In 1957, Braunstein further demonstrated that the rudimentary devices could be used for non-radio communication across a short distance. As noted by Kroemer Braunstein".. had set up a simple optical communications link: Music emerging from a record player was used via suitable electronics to modulate the forward current of a GaAs diode. The emitted light was detected by a PbS diode some distance away. This signal was fed into an audio amplifier, and played back by a loudspeaker. Intercepting the beam stopped the music. We had a great deal of fun playing with this setup." This setup presaged the use of LEDs for optical communication applications.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"):  What first device was needed to hear the signal from the initial GaAs diode?
Ah, so.. unanswerable

According to the Namibia Labour Force Survey Report 2012, conducted by the Namibia Statistics Agency, the country's unemployment rate is 27.4%. "Strict unemployment" (people actively seeking a full-time job) stood at 20.2% in 2000, 21.9% in 2004 and spiraled to 29.4% in 2008. Under a broader definition (including people that have given up searching for employment) unemployment rose to 36.7% in 2004. This estimate considers people in the informal economy as employed. Labour and Social Welfare Minister Immanuel Ngatjizeko praised the 2008 study as "by far superior in scope and quality to any that has been available previously", but its methodology has also received criticism.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Who leads the Namibia Statistics Agency?
Ah, so.. unanswerable

The port of Palermo, founded by the Phoenicians over 2,700 years ago, is, together with the port of Messina, the main port of Sicily. From here ferries link Palermo to Cagliari, Genoa, Livorno, Naples, Tunis and other cities and carry a total of almost 2 million passengers annually. It is also an important port for cruise ships. Traffic includes also almost 5 million tonnes of cargo and 80.000 TEU yearly. The port also has links to minor sicilian islands such as Ustica and the Aeolian Islands (via Cefalù in summer). Inside the Port of Palermo there is a section known as "tourist marina" for sailing yachts and catamarans.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): For what is the "tourist marina" dedicated?
Ah, so..
sailing yachts and catamarans