Problem: Vacuum:

In quantum mechanics and quantum field theory, the vacuum is defined as the state (that is, the solution to the equations of the theory) with the lowest possible energy (the ground state of the Hilbert space). In quantum electrodynamics this vacuum is referred to as 'QED vacuum' to distinguish it from the vacuum of quantum chromodynamics, denoted as QCD vacuum. QED vacuum is a state with no matter particles (hence the name), and also no photons. As described above, this state is impossible to achieve experimentally. (Even if every matter particle could somehow be removed from a volume, it would be impossible to eliminate all the blackbody photons.) Nonetheless, it provides a good model for realizable vacuum, and agrees with a number of experimental observations as described next.

why is a QED vacuum impossible to achieve ?
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A: impossible to eliminate all the blackbody photons


Problem: Hokkien dialects are analytic; in a sentence, the arrangement of words is important to its meaning. A basic sentence follows the subject–verb–object pattern (i.e. a subject is followed by a verb then by an object), though this order is often violated because Hokkien dialects are topic-prominent. Unlike synthetic languages, seldom do words indicate time, gender and plural by inflection. Instead, these concepts are expressed through adverbs, aspect markers, and grammatical particles, or are deduced from the context. Different particles are added to a sentence to further specify its status or intonation.
What is added to a sentence to specify plural by inflection?
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Answer: unanswerable


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
As the school suffered reduced income while still under construction, the completion and further development of the school has since depended to some extent on wealthy benefactors. Building resumed when Roger Lupton was Provost, around 1517. His name is borne by the big gate-house in the west range of the cloisters, fronting School Yard, perhaps the most famous image of the school. This range includes the important interiors of the Parlour, Election Hall, and Election Chamber, where most of the 18th century "leaving portraits" are kept.
In what year was Election Hall built?
A: unanswerable


Context and question: The inclusiveness of Weinreich's definition (above) directs attention to the totality of one's identity at a given phase in time, and assists in elucidating component aspects of one's total identity, such as one's gender identity, ethnic identity, occupational identity and so on. The definition readily applies to the young child, to the adolescent, to the young adult, and to the older adult in various phases of the life cycle. Depending on whether one is a young child or an adult at the height of one's powers, how one construes oneself as one was in the past will refer to very different salient experiential markers. Likewise, how one construes oneself as one aspires to be in the future will differ considerably according to one's age and accumulated experiences. (Weinreich & Saunderson, (eds) 2003, pp 26–34).
What are the parts of one's family identity?
Answer: unanswerable


Question: Copper is biostatic, meaning bacteria will not grow on it. For this reason it has long been used to line parts of ships to protect against barnacles and mussels. It was originally used pure, but has since been superseded by Muntz metal. Similarly, as discussed in copper alloys in aquaculture, copper alloys have become important netting materials in the aquaculture industry because they are antimicrobial and prevent biofouling, even in extreme conditions and have strong structural and corrosion-resistant properties in marine environments.
Is there an answer to this question: Name a property that makes copper a good material to use in marine environments?

Answer: corrosion-resistant


Q: What is a question about this article? If the question is unanswerable, say "unanswerable".
Sociologist James A. Beckford, in his 1975 study of Jehovah's Witnesses, classified the religion's organizational structure as Totalizing, characterized by an assertive leadership, specific and narrow objectives, control over competing demands on members' time and energy, and control over the quality of new members. Other characteristics of the classification include likelihood of friction with secular authorities, reluctance to co-operate with other religious organizations, a high rate of membership turnover, a low rate of doctrinal change, and strict uniformity of beliefs among members. Beckford identified the religion's chief characteristics as historicism (identifying historical events as relating to the outworking of God's purpose), absolutism (conviction that Jehovah's Witness leaders dispense absolute truth), activism (capacity to motivate members to perform missionary tasks), rationalism (conviction that Witness doctrines have a rational basis devoid of mystery), authoritarianism (rigid presentation of regulations without the opportunity for criticism) and world indifference (rejection of certain secular requirements and medical treatments).
Who issued a positive report about Jehovah's Witnesses in 1975?
A:
unanswerable