Question: Historical aspects of the Expo line route are noteworthy. It uses the right-of-way for the Santa Monica Air Line that provided electric-powered freight and passenger service between Los Angeles and Santa Monica beginning in the 1920s. Service was discontinued in 1953 but diesel-powered freight deliveries to warehouses along the route continued until March 11, 1988. The abandonment of the line spurred concerns within the community and the entire right-of-way was purchased from Southern Pacific by Los Angeles Metropolitan Transportation Authority. The line was built in 1875 as the steam-powered Los Angeles and Independence Railroad to bring mining ore to ships in Santa Monica harbor and as a passenger excursion train to the beach.
Is there an answer to this question: In what year did the Los Angeles Metropolitan Transportation Authority by the Expo Line from Southern Pacific?

Answer: unanswerable


Question: The spectrum emitted by a blackbody radiator at temperatures of incandescent bulbs does not match the sensitivity characteristics of the human eye; the light emitted does not appear white, and most is not in the range of wavelengths at which the eye is most sensitive. Tungsten filaments radiate mostly infrared radiation at temperatures where they remain solid – below 3,695 K (3,422 °C; 6,191 °F). Donald L. Klipstein explains it this way: "An ideal thermal radiator produces visible light most efficiently at temperatures around 6,300 °C (6,600 K; 11,400 °F). Even at this high temperature, a lot of the radiation is either infrared or ultraviolet, and the theoretical luminous efficacy (LER) is 95 lumens per watt." No known material can be used as a filament at this ideal temperature, which is hotter than the sun's surface. An upper limit for incandescent lamp luminous efficacy (LER) is around 52 lumens per watt, the theoretical value emitted by tungsten at its melting point.
Is there an answer to this question: What is the lower limit for LER of an incandescent lamp?

Answer: unanswerable


Question: The Roman expansion brought the defeat of the Allobrogi in 121 BC and during the Gallic Wars in 58 BC Julius Caesar overcame the Helvetii. The Rhaetians continued to resist but were eventually conquered when the Romans turned northward to the Danube valley in Austria and defeated the Brigantes. The Romans built settlements in the Alps; towns such as Aosta (named for Augustus) in Italy, Martigny and Lausanne in Switzerland, and Partenkirchen in Bavaria show remains of Roman baths, villas, arenas and temples. Much of the Alpine region was gradually settled by Germanic tribes, (Lombards, Alemanni, Bavarii, and Franks) from the 6th to the 13th centuries mixing with the local Celtic tribes.
Is there an answer to this question: What brought the defeat of the Allobrogi?

Answer: The Roman expansion


Question: On June 18, 2009, the National Archives announced the launching of a YouTube channel "to showcase popular archived films, inform the public about upcoming events around the country, and bring National Archives exhibits to the people." Also in 2009, the National Archives launched a Flickr photostream to share portions of its photographic holdings with the general public. A new teaching with documents website premiered in 2010 and was developed by the education team. The website features 3,000 documents, images, and recordings from the holdings of the Archives. The site also features lesson plans and tools for creating new classroom activities and lessons.
Is there an answer to this question: What website was created in 2009 that was developed by the public?

Answer:
unanswerable