Here is the second part of the GMAT Reading Comprehension Article from Manhattan Review Germany, a provider of GMAT tutoring in Berlin, Frankfurt, and Munich. In this article, they reveal Manhattan Review’s best five strategies how to tackle GMAT Reading Comprehension questions. If you have missed the first part of this post, you can find it here.
Let’s see how these tips might help. Here is a Reading Comprehension exercise from Manhattan Review’s Study Companion. The subject matter is the historic transition from classical physics to quantum physics. It is intellectually difficult; so the challenge is to read quickly AND to get a handle on the author’s central argument on the first read through:
However inventive Newton’s clockwork universe seemed to his contemporaries, by the early twentieth century, it had become a sort of smugly accepted dogma. Luckily for us, this deterministic picture of the universe breaks down at the atomic level.
The clearest demonstration that the laws of physics contain elements of randomness is the behavior of radioactive atoms. Pick two identical atoms of a radioactive isotope, say naturally occurring uranium 238, and watch them carefully. They will begin to decay at different times, even though there was no difference in their initial behavior. We would be in big trouble if these atoms’ behavior were as predictable as expected in the Newtonian world-view, because radioactivity is an important source of heat for our planet. In reality, each atom chooses a random moment at which to release its energy, resulting in a nice steady heating effect. The earth would be a much colder planet if only sunlight heated it and not radioactivity. Probably there would be no volcanoes, and the oceans would never have been liquid. The deep-sea geothermal vents in which life first evolved would never have existed.
But there would be an even worse consequence if radioactivity were deterministic: after a few billion years of peace, all the uranium 238 atoms in our planet would presumably pick the same moment to decay. The huge amount of stored nuclear energy, instead of being spread out over eons, would all be released simultaneously, blowing our whole planet to kingdom come. (This is under the assumption that all the uranium atoms were created at the same time. In reality, we have only a general idea of the process that might have created the heavy elements in the gas cloud from which our solar system condensed. Some portion may have come from nuclear reactions in supernova explosions in that nebula, some from intra-galactic supernova explosions and others still from exotic events like the collisions of white dwarf stars.)
The new version of physics, incorporating certain kinds of randomness, is called quantum physics. It represented such a dramatic break with the previous, deterministic tradition that everything that came before is considered classical, even the theory of relativity.
The first paragraph informs us that the deterministic picture of the universe fails at the atomic level. The second paragraph focuses on the importance of randomness in the universe. The third paragraph continues with the theme of the importance of randomness and spells out the catastrophic consequences that would transpire were randomness not the rule the universe. The fourth and last paragraph introduces us to quantum physics, which partially supplanted the Newtonian world and offered a picture of the universe based on randomness. Let’s go through the questions:
- The main theme of this passage discusses:
(A) How Newtonian physics is irrelevant
(B) The difference between supernova explosions and star collisions
(C) The worldly benefits of uranium 238
(D) How randomness is a fundamental principle of modern physics
(E) The danger of accepting an idea without continuing to challenge it
The first question is a Main Idea question and is fairly straightforward. (A) is a contentious and erroneous statement and can be ruled out right away. (B) involves details and thus can’t express a Main Idea. (C) involves details and has little to do with the passage. (E) is a possibility but is far too vague to be the Main Idea of a detail-rich passage such as this one. So the answer has to be (D). The issue of randomness comes up in the beginning and at the end.
- The author discusses the activity of uranium 238 atoms to show:
(A) That no two atoms are exactly alike
(B) The dangers of nuclear power
(C) How sunlight alone could never heat the planet
(D) How Newtonian physics can explain all aspects of the physical world
(E) How randomness exists in the most basic constructs of the physical world
This is an Inference question. It presupposes an understanding of the argument as a whole. The passage describes the transition from the Newtonian, deterministic view of the universe to the modern view that emphasizes randomness. The key sentences referring to Uranium 238 appear in Paragraph 2:
Pick two identical atoms of a radioactive isotope, say naturally occurring uranium 238, and watch them carefully. They will begin to decay at different times, even though there was no difference in their initial behavior. We would be in big trouble if these atoms’ behavior were as predictable as expected in the Newtonian world-view, because radioactivity is an important source of heat for our planet. In reality, each atom chooses a random moment at which to release its energy, resulting in a nice steady heating effect.
Once again, the issue is randomness. If Newtonian physics were correct and U-238 atoms decayed at the same time, the author is saying, the universe would be in big trouble. The answer clearly is (E).
- According to the passage, identical radioactive isotopes:
(A) Were overlooked by Newton
(B) Can have different chemical properties
(C) Are subject to different physical events
(D) Decay at different rates
(E) May begin to decay at different times
Any question starting with “According to” is a Supplementary Idea question. This means that the wording in the correct answer choice will follow fairly closely the wording of the passage. The answer here follows logically from the answer to No. 2. Identical radioactive isotopes decay at different times. Once again the answer is (E).
- According to the passage, the Theory of Relativity is considered:
(A) The pinnacle of quantum physics
(B) A Newtonian explanation of randomness
(C) Incorrect
(D) Deterministic
(E) A bridge between the classical tradition and quantum physics
Again this is a Supplementary Idea question. The theory of relativity is mentioned at the end in order to illustrate that even this revolutionary theory belonged to the world of classical, deterministic physics. The answer therefore is (D).
- The passage demonstrates how central randomness was to the development of life on Earth by saying that if it had not existed the most important consequence would have been that:
(A) Deep sea vents could never have evolved
(B) Light would travel at different speeds depending on its point of origin
(C) Uranium 238 atoms would decay simultaneously and destroy the earth
(D) The earth would not have a way to store the sun’s heat
(E) Genetic mutations
This is an Inference question. We are asked to speculate about what the author thinks would happen were the universe deterministic rather than random. The author spells out his belief in the third paragraph:
[A]fter a few billion years of peace, all the uranium 238 atoms in our planet would presumably pick the same moment to decay. The huge amount of stored nuclear energy, instead of being spread out over eons, would all be released simultaneously, blowing our whole planet to kingdom come.
The answer therefore is clearly (C).
- An appropriate title for this piece might be:
(A) Randomness and Supernovas: Theories and Events Which Lead to Life
(B) A Review of Classical Physics and Newtonian Tenets
(C) Revising the Model: The Most Basic Principle of Physics
(D) Einstein’s Dice: The Classic-Quantum Debate
(E) Renaming Physics: Accepting the Role of Randomness in the Principles We Learned
This is a classic Main Idea question. Anytime you are asked to supply a title to a passage, you are essentially being asked to identify the author’s central argument. By now, we have a pretty good idea as to what the author is trying to say. The answer has to be (E).
- The style of this piece can be best regarded as:
(A) Journalistic
(B) Extemporaneous
(C) Hortatory
(D) Encyclopedic
(E) Considered
This too is a Main Idea question. The author’s tone is serious and thoughtful. Therefore, the answer again is (E).
- The author presents quantum physics as:
(A) The incorrect interpretation of physical events
(B) A way of explaining events using Newtonian physics
(C) An explanation of the rules of the physical world
(D) The replacement of Newtonian physics
(E) The missing piece of Newtonian physics
This is an Inference question and is perhaps the hardest of the lot since there are a number of possible answers. (A) and (B) are obviously wrong. However, (C), (D) and (E) could all be correct. So how do we decide? Quantum physics is mentioned in the last paragraph. It is a
new version of physics, incorporating certain kinds of randomness….It represented such a dramatic break with the previous, deterministic tradition that everything that came before is considered classical, even the theory of relativity.
(E) can therefore be ruled out. There is nothing here to suggest that quantum physics is part of Newtonian physics. Between (D) and (C), the best choice is (C). The passage suggests that quantum physics offers an explanation of how the universe works. However, there is no suggestion that quantum physics replaced Newtonian physics. Indeed, it did not. Newton’s laws remain valid for all non-atomic particles.
Even difficult passages such as this one will turn out to be relatively painless as long as you come at them armed with the right strategy.
Best of luck on your GMAT! If you want to know more about the GMAT Preparation options from Manhattan Review, please attend a free interactive GMAT webinar that will feature many suggestions and tricks how to prepare for the test.
