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Quantum mechanics is a highly successful theory: it supplies methods

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Quantum mechanics is a highly successful theory: it supplies methods  [#permalink]

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28 Oct 2019, 02:15
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2
Question 1
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Question 2
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39% (01:26) correct 61% (01:49) wrong

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Question 3
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Kudos for the OA and Explanation

[This passage was excerpted from an article published in 1979.]

Quantum mechanics is a highly successful theory: it supplies methods for accurately calculating the results of diverse experiments, especially with minute particles. The predictions of quantum mechanics, however, give only the probability of an event, not a deterministic statement of whether or not the event will occur.

Because of this probabilism, Einstein remained strongly dissatisfied with the theory throughout his life, though he did not maintain that quantum mechanics is wrong. Rather, he held that it is incomplete: in quantum mechanics the motion of a particle must be described in terms of probabilities, he argued, only because some parameters that determine the motion have not been specified. If these hypothetical "hidden parameters" were known, a fully deterministic trajectory could be defined. Significantly, this hidden-parameter quantum theory leads to experimental predictions different from those of traditional quantum mechanics. Einstein's ideas have been tested by experiments performed since his death, and as most of these experiments support traditional quantum mechanics, Einstein's approach is almost certainly erroneous.

Spoiler: :: OA
E

1. The author regards the idea that traditional quantum mechanics is incomplete with

(A) approval
(B) surprise
(C) indifference
(D) apprehension
(E) skepticism

Spoiler: :: OA
B

2. It can be inferred from the passage that the author's conclusion that Einstein's approach is "erroneous" might have to be modified because

(A) it is theoretically possible to generate plausible theories with hidden parameters within them
(B) some experimental tests of Einstein's theory do not disconfirm the hidden-parameter theory of quantum mechanics
(C) it is possible for a theory to have hidden parameters and yet be probabilistic
(D) traditional quantum mechanics has not yet been used to analyze all of the phenomena to which it could be applied
(E) there are too many possible hidden parameters to develop meaningful tests of hidden parameter theories

Spoiler: :: OA
B

3. According to the passage, Einstein posed objections to the

(A) existence of hidden parameters in quantum theory
(B) probabilistic nature of quantum mechanics
(C) idea that quantum mechanics is incomplete
(D) results of experiments testing quantum theory
(E) the importance accorded quantum mechanics in physics

Spoiler: :: OA
C

4. The passage suggests that which of the following would have resulted if the experiments mentioned had not supported the predictions of traditional quantum mechanics?

(A) Einstein, had he been alive, would have revised his approach to quantum mechanics.
(B) Hidden-parameter theories would have been considered inaccurate descriptions of real-world phenomena.
(C) A deterministic description of the motion of a particle might still be considered possible.
(D) Quantum mechanics would have ceased to attract the attention of physicists.
(E) Einstein, had he been alive, would have abandoned attempts to specify the hidden parameters that describe motion.

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Re: Quantum mechanics is a highly successful theory: it supplies methods  [#permalink]

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31 Oct 2019, 23:25
2
All correct except Q2 in 6 mins 30 seconds, including 2 mins 20 seconds to read.

Para 1- Quantum mechanics- use(accurately calculating the results of diverse experiments, especially with minute particles) and limitations(give only the probability of an event)
Para 2- Einstein's view on QM- hypothetical "hidden parameters"; experimentation of hidden-parameter quantum theory vs traditional quantum mechanics;

1. The author regards the idea that traditional quantum mechanics is incomplete with
(E) skepticism - Correct

Einstein remained strongly dissatisfied with the theory throughout his life, though he did not maintain that quantum mechanics is wrong. Rather, he held that it is incomplete
Significantly, this hidden-parameter quantum theory leads to experimental predictions different from those of traditional quantum mechanics. Einstein's ideas have been tested by experiments performed since his death, and as most of these experiments support traditional quantum mechanics, Einstein's approach is almost certainly erroneous.

2. It can be inferred from the passage that the author's conclusion that Einstein's approach is "erroneous" might have to be modified because
(A) it is theoretically possible to generate plausible theories with hidden parameters within them - incorrect, Einstein did generate one and the possibility of generating one was not an issue but rather the results were
(B) some experimental tests of Einstein's theory do not disconfirm the hidden-parameter theory of quantum mechanics
(C) it is possible for a theory to have hidden parameters and yet be probabilistic - incorrect, Einstein added hidden parameters to shift QM from probabilistic to determinsitic
(D) traditional quantum mechanics has not yet been used to analyze all of the phenomena to which it could be applied - irrelevant
(E) there are too many possible hidden parameters to develop meaningful tests of hidden parameter theories

I was down to options B and E and ended up choosing option E. But if option E is true, then it will NEVER be possible to test such theories.
E might have been correct if it said as of now, scientists do not have the ability to develop meaningful tests of hidden parameter theories

Whereas option B, some experimental tests of Einstein's theory do not disconfirm the hidden-parameter theory of quantum mechanics
Passage states-"as most of these experiments support traditional quantum mechanics". Since some experiments do not disconfirm, we cannot conclusively claim that Einstein's approach is almost certainly erroneous.
I thought that since the majority of experiments support traditional quantum mechanics, there is a high probability of it being correct.

AjiteshArun , GMATNinja , MagooshExpert , GMATGuruNY , VeritasPrepBrian , MartyTargetTestPrep , DmitryFarber , VeritasKarishma , generis , other experts - please enlighten

3. According to the passage, Einstein posed objections to the
(B) probabilistic nature of quantum mechanics
Rather, he held that it is incomplete: in quantum mechanics the motion of a particle must be described in terms of probabilities, he argued, only because some parameters that determine the motion have not been specified.

4. The passage suggests that which of the following would have resulted if the experiments mentioned in lines 18-20 had not supported the predictions of traditional quantum mechanics?
(C) A deterministic description of the motion of a particle might still be considered possible. - Correct, we would still be open that Einstein's view is possible

Rather, he held that it is incomplete: in quantum mechanics the motion of a particle must be described in terms of probabilities, he argued, only because some parameters that determine the motion have not been specified. If these hypothetical "hidden parameters" were known, a fully deterministic trajectory could be defined.

carcass wrote:
Quantum mechanics is a highly successful theory: it supplies methods for accurately calculating the results of diverse experiments, especially with minute particles. Line The predictions of quantum mechanics, however, give only the probability of an event, not a deterministic statement of whether or not the event will occur.

Because of this probabilism, Einstein remained strongly dissatisfied with the theory throughout his life, though he did not maintain that quantum mechanics is wrong. Rather, he held that it is incomplete: in quantum mechanics the motion of a particle must be described in terms of probabilities, he argued, only because some parameters that determine the motion have not been specified. If these hypothetical "hidden parameters" were known, a fully deterministic trajectory could be defined. Significantly, this hidden-parameter quantum theory leads to experimental predictions different from those of traditional quantum mechanics. Einstein's ideas have been tested by experiments performed since his death, and as most of these experiments support traditional quantum mechanics, Einstein's approach is almost certainly erroneous.

carcass ,
It seems that the word 'line', which precedes 'The predictions of quantum mechanics' in the second sentence of the first paragraph, isn't correct.
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Re: Quantum mechanics is a highly successful theory: it supplies methods  [#permalink]

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01 Nov 2019, 10:47
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Top Contributor
Because of this probabilism, Einstein remained strongly dissatisfied with the theory throughout his life, though he did not maintain that quantum mechanics is wrong. Rather, he held that it is incomplete: in quantum mechanics, the motion of a particle must be described in terms of probabilities, he argued, only because some parameters that determine the motion have not been specified.

The greatest genius of the 20th century was not fully satisfied of the quantum theory due to incompleteness. Because we have to use the probability of motion of some particles, as it turns out, some parameters are NOT SPECIFIED. From this we do know that they are somewhere in there, in the motion or dynamic of the particles.

If these hypothetical "hidden parameters" were known, a fully deterministic trajectory could be defined.

A fully deterministic trajectory, which means that some determination of it is still possible with the classic quantum. A certain percentage of it.

Significantly, this hidden-parameter quantum theory leads to [u]experimental predictions[/u] different from those of traditional quantum mechanics.

Einstein's ideas have been tested by experiments performed since his death, and as most of these experiments support traditional quantum mechanics, Einstein's approach is almost certainly erroneous.

--------------------------------------------------------------------------------------------------------------------------

It can be inferred from the passage that the author's conclusion that Einstein's approach is "erroneous" might have to be modified because

(A) it is theoretically possible to generate plausible theories with hidden parameters within them

To broad. We can still generate theories even if we do not know the hidden stuff. Traditional quantum theory permits us to do so.

(B) some experimental tests of Einstein's theory do not disconfirm the hidden-parameter theory of quantum mechanics

Yes. The genius was not wrong after all. In fact, the experiments were conducted with classic QT, Einstein instead talked about an experimental approach to follow but the constraint were the HPs.
we do not know how they unfold and how these HP lead the particles in their motion.

Basically the answer that B is correct is in this sentence

Quote:
Significantly, this hidden-parameter quantum theory leads to experimental predictions different from those of traditional quantum mechanics.

The experimental approach that Einstein followed suggested us experimental paths which are DIFFERENT from those in the traditional theory. But here, nobody says that they are mutually exclusive. The traditional theory follows one way and the experimental another way BUT the traditional did not say that the experimental is totally wrong OR we do not have the HPs.

Correct

(C) it is possible for a theory to have hidden parameters and yet be probabilistic

Remember: if we do know the HP we can assess a fully deterministic trajectory. Which means even without we can design it to a certain %

(D) traditional quantum mechanics has not yet been used to analyze all of the phenomena

out of scope. I did not even see the mention of all phenomena in the passage

(E) there are too many possible hidden parameters to develop meaningful tests of hidden parameter theories

The one that tricks you: this question, reading it at a closer look, say a stupid thing: we do have too many parameters to develop meaningful tests of hidden parameter theories

Notice the wording: having tests without any possible significance of the buried parameter theories. We are not talking about the theories of HP. we are saying that we do have a motion of the particles, this motion is not fully understood and IF we do fully understand where are these HPs, how they act and so forth. we could FULLY have a deterministic trajectory. Turns out, even without we can STILL have a good determination of the same paths.

if you read it E is dull as a question. Do not infer too much. The secret of RC passages is to break down the passages sentence by sentence: or you simply them, or you reword them or else when you attack the questions you bet that the answer suddenly is revealed to you.

Hope this helps. Give kudo if yes.

PS: It seems that the word 'line', which precedes 'The predictions of quantum mechanics' in the second sentence of the first paragraph, isn't correct.
Fixed. Thank you
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Re: Quantum mechanics is a highly successful theory: it supplies methods  [#permalink]

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09 May 2020, 00:33
carcass wrote:
Kudos for the OA and Explanation

[This passage was excerpted from an article published in 1979.]

Quantum mechanics is a highly successful theory: it supplies methods for accurately calculating the results of diverse experiments, especially with minute particles. The predictions of quantum mechanics, however, give only the probability of an event, not a deterministic statement of whether or not the event will occur.

Because of this probabilism, Einstein remained strongly dissatisfied with the theory throughout his life, though he did not maintain that quantum mechanics is wrong. Rather, he held that it is incomplete: in quantum mechanics the motion of a particle must be described in terms of probabilities, he argued, only because some parameters that determine the motion have not been specified. If these hypothetical "hidden parameters" were known, a fully deterministic trajectory could be defined. Significantly, this hidden-parameter quantum theory leads to experimental predictions different from those of traditional quantum mechanics. Einstein's ideas have been tested by experiments performed since his death, and as most of these experiments support traditional quantum mechanics, Einstein's approach is almost certainly erroneous.

Spoiler: :: OA
E

1. The author regards the idea that traditional quantum mechanics is incomplete with

(A) approval
(B) surprise
(C) indifference
(D) apprehension
(E) skepticism

Spoiler: :: OA
B

2. It can be inferred from the passage that the author's conclusion that Einstein's approach is "erroneous" might have to be modified because

(A) it is theoretically possible to generate plausible theories with hidden parameters within them
(B) some experimental tests of Einstein's theory do not disconfirm the hidden-parameter theory of quantum mechanics
(C) it is possible for a theory to have hidden parameters and yet be probabilistic
(D) traditional quantum mechanics has not yet been used to analyze all of the phenomena to which it could be applied
(E) there are too many possible hidden parameters to develop meaningful tests of hidden parameter theories

Spoiler: :: OA
B

3. According to the passage, Einstein posed objections to the

(A) existence of hidden parameters in quantum theory
(B) probabilistic nature of quantum mechanics
(C) idea that quantum mechanics is incomplete
(D) results of experiments testing quantum theory
(E) the importance accorded quantum mechanics in physics

Spoiler: :: OA
C

4. The passage suggests that which of the following would have resulted if the experiments mentioned had not supported the predictions of traditional quantum mechanics?

(A) Einstein, had he been alive, would have revised his approach to quantum mechanics.
(B) Hidden-parameter theories would have been considered inaccurate descriptions of real-world phenomena.
(C) A deterministic description of the motion of a particle might still be considered possible.
(D) Quantum mechanics would have ceased to attract the attention of physicists.
(E) Einstein, had he been alive, would have abandoned attempts to specify the hidden parameters that describe motion.

Can someone please explain Q1? I took this passage to be completely narrative in nature and hence marked choice c that the author is indifferent towards the fact that Einstein considered the theory to be incomplete.
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Quantum mechanics is a highly successful theory: it supplies methods  [#permalink]

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19 May 2020, 23:26
Hi everyone,
Got all correct in 7:20 minutes, including 2:30 minutes to read and 4:50 minutes to answer the questions.

------------------------------------------------------------------------------------------------------

P1

Here the author talks about quantum mechanic and claims that the probabilistic side of it is a drawback.

Purpose: To describe quantum mechanic and one of its drawback

P2

In this paragraph the author claims that Einstein was dissatisfied with the traditional theory of Quantum mechanics and that he formulated and alternative theory. The the author proceeds to refute such theory on the basis of some experiments.

Purpose: To present Einstein's point of view and to reject one of his theories.

Main point

The main point is to consider Quantum mechanics and to refute one theory related to it and formulated by Einstein.

------------------------------------------------------------------------------------------------------

1. The author regards the idea that traditional quantum mechanics is incomplete with

Pre-thinking

Detail question

The author clearly refutes the theory because she claims that a lot of verified experiments made after Einstein's death went against such theory ( Apoorva2705 )

(A) approval opposite
(B) surprise no surprise anywhere
(C) indifference no, the author disapproves of the theory
(D) apprehension no apprehension
(E) skepticism Correct

------------------------------------------------------------------------------------------------------

2. It can be inferred from the passage that the author's conclusion that Einstein's approach is "erroneous" might have to be modified because

Pre-thinking

Inference question

From P2:
Einstein's ideas have been tested by experiments performed since his death, and as most of these experiments support traditional quantum mechanics, Einstein's approach is almost certainly erroneous.

We can simply infer that if we just look at the other experiments, such experiments would support Einstein's point of view.

(A) it is theoretically possible to generate plausible theories with hidden parameters within them incorrect
(B) some experimental tests of Einstein's theory do not disconfirm the hidden-parameter theory of quantum mechanics in line with pre-thinking
(C) it is possible for a theory to have hidden parameters and yet be probabilistic quite the opposite direction
(D) traditional quantum mechanics has not yet been used to analyze all of the phenomena to which it could be applied out of scope
(E) there are too many possible hidden parameters to develop meaningful tests of hidden parameter theories cannot be inferred

------------------------------------------------------------------------------------------------------

3. According to the passage, Einstein posed objections to the

Pre-thinking

Detail question

From P2:
Rather, he held that it is incomplete: in quantum mechanics the motion of a particle must be described in terms of probabilities, he argued, only because some parameters that determine the motion have not been specified. If these hypothetical "hidden parameters" were known, a fully deterministic trajectory could be defined.

(A) existence of hidden parameters in quantum theory opposite
(B) probabilistic nature of quantum mechanics Mentioned
(C) idea that quantum mechanics is incomplete opposite
(D) results of experiments testing quantum theory Not mentioned
(E) the importance accorded quantum mechanics in physics not mentioned

------------------------------------------------------------------------------------------------------

4. The passage suggests that which of the following would have resulted if the experiments mentioned had not supported the predictions of traditional quantum mechanics?

Pre-thinking

Inference question

From P1:
The predictions of quantum mechanics, however, give only the probability of an event, not a deterministic statement of whether or not the event will occur.

+

From P2:
Significantly, this hidden-parameter quantum theory leads to experimental predictions different from those of traditional quantum mechanics.

We can easily infer that Quantum mechanics would have a deterministic nature.

(A) Einstein, had he been alive, would have revised his approach to quantum mechanics. Cannot be inferred from this passage
(B) Hidden-parameter theories would have been considered inaccurate descriptions of real-world phenomena. Probably opposite
(C) A deterministic description of the motion of a particle might still be considered possible. In line with pre-thinking
(D) Quantum mechanics would have ceased to attract the attention of physicists. Cannot be inferred from this passage
(E) Einstein, had he been alive, would have abandoned attempts to specify the hidden parameters that describe motion. Cannot be inferred from this passage

------------------------------------------------------------------------------------------------------

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Quantum mechanics is a highly successful theory: it supplies methods   [#permalink] 19 May 2020, 23:26