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A key feature of quantum information science is the understanding that
groups of two or more quantum objects can have states that are entangled, such
that the members of an entangled collection of objects do not have their own
Line individual quantum states, only the group as a whole. Although one can use the
(5) mathematics of quantum theory to reason about entanglement, there is a great
danger that the classical basis of our analogies will mislead us. Despite its
strangeness, for a long time entanglement was regarded as a curiosity and was
mostly ignored by physicists and this changed when Bell predicted and
confirmed that entangled quantum systems exhibit behavior. that is impossible in
(10) a classical world-impossible even if one could change the laws of physics to try
to emulate the quantum predictions within a classical framework of any sort.
The idea that entanglement falls wholly outside the scope of classical physics
prompted researchers to ask whether entanglement might be useful as a
resource for solving information-processing problems in new ways.
(15) Entanglement measures improve how researchers can analyze tasks such as
quantum teleportation and algorithms on quantum-mechanical computers.
Classical computation and communications have a well-developed assortment of
error-correcting codes to protect information against the depredations of noise,
an example being the repetition code. This scheme represents the bit 0 as a
(20) string of three bits, 000, and the bit 1 as a string of three bits, 111. If the
noise is relatively weak, it may sometimes flip one of the bits in a triplet,
changing, for instance, 000 to 010, but it will flip two bits in a triplet far less
often. Whenever we encounter 010 (or 100 or 001), we can be almost certain
the correct value is 000, or 0.
(25) Initially it appeared to be impossible to develop codes for quantum error
correction because quantum mechanics forbids us from learning with certainty
the unknown state of a quantum object-the obstacle, again, of trying to
extract more than one bit from a quantum bit. One cannot examine each copy of
a quantum bit and see that one copy must be discarded without altering each and
(30) every copy in the process, and making the copies in the first place is nontrivial:
quantum mechanics forbids taking an unknown quantum bit and reliably making
a duplicate, a result known as the no-cloning theorem. Clever ideas developed
independently by Shor showed quantum error correction can be performed
without ever learning the states of the quantum bits or needing to clone them.
(35) As with the triplet code, each value is represented by a set of quantum bits and
it is as if one ran the triplet 010 through a circuit that could spot that the middle
bit was different and flip it "sight unseen".
The author suggests that, prior to Bell, the suggestion that entangled quantum systems exhibit behavior. impossible in the world of classical physics would probably have been viewed with
The author implies that scientists who regard the notion of a final state of truth without
Society is generally amenable to subsidizing science's expensive
machinery, which at some point will provide civilization with another advance
on the scale of relativity theory, but such heedless optimism can mislead one
Line into the notion that the aim of science is to find the "meaning" of the world.
(5) That there must be a meaning seems certain, for otherwise there could be no
such a thing as progress, but we must also acknowledge that as science keeps
uncovering more and more secrets, it progresses in the way that computations
in the infinitesimal calculus keep approaching nearer and nearer to infinity
without ever getting there, and we must not assume that progress should seek a
(10) final end to the quest for knowledge.
The amateur scientist Goethe, though vehemently and mistakenly opposed
to Newton's mechanistic model of reality, demonstrated the dangers of his
co/league's positivist approach, for though his science was bad science, his
scientific writings are not bad philosophy. Goethe demanded that science should
(15) always hold to the human scale, opposing the use of the microscope on the
grounds that what cannot be seen with the naked eye should not be seen, that
what is hidden from us is hidden for a purpose. In this, Goethe was a scandal
among scientists, whose first, firm, and necessary principle is that if something
can be done, it should he, and his furious denial of Newton was more than
(20) merely the bloodshot jealousy of one great mind drawing a bead on another.
Goethe's theory of light is wrong insofar as the science of optics is concerned,
yet in the expression of his theory Goethe achieves a pitch of poetic intensity
that is as persuasive, in its way, as anything Newton did: there is, Goethe
suggested, a world beyond the current state of science.
(25) At the end of the 19th century, before Einstein, professors were steering
students away from physics because they believed little was left undiscovered
about the nature of physical reality. As we approach the end of the 20th
century, we are still guilty of hubris: probably a Unified Field Theory will be
achieved, and will seem for a time, perhaps even as long as the period between
(30) Newton's Principia and Einstein's first paper on the theory of relativity, to
explain everything; but then a Heisenberg or a Gdel will come forward and
unravel the entire structure. Einstein correctly remarked more than once how
strange and suspicious it is that reality, as we know it, keeps proving itself
amenable to the rules of man-made science. Our thought extends only as far as
(35) our capacity to express it, and thus what we consider reality is only that stratum
of the world that we have the faculties to comprehend. There is a truth that
scientists not blinded by hubris, or a cramped imagination, have always
acknowledged: that there is no end to the venture.
The author discusses Goethe's theories in the second paragraph primarily to do which of the following？
It can be inferred from the passage that the author views the European conquest of America
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