Find all School-related info fast with the new School-Specific MBA Forum

It is currently 30 Sep 2014, 05:56

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Around 1960, mathematician Edward Lorenz found unexpected

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
2 KUDOS received
Current Student
User avatar
Joined: 03 Sep 2012
Posts: 339
Location: United States
Concentration: Healthcare, Strategy
GMAT 1: 730 Q48 V42
GPA: 3.88
WE: Medicine and Health (Health Care)
Followers: 10

Kudos [?]: 76 [2] , given: 31

Around 1960, mathematician Edward Lorenz found unexpected [#permalink] New post 18 Nov 2012, 03:20
2
This post received
KUDOS
Around 1960, mathematician Edward Lorenz found unexpected behavior in apparently simple equations representing atmospheric air flows. Whenever he ran his model with the same inputs, different outputs resulted - although the model lacked any random elements. Lorenz realized that the tiny rounding errors in his analog computer mushroomed over time, leading to erratic results. His findings marked a seminal moment in the development of chaos theory, which despite its name, has little to do with randomness.

TO understand how unpredictability can arise from deterministic equations, which do not involve chance outcomes, consider the non-chaotic system of two poppy seeds placed in a round bowl. As the seeds roll to the bowl's center, a position known as a point attractor, the distance between the seeds shrinks. If instead, the bowl is flipped over, two seeds placed on top will roll away from each other. Such a system, while still technically chaotic, enlarges initial differences in position.

Chaotic systems, such as a machine mixing bread dough, are characterized by both attraction and repulsion. As the dough is stretched, folded and pressed back together, any poppy seeds sprinkled in are intermixed seemingly at random. But this randomness is illusory. In fact, the poppy seeds are captured by "strange attactors," staggeringly complex pathways whose tangles appear accidental but are in fact determined by the system's fundamental equations.

During the dough-kneading process, two poppy seeds positioned next to each other eventually go their separate ways. Any early divergence or measurement error is repeatedly amplified by the mixing until the position of any seed becomes effectively unpredictable. It is this "sensitive dependence on initial conditions" and not true randomness that generates unpredictability in chaotic systems, of which one example may be the Earth's weather. According to the popular interpretation of the "Butterfly effect", a butterfly flapping its wings caused hurricanes. A better understanding is that the butterfly causes uncertainty about the precise state of the air. This microscopic uncertainty grows until it encompasses even hurricanes. Few meteorologists believe that we will ever ben able to predict rain or shine for a particular day years in the future.
1. The main purpose of this passage is to
(A) Explain complicated aspects of certain physical systems
(B) trace the historical development of scientific theory
(C) distinguish a mathematical patter from its opposition
(D) describe the spread of a technical model from one field of study to others
(E) contrast possible causes of weather phenomena
[Reveal] Spoiler:
A


2. In the example discussed in the passage, what is true about poppy seeds in bread dough, once the dough has been thoroughly mixed?
(A) They have been individually stretched and folded over, like miniature versions of the entire dough
(B) They are scattered in random clumps throughout the dough
(C) They are accidentally caught in tangled objects called strange attractors
(D) They are bound to regularly dispersed patterns of point attractors
(E) They are positions dictated by the underlying equations that govern the mixing process
[Reveal] Spoiler:
E


3. According to the passage, the rounding errors in Lorenz's model
(A) Indicated that the model was programmed in a fundamentally faulty way
(B) were deliberately included to represent tiny fluctuations in atmospheric air currents
(C) were imperceptibly small at first, but tended to grow
(D) were at least partially expected, given the complexity of the actual atmosphere
(E) shrank to insignificant levels during each trial of the model
[Reveal] Spoiler:
C


4. The passage mentions each of the following as an example of potential example of chaotic or non-chaotic system Except
(A) a dough-mixing machine
(B) atmospheric weather patters
(C) poppy seeds place on top of an upside-down bowl
(D) poppy seeds placed in a right-side up bowl
(E) fluctuating butterfly flight patterns
[Reveal] Spoiler:
E


5. It can be inferred from the passage that which of the following pairs of items would most likely follow typical pathways within a chaotic system?
(A) two particles ejected in random directions from the same decaying atomic nucleus
(B) two stickers affixed to balloon that expands and contracts over and over again
(C) two avalanches sliding down opposite sides of the same mountain
(D) two baseballs placed into an active tumble dryer
(E) two coins flipped into a large bowl
[Reveal] Spoiler:
D



OA's to follow..
_________________

"When you want to succeed as bad as you want to breathe, then you’ll be successful.” - Eric Thomas

4 KUDOS received
Intern
Intern
avatar
Joined: 15 Dec 2007
Posts: 13
Followers: 3

Kudos [?]: 2 [4] , given: 138

Re: Around 1960, mathematician Edward Lorenz found unexpected [#permalink] New post 12 Mar 2013, 06:16
4
This post received
KUDOS
Had to google the answers (they are from MGMAT RC), here's the OA:
[Reveal] Spoiler:
1. A
2. E
3. C
4. E
5. D
Intern
Intern
avatar
Joined: 19 May 2012
Posts: 36
Location: India
Concentration: International Business, Healthcare
GMAT Date: 03-03-2014
WE: Information Technology (Computer Software)
Followers: 1

Kudos [?]: 7 [0], given: 0

Re: Around 1960, mathematician Edward Lorenz found unexpected [#permalink] New post 01 Jan 2013, 08:09
tough RC
IMO
A
C
C
E
B

Please post OAs.
_________________

Thanks
crazy4priya
GMATPrep 1 710/Q49/V38
GMATPrep 2 690/Q49/V34
Veritas Prep 700/Q50/V36/IR5
MGMT Test 1 700/Q51/V35/IR3

Intern
Intern
avatar
Joined: 31 Oct 2012
Posts: 9
Followers: 0

Kudos [?]: 0 [0], given: 13

Re: Around 1960, mathematician Edward Lorenz found unexpected [#permalink] New post 01 Jan 2013, 09:10
is the answer: A,C,C,D,A
Intern
Intern
avatar
Joined: 28 Nov 2010
Posts: 3
Followers: 0

Kudos [?]: 0 [0], given: 4

Re: Around 1960, mathematician Edward Lorenz found unexpected [#permalink] New post 26 Jan 2013, 14:42
A E C E D

Question 2 - the third paragraph discusses how poppy seeds are niter mixed seemingly at random, but the positions of the seeds are not random. They a actually determined by the system's fundamental equations.

Question 5 - this question asks to infer which system would be the most chaotic and resemble the typical pathways. Only answer D mentions a system by which the system's fundamental equations are pre-determined and thus two baseballs placed into a tumble dryer reflect this.

Hope this is helpful! :)
Intern
Intern
avatar
Joined: 30 Aug 2007
Posts: 4
Followers: 0

Kudos [?]: 3 [0], given: 4

Re: Around 1960, mathematician Edward Lorenz found unexpected [#permalink] New post 29 Jan 2013, 19:45
I believe answers should be

1 D (Chaotic model is used to explain different areas or field of study)
2 B
3 C
4 D
5 D (very similar to poppy seed & dough example)
Intern
Intern
avatar
Joined: 24 Sep 2012
Posts: 41
Followers: 0

Kudos [?]: 3 [0], given: 76

Re: Around 1960, mathematician Edward Lorenz found unexpected [#permalink] New post 11 Mar 2013, 09:18
Hi,
1. B
2. A
3. C
4. D
5. B

Please post the OA.

Regards,
Pritish
Manager
Manager
avatar
Status: Training
Joined: 03 Jun 2013
Posts: 90
Location: Canada
GPA: 3.7
Followers: 2

Kudos [?]: 31 [0], given: 3

GMAT ToolKit User Reviews Badge
Re: Around 1960, mathematician Edward Lorenz found unexpected [#permalink] New post 21 Jun 2013, 10:47
Hmm, despite correctly answering this question, I have a concern:

Question 3:
I agree that C is the "best" answer, but I use the word "best" with reservation.
The passage states that "Whenever he reran his model with the same inputs, different outputs resulted"
This implies that even at the beginning, he could see the impact of these rounding errors.
Thus, how can we say that these errors started off as being "imperceptibly small"?

- Do people agree on this or am I incorrect?
_________________

KUDOS please if my post was useful!

Manager
Manager
User avatar
Joined: 19 Oct 2012
Posts: 111
Location: India
Concentration: General Management, Operations
GMAT 1: 660 Q47 V35
GPA: 3.81
WE: Information Technology (Computer Software)
Followers: 0

Kudos [?]: 22 [0], given: 12

Re: Around 1960, mathematician Edward Lorenz found unexpected [#permalink] New post 22 Jun 2013, 13:25
mattce wrote:
Hmm, despite correctly answering this question, I have a concern:

Question 3:
I agree that C is the "best" answer, but I use the word "best" with reservation.
The passage states that "Whenever he reran his model with the same inputs, different outputs resulted"
This implies that even at the beginning, he could see the impact of these rounding errors.
Thus, how can we say that these errors started off as being "imperceptibly small"?

- Do people agree on this or am I incorrect?


Hi,

Here is a piece of my mind. Lets re-read this line from the passage again with a certain degree of criticality:
" Lorenz realized that the tiny rounding errors in his analog computer mushroomed over time, leading to erratic results."
The word "realized" clearly indicates that over the period of time iterating through his experiments he realized the imperceptible or "difficult to perceive" errors are indeed making a difference to the final result.

Hence the correct answer speaks out among the rest. Hope that helps :wink:

Btw a good passage. A difficult read but comparatively easier questions. All correct within 9mins & xx secs :!: :!:
_________________

Citius, Altius, Fortius

Intern
Intern
User avatar
Joined: 10 Sep 2013
Posts: 27
Location: India
Concentration: Accounting, Finance
GMAT Date: 10-25-2013
GPA: 3.66
Followers: 0

Kudos [?]: 10 [0], given: 30

Re: Around 1960, mathematician Edward Lorenz found unexpected [#permalink] New post 24 Oct 2013, 07:10
Is this a 700 level or a 600-700 level RC??
_________________

Strive for Excellence....!!!!!

Manager
Manager
avatar
Joined: 04 Sep 2012
Posts: 144
Followers: 1

Kudos [?]: 21 [0], given: 27

GMAT ToolKit User
Re: Around 1960, mathematician Edward Lorenz found unexpected [#permalink] New post 26 Oct 2013, 05:00
took me 10 mins for this RC dont know good or bad.Got 4 questions right had no clue about the 5th one ...

1.A
2.E
3.C
4.E
5.C

Can any one please explain the 5th one ....

Regards,
abhinav
_________________

Regards,
Abhinav

GMAT 1 - 580 (Q47 V23) a-tight-slap-on-face-149457.html

GMAT 2 - 670 (Q48 V34) 670-one-month-off-from-office-and-2-months-hard-work-163761.html#p1297561

“If you don't change your life; your life will change you.”

Intern
Intern
avatar
Joined: 14 Apr 2012
Posts: 13
Followers: 0

Kudos [?]: 10 [0], given: 12

Re: Around 1960, mathematician Edward Lorenz found unexpected [#permalink] New post 26 Oct 2013, 11:05
Here is the explanation for the 5th question. Hope this helps.

It can be inferred from the passage that which of the following pairs of items would most likely follow typical pathways within a chaotic system? - On a bigger picture this question is asking which system is similar to the systems described in the passge. There are two systems described in the passage to explain chaotic system 1. poppy seeds in bowl/ dough 2. butterfly effect on weather (very vaguely)

(A) two particles ejected in random directions from the same decaying atomic nucleus - Nothing is mentioned about decaying atomic nucleus. This is not remotely closer to either of the two systems described in the passage
(B) two stickers affixed to balloon that expands and contracts over and over again - Nothing is mentioned about balloon expanding and contracting. This is not remotely closer to either of the two systems described in the passage
(C) two avalanches sliding down opposite sides of the same mountain - This may be remotely related to weather. keep it.
(D) two baseballs placed into an active tumble dryer - Very similar to the poppy seeds in bowl. This is it!
(E) two coins flipped into a large bowl - Nothing is mentioned about flipping coins. This is not remotely closer to either of the two systems described in the passage

abhinav11 wrote:
took me 10 mins for this RC dont know good or bad.Got 4 questions right had no clue about the 5th one ...

1.A
2.E
3.C
4.E
5.C

Can any one please explain the 5th one ....

Regards,
abhinav
Senior Manager
Senior Manager
avatar
Joined: 07 Apr 2012
Posts: 465
Followers: 1

Kudos [?]: 4 [0], given: 58

CAT Tests
Re: Around 1960, mathematician Edward Lorenz found unexpected [#permalink] New post 14 Nov 2013, 08:32
vomhorizon wrote:
Around 1960, mathematician Edward Lorenz found unexpected behavior in apparently simple equations representing atmospheric air flows. Whenever he ran his model with the same inputs, different outputs resulted - although the model lacked any random elements. Lorenz realized that the tiny rounding errors in his analog computer mushroomed over time, leading to erratic results. His findings marked a seminal moment in the development of chaos theory, which despite its name, has little to do with randomness.

TO understand how unpredictability can arise from deterministic equations, which do not involve chance outcomes, consider the non-chaotic system of two poppy seeds placed in a round bowl. As the seeds roll to the bowl's center, a position known as a point attractor, the distance between the seeds shrinks. If instead, the bowl is flipped over, two seeds placed on top will roll away from each other. Such a system, while still technically chaotic, enlarges initial differences in position.

Chaotic systems, such as a machine mixing bread dough, are characterized by both attraction and repulsion. As the dough is stretched, folded and pressed back together, any poppy seeds sprinkled in are intermixed seemingly at random. But this randomness is illusory. In fact, the poppy seeds are captured by "strange attactors," staggeringly complex pathways whose tangles appear accidental but are in fact determined by the system's fundamental equations.

During the dough-kneading process, two poppy seeds positioned next to each other eventually go their separate ways. Any early divergence or measurement error is repeatedly amplified by the mixing until the position of any seed becomes effectively unpredictable. It is this "sensitive dependence on initial conditions" and not true randomness that generates unpredictability in chaotic systems, of which one example may be the Earth's weather. According to the popular interpretation of the "Butterfly effect", a butterfly flapping its wings caused hurricanes. A better understanding is that the butterfly causes uncertainty about the precise state of the air. This microscopic uncertainty grows until it encompasses even hurricanes. Few meteorologists believe that we will ever ben able to predict rain or shine for a particular day years in the future.
1. The main purpose of this passage is to
(A) Explain complicated aspects of certain physical systems
(B) trace the historical development of scientific theory
(C) distinguish a mathematical patter from its opposition
(D) describe the spread of a technical model from one field of study to others
(E) contrast possible causes of weather phenomena
[Reveal] Spoiler:
A


2. In the example discussed in the passage, what is true about poppy seeds in bread dough, once the dough has been thoroughly mixed?
(A) They have been individually stretched and folded over, like miniature versions of the entire dough
(B) They are scattered in random clumps throughout the dough
(C) They are accidentally caught in tangled objects called strange attractors
(D) They are bound to regularly dispersed patterns of point attractors
(E) They are positions dictated by the underlying equations that govern the mixing process
[Reveal] Spoiler:
E


3. According to the passage, the rounding errors in Lorenz's model
(A) Indicated that the model was programmed in a fundamentally faulty way
(B) were deliberately included to represent tiny fluctuations in atmospheric air currents
(C) were imperceptibly small at first, but tended to grow
(D) were at least partially expected, given the complexity of the actual atmosphere
(E) shrank to insignificant levels during each trial of the model
[Reveal] Spoiler:
C


4. The passage mentions each of the following as an example of potential example of chaotic or non-chaotic system Except
(A) a dough-mixing machine
(B) atmospheric weather patters
(C) poppy seeds place on top of an upside-down bowl
(D) poppy seeds placed in a right-side up bowl
(E) fluctuating butterfly flight patterns
[Reveal] Spoiler:
E


5. It can be inferred from the passage that which of the following pairs of items would most likely follow typical pathways within a chaotic system?
(A) two particles ejected in random directions from the same decaying atomic nucleus
(B) two stickers affixed to balloon that expands and contracts over and over again
(C) two avalanches sliding down opposite sides of the same mountain
(D) two baseballs placed into an active tumble dryer
(E) two coins flipped into a large bowl
[Reveal] Spoiler:
D



OA's to follow..

I am having trouble with q 4.
I don't understand how E is the answer.
" It is this "sensitive dependence on initial conditions" and not true randomness that generates unpredictability in chaotic systems, of which one example may be the Earth's weather. According to the popular interpretation of the "Butterfly effect", a butterfly flapping its wings caused hurricanes."
It's written that the butterfly effect is "in chaotic systems".... So why is E the answer?
Intern
Intern
avatar
Joined: 14 Sep 2013
Posts: 10
Followers: 0

Kudos [?]: 0 [0], given: 1

Re: Around 1960, mathematician Edward Lorenz found unexpected [#permalink] New post 24 Nov 2013, 14:47
For question 4, I could understand that E is correct , but I also don't see answer D being mentioned anywhere in the passage. Could someone please explain where in the passage mentions answer D?
Re: Around 1960, mathematician Edward Lorenz found unexpected   [#permalink] 24 Nov 2013, 14:47
    Similar topics Author Replies Last post
Similar
Topics:
2 Experts publish their posts in the topic In 1960 s studies of rats, scientists found that crowding enigma123 10 08 Nov 2011, 15:44
4 In 1960 s studies of rats, scientists found that crowding raghavs 8 09 Nov 2010, 09:48
In 1960 s studies of rats, scientists found that crowding reply2spg 5 19 Feb 2009, 11:12
7 Experts publish their posts in the topic In 1960 s studies of rats, scientists found that crowding eyunni 8 28 Jan 2008, 13:52
In 1960 s studies of rats, scientists found that crowding jerrywu 13 25 Sep 2006, 09:57
Display posts from previous: Sort by

Around 1960, mathematician Edward Lorenz found unexpected

  Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Privacy Policy| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group and phpBB SEO

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.