Starting in the 1960s and continuing until the 1980s, sailors in Russian submarines patrolling the North Atlantic and Arctic Ocean would occasionally hear strange sounds. These underwater noises reminded the submarine crews of frog croaks, so they called the sounds “quackers” (from the Russian word for frog sounds). The sources of the sound seemed to be moving with great speed and agility; however, the submarines’ sonar (a method of detecting objects underwater) was unable to detect any solid moving objects in the area. There are several theories about what might have caused the odd sounds.
The first theory suggests that the strange noises were actually the calls of male and female orca whales during a courtship ritual. Orca whales are known to inhabit the areas where the submarines were picking up the bizarre noises. Orcas have been studied extensively, and the sounds they make when trying to attract a mate are similar to those that the submarines were detecting.
A second idea is that the sounds were caused by giant squid. Giant squid are giant marine invertebrates that live deep in the ocean and prey on large fish. They are difficult to detect by sonar because they have soft bodies with no skeleton. Not much is known about giant squid behavior, but their complex brains suggest they are intelligent animals. It is possible they have the ability to emit sound, and perhaps they approached the submarines out of curiosity.
A third theory suggests the Russian submarines were picking up stray sounds from some military technology, like another country’s submarines that were secretly patrolling the area. Perhaps the foreign submarines did not register on the sonar because they were using a kind of technology specifically designed to make them undetectable by sonar. The strange froglike sounds may have been emitted by the foreign submarines unintentionally.
The reading passage presents three theories to explain the sounds that some russian sailors heard while patrolling in their submarines. However, the speaker in the lecture casts doubt on the claims made in the article. She indicates many problems with these proposals.
First and foremost, the author argues that the sounds might have been from courtship rituals of female and male orcas since it was known that they inhabited the area. Nevertheless, the lecturer challenges this argument. She points out that orcas usually live near the surface. On the other hand, submarines move deep in the ocean and the submarines would not have been able to pick up any sounds from the surface. In addition, if the orcas were responsible for those noises, sonar devices would have detected them.
Secondly, the writer assumes that giant squids could have been the source. According to the excerpt, squids could have approached the submarine out of curiosity and they were not visible on the sonar since they only have soft bodies with no skeletons. Conversely, the lecturer holds that sailors only started to hear the noise around 1960s then it stopped around 1980s. She mentions that since squids always lived in the area, the question why the noise began then stopped 20 years later would not be answered under this hypothesis.
Lastly, the author contends that the sound could have been for a military submarine that was not registered on the sonar or it had a stealth technology that enabled it to be invisible to sonar. On the contrary, the lecturer brings up the fact that the noise showed that the source was moving very quickly and submarines move slowly. Besides, there was no known technology at that time that allowed building submarines with silent engines that also moved so fast.
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Grammar and spelling errors:
Line 13, column 464, Rule ID: WHITESPACE_RULE
Message: Possible typo: you repeated a whitespace
Suggestion:
...silent engines that also moved so fast.
^^^^^^^
Transition Words or Phrases used:
also, besides, conversely, first, however, if, lastly, nevertheless, second, secondly, so, then, while, in addition, on the contrary, on the other hand
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 12.0 10.4613686534 115% => OK
Auxiliary verbs: 7.0 5.04856512141 139% => OK
Conjunction : 6.0 7.30242825607 82% => OK
Relative clauses : 15.0 12.0772626932 124% => OK
Pronoun: 31.0 22.412803532 138% => Less pronouns wanted
Preposition: 35.0 30.3222958057 115% => OK
Nominalization: 3.0 5.01324503311 60% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1503.0 1373.03311258 109% => OK
No of words: 298.0 270.72406181 110% => OK
Chars per words: 5.04362416107 5.08290768461 99% => OK
Fourth root words length: 4.15483772266 4.04702891845 103% => OK
Word Length SD: 2.34290678382 2.5805825403 91% => OK
Unique words: 167.0 145.348785872 115% => OK
Unique words percentage: 0.560402684564 0.540411800872 104% => OK
syllable_count: 449.1 419.366225166 107% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 3.0 3.25607064018 92% => OK
Article: 9.0 8.23620309051 109% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 4.0 2.5761589404 155% => OK
Performance on sentences:
How many sentences: 15.0 13.0662251656 115% => OK
Sentence length: 19.0 21.2450331126 89% => OK
Sentence length SD: 45.3720422972 49.2860985944 92% => OK
Chars per sentence: 100.2 110.228320801 91% => OK
Words per sentence: 19.8666666667 21.698381199 92% => OK
Discourse Markers: 10.0666666667 7.06452816374 142% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 1.0 4.19205298013 24% => OK
Sentences with positive sentiment : 2.0 4.33554083885 46% => More positive sentences wanted.
Sentences with negative sentiment : 9.0 4.45695364238 202% => Less negative sentences wanted.
Sentences with neutral sentiment: 4.0 4.27373068433 94% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.168171907383 0.272083759551 62% => OK
Sentence topic coherence: 0.0507899151949 0.0996497079465 51% => OK
Sentence topic coherence SD: 0.048104779869 0.0662205650399 73% => OK
Paragraph topic coherence: 0.0945442857584 0.162205337803 58% => OK
Paragraph topic coherence SD: 0.0216633951877 0.0443174109184 49% => Paragraphs are similar to each other. Some content may get duplicated or it is not exactly right on the topic.
Essay readability:
automated_readability_index: 12.2 13.3589403974 91% => Automated_readability_index is low.
flesch_reading_ease: 60.65 53.8541721854 113% => OK
smog_index: 8.8 5.55761589404 158% => OK
flesch_kincaid_grade: 9.5 11.0289183223 86% => OK
coleman_liau_index: 11.95 12.2367328918 98% => OK
dale_chall_readability_score: 8.13 8.42419426049 97% => OK
difficult_words: 67.0 63.6247240618 105% => OK
linsear_write_formula: 7.0 10.7273730684 65% => OK
gunning_fog: 9.6 10.498013245 91% => OK
text_standard: 10.0 11.2008830022 89% => OK
What are above readability scores?
---------------------
Rates: 80.0 out of 100
Scores by essay e-grader: 24.0 Out of 30
---------------------
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.