A little over 2,200 years ago, the Roman navy attacked the Greek port city of Syracuse. According to some ancient historians, the Greeks defended themselves with an ingenious weapon called a “burning mirror”: a polished copper surface curved to focus the Sun’s rays onto Roman ships, causing them to catch fire. However, we have several reasons to suspect that the story of the burning mirror is just a myth and the Greeks of Syracuse never really built such a device.
First, the ancient Greeks were not technologically advanced enough to make such a device. A mirror that would focus sunlight with sufficient intensity to set ships on fire would have to be several meters wide. Moreover, the mirror would have to have a very precise parabolic curvature (a curvature derived from a geometric shape known as the parabola). The technology for manufacturing a large sheet of copper with such specifications did not exist in the ancient world.
Second, the burning mirror would have taken a long time to set the ships on fire. In an experiment conducted to determine whether a burning mirror was feasible, a device concentrating the Sun’s rays on a wooden object 30 meters away took ten minutes to set the object on fire; and during that time, the object had to be unmoving. It is unlikely that Roman ships stayed perfectly still for that much time. Such a weapon would therefore have been very impractical and ineffective.
Third, a burning mirror does not seem like an improvement on a weapon that the Greeks already had: flaming arrows. Shooting at an enemy’s ships with flaming arrows was a common way of setting the ships on fire. The burning mirror and flaming arrows would have been effective at about the same distance. So the Greeks had no reason to build a weapon like a burning mirror.
The reading and the lecture are both about ancient Greek's use of "burning mirror" to defend themselves from a navy attack of Romans. The author of the reading feels that it was just a myth and Greeks of Syracuse never used them. The lecturer challenges the claim made by the author. She is of the opinion that this weapon was actually used.
To begin with, the author argues that the Greeks then were not technologically improved enough to build this type of weapon. The argument mentions that it would require a very precise parabolic curvature, which will need a large sheet of copper. This specific argument is challenged by the lecturer. She says dozens of small copper pieces could have been used to produce the same result. Additionally, she describes that, the mathematical knowledge of the Greeks were sound enough to produce a precise curvature of parabolla.
Secondly, the writer suggests that burning with this weapon would have taken a long time. In the article, it is stated that a wooden object takes 10 minutes to burn with the help of that weapon. The lecturer, however, refutes this by mentioning that there were other parts of the ship which were not wooden. She elaborates on this by bringing up the point that there was a substance called pitch that would fire up within seconds after the sunlight had been concentrated on it.
Finally, the author posits that Greeks were already using flaming arrows that were producing the same result. Moreover, in the article, it is stated that "burning mirror" would not have been considered as an improvement to arrows. In contrast, the lecturer's position is that this weapon would have been better in the sense that they have an element of surprise. She notes they are better as they are not as predictable as arrows.
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| 2020-01-17 | Shiimaaa | 80 | view |
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Grammar and spelling errors:
Line 1, column 240, Rule ID: ENGLISH_WORD_REPEAT_BEGINNING_RULE
Message: Three successive sentences begin with the same word. Reword the sentence or use a thesaurus to find a synonym.
...and Greeks of Syracuse never used them. The lecturer challenges the claim made by t...
^^^
Transition Words or Phrases used:
actually, finally, however, if, moreover, second, secondly, so, then, in contrast, to begin with
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 21.0 10.4613686534 201% => Less to be verbs wanted.
Auxiliary verbs: 8.0 5.04856512141 158% => OK
Conjunction : 2.0 7.30242825607 27% => More conjunction wanted.
Relative clauses : 18.0 12.0772626932 149% => OK
Pronoun: 38.0 22.412803532 170% => Less pronouns wanted
Preposition: 39.0 30.3222958057 129% => OK
Nominalization: 6.0 5.01324503311 120% => OK
Performance on vocabulary words:
No of characters: 1508.0 1373.03311258 110% => OK
No of words: 305.0 270.72406181 113% => OK
Chars per words: 4.94426229508 5.08290768461 97% => OK
Fourth root words length: 4.17902490978 4.04702891845 103% => OK
Word Length SD: 2.59696140635 2.5805825403 101% => OK
Unique words: 159.0 145.348785872 109% => OK
Unique words percentage: 0.52131147541 0.540411800872 96% => OK
syllable_count: 465.3 419.366225166 111% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 8.0 3.25607064018 246% => Less pronouns wanted as sentence beginning.
Article: 10.0 8.23620309051 121% => OK
Subordination: 0.0 1.25165562914 0% => More adverbial clause wanted.
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 5.0 2.5761589404 194% => OK
Performance on sentences:
How many sentences: 17.0 13.0662251656 130% => OK
Sentence length: 17.0 21.2450331126 80% => The Avg. Sentence Length is relatively short.
Sentence length SD: 32.7415167702 49.2860985944 66% => OK
Chars per sentence: 88.7058823529 110.228320801 80% => OK
Words per sentence: 17.9411764706 21.698381199 83% => OK
Discourse Markers: 5.64705882353 7.06452816374 80% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 1.0 4.19205298013 24% => OK
Sentences with positive sentiment : 5.0 4.33554083885 115% => OK
Sentences with negative sentiment : 7.0 4.45695364238 157% => OK
Sentences with neutral sentiment: 5.0 4.27373068433 117% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.191352163648 0.272083759551 70% => OK
Sentence topic coherence: 0.0617652127073 0.0996497079465 62% => OK
Sentence topic coherence SD: 0.0807197689466 0.0662205650399 122% => OK
Paragraph topic coherence: 0.123308030739 0.162205337803 76% => OK
Paragraph topic coherence SD: 0.0591037019204 0.0443174109184 133% => OK
Essay readability:
automated_readability_index: 10.8 13.3589403974 81% => Automated_readability_index is low.
flesch_reading_ease: 62.68 53.8541721854 116% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 8.7 11.0289183223 79% => OK
coleman_liau_index: 11.08 12.2367328918 91% => OK
dale_chall_readability_score: 8.36 8.42419426049 99% => OK
difficult_words: 75.0 63.6247240618 118% => OK
linsear_write_formula: 8.0 10.7273730684 75% => OK
gunning_fog: 8.8 10.498013245 84% => OK
text_standard: 9.0 11.2008830022 80% => OK
What are above readability scores?
---------------------
Rates: 78.3333333333 out of 100
Scores by essay e-grader: 23.5 Out of 30
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Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.