Galileo's theory that ours was indeed a solar system, in

So, here is OE:

The sentence creates a parallel between Galileo's theory and Copernicus's theory, as you can se when you simplify the sentence structure: Galileo's theory ... reinforced those of Copernicus. The original sentence is right to try to compare theory to theory, but those is the incorrect pronoun; since theory is singular, the pronoun that refers to it needs to be that. Eliminate (A) and (D). Next, reinforced needs to be in the past tense like was earlier in the sentence. Eliminate (E). Finally, (C) presents less clear and less direct alternative to (B), leaving (B) as the right answer.

Answer: B (as far as I can see, this is the best possible answer. I do agree that 'ours was' does not seem right)
A - We are talking about Galileo's theory reinforcing Copernicus' theory. Theory is singular here. So, it should be 'that' and not 'those'.
C - nonsense.
D - nonsense.
E - alteration in meaning. In original, Galileo theorised about what sort of system ours is -> solar system (i.e. every planet revolves around the sun). However, in option E, Galileo theorised about the revolution of the planets.

Pretty sure B is correct.



The use of simple past seems fine, because when Galileo came up with his theory, it was just that: a theory. It had not been proven to be a fact, yet.

This must be in present tense, because it's simply the definition of a solar system.

This must be in simple past, too, since the sentence describes a situation in the past. At that time, Galileo's theory reinforced that of Copernicus.

So either both the red and the blue part of the sentence are in a present tense or both are in a past tense, as is the case in answer choice B. Choice E would take care of the tenses, as well, but it integrates the term "solar system" into its own definition. Both "planets revolve around the sun" and "solar system" basically mean the same. The difference between B and E with regard to this is that B does refer back to the term "solar system" in order to explain it in a relative sentence, while E fails to establish that causal/explanatory connection between planets revolving around the sun and what that means for the type of our planetary system.

Galileo's theory that ours was indeed a solar system, in which Earth and other planets revolve around the sun, reinforced those of Copernicus.

Meaning :
1. Galileo's Theory Reinforced Theory of Copernicus.
2. G's Theory is "Ours was indeed a solar system, in which Earth and other planets revolve around the sun"

Error Analysis :
1. "those of" - those a plural is used to refer back to Theory singular noun.

POE.
A) ours was indeed a solar system, in which Earth and other planets revolve around the sun, reinforced those of Copernicus
Incorrect - Explained Above

(B) ours was indeed a solar system, in which Earth and other planets revolve around the sun, reinforced that of Copernicus
Correct - Corrected plural Error with replacement of "that"

(C) our solar system was indeed solar for Earth and the other planets revolve around the sun, reinforced Copernicus'
Galileo's theory reinforced Copernicus' - Correct (ellipses - theory silent )
our solar system was indeed solar for Earth and the other planets revolve around the sun - illogical meaning and sentence structure sound incorrect


(D) our system was indeed solar, in which Earth and other planets revolved around the sun, reinforced those of Copernicus
1. Those - Plural refers to singular theory
2. our system was indeed solar - Indeed solar o_0 -- Indeed solar something fishy .. but can be true - lets not eliminate on this (Although it is nonsensical)
3. Earth and other planets revolved around the sun - Past tense revolved, so have they stop doing that - No - It is universal fact- must be presented with simple present.

(E) Earth and the other planets revolve around the sun in our solar system reinforces that of Copernicus
G Theory reinforces that of Copernicus - Correct
Theory that Earth and the other planets revolve around the sun in our solar system - correct

the option E, is grammatically correct but introduces subtle change of meaning.
Original Says Theory is "Our is solar system, In which (Non-Essential) Earth and other planet revolve"
Option E says theory is "Earth and Other planet revolve in our solar system " ---- Did you notice the change in meaning.

Change in meaning should be avoided as far as possible.


P.S bumping .. it may help someone

I am skeptical about the OA ‘B’. Let’s look at it this way. What is the truth? Is ours still a solar system or was it so only in Galileo’s time? Notwithstanding other errors, IMO, A to D are wrong for this one single reason.

One problem about E is that if Earth and the other planets revolve around the sun in our solar system, what do they revolve around in other systems? GOK

If one can make bold to ignore this insinuation about E, that may perhaps make the correct choice by compulsion rather than by conviction.

Absolutely right! When the pronouns "that"/ "those" are used to create copy / copies of noun/nouns, the pronoun must agree in number with the noun. The following example is from Manhattan GMAT:

Wrong: Her company is outperforming THOSE OF her competitors.
Right: Her company is outperforming THE COMPANIES OF her competitors.

There is a major issue with option B: when stating a universal truth in indirect speech, simple present must be used, even when the speech is made in the past.

I knew that the sky was blue... wrong.
I knew that the sky IS blue... right.

For this reason using past tense (ours was indeed a solar system) is definitely wrong. Option B cannot be the OA.

You do not need antecedents for first person and second person pronouns (e.g., I, you, my, our etc.) Antecedents are required only for 3rd person pronouns (he, she its, his, her its etc.). For example:

I am very close to being happy. ... in this sentence you do not need an antecedent for "I".

Hi AdrianG,

Thank you for your question. Let's tackle this one problem at a time, and hopefully we can narrow things down to the right answer!

After a quick glance, it's clear the sentence is making a comparison. Whenever you see a comparison, the first thing to check is consistency or parallel structure. The sentence is comparing the theories of Galileo and Copernicus, which means each side of the comparison should be singular (Galileo's one theory vs. Copernicus' one theory). Let's see how each answer stacks up:

Galileo's theory that ours was indeed a solar system, in which Earth and other planets revolve around the sun, reinforced those of Copernicus.

A) ours was indeed a solar system, in which Earth and other planets revolve around the sun, reinforced those of Copernicus (singular/plural = WRONG)
B) ours was indeed a solar system, in which Earth and other planets revolve around the sun, reinforced that of Copernicus (singular/singular = OK)
C) our solar system was indeed solar for Earth and the other planets revolve around the sun, reinforced Copernicus' (singular/singular = OK)
D) our solar system was indeed solar, in which Earth and other planets revolve around the sun, reinforced those of Copernicus (singular/plural = WRONG)
E) Earth and the other planets revolve around the sun in our solar system reinforces that of Copernicus (singular/singular = OK)

We can rule out answers A & D because they compare Galileo's one theory to "those of" Copernicus, which is plural. Now, let's look at the answers we have left with the entire sentence intact and see if we can find the best answer:

B) Galileo's theory that ours was indeed a solar system, in which Earth and other planets revolve around the sun, reinforced that of Copernicus.

This is CORRECT because it uses parallel structure, and it keeps the modifier information between commas to show it's not vital information.

C) Galileo's theory that our solar system was indeed solar for Earth and the other planets revolve around the sun, reinforced Copernicus'.

This answer is INCORRECT because it uses the word "for" as a conjunction, but it doesn't have a comma before it. Therefore, this is a run-on sentence!

E) Galileo's theory that Earth and the other planets revolve around the sun in our solar system reinforces that of Copernicus.

This answer is INCORRECT because it changes the meaning of the sentence. Galileo's theory was that we live in a solar system, NOT that the Earth and other planets revolve around the sun (someone already came up with that...he just gave it a name).

Of course residential solar panels have their limitations, like any form of energy. While they can vary in power, they will generally be rated at between 80-100 Watts. This is how much energy a single panel would put out while in direct sunlight. As the panels won’t always be exposed to direct sunlight, the total is actually somewhat less most of the time. On a sloped roof you can expect about 12 hours of light and 4 hours of direct light. The weather also plays a role.

That said, most solar panels will be arranged in an array, meaning that they can generate several times that amount when used together. Possibly then, you might be looking at several hundred watts of energy for a few days. To put this in perspective, something like a games console would use around 150-200 watts.

There is another limitation of using residential solar panels, which is that there is as-yet no way to store all that energy. This means that if you’re out during those peak hours of sunlight, you won’t be able to benefit from it. The goods news though is that you’ll be selling that energy back to the grid at this point, so you’ll still get to benefit.

But the better option? Get a solar power generator and that way you can store the energy – and you also won’t need to make the considerable investment of having solar panel arrays attached to your roof. Just make sure that you are getting the right size of solar panel for your needs and that it will work with your portable solar power system.

I am afraid that this question is flouting norms. As in B, the OA, if ours was a solar system only in the past, then, what system is it today or going to be tomorrow? Similarly, if G's theory reinforced C's theory just in the past, is the theory not reinforcing today?

These are all universal facts that one has to stick to the norm using simple present tense. Going in for mechanical parallelism, by flouting rationale is not the purpose of GMAT.
Even in E, the meaning is distorted. It looks as if the earth and other planets revolve around the Sun in the solar system and some other stars in some other systems.

Respected experts ! I feel that though in SC both the grammar and the meaning should be taken care of but if we have to choose one we should give preference to grammar. Our task is to choose the correct version, not the one which author wants to convey. Option B is in line with the author's original meaning but don't you think there is a grammatical error. How can a universal truth be written in past tense because our system is still a solar system and will continue to be so. daagh and sayantanc2k support what I think.

Other experts kindly help generis VeritasKarishma Magoosh GMATNinja

If I had to, I would go with (E) and walk away from the question. Look, official questions tell us the official stand on acceptability aspect so it is a good idea to peruse them closely. Rest, learn what they try to teach you and don't worry about much else.

B cannot be the correct answer, "was", are you all flat earth believers too now ?

E is the strongest choice amongst the options, sorry Kaplan wont buy your "theory" on this.

Question is testing modifiers and comparison, galileo’s theory should be compared to Copernicus’ theory


Incorrect usage of ‘those’ in comparison


Right usage of modifier for solar system, correctly conveys the meaning


Sentence conveys that our solar system is indeed solar for Earth which is incorrect, that is not the intended meaning


Incorrect usage of ‘those’ in comparison


Galileo’s theory was that ours is a solar system, (E) conveys that theory is that Earth and the other planets revolve around the sun.. which is not the intended meaning, hence incorrect

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