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 the 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.
Both the reading and lecture discuss whether the Greeks uses weapon refers as burning mirror to attacked their foe the Roman navy. The former argues that the burning mirror actually not built by the Greek to fire the ship of military of the Roman and there are three possible reasons to doing so, but latter challenges each of these points.
First of all, the author of the passage asserts that earlier Greek people were not advanced in technology that manufacturing such large sheet of copper with mirror which precise parabolic was also impossible. However, the professor in lecture contends that this hypothesis does not hold true because many mathematician at that time were from the Greek and they can make small mirror parabolic shape precisely. Indeed, that would burn the ship their enemy.
Secondly, according to the passage, the expert opined that the burning mirror take huge time to set a fire and it is totally inconvincing and impractical, since the Roman navy would stay constantly at same time. In contrast, the lecture objects this idea. She supports her argument by presenting the example of pitch, which is kept between wooden portion of ship so that they cannot penetrate the water through it. In fact, the fire catches more quickly in pitch, even though ship is moving.
Finally, the passage claims that flaming arrow was already effective weapons, so that there was not any reason to made weapon such as burning mirror. Nevertheless, like two hypothesis before, the professor in her lecture proclaims that this reason is not feasible because flaming arrows were also buit by the Roman. To surprise the enemy just by pretending mirror the burning fire surprises enemy which would be effective weapons at that time.
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Grammar and spelling errors:
Line 3, column 301, Rule ID: MANY_NN[1]
Message: Possible agreement error. The noun mathematician seems to be countable; consider using: 'many mathematicians'.
Suggestion: many mathematicians
...s hypothesis does not hold true because many mathematician at that time were from the Greek and th...
^^^^^^^^^^^^^^^^^^
Line 7, column 358, Rule ID: AFFORD_VB[1]
Message: This verb is used with the infinitive: 'to mirror'
Suggestion: to mirror
...o surprise the enemy just by pretending mirror the burning fire surprises enemy which ...
^^^^^^
Transition Words or Phrases used:
actually, also, but, finally, first, however, nevertheless, second, secondly, so, in contrast, in fact, such as, first of all
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 12.0 10.4613686534 115% => OK
Auxiliary verbs: 5.0 5.04856512141 99% => OK
Conjunction : 6.0 7.30242825607 82% => OK
Relative clauses : 15.0 12.0772626932 124% => OK
Pronoun: 25.0 22.412803532 112% => OK
Preposition: 35.0 30.3222958057 115% => 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: 1478.0 1373.03311258 108% => OK
No of words: 289.0 270.72406181 107% => OK
Chars per words: 5.11418685121 5.08290768461 101% => OK
Fourth root words length: 4.12310562562 4.04702891845 102% => OK
Word Length SD: 2.38289502895 2.5805825403 92% => OK
Unique words: 166.0 145.348785872 114% => OK
Unique words percentage: 0.574394463668 0.540411800872 106% => OK
syllable_count: 449.1 419.366225166 107% => OK
avg_syllables_per_word: 1.6 1.55342163355 103% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 2.0 3.25607064018 61% => OK
Article: 8.0 8.23620309051 97% => OK
Subordination: 3.0 1.25165562914 240% => Less adverbial clause wanted.
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 6.0 2.5761589404 233% => Less preposition wanted as sentence beginnings.
Performance on sentences:
How many sentences: 12.0 13.0662251656 92% => OK
Sentence length: 24.0 21.2450331126 113% => OK
Sentence length SD: 58.9596731297 49.2860985944 120% => OK
Chars per sentence: 123.166666667 110.228320801 112% => OK
Words per sentence: 24.0833333333 21.698381199 111% => OK
Discourse Markers: 10.4166666667 7.06452816374 147% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 2.0 4.19205298013 48% => OK
Sentences with positive sentiment : 1.0 4.33554083885 23% => More positive sentences wanted.
Sentences with negative sentiment : 9.0 4.45695364238 202% => Less negative sentences wanted.
Sentences with neutral sentiment: 2.0 4.27373068433 47% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.165526386336 0.272083759551 61% => OK
Sentence topic coherence: 0.0593848362647 0.0996497079465 60% => OK
Sentence topic coherence SD: 0.0516114258288 0.0662205650399 78% => OK
Paragraph topic coherence: 0.107086934707 0.162205337803 66% => OK
Paragraph topic coherence SD: 0.0493555365346 0.0443174109184 111% => OK
Essay readability:
automated_readability_index: 14.7 13.3589403974 110% => OK
flesch_reading_ease: 47.12 53.8541721854 87% => OK
smog_index: 8.8 5.55761589404 158% => OK
flesch_kincaid_grade: 12.7 11.0289183223 115% => OK
coleman_liau_index: 12.65 12.2367328918 103% => OK
dale_chall_readability_score: 8.49 8.42419426049 101% => OK
difficult_words: 67.0 63.6247240618 105% => OK
linsear_write_formula: 14.0 10.7273730684 131% => OK
gunning_fog: 11.6 10.498013245 110% => OK
text_standard: 13.0 11.2008830022 116% => OK
What are above readability scores?
---------------------
Rates: 80.0 out of 100
Scores by essay e-grader: 24.0 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.