Physicists posit that at first our universe was infmitesimally small

Question

Physicists posit that at first our universe was infmitesimally small and infinitely hot and dense. It then underwent a period of extremely rapid, massive inflation (the Big Bang), and it has since continued to expand and coop.

According to physicists Sean Carroll and Jennifer Chen, the Big Bang was not a unique event; events like it happen periodically over an incredibly vast time scale. This is based on the suggestion of some physicists that the Big Bang was the beginning of our universe as we know it, but not the beginning of a larger Univers—or "multiverse"—that encompasses everything, including that which we can never see because it is beyond our "cosmic bubble."

Carroll and Chen were initially interested in why time flows in only one direction. In physics the flow of time is captured by the second law of thermodynamics, which implies that entropy—a measure of total disorder—naturally increases with time. Entropy increases because there are more ways for a system to be disordered than for it to be ordered. Therefore, if change occurs, it is more likely to be change toward greater disorder. For example, in a moderately orderly room, if one moves an object in the room randomly, there are many more places one can put it that will make the room less orderly than there are places that will make it more orderly. So if, over time, objects in the room are continually moved randomly, it is most likely that the room will get increasingly disordered.

While the Big Bang process and what followed obey the second law of thermodynamics, it is a mystery why there should have been a small, hot, and dense universe to begin with. Such a low entropy universe is an extremely unlikely configuration, not what scientists would expect from a randomly occurring initial condition. Carroll and Chen's innovation is to argue that the most common initial condition is actually likely to resemble cold, empty space--not an obviously favorable starting point for the onset of inflation.

Recent research has shown that even empty space has faint traces of energy that fluctuate on the subatomic scale. Physicists Jaume Garriga and Alexander Vilenkin have suggested that these fluctuations can generate their own big bangs in tiny areas widely separated in time and space. Carroll and Chen take our universe, and others, to be such fluctuations in a high entropy multiverse.

On this view, while the initial state that produced our universe would appear to be, taken by itself, a highly improbable one, in the vastness of the multiverse the creation of our universe is not that unlikely. Indeed it is likely not even a unique event.    1 
 1. Which one of the following most accurately states the main idea of the passage?

(A) Carroll and Chen theorize that our universe is the result of an energy fluctuation in a high entropy multiverse.
(B) According to Carroll and Chen, entropy increases because there are more ways for a system to be disordered than for it to be ordered.
(C) Carroll and Chen challenge the prevailing view of physicists that our universe underwent a period of extremely rapid, massive inflation.
(D) According to Carroll and Chen, a small, hot, and dense configuration is unlikely as a random initial condition for a universe.
(E) Carroll and Chen posit that our universe is one of many universes in an all-encompassing multiverse.

2 
 2. Which one of the following comes closest to capturing what the term "cosmic bubble" means in the last sentence of the second paragraph?

(A) all-encompassing larger universe
(B) universe contained in the multiverse
(C) inflation following a big bang
(D) theoretical preconceptions
(E) low entropy state

3 
 3. The author's stance toward Carroll and Chen's theory is most accurately characterized as that of

(A) an ardent adversary
(B) a dismissive critic
(C) a disinterested skeptic
(D) a sympathetic reporter
(E) a zealous proponent

4 
 4. The claim in the fourth paragraph that an initial condition is likely to resemble cold, empty space is most strongly supported by information in the

(A) first paragraph
(B) second paragraph
(C) third paragraph
(D) fifth paragraph
(E) sixth paragraph

5 
 5. The author's reference to a suggestion by Garriga and Vilenkin in the fifth paragraph primarily serves to

(A) question a presupposition of the Big Bang theory
(B) raise a potential objection-to Carroll and - Chen's theory
(C) illustrate an implication of Carroll and Chen's theory
(D) show how a puzzle raised by Carroll and Chen is resolved within Carroll and Chen's theory
(E) suggest an alternative explanation of the evidence upon which Carroll and Chen's theory is based

6 
 6. The primary purpose of the passage is to

(A) draw novel consequences from an established principle
(B) challenge a dominant point of view
(C) chronicle the history of a dispute
(D) adjudicate between two theories
(E) give the rationale for a theory

7 
 7. It can be inferred from the passage that the author presumes which one of the following to be true?

(A) The multiverse originated in a big bang.
(B) The initial state of our universe resembles cold, empty space.
(C) A hot and dense state is a state of low entropy.
(D) The multiverse is part of a larger system of multiverses.
(E) The second law of thermodynamics was formulated to answer a question about time.

Sajjad1994 · Answer

Explanation

3. The author's stance toward Carroll and Chen's theory is most accurately characterized as that of

Explanation

Step 1: Identify the Question Type

The question asks for the  “author’s stance,”  which is similar to asking for the author’s attitude. An attitude is implied by the language of the passage rather than directly stated, making this an Inference question.

Step 2: Research the Relevant Text

The author remains fairly neutral until the very last paragraph. Use that paragraph for reference.

Step 3: Make a Prediction

In the last sentence of the last paragraph, the author claims the theory to be likely. It’s certainly a favorable stance, if not a particularly forceful one. The correct answer should be generally positive, but not overly so.

Step 4: Evaluate the Answer Choices

(D)  is correct. The author is mostly just reporting the details, but is sympathetic (i.e., expressing some agreement).

(A)  is a 180. The author is supportive of the theory and says nothing adversarial about it.

(B)  is a 180. The author is supportive, not dismissive.

(C)  is a 180. The author shows no skepticism. In fact, the author claims the theory is likely.

(E)  is Extreme. The author merely claims the theory is likely. That’s far short of being a zealous proponent.

Answer: D

Sajjad1994 · Answer

Explanation

4. The claim in the fourth paragraph that an initial condition is likely to resemble cold, empty space is most strongly supported by information in the

Explanation

Step 1: Identify the Question Type

This is an unusual question stem that works like a Logic Function question, but in reverse. Logic Function questions typically provide some detail from the passage and ask for its purpose. In this case, the question provides the purpose (the correct answer will support a given claim) and asks for the detail that serves that purpose.

Step 2: Research the Relevant Text

The claim in question is in lines 36–39. Start there, and use Keywords and the surrounding lines for context to õnd support for that claim.

Step 3: Make a Prediction

The claim in question is part of the fourth paragraph, which raises the mystery of why our universe would start so small and dense. This is a mystery because it goes against the random nature of the universe, as described in the previous paragraph. Carroll and Chen use those details from the third paragraph to support their innovative idea that everything actually started out in a large, cold, empty space, and the beginning of our universe was just one occurrence within that space. So,the correct answer should cite the third paragraph as the support for the claim in question.

Step 4: Evaluate the Answer Choices

(C)  is correct.

(A)  is incorrect. The õrst paragraph just describes the Big Bang that started our universe, but oðers no support for the vast, empty space theory.

(B)  is incorrect. The second paragraph presents the theory posited by Carroll and Chen, but no support is given for that theory or the claim in question until the third paragraph.

(D)  gets the logic backwards. The details in the fourth paragraph support the ideas in the õøh paragraph, not the other way around.

(E)  is incorrect. The sixth paragraph provides the author’s opinion about the claims of Carroll and Chen, but does not provide any logical support.

Answer: C

Sajjad1994 · Answer

Explanation

7. It can be inferred from the passage that the author presumes which one of the following to be true?

Explanation

Step 1: Identify the Question Type

The question asks for something that  “can be inferred,”  making this an Inference question.

Step 2: Research the Relevant Text

The question provides no line reference or Content Clue, so the entire text is relevant.

Step 3: Make a Prediction

As the correct answer could be based on any details from the passage, making a prediction will not be possible. Instead, go through the choices and use the big picture to eliminate choices that are outside the scope of the passage. Then, use the clues in the choices to research as necessary.

Step 4: Evaluate the Answer Choices

(C) is correct.   This is directly supported in  lines 31–34     . The author says  “such a low entropy universe,”  referring directly back to the previous sentence, which describes a  “small, hot, and dense universe.”

(A) is a 180.  The suggestion is that the multiverse started as a vast, cold, and empty space. Big bangs occurred within that cold and empty space.

(B) is a 180.  The initial state of the larger multiverse is assumed to be a cold, empty space. Our universe began with the Big Bang, as a small, hot, dense universe.

(D) is Out of Scope.  Our universe is said to be part of one big multiverse, but the author never goes up another level to suggest that that multiverse is part of an even bigger series of multiverses.

(E) is a Distortion.  The second law of thermodynamics provides a rule about time, but there’s no indication that it was devised to answer any question in particular.

Answer: C

Sajjad1994 · Answer

Explanation

1. Which one of the following most accurately states the main idea of the passage?

Explanation

Step 1: Identify the Question Type

The question asks for the  “main idea of the passage,”  which makes this a Global question.

Step 2: Research the Relevant Text

As with any Global question, the entire text is relevant. Don’t go back into the details. Instead, focus on the big picture as predicted while reading the passage.

Step 3: Make a Prediction

The Main Idea of the passage is that Carroll and Chen have developed a theory that our universe’s beginning was just one of several similar events as part of a much larger multiverse—a theory that the author endorses.

Step 4: Evaluate the Answer Choices

(A)   is correct, providing a succinct summary of the supported theory.

(B)  is too narrow. This focuses on a detail about entropy from the third paragraph, but completely misses the bigger picture about how that relates to our universe and its place in a larger multiverse.

(C)  is a 180. Carroll and Chen do not dispute this view. They just argue that it wasn’t the only occurrence of such an event.

(D)  is too narrow. This point is suggested in the fourth paragraph, but that is just one minor point in service of the main point about how the beginning of our universe was not unique and is one of several similar instances within a larger multiverse.

(E)  is a Faulty Use of Detail. Carroll and Chen are not merely interested in the existence of other universes. Their point is more about how our universe began (with the Big Bang) and the regular occurrence of other similar events. It’s about the events that create universes, not the universes themselves.

Answer: A

Sajjad1994 · Answer

Explanation

5. The author's reference to a suggestion by Garriga and Vilenkin in the fifth paragraph primarily serves to

Explanation

Step 1: Identify the Question Type

The phrase  “primarily serves to”  indicates a Logic Function question. The question is asking why the author mentions certain people in the fifth paragraph.

Step 2: Research the Relevant Text

The question stem directly refers to details from the fifthh paragraph, but be sure to consult the margin notes to understand the context.

Step 3: Make a Prediction

The details provided by Garriga and Vilenkin help resolve the mystery posited in the previous paragraph. Then, Carroll and Chen use that information to further their own point of view. The correct answer will describe one or both of these purposes.

Step 4: Evaluate the Answer Choices

(D)  is correct. Garriga and Vilenkin’s claims address the mystery raised in the fourth paragraph, and provide support for how Carroll and Chen’s theory resolve that mystery.

(A)  is a 180, at worst. Garriga and Vilenkin actually suggest why big bangs would happen in the first place. They don’t question any assumptions of the Big Bang theory.

(B)  is a 180. The evidence from Garriga and Vilenkin support, not reject, the claims of Carroll and Chen.

(C)  is a Distortion. The claims of Garriga and Vilenkin offer support for Carroll and Chen’s theory, but do not illustrate any implications of that theory.

(E)  is a 180, at worst. Their observations provide a basis for Carroll and Chen’s theory. It’s consistent with that theory, not an alternative.

Answer: D

nikitathegreat · Answer

Can you post solution for Q6 as well.

GMATNinja  - Can you please help in explaining the option choices for Q1 ?

(A) Carroll and Chen theorize that our universe is the result of an energy fluctuation in a high entropy multiverse.
(B) According to Carroll and Chen, entropy increases because there are more ways for a system to be disordered than for it to be ordered.
(C) Carroll and Chen challenge the prevailing view of physicists that our universe underwent a period of extremely rapid, massive inflation. - They are not challenging the view that that the universe underwent inflation. Infact, they also create their own big bangs (inflation).  GMATNinja  - is this reasoning correct?
(D) According to Carroll and Chen, a small, hot, and dense configuration is unlikely as a random initial condition for a universe. - Why is this option choice incorrect?
(E) Carroll and Chen posit that our universe is one of many universes in an all-encompassing multiverse

GMATNinja · Answer

Question 1 
 
Sounds like you have it!

As stated in paragraph 4, "Carroll and Chen's innovation is to argue that the most common initial condition is actually likely to resemble cold, empty space--not an obviously favorable starting point for the onset of inflation". Carroll and Chen agree that the inflation occurred, but they believe that the inflation of our universe (and others) would have started with "cold, empty space", not a "small and infinitely hot and dense" point.

Paragraph 5 explains how there can be energy fluctuations that lead to "big bangs" in those "cold, empty" voids. Carroll and Chen's position is that our universe is the result of one of those fluctuations, and that represents the main idea of the passage. So choice (A) is the best answer.

VerbalBot · Answer

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Physicists posit that at first our universe was infmitesimally small

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Physicists posit that at first our universe was infmitesimally small

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