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What is dark matter?

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Introduction

John Smith  Physics Essay                                  

What is dark matter? By John Smith

The world of physics has many questions that need to be answered and analysed, so that we can unravel the mysteries of the world today.

Dark matter is one such topic that we need to investigate, with this essay I hope to give light upon the dark topic of dark matter.

Firstly, what is dark matter?

[1]Our galaxies are made up of clusters, such as stars. The clusters are held together by gravity. Scientists have tried to measure, how much is being squeezed by the gravity. The outcome from the tests is to identify, how much matter there is or the squeeze force.      

However our galaxies have clusters that are invisible, meaning we can’t see it. This invisible matter is classified as “dark matter”.

The term “dark matter” was forged by Fritz Zwicky who discovered evidence for missing mass in galaxies in the 1930s.

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Middle

The difference is that, what we know and see, or in this case can’t see, is different to what we know.                                                                                                  For example, you know I cannot breathe fire so if I was breathing fire, you would suspect that I have oil in my mouth that is causing me to breathe fire, therefore in terms of science, the unidentified name for this force is “dark matter”.

Who came up with the theory of dark matter?

[3] While examining the Coma galaxy cluster ([4]a large cluster of galaxies) in 1933, Fritz Zwicky was the first to use the virial theorem  to suppose the reality of dark matter. He was able to find the average mass of galaxies within the cluster, and obtained a value about 160 times greater than expected from their luminosity, and proposed that most of the matter was dark. The same

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Conclusion

So where does this leave us?

Through my essay we now know what dark matter is in our universe, who discovered it and how we measure it. When will we find out the exact amount, we don’t know but what we do know is that; as science progresses we will become closer to finding the answer to the key question that shrouds us to this day.

References

The paragraphs I have wrote have been taken from the sources below and edited by me for use in my essay.  

[1] http://imagine.gsfc.nasa.gov/docs/science/know_l1/dark_matter.html date 18th February 2011      

[2] http://spaceplace.nasa.gov/en/kids/phonedrmarc/2003_october.shtml date 18th February 2011      

[3] http://en.wikipedia.org/wiki/Fritz_Zwicky date 10th February 2011

[4] http://en.wikipedia.org/wiki/Coma_galaxy_cluster date 10th February 2011

[5] http://en.wikipedia.org/wiki/Virial_theorem  date 10th February 2011

John Smith Physics Essay                                  

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Response to the question

The candidate gives a thorough response, they explain what dark matter is and go on to discuss how the underlying theory was first developed. Furthermore, though only brief the candidates introduction is actually quite good, they clearly state what they ...

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Response to the question

The candidate gives a thorough response, they explain what dark matter is and go on to discuss how the underlying theory was first developed. Furthermore, though only brief the candidates introduction is actually quite good, they clearly state what they will go on to discuss and they have attempted to engage the reader by stating an interesting fact and injecting a little humour. There is nothing wrong with trying to catch the attention of the reader using humour, as long as the rest of your essay is written in a more formal manor.

Level of analysis

The candidate has taken the time to research this subject, this is clear, as they have provided names and dates relating to the theory of dark matter. Taking the time to research your subject demonstrates your ability to study independently which is an important skill for further education. In addition to this it shows the reader that you are interested in your subject and the extra information you are able to include in your work can make your essay more enjoyable to read. The candidate has also taken the time to write up a bibliography which is important, by declaring the resources you have used you can avoid being accused of plagiarism and you allow the reader to see the steps you have taken to prepare your essay.

Quality of writing

This essay is quite well written, the candidate has used a good range of vocabulary and they have used scientific terms accurately, which demonstrates a good understating of the topic they have discussed. However there are occasions where the essay doesn’t flow as well as it could, it can be difficult to get all the information you want into an essay without it feeling jumpy. I would advise that you take the time to write out a plan and think carefully about the information you want to include. You should also read over your work as you write it, this will allow you to see if the information fits together. That said, there are no errors which spelling, punctuation or grammar.


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