Context and question: A CD is read by focusing a 780 nm wavelength (near infrared) semiconductor laser housed within the CD player, through the bottom of the polycarbonate layer. The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode, the data can be read from the disc. In order to accommodate the spiral pattern of data, the semiconductor laser is placed on a swing arm within the disc tray of any CD player. This swing arm allows the laser to read information from the centre to the edge of a disc, without having to interrupt the spinning of the disc itself.
How long is the swing arm?
Answer: unanswerable
Context and question: The distinctive characteristic of Gothic cathedrals of the Iberian Peninsula is their spatial complexity, with many areas of different shapes leading from each other. They are comparatively wide, and often have very tall arcades surmounted by low clerestories, giving a similar spacious appearance to the 'Hallenkirche of Germany, as at the Church of the Batalha Monastery in Portugal. Many of the cathedrals are completely surrounded by chapels. Like English cathedrals, each is often stylistically diverse. This expresses itself both in the addition of chapels and in the application of decorative details drawn from different sources. Among the influences on both decoration and form are Islamic architecture and, towards the end of the period, Renaissance details combined with the Gothic in a distinctive manner. The West front, as at Leon Cathedral, typically resembles a French west front, but wider in proportion to height and often with greater diversity of detail and a combination of intricate ornament with broad plain surfaces. At Burgos Cathedral there are spires of German style. The roofline often has pierced parapets with comparatively few pinnacles. There are often towers and domes of a great variety of shapes and structural invention rising above the roof.
What is the distinctive design element of Gothic cathedrals of the Iberian Peninsula?
Answer: their spatial complexity
Context and question: Ethnic tensions had escalated between the Armenians and Azerbaijanis in spring and summer 1988. On January 9, 1990, after the Armenian parliament voted to include Nagorno-Karabakh within its budget, renewed fighting broke out, hostages were taken, and four Soviet soldiers were killed. On January 11, Popular Front radicals stormed party buildings and effectively overthrew the communist powers in the southern town of Lenkoran. Gorbachev resolved to regain control of Azerbaijan; the events that ensued are known as "Black January." Late on January 19, 1990, after blowing up the central television station and cutting the phone and radio lines, 26,000 Soviet troops entered the Azerbaijani capital Baku, smashing barricades, attacking protesters, and firing into crowds. On that night and during subsequent confrontations (which lasted until February), more than 130 people died the majority of whom were civilians. More than 700 civilians were wounded, hundreds were detained, but only a few were actually tried for alleged criminal offenses.
How many people died in the Soviet response to the clashes?
Answer:
more than 130