Summer is Coming! Join the Game of Timers Competition to Win Epic Prizes. Registration is Open. Game starts Mon July 1st.

It is currently 16 Jul 2019, 20:10

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Images from ground-based telescopes are invariably distorted by the Ea

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

Find Similar Topics 
Intern
Intern
User avatar
S
Joined: 14 Sep 2017
Posts: 31
Location: Italy
Re: Images from ground-based telescopes are invariably distorted by the Ea  [#permalink]

Show Tags

New post 03 Apr 2018, 10:38
1
Sorry experts I just don't understand how E is the correct answer:

It just says that for more detailed studies astronomers should use telescopes with more light-gathering capacity than space telescopes can provide......... NO ONE SAYS THAT GROUND-BASED TELESCOPES CAN PROVIDE THAT CAPACITY, CHOOSING ANSWER E I HAVE TO MAKE AN IMPORTANT ASSUMPTION THAT IS NOT SPECIFIED ANYWHERE IN THE TEXT....
CEO
CEO
User avatar
V
Joined: 15 Jul 2015
Posts: 2848
Location: India
GMAT 1: 780 Q50 V51
GRE 1: Q170 V169
Re: Images from ground-based telescopes are invariably distorted by the Ea  [#permalink]

Show Tags

New post 03 Apr 2018, 18:56
1
Fedemaravilla wrote:
Sorry experts I just don't understand how E is the correct answer:

It just says that for more detailed studies astronomers should use telescopes with more light-gathering capacity than space telescopes can provide......... NO ONE SAYS THAT GROUND-BASED TELESCOPES CAN PROVIDE THAT CAPACITY, CHOOSING ANSWER E I HAVE TO MAKE AN IMPORTANT ASSUMPTION THAT IS NOT SPECIFIED ANYWHERE IN THE TEXT....
Let's put some of the information given in the stimulus and in option E down:

1. Astronomers rely on DSA. This means that astronomers are already using DSA to determine the chemical composition and evolutionary history of stars.
2. Space telescopes cannot provide DSA; DSA can be provided only by telescopes with more light-gathering capacity than space telescopes can provide. So DSA needs non-space telescopes.

Because astronomers are already using DSA, and space telescopes can't do DSA, astronomers must be using telescopes that are not space telescopes. Such telescopes must be terrestrial (the opposite of space). Hence E is quite solid as an answer choice.

More generally, you'll find that the correct option does very often involve a "stretch". The GMAT doesn't say how much of a stretch is too much, but a little bit is okay. It'd be very hard to make a compact CR question if the question makers could not take certain things for granted. In this case, as soon as we see that E gives us a weakness (of space telescopes), we should be seriously considering it as a "candidate" option.
_________________
GMAT Club Verbal Expert
User avatar
D
Status: GMAT and GRE tutor
Joined: 13 Aug 2009
Posts: 2666
Location: United States
GMAT 1: 780 Q51 V46
GMAT 2: 800 Q51 V51
GRE 1: Q170 V170
Re: Images from ground-based telescopes are invariably distorted by the Ea  [#permalink]

Show Tags

New post 08 Apr 2018, 18:29
1
AjiteshArun wrote:
Fedemaravilla wrote:
Sorry experts I just don't understand how E is the correct answer:

It just says that for more detailed studies astronomers should use telescopes with more light-gathering capacity than space telescopes can provide......... NO ONE SAYS THAT GROUND-BASED TELESCOPES CAN PROVIDE THAT CAPACITY, CHOOSING ANSWER E I HAVE TO MAKE AN IMPORTANT ASSUMPTION THAT IS NOT SPECIFIED ANYWHERE IN THE TEXT....
Let's put some of the information given in the stimulus and in option E down:

1. Astronomers rely on DSA. This means that astronomers are already using DSA to determine the chemical composition and evolutionary history of stars.
2. Space telescopes cannot provide DSA; DSA can be provided only by telescopes with more light-gathering capacity than space telescopes can provide. So DSA needs non-space telescopes.

Because astronomers are already using DSA, and space telescopes can't do DSA, astronomers must be using telescopes that are not space telescopes. Such telescopes must be terrestrial (the opposite of space). Hence E is quite solid as an answer choice.

More generally, you'll find that the correct option does very often involve a "stretch". The GMAT doesn't say how much of a stretch is too much, but a little bit is okay. It'd be very hard to make a compact CR question if the question makers could not take certain things for granted. In this case, as soon as we see that E gives us a weakness (of space telescopes), we should be seriously considering it as a "candidate" option.

AjiteshArun, thanks for the great response!

The other key to this question is that we are looking for something that "would cast the most doubt on the conclusion drawn above."

So we just need something that would make us question the author's logic/conclusion. The author says that space telescopes should provide superbly detailed images. Therefore, ground telescopes will soon become obsolete. In reaching the conclusion, the author is only considering image quality.

Choice (E) says, "You (author) might be right about image quality, but you haven't considered DSA." So even if we don't know that ground telescopes have the capacity needed for DSA, we already have a reason to doubt the author's logic. The author was ONLY considering image quality and failed to consider DSA.

As explained perfectly by AjiteshArun, it is very reasonable to suspect that ground telescopes have such capacity. However, even without knowing that for sure, we've already poked a hole in the author's argument. That doesn't necessarily PROVE that the author is wrong, but it certainly casts doubt on the argument/conclusion.

None of the other answer choices affect the author's argument, so (E) is definitely the best answer.
_________________
GMAT/GRE tutor @ www.gmatninja.com (we're hiring!) | GMAT Club Verbal Expert | Instagram | Blog | Bad at PMs

Beginners' guides to GMAT verbal: RC | CR | SC

YouTube LIVE verbal webinars: Series 1: Fundamentals of SC & CR | Series 2: Developing a Winning GMAT Mindset

SC & CR Questions of the Day (QOTDs), featuring expert explanations: All QOTDs | Subscribe via email | RSS

Need an expert reply? Hit the request verbal experts' reply button; be specific about your question, and tag @GMATNinja. Priority is always given to official GMAT questions.

SC articles & resources: How to go from great (760) to incredible (780) on GMAT SC | That "-ing" Word Probably Isn't a Verb | That "-ed" Word Might Not Be a Verb, Either | No-BS Guide to GMAT Idioms | "Being" is not the enemy | WTF is "that" doing in my sentence?

RC, CR, and other articles & resources: All GMAT Ninja articles on GMAT Club | Using LSAT for GMAT CR & RC |7 reasons why your actual GMAT scores don't match your practice test scores | How to get 4 additional "fake" GMAT Prep tests for $29.99 | Time management on verbal
CEO
CEO
User avatar
V
Joined: 12 Sep 2015
Posts: 3847
Location: Canada
Re: Images from ground-based telescopes are invariably distorted by the Ea  [#permalink]

Show Tags

New post 29 Nov 2018, 17:07
1
Top Contributor
kahipz wrote:
Images from ground-based telescopes are invariably distorted by the Earth's atmosphere. Orbiting space telescopes, however, operating above Earth's atmosphere, should provide superbly detailed images. Therefore, ground-based telescopes will soon become obsolete for advanced astronomical research purposes.

Which of the following statements, if true, would cast the most doubt on the conclusion drawn above?

(A) An orbiting space telescope due to be launched this year is far behind schedule and over budget, whereas the largest ground-based telescope was both within budget and on schedule.

(B) Ground-based telescopes located on mountain summits are not subject to the kinds of atmospheric distortion which, at low altitudes, make stars appear to twinkle.

(C) By careful choice of observatory location, it is possible for large-aperture telescopes to avoid most of the kind of wind turbulence that can distort image quality.

(D) When large-aperture telescopes are located at high altitudes near the equator, they permit the best Earth-based observations of the center of the Milky Way Galaxy, a prime target of astronomical research.

(E) Detailed spectral analyses, upon which astronomers rely for determining the chemical composition and evolutionary history of stars, require telescopes with more light-gathering capacity than space telescopes can provide.


A student asked me to respond to this question, so . . .

1) Read question stem to determine question type.
Which of the following statements, if true, would cast the most doubt on the conclusion drawn above?
We have a Weaken the Argument question.

2) Read passage and summarize premises and the conclusion.
PREMISE: Images from GBTs (ground-based telescopes) distorted by atmosphere
PREMISE: Space telescopes above atmosphere should make detailed images
CONCLUSION: GBTs to become obsolete for advanced research

3) Check the answer choices while reminding yourself of the CONCLUSION.

(A) An orbiting space telescope due to be launched this year is far behind schedule and over budget, whereas the largest ground-based telescope was both within budget and on schedule.
Does this weaken the conclusion that GBTs will become obsolete for advanced research?
These project-management issues do NOT affect the conclusion.
ELIMINATE A

(B) Ground-based telescopes located on mountain summits are not subject to the kinds of atmospheric distortion which, at low altitudes, make stars appear to twinkle.
In other words, high GBTs are better than low GBTs with regard to one particular phenomenon: the twinkling star effect.
Does this weaken the conclusion that GBTs will become obsolete for advanced research?
Not really. The reason for the soon-to-be demise of GBTs is that they suffer from atmospheric effects.
So, regardless of whether some GBTs are immune to ONE TYPE of atmospheric effect, the space telescopes are immune to ALL atmospheric effects.
ELIMINATE B

(C) By careful choice of observatory location, it is possible for large-aperture telescopes to avoid most of the kind of wind turbulence that can distort image quality.
This is similar to answer choice B.
In other words, SOME (well-placed) GBTs are better than other GBTs with regard to ONE particular atmospheric phenomenon: wind turbulence.
Does this weaken the conclusion that GBTs will become obsolete for advanced research?
ELIMINATE C (see answer choice B for rationale)

(D) When large-aperture telescopes are located at high altitudes near the equator, they permit the best Earth-based observations of the center of the Milky Way Galaxy, a prime target of astronomical research.
This is similar to answer choices B & C.
Once again, we're told that SOME GBTs are better than other GBTs for a specific reason.
Does this weaken the conclusion that GBTs will become obsolete for advanced research?
No.
Answer choice D does not suggest that any GBTs are better suited than space telescopes are to study the universe.
ELIMINATE D

(E) Detailed spectral analyses, upon which astronomers rely for determining the chemical composition and evolutionary history of stars, require telescopes with more light-gathering capacity than space telescopes can provide.
Does this weaken the conclusion that GBTs will become obsolete for advanced research?
Yes!
If space telescopes are too small for certain research, then researches will still need some GBTs to perform the research described above.

Answer: E

Cheers,
Brent
_________________
Test confidently with gmatprepnow.com
Image
Director
Director
avatar
P
Joined: 02 Oct 2017
Posts: 727
Re: Images from ground-based telescopes are invariably distorted by the Ea  [#permalink]

Show Tags

New post 20 Dec 2018, 23:26
E is best choice here
As it states the most important aspect of any astronomical research and hence weaken the conclusion of obseleteness of ground based telescopes
_________________
Give kudos if you like the post
Manager
Manager
avatar
G
Joined: 12 Jan 2019
Posts: 238
Concentration: Strategy, Leadership
Reviews Badge
Re: Images from ground-based telescopes are invariably distorted by the Ea  [#permalink]

Show Tags

New post 16 Jan 2019, 11:24
But option E doesn't tell that ground based telescope will do this work, better.
_________________
In case my post helps you, please provide me with kudos. Thank you
Manager
Manager
User avatar
G
Status: Private GMAT Tutor
Joined: 22 Oct 2012
Posts: 139
Location: India
Concentration: Economics, Finance
Schools: IIMA (A)
GMAT 1: 780 Q51 V47
Re: Images from ground-based telescopes are invariably distorted by the Ea  [#permalink]

Show Tags

New post 23 May 2019, 11:29
1
Top Contributor
kahipz wrote:
Images from ground-based telescopes are invariably distorted by the Earth's atmosphere. Orbiting space telescopes, however, operating above Earth's atmosphere, should provide superbly detailed images. Therefore, ground-based telescopes will soon become obsolete for advanced astronomical research purposes.

Which of the following statements, if true, would cast the most doubt on the conclusion drawn above?


(A) An orbiting space telescope due to be launched this year is far behind schedule and over budget, whereas the largest ground-based telescope was both within budget and on schedule.

(B) Ground-based telescopes located on mountain summits are not subject to the kinds of atmospheric distortion which, at low altitudes, make stars appear to twinkle.

(C) By careful choice of observatory location, it is possible for large-aperture telescopes to avoid most of the kind of wind turbulence that can distort image quality.

(D) When large-aperture telescopes are located at high altitudes near the equator, they permit the best Earth-based observations of the center of the Milky Way Galaxy, a prime target of astronomical research.

(E) Detailed spectral analyses, upon which astronomers rely for determining the chemical composition and evolutionary history of stars, require telescopes with more light-gathering capacity than space telescopes can provide.




I think we still need to do justice to this well-crafted question. Here's my attempt:

I'll just focus on options B, D, and E. However, before I get to the options, let me create a parallel argument.

Students of Class 9A are invariably ill-dressed. Students of Class 9B, however, are well-dressed. Therefore, students of Class 9A will never represent the school in inter-school competitions.

While this argument is not parallel to the original argument in every nuance, I believe it captures the essence of the original argument. If you do not agree, feel free to let me know.

Now, let me create parallel options for this argument:

Option B: Students of Class 9A mentored by their class-teacher do not have the kinds of dressing problems that make students look like beggars.

Does this option weaken the above argument?

The answer is NO. The reason is that this option says that some students of Class 9A (i.e. students mentored by the class-teacher) do not have some kinds of dressing problems. Okay. So, these students are probably better than other students of Class 9A in this respect. However, vis-a-vis students of Class 9B, are these students comparable? There is no indication of this comparison. The reasoning of the argument still holds as is. Even though these students do not have certain kinds of dressing problems, they still are ill-dressed, as originally stated in the argument. Thus, it still doesn't make any sense to ask these students to represent the school. Think about it. The reasoning in the argument was that students of Class 9A are shabby and students of Class 9B are not and that thus students of Class 9A will not represent the school. Even if some students of Class 9A are less shabby than some other students of Class 9A, all the students of Class 9A are still shabby, and thus the reasoning of the argument is still intact.

Similarly, the given option B just says that certain ground-based telescopes (i.e. located on mountain summits) do not have 'certain' kinds of distortions. However, they still have distortions as should every ground-based telescope have (given the facts in the passage). Thus, the reasoning of the argument still holds as is.

Option D (The Parallel form): When students of Class 9A are mentored by their class teacher, they become the best-dressed of the students of Class 9A.

Again, in this option too, just as in option B, we are comparing shabbiness or the sense of dressing among the students of Class 9A. We still are not presenting any advantage students of Class 9A have over students of Class 9B. Of course, if we rank some students of Class 9A in terms of their dressing sense, some students are going to come at the top. However, this doesn't have any effect on the given fact that all students of Class 9A are ill-dressed. Thus, the reasoning of the argument still stands as is.

Similarly, the given option D says that the telescopes located at high altitudes near the equator provide the best 'Earth-based' observations (not the best 'overall' - in which case this option will present an advantage of ground-based telescopes over space telescopes and thus will weaken the argument). Comparing different ground-based telescopes will not help; of course, some of them will be better than the others. However, they all are invariably inferior to the orbiting space telescopes, as stated in the passage. Thus, the reasoning of the passage holds as is.

Option E: This option presents a shortcoming of the orbiting space telescopes. Let me also state that this shortcoming is with respect to ground-based telescopes, not a shortcoming in general. Why do I say that this shortcoming is w.r.t ground-based telescopes?

Because of what the non-essential modifier(within double commas) means. The modifier means that the astronomers rely upon detailed spectral analyses for determining the chemical composition and evolutionary history of stars. If they rely on this capability for determining X (chemical composition etc), they must already be having this capability because, from the context, it seems that they are already determining the chemical composition and evolutionary history of stars. Now, if they have this capability and the orbiting space telescopes cannot provide this capability, it's likely that ground-based telescopes currently provide this capability. Thus, this option presents an advantage ground-based telescopes have over orbiting space telescopes and thus gives us a reason to doubt that ground-based telescopes will become obsolete.

I hope it helps!

- CJ
_________________
Manager
Manager
avatar
B
Joined: 18 Aug 2012
Posts: 87
Re: Images from ground-based telescopes are invariably distorted by the Ea  [#permalink]

Show Tags

New post 29 May 2019, 11:04
I don't agree with option E. The argument concludes that land based telescope will soon be obsolete for one defined reason. Option E gives one drawback of satellite telescope. But it doesn't say that Land based telescope has that quality. May be it is not in either type of telescope?
Someone please explain whats wrong in my analysis?
CEO
CEO
User avatar
V
Joined: 15 Jul 2015
Posts: 2848
Location: India
GMAT 1: 780 Q50 V51
GRE 1: Q170 V169
Re: Images from ground-based telescopes are invariably distorted by the Ea  [#permalink]

Show Tags

New post 29 May 2019, 22:15
rashwiniyer wrote:
I don't agree with option E. The argument concludes that land based telescope will soon be obsolete for one defined reason. Option E gives one drawback of satellite telescope. But it doesn't say that Land based telescope has that quality. May be it is not in either type of telescope?
Someone please explain whats wrong in my analysis?
Hi rashwiniyer, does this post help?
_________________
Manager
Manager
User avatar
B
Joined: 04 Dec 2015
Posts: 123
WE: Operations (Commercial Banking)
Images from ground-based telescopes are invariably distorted by the Ea  [#permalink]

Show Tags

New post 30 May 2019, 08:11
AjiteshArun

GMATNinja

i have gone through your explanation regarding option e. i am still not convinced why e is correct and b is not as, as per me, both b and e weaken the argument.

the argument is precisely about two types of telescopes ie type X and type Y. The author tells us something bad(in terms of image quality) about type X and tells us something good(in terms of image quality) about type Y. The author draws a conclusion regarding type X ie that type X will become obsolete due to bad image quality. ........... Clearly the author has assumed something good about type Y ie. type Y will not become obsolete. So to weaken the assumption, we need an option that tells us something bad about the type Y telescope. Option E clearly does that.

Option B clearly indicates that Type X will not / should not become obsolete as type X's position can be adjusted(if kept on mountain summits) to get a decent image quality. Also the fact that type X, if kept on mountain summit, won't be influenced by atmospheric pressure clearly makes answer choice B an interesting one.

All in all, option B directly attacks the entire argument and option E clearly weakens the assumption. You and I both know that both 'attacking/weakening the entire argument' and 'weakening the assumption' are correct when it comes to weaken questions. how do i choose between the two??

kindly help..

I look forward to hearing from you.
CEO
CEO
User avatar
V
Joined: 15 Jul 2015
Posts: 2848
Location: India
GMAT 1: 780 Q50 V51
GRE 1: Q170 V169
Re: Images from ground-based telescopes are invariably distorted by the Ea  [#permalink]

Show Tags

New post 30 May 2019, 18:44
Hi aditliverpoolfc,

You're thinking along the right lines. Just a couple of quick points:

aditliverpoolfc wrote:
the argument is precisely about two types of telescopes ie type X and type Y. The author tells us something bad(in terms of image quality) about type X and tells us something good(in terms of image quality) about type Y. The author draws a conclusion regarding type X ie that type X will become obsolete due to bad image quality. ........... Clearly the author has assumed something good about type Y ie. type Y will not become obsolete. So to weaken the assumption, we need an option that tells us something bad about the type Y telescope. Option E clearly does that.
Your reasoning is spot on. According to E, ground-based telescopes have more light-gathering capacity than space telescopes do. So ground-based telescopes make "detailed spectral analyses" possible, even though the pictures they generate are affected by atmospheric distortion.

For example, if someone argues that mobile phone screens always have higher DPI than desktop monitors and will therefore make desktop monitors obsolete, we can weaken that by saying that working on large spreadsheets and documents is easier on desktop monitors than it is on phone screens. That is, monitors may not be as sharp as phone screens, but more content can fit on a monitor than on a phone screen.

aditliverpoolfc wrote:
Option B clearly indicates that Type X will not / should not become obsolete as type X's position can be adjusted(if kept on mountain summits) to get a decent image quality. Also the fact that type X, if kept on mountain summit, won't be influenced by atmospheric pressure clearly makes answer choice B an interesting one.
The first sentence says:
Images from ground-based telescopes are invariably distorted by the Earth's atmosphere.

Option B says:
Ground-based telescopes located on mountain summits are not subject to the kinds of atmospheric distortion which, at low altitudes, make stars appear to twinkle.

It's important to recognize that this option does not mean that ground-based telescopes located on mountain summits are not affected by atmospheric distortion at all. It just means that such telescopes are not affected by some (specific) types of atmospheric distortion (the ones that make stars appear to twinkle).

It may help if we replace the which with a that (GMAT sentence correction to the rescue :)):

Ground-based telescopes located on mountain summits are not subject to the kinds of atmospheric distortion that make stars appear to twinkle.
_________________
Manager
Manager
User avatar
B
Joined: 04 Dec 2015
Posts: 123
WE: Operations (Commercial Banking)
Re: Images from ground-based telescopes are invariably distorted by the Ea  [#permalink]

Show Tags

New post 01 Jun 2019, 00:34
1
AjiteshArun THANK YOU. i am able to understand why b is incorrect.
Intern
Intern
User avatar
B
Joined: 20 Mar 2019
Posts: 18
GMAT 1: 710 Q48 V38
GPA: 3.93
Reviews Badge CAT Tests
Re: Images from ground-based telescopes are invariably distorted by the Ea  [#permalink]

Show Tags

New post 01 Jun 2019, 02:36
The question is looking for reasoning that will justify that ground-based telescope will still be needed.

Choice E gives us that. Even though space-based telescope can offer better image. But there are still some functions that ground-based telescope is needed for, thus, weakening the argument that it will be obsolete.

Choice B does mentioned that the flaw of ground-based telescope can be avoid. However, there is still possibility that space-based can do the same job better and ground-based telescope will still be obsolete at one point.
I think that’s why choice B is not the best choice.

Posted from my mobile device
GMAT Club Bot
Re: Images from ground-based telescopes are invariably distorted by the Ea   [#permalink] 01 Jun 2019, 02:36

Go to page   Previous    1   2   [ 33 posts ] 

Display posts from previous: Sort by

Images from ground-based telescopes are invariably distorted by the Ea

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  





Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne