A little over 2200 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 arrow. 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 Greek had no reason to build a weapon like a burning mirror
The reading passage and lecture have a conflicting opinion about whether or not Greek used a burning mirror to ignite the fire on the Roman ships. The article strongly postulates that story of the burning mirror is a fiction due to several compelling reasons. On the other hand, the listening adamantly delinates that the mentioned reasons are impractical and not convincing to say that the weapon burning mirror didn't exist before 2,200 years ago.
First and foremost, according to the author of the excerpt, the Greeks weren't sophisticated enough to build an enormous mirror, which effectively intensifies the sunlight in order to set the Roman ships on fire. Nonetheless, the lecture offsets these points by declaring that the Greeks used a huge number of small mirrors from practical shape to build a burning mirror.
The professor in lecture further points out that it takes a long time is to set the wood on the fire, but the Roman ships were made from different materials one of them called a pitch, which is used to make the ship waterproof. Also, this material could be burned with concentrating sunlight on it in seconds. These claims refute the writer implication of how the burning mirror was used to set the ships on fire in a short time.
The article lastly asserts that the Greek didn't need the burning mirror to set the Roman ships on fire although they had flaming arrows which were known in that time. The speaker in lecture counters these points by insisting that Romans was ready to prevent flaming arrow from set their ships on fire. However, the burning laser was invisible thereby an effective way to surprise the Romans.
| Post date | Users | Rates | Link to Content |
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| 2020-01-17 | Shiimaaa | 80 | view |
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Grammar and spelling errors:
Line 1, column 66, Rule ID: WHETHER[7]
Message: Perhaps you can shorten this phrase to just 'whether'. It is correct though if you mean 'regardless of whether'.
Suggestion: whether
...ecture have a conflicting opinion about whether or not Greek used a burning mirror to ignite t...
^^^^^^^^^^^^^^
Line 1, column 376, Rule ID: ALLOW_TO[1]
Message: Did you mean 'saying'? Or maybe you should add a pronoun? In active voice, 'convince' + 'to' takes an object, usually a pronoun.
Suggestion: saying
...sons are impractical and not convincing to say that the weapon burning mirror didnt ex...
^^^^^^
Line 1, column 414, Rule ID: EN_CONTRACTION_SPELLING
Message: Possible spelling mistake found
Suggestion: didn't
...g to say that the weapon burning mirror didnt exist before 2,200 years ago. First ...
^^^^^
Line 3, column 72, Rule ID: EN_CONTRACTION_SPELLING
Message: Possible spelling mistake found
Suggestion: weren't
...o the author of the excerpt, the Greeks werent sophisticated enough to build an enormo...
^^^^^^
Line 7, column 43, Rule ID: EN_CONTRACTION_SPELLING
Message: Possible spelling mistake found
Suggestion: didn't
...e article lastly asserts that the Greek didnt need the burning mirror to set the Roma...
^^^^^
Line 7, column 393, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...n effective way to surprise the Romans.
^^^^
Transition Words or Phrases used:
also, but, first, however, if, lastly, nonetheless, second, so, on the other hand
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 10.0 10.4613686534 96% => OK
Auxiliary verbs: 2.0 5.04856512141 40% => OK
Conjunction : 5.0 7.30242825607 68% => OK
Relative clauses : 11.0 12.0772626932 91% => OK
Pronoun: 17.0 22.412803532 76% => OK
Preposition: 41.0 30.3222958057 135% => OK
Nominalization: 2.0 5.01324503311 40% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1373.0 1373.03311258 100% => OK
No of words: 281.0 270.72406181 104% => OK
Chars per words: 4.88612099644 5.08290768461 96% => OK
Fourth root words length: 4.09427095027 4.04702891845 101% => OK
Word Length SD: 2.46622041446 2.5805825403 96% => OK
Unique words: 152.0 145.348785872 105% => OK
Unique words percentage: 0.540925266904 0.540411800872 100% => OK
syllable_count: 419.4 419.366225166 100% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 2.0 3.25607064018 61% => OK
Article: 9.0 8.23620309051 109% => OK
Subordination: 0.0 1.25165562914 0% => More adverbial clause wanted.
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 2.0 2.5761589404 78% => OK
Performance on sentences:
How many sentences: 11.0 13.0662251656 84% => Need more sentences. Double check the format of sentences, make sure there is a space between two sentences, or have enough periods. And also check the lengths of sentences, maybe they are too long.
Sentence length: 25.0 21.2450331126 118% => OK
Sentence length SD: 45.2670679194 49.2860985944 92% => OK
Chars per sentence: 124.818181818 110.228320801 113% => OK
Words per sentence: 25.5454545455 21.698381199 118% => OK
Discourse Markers: 7.36363636364 7.06452816374 104% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 6.0 4.19205298013 143% => OK
Sentences with positive sentiment : 4.0 4.33554083885 92% => OK
Sentences with negative sentiment : 6.0 4.45695364238 135% => OK
Sentences with neutral sentiment: 1.0 4.27373068433 23% => More facts, knowledge or examples wanted.
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.170185568238 0.272083759551 63% => OK
Sentence topic coherence: 0.0734472957508 0.0996497079465 74% => OK
Sentence topic coherence SD: 0.0346436935375 0.0662205650399 52% => OK
Paragraph topic coherence: 0.115818279203 0.162205337803 71% => OK
Paragraph topic coherence SD: 0.0396598154287 0.0443174109184 89% => OK
Essay readability:
automated_readability_index: 14.4 13.3589403974 108% => OK
flesch_reading_ease: 54.56 53.8541721854 101% => OK
smog_index: 8.8 5.55761589404 158% => OK
flesch_kincaid_grade: 11.9 11.0289183223 108% => OK
coleman_liau_index: 11.38 12.2367328918 93% => OK
dale_chall_readability_score: 8.59 8.42419426049 102% => OK
difficult_words: 66.0 63.6247240618 104% => OK
linsear_write_formula: 14.5 10.7273730684 135% => OK
gunning_fog: 12.0 10.498013245 114% => OK
text_standard: 12.0 11.2008830022 107% => OK
What are above readability scores?
---------------------
Rates: 66.6666666667 out of 100
Scores by essay e-grader: 20.0 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.