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

It is currently 16 Sep 2014, 07:42

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

passage 33 until recently most astronomers believed that the

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Manager
Manager
User avatar
Joined: 09 Jun 2003
Posts: 188
Location: work chair
Followers: 2

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

passage 33 until recently most astronomers believed that the [#permalink] New post 12 Mar 2004, 06:21
passage 33
until recently most astronomers believed that the
space between the galaxies in our universe was a near-
perfect vacuum. this orthodox view of the universe is
now being challenged by astronomers who believe that a
<b>(5)</b> heavy "rain" of gas is falling into many galaxies from
the supposedly empty space around them. the gas
apparently condenses into a collection of small stars,
each a little larger than the planet jupiter. these stars
vastly outnumber the other stars in a given galaxy. the
<b>(10)</b> amount of "intergalactic rainfall" into some of these
galaxies has been enough to double their mass in the
time since they formed. scientists have begun to suspect
that this intergalactic gas is probably a mixture of gases
left over from the "big bang" when the galaxies were
<b>(15)</b> formed and gas was forced out of galaxies by supernova
explosions.
it is well known that when gas is cooled at a constant
pressure its volume decreases. thus, the physicist fabian
reasoned that as intergalactic gas cools, the cooler gas
<b>(20)</b> shrinks inward toward the center of the galaxy. mean-
while its place is taken by hotter intergalactic gas from
farther out on the edge of the galaxy, which cools as it is
compressed and flows into the galaxy. the net result is a
continuous flow of gas, starting as hot gases in inter-
<b>(25)</b> galactic space and ending as a drizzle of cool gas called a
"cooling flow," falling into the central galaxy.
a fairly heretical idea in the 1970's, the cooling-flow
theory gained support when fabian observed a cluster
of galaxies in the constellation perseus and found the
<b>(30)</b> central galaxy, ngc 1275, to be a strange-looking object
with irregular, thin strands of gas radiating from it.
according to previous speculation, these strands were
gases that had been blown out by an explosion in the
galaxy. fabian, however, disagreed. because the strands
<b>(35)</b> of gas radiating from ngc 1275 are visible in optical
photographs, fabian suggested that such strands consisted
not of gas blown out of the galaxy but of cooling flows
of gas streaming inward. he noted that the wavelengths
of the radiation emitted by a gas would changes as the
<b>(40)</b> gas cooled, so that as the gas flowed into the galaxy and
became cooler, it would emit not x-rays, but visible light,
like that which was captured in the photographs. fabian's
hypothesis was supported by canizares' determination in
1982 that most of the gas in the perseus cluster was at a
<b>(45)</b> temperature of 80 million degrees kelvin, whereas the
gas immediately surrounding ngc 1275 (the subject of
the photographs) was at one-tenth this temperature.

1. the primary purpose of the passage is to
(a) illustrate a hypothesis about the origin of galaxies
(b) provide evidence to dispute an accepted theory about the evolution of galaxies
(c) summarize the state of and prospects for research in intergalactic astronomy
(d) report new data on the origins of intergalactic gas
(e) reconcile opposing views on the formation of intergalactic gas

2. the author uses the phrase "orthodox view of the universe" (line 3) to refer to the belief that
(a) the space between the galaxies is devoid of matter
(b) the space between galaxies is occupied by stars that cannot be detected by optical photographs
(c) galaxies have decreased in mass by half since their formation
(d) galaxies contain stars, each the size of jupiter, which form clusters
(e) galaxies are being penetrated by gas forced out of other galaxies by supernova explosions.

3. it can be inferred from the passage that, if fabian is correct, gas in the peripheral regions of a galaxy cluster
(a) streams outward into intergalactic space
(b) is hotter than gas in the central regions of the galaxy
(c) is composed primarily of gas left over from the big bang
(d) results in the creation of unusually large stars
(e) expands to increase the size of the galaxy

4. the author of the passage probably mentions canizares' determination in order to
(a) clarify an ambiguity in fabian's research findings
(b) illustrate a generalization about the temperature of gas in a galaxy cluster
(c) introduce a new argument in support of the orthodox view of galaxies
(d) provide support for fabian's assertions about the perseus galaxies
(e) provide an alternate point of view concerning the movement of gas within a galaxy cluster

5. according to the passage, fabian believes that gas flowing into a central galaxy has which of the following characteristics?
(a) it is one-tenth hotter than it was in the outer regions of the galaxy cluster.
(b) it emits radiation with wavelengths that change as the gas moves toward the center of the galaxy.
(c) the total amount of radiation emitted diminishes as the gas cools.
(d) it loses 90 percent of its energy as it moves to the center of the galaxy.
(e) it condenses at a rate much slower than the rate of decrease in temperature as the gas flows inward.

6. according to the passage, fabian's theory makes use of which of the following principles?
(a) gas emanating from an explosion will be hotter the more distant it is from the origin.
(b) the wavelength of radiation emitted by a gas as it cools remains constant.
(c) if pressure remains constant, the volume of a gas will decrease as it is cooled.
(d) the volume of a gas will increase as the pressure increases.
(e) as gas cools, its density decreases.

7. it can be inferred from the passage that which of the following is true of fabian's theory?
(a) it did not receive approval until canizares' work was published.
(b) it was not widely accepted in the 1970's.
(c) it did not receive support initially because technology was not available to confirm its tenets.
(d) it supports earlier speculation that intergalactic gas was largely the result of explosions outside the galaxy.
(e) it was widely challenged until x-ray evidence of gas temperatures in ngc 1275 had been presented.
Senior Manager
Senior Manager
avatar
Joined: 23 Sep 2003
Posts: 295
Location: US
Followers: 1

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

GMAT Tests User
 [#permalink] New post 12 Mar 2004, 11:07
1) E
2) A
3) B
4) D
5) B
6) C
7) B
GMAT Instructor
User avatar
Joined: 07 Jul 2003
Posts: 771
Location: New York NY 10024
Schools: Haas, MFE; Anderson, MBA; USC, MSEE
Followers: 9

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

GMAT Tests User
 [#permalink] New post 15 Mar 2004, 01:52
ndidi204 wrote:
1) E
2) A
3) B
4) D
5) B
6) C
7) B


1: Once upon a time, we had a theory; a nice theory that everyone liked until most recently, when support for another theory started growning?
In which way(s) is(are) the two theories "reconciled"?
_________________

Best,

AkamaiBrah
Former Senior Instructor, Manhattan GMAT and VeritasPrep
Vice President, Midtown NYC Investment Bank, Structured Finance IT
MFE, Haas School of Business, UC Berkeley, Class of 2005
MBA, Anderson School of Management, UCLA, Class of 1993

Intern
Intern
avatar
Joined: 09 Mar 2004
Posts: 37
Location: Bombay
Followers: 0

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

 [#permalink] New post 16 Mar 2004, 21:19
AkamaiBrah wrote:

1: Once upon a time, we had a theory; a nice theory that everyone liked until most recently, when support for another theory started growning?
In which way(s) is(are) the two theories "reconciled"?


1. E
2. A
3. B
4. D
5. B
6. C
7. B

AkamaiBrah, what according to you is the first answer ?
  [#permalink] 16 Mar 2004, 21:19
    Similar topics Author Replies Last post
Similar
Topics:
1 Until the 1980s, most scientists believed that mojorising800 14 10 Mar 2010, 02:24
Until recently many astronomers believed that asteroids lahoosaher 11 20 Sep 2009, 05:15
Until recently astronomers have been puzzled by the fate of nitya34 10 31 Mar 2009, 06:19
Until recently many astronomers believed that asteroids nitya34 10 30 Mar 2009, 07:21
1 Experts publish their posts in the topic Until recently most astronomers believed that the space marcodonzelli 8 16 Jan 2008, 21:39
Display posts from previous: Sort by

passage 33 until recently most astronomers believed that the

  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®.