere to the Laws of Attraction, which state that two particles of opposing charge are attracted to each other. On their collision they, theoretically, annihilate each other resulting in a gamma ray (pure radiation). This can be shown by;

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e+ + e- → γ

(A positron plus and electron results in a gamma ray)

Equations like these show the fundamental properties of all interactions. Here, the resultant is a gamma ray, which indicates that (considering that gamma particles travel at the speed of light) we should supposedly be living in a universe filled with light. There should be no preference for matter yet the omnipresent solid mass that surrounds us obviously denotes something missing in the above equation. Sakharov's conditions describe what would have to happen in order for this imbalance to occur.

Sakharov himself was a prominent Soviet Nuclear ...

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The candidate uses technical terms accurately through the essay and their work is fairly coherent which demonstrates an understanding of the concepts they have discussed. In addition to this there are no real issues with either spelling or grammar.

I feel that the candidate's response to the set topic and their analysis is a little weak, the topic is annihilation theory, so a good start would be to discuss this, what it means and how the theory was discovered. Furthermore the candidate’s entire essay seems to focus on the ideas of Andrei Sakharov and his theories for creating antimatter. A good quality essay should cover several key points and theories relating to your set topic, you can also show a good understanding of physics by bringing together several different topics, this demonstrates a good subject knowledge and a general enthusiasm for physics. Though the information relating to this particular scientist’s ideas, is a nice addition and is interesting to read, it would of been more suitable to discuss this briefly and move on to another idea. That said, I would also recommend writing a short bibliography if you undergo any independent research, you should state any sources you use and if you use information from an online source you should also provide a link to that webpage.

The candidate’s introduction starts well, it is interesting and they have attempted to engage the reader by stating that the imbalance between matter and antimatter is unusual and goes against predictions made using the laws of physics. By using your introduction to catch the attention of the reader, you make them interested in what you have to say, making it more likely that they will read all of your essay rather than just skim through it. However an introduction should state what you plan to discuss so that premise of your essay is clear and the candidate fails to do this.