Problem: 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.
What are blackbody photons in quantum mechanics?
---
Answer: unanswerable


Problem: Affirmative action is a subject of controversy. Some policies adopted as affirmative action, such as racial quotas or gender quotas for collegiate admission, have been criticized as a form of reverse discrimination, and such implementation of affirmative action has been ruled unconstitutional by the majority opinion of Gratz v. Bollinger. Affirmative action as a practice was upheld by the Supreme Court's decision in Grutter v. Bollinger in 2003. Affirmative action policies were developed in order to correct decades of discrimination stemming from the Reconstruction Era by granting disadvantaged minorities opportunities. Many believe that the diversity of current American society suggests that affirmative action policies succeeded and are no longer required. Opponents of affirmative action argue that these policies are outdated and lead to reverse discrimination which entails favoring one group over another based upon racial preference rather than achievement.
Not having quotas regarding admissions or employment has been criticized and said to be what kind of discrimination?
---
Answer: unanswerable


Problem: From around 750, during the Abbasid Caliphate, women “became renowned for their brains as well as their beauty”. In particular, many well known women of the time were trained from childhood in music, dancing and poetry. Mahbuba was one of these. Another feminine figure to be remembered for her achievements was Tawaddud, "a slave girl who was said to have been bought at great cost by Hārūn al-Rashīd because she had passed her examinations by the most eminent scholars in astronomy, medicine, law, philosophy, music, history, Arabic grammar, literature, theology and chess". Moreover, among the most prominent feminine figures was Shuhda who was known as "the Scholar" or "the Pride of Women" during the 12th century in Baghdad. Despite the recognition of women's aptitudes during the Abbasid dynasty, all these came to an end in Iraq with the sack of Baghdad in 1258.
 Where did Shuhda work?
---
Answer:
unanswerable