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.
The reading and the lecture are both about the ancient Greeks weapon, burning mirror. The author of the reading provides three statements about why the burning mirror is only a myth. However, the lecturer disputes the arguments made in the article. The professor's position is that the theories do not truly prove the burning mirror is impractical in ancient times.
According to the reading, the author claims that ancient Greeks didn't have enough technological advances to make the large sheet of polished copper that was required in the burning mirror. This specific argument is challenged by the lecturer. She states that there is no need to use a single sheet of copper to make the boat on fire. In fact, dozens of pieces of flat polished copper also could burn the ship.
Secondly, the author suggests that using the burning mirror would take a long time to set the ship on fire. In the article, it is said that the scientists had launched an experiment which indicates that it takes about ten minutes to set fire on ship. However, there are other materials instead of wood that composed the boat. The ancient people use the sticky pitch to make the boat to become waterproof. The experiment also proves that it only needs a second to set the boat on fire and the fire could spread to the wood even the boat is moving. The process works really quickly.
Finally, the author posits that the burning mirror isn't the improvement of flaming arrows, a weapon that the Greeks already had. Both of them will be effective at a similar distance, so the Greeks might not advance the burning mirror as the new weapon. The author contends that the function of the burning mirror is different from flaming arrows. In contrast, the lecturer's stance is that the opponent of the Greeks had already familiar with flaming arrows, so they could make a wonderful preparation for addressing the flame from the arrows. However, they could not clearly see the attack of the burning mirror, because it is just a mirror at all. When the Greeks caused the fire on the ship, it is more effective and surprising than flaming arrows.
Grammar and spelling errors:
Line 3, column 65, Rule ID: EN_CONTRACTION_SPELLING
Message: Possible spelling mistake found
Suggestion: didn't
..., the author claims that ancient Greeks didnt have enough technological advances to m...
^^^^^
Line 5, column 548, 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.
...ad to the wood even the boat is moving. The process works really quickly. Finall...
^^^
Line 7, column 52, Rule ID: EN_CONTRACTION_SPELLING
Message: Possible spelling mistake found
Suggestion: isn't
...e author posits that the burning mirror isnt the improvement of flaming arrows, a we...
^^^^
Line 7, column 365, Rule ID: POSSESIVE_APOSTROPHE[1]
Message: Possible typo: apostrophe is missing. Did you mean 'lecturers'' or 'lecturer's'?
Suggestion: lecturers'; lecturer's
...t from flaming arrows. In contrast, the lecturers stance is that the opponent of the Gree...
^^^^^^^^^
Transition Words or Phrases used:
also, finally, however, if, really, second, secondly, so, in contrast, in fact
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 15.0 10.4613686534 143% => OK
Auxiliary verbs: 8.0 5.04856512141 158% => OK
Conjunction : 3.0 7.30242825607 41% => More conjunction wanted.
Relative clauses : 15.0 12.0772626932 124% => OK
Pronoun: 23.0 22.412803532 103% => OK
Preposition: 41.0 30.3222958057 135% => OK
Nominalization: 9.0 5.01324503311 180% => OK
Performance on vocabulary words:
No of characters: 1754.0 1373.03311258 128% => OK
No of words: 367.0 270.72406181 136% => OK
Chars per words: 4.77929155313 5.08290768461 94% => OK
Fourth root words length: 4.37689890912 4.04702891845 108% => OK
Word Length SD: 2.35674504172 2.5805825403 91% => OK
Unique words: 176.0 145.348785872 121% => OK
Unique words percentage: 0.479564032698 0.540411800872 89% => More unique words wanted or less content wanted.
syllable_count: 529.2 419.366225166 126% => OK
avg_syllables_per_word: 1.4 1.55342163355 90% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 5.0 3.25607064018 154% => OK
Article: 13.0 8.23620309051 158% => OK
Subordination: 2.0 1.25165562914 160% => OK
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 4.0 2.5761589404 155% => OK
Performance on sentences:
How many sentences: 20.0 13.0662251656 153% => OK
Sentence length: 18.0 21.2450331126 85% => The Avg. Sentence Length is relatively short.
Sentence length SD: 39.7155825842 49.2860985944 81% => OK
Chars per sentence: 87.7 110.228320801 80% => OK
Words per sentence: 18.35 21.698381199 85% => OK
Discourse Markers: 3.9 7.06452816374 55% => More transition words/phrases wanted.
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 4.0 4.19205298013 95% => OK
Sentences with positive sentiment : 3.0 4.33554083885 69% => OK
Sentences with negative sentiment : 10.0 4.45695364238 224% => Less negative sentences wanted.
Sentences with neutral sentiment: 7.0 4.27373068433 164% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.198590518119 0.272083759551 73% => OK
Sentence topic coherence: 0.0649457540062 0.0996497079465 65% => OK
Sentence topic coherence SD: 0.0610962327886 0.0662205650399 92% => OK
Paragraph topic coherence: 0.125627356731 0.162205337803 77% => OK
Paragraph topic coherence SD: 0.0522698547331 0.0443174109184 118% => OK
Essay readability:
automated_readability_index: 10.3 13.3589403974 77% => Automated_readability_index is low.
flesch_reading_ease: 70.13 53.8541721854 130% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 7.9 11.0289183223 72% => OK
coleman_liau_index: 10.44 12.2367328918 85% => OK
dale_chall_readability_score: 7.54 8.42419426049 90% => OK
difficult_words: 70.0 63.6247240618 110% => OK
linsear_write_formula: 7.5 10.7273730684 70% => OK
gunning_fog: 9.2 10.498013245 88% => OK
text_standard: 8.0 11.2008830022 71% => OK
What are above readability scores?
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Write the essay in 20 minutes.
Rates: 73.3333333333 out of 100
Scores by essay e-grader: 22.0 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.